More reasons to eat your broccoli
Love it or hate it, broccoli is touted as a superfood, offering an array of health benefits. And it's about to get even more super.
University of Illinois researchers have identified candidate genes controlling the accumulation of phenolic compounds in broccoli. Consumption of phenolic compounds, including certain flavonoids, is associated with a lower risk of coronary heart disease, type II diabetes, asthma, and several types of cancer.
"Phenolic compounds have good antioxidant activity, and there is increasing evidence that this antioxidant activity affects biochemical pathways affiliated with inflammation in mammals. We need inflammation because it's a response to disease or damage, but it's also associated with initiation of a number of degenerative diseases. People whose diets consist of a certain level of these compounds will have a lesser risk of contracting these diseases," explains U of I geneticist Jack Juvik.
The researchers crossed two broccoli lines and tested their progeny in terms of total phenolic content and their ability to neutralize oxygen radicals in cellular assays. They then used a genetic technique called quantitative trait locus analysis to search for the genes involved in generating phenolics in the most promising progeny.
By identifying the genes involved in accumulating these compounds, the researchers are one step closer to breeding broccoli and related Brassica vegetables like kale and cabbage with mega-doses of phenolic compounds.
"It's going to take awhile," Juvik notes. "This work is a step in that direction, but is not the final answer. We plan to take the candidate genes we identified here and use them in a breeding program to improve the health benefits of these vegetables. Meanwhile, we'll have to make sure yield, appearance, and taste are maintained as well."
The good news is that phenolic compounds are flavorless and stable, meaning the vegetables can be cooked without losing health-promoting qualities.
Once these vegetables are consumed, the phenolic compounds are absorbed and targeted to certain areas of the body or concentrated in the liver. Flavonoids spread through the bloodstream, reducing inflammation through their antioxidant activity.
"These are things we can't make ourselves, so we have to get them from our diets," Juvik says. "The compounds don't stick around forever, so we need to eat broccoli or some other Brassica vegetable every three or four days to lower the risk of cancers and other degenerative diseases."
Broccoli and garlic fight melanoma, prostate
cancer and leukemia
Cancer types such as melanoma,
prostate cancer and certain types of leukaemia weaken the body by
over-activating the natural immune system. Researchers from the University of
Copenhagen have now demonstrated that selenium – naturally found in, e.g.,
garlic and broccoli – slows down the immune over-response. In the long term,
this may improve cancer treatment. The findings have been published in the Journal of Biological Chemistry.
The immune system is designed to remove things
not normally found in the body. Cells undergoing change, e.g. precursors of
cancer cells, are therefore normally recognised and removed by the immune
system. Unfortunately, the different cancer cells contain mechanisms that block
the immune system's ability to recognise them, allowing them to freely continue
cance.
Certain cancer cells overexpress
immunostimulatory molecules in liquid form. Such over-stimulation has a
negative impact on the immune system:
You can say that the stimulating molecules over-activate the
immune system and cause it to collapse, and we are, of course, interested in
blocking this mechanism. We have now shown that certain selenium compounds,
which are naturally found in, e.g., garlic and broccoli, effectively block the
special immunostimulatory molecule that plays a serious role for aggressive
cancers such as melanoma, prostate cancer and certain types of leukaemia.
Broccoli Sprout Beverage
Enhances Detoxification of Air Pollutants
A
clinical trial involving nearly 300 Chinese men and women residing in one of
China’s most polluted regions found that daily consumption of a half cup of
broccoli sprout beverage produced rapid, significant and sustained higher
levels of excretion of benzene, a known human carcinogen, and acrolein, a lung
irritant. Researchers from the Johns Hopkins Bloomberg School of Public Health,
working with colleagues at several U.S. and Chinese institutions, used the
broccoli sprout beverage to provide sulforaphane, a plant compound already
demonstrated to have cancer preventive properties in animal studies. The study
was published in the June 9, 2014 online edition of the journal Cancer Prevention Research.
“Air
pollution is a complex and pervasive public health problem,” notes John
Groopman, PhD, Anna M. Baetjer Professor
of Environmental Health at the Johns Hopkins Bloomberg School of Public Health
and one of the study’s co-authors. “To address this problem comprehensively, in
addition to the engineering solutions to reduce regional pollution emissions,
we need to translate our basic science into strategies to protect individuals from
these exposures. This study supports the development of food-based strategies
as part of this overall prevention effort.”
Air
pollution, an increasing global problem, causes as many as seven million deaths
a year worldwide, according to the World Health Organization, and has in recent
years reached perilous levels in many parts of China. Last year, the
International Agency for Research on Cancer classified air pollution and
particulate matter (PM) from air pollution as carcinogenic to humans. Diets rich
in cruciferous vegetables, of which broccoli is one, have been found to reduce
risk of chronic degenerative diseases, including cancer. Broccoli sprouts are a
source of glucoraphanin, a compound that generates sulforaphane when the plant
is chewed or the beverage swallowed. It acts to increase enzymes that enhance
the body’s capacity to expunge these types of the pollutants.
The
12-week trial included 291 participants who live in a rural farming community
in Jiangsu Province, China, approximately 50 miles north of Shanghai, one of
China’s more heavily industrialized regions. Participants in the control group
drank a beverage made of sterilized water, pineapple and lime juice while the
beverage for the treatment group additionally contained a dissolved freeze-dried
powder made from broccoli sprouts that contained glucoraphanin and
sulforaphane. Sixty-two men (21%) and 229 women (79%) with a median age of 53
(ranging from 21 to 65) years were enrolled in the study. Urine and blood
samples were taken over the course of the trial to measure the fate of the
inhaled air pollutants.
The
research team found that among participants receiving the broccoli sprout
beverage, the rate of excretion of the carcinogen benzene increased 61%
beginning the first day and continuing throughout the 12-week period. In
addition, the rate of excretion of the irritant acrolein, rapidly and durably
increased 23% during the 12-week trial. Secondary analyses by the investigators
indicated that the sulforaphane may be exerting its protective actions by
activating a signaling molecule, NRF2, that elevates the capacity of cells to
adapt to and survive a broad range of environmental toxins. This strategy may
also be effective for some contaminants in water and food.
“This
study points to a frugal, simple and safe means that can be taken by
individuals to possibly reduce some of the long-term health risks associated
with air pollution,” notes Thomas Kensler, PhD, professor at the Johns Hopkins
Bloomberg School and one of the study’s co-authors. “This while government
leaders and policy makers define and implement more effective regulatory
policies to improve air quality.”
The
clinical trial targeting prevention is notable in that it evaluated a possible
means to reduce the body burden of toxins following unavoidable exposures to
pollutants. The majority of clinical trials involve treatments of diseases that
have already presented or advanced into later stages. Further clinical trials,
to evaluate optimal dosage and frequency of the broccoli sprout beverage, are
planned in the same general region of China.
Broccoli Fights
Osteoarthritis
A
compound found in broccoli could be key to preventing or slowing the progress
of the most common form of arthritis, according to new research led by the
University of East Anglia (UEA).
Results
from the laboratory study show that sulforaphane slows down the destruction of
cartilage in joints associated with painful and often debilitating
osteoarthritis. The researchers found that mice fed a diet rich in the compound
had significantly less cartilage damage and osteoarthritis than those that were
not.
The
study, which also examined human cartilage cells and cow cartilage tissue, was
funded by medical research charity Arthritis Research UK, the Biotechnology and
Biological Sciences Research Council's (BBSRC) Diet and Health Research
Industry Club (DRINC) and The Dunhill Medical Trust.
Sulforaphane
is released when eating cruciferous vegetables such as Brussels sprouts and
cabbage, but particularly broccoli. Previous research has suggested that
sulforaphane has anti-cancer and anti-inflammatory properties, but this is the
first major study into its effects on joint health.
The
researchers discovered that sulforaphane blocks the enzymes that cause joint
destruction by stopping a key molecule known to cause inflammation. They wanted
to find out if the compound got into joints in sufficient amounts to be
effective and their findings are published today in the journal Arthritis & Rheumatism.
More
than 8.5 million people in the UK have osteoarthritis, a degenerative disease
affecting the hands, feet, spine, hips and knees in particular. According to
Arthritis Research UK, the annual cost of the condition to the NHS is £5.2
billion. In 2011, more than 77,000 knee and 66,000 hip replacements were
carried out due to osteoarthritis -- approximately one every four minutes.
Aging
and obesity are the most common contributors to the condition and due to their
effects, the number of people in the UK consulting a GP about knee osteoarthritis
alone could rise from 4.7 million in 2010 to 8.3 million by 2035. Currently one
in five people over the age of 45 has osteoarthritis in their knee. There is no
cure or effective treatment for the disease other than pain relief, which is
often inadequate, or joint replacement.
The
study involved researchers from UEA's schools of Biological Sciences, Pharmacy
and Norwich Medical School, along with the University of Oxford and Norfolk and
Norwich University Hospital.
Researchers
from the School of Biological Sciences and Norwich Medical School are now
embarking on a small scale trial in osteoarthritis patients due to have knee
replacement surgery, to see if eating broccoli has similar effects on the human
joint. If successful, they hope it will lead to funding for a large scale
clinical trial to show the effect of broccoli on osteoarthritis, joint function
and pain itself.
Ian
Clark, professor of musculoskeletal biology at UEA and the lead researcher,
said: "The results from this study are very promising. We have shown that
this works in the three laboratory models we have tried, in cartilage cells,
tissue and mice. We now want to show this works in humans. It would be very
powerful if we could.
"As
well as treating those who already have the condition, you need to be able to
tell healthy people how to protect their joints into the future. There is
currently no way in to the disease pharmaceutically and you cannot give healthy
people drugs unnecessarily, so this is where diet could be a safe alternative.
"Although
surgery is very successful, it is not really an answer. Once you have
osteoarthritis, being able to slow its progress and the progression to surgery
is really important. Prevention would be preferable and changes to lifestyle,
like diet, may be the only way to do that."
Prof
Clark added: "Osteoarthritis is a major cause of disability. It is a huge
health burden but a huge financial burden too, which will get worse in an
increasingly aging and obese population such as ours.
"This
study is important because it is about how diet might work in osteoarthritis.
Once you know that you can look at other dietary compounds which could protect
the joint and ultimately you can advise people what they should be eating for
joint health. Developing new strategies for combating age-related diseases such
as osteoarthritis is vital, both to improve the quality of life for sufferers
and to reduce the economic burden on society."
Arthritis
Research UK's medical director Prof Alan Silman said: "This is an interesting
study with promising results as it suggests that a common vegetable, broccoli,
might have health benefits for people with osteoarthritis and even possibly
protect people from developing the disease in the first place.
"Until
now research has failed to show that food or diet can play any part in reducing
the progression of osteoarthritis, so if these findings can be replicated in
humans, it would be quite a breakthrough. We know that exercise and keeping to
a healthy weight can improve people's symptoms and reduce the chances of the
disease progressing, but this adds another layer in our understanding of how
diet could play its part."
Steaming Broccoli
Preserves Potential Power to Fight Cancer
The
way you prepare broccoli and related vegetables can alter their potentially
cancer-fighting powers, new research shows.
Broccoli
and other cruciferous vegetables are a good source of sulforaphane, a
phytochemical (naturally occurring plant compound) that has shown strong
anti-cancer properties in lab studies.
However,
the enzyme myrosinase in broccoli is needed for sulforaphane to form. If the
myrosinase is destroyed, sulforaphane cannot form.
Researchers
compared boiled, microwaved and steamed broccoli, and found that steaming
broccoli for up to five minutes was the best way to retain its myrosinase.
Boiling and microwaving broccoli for one minute or less destroyed the majority
of the enzyme, according to Elizabeth Jeffery, a researcher at University of
Illinois at Urbana-Champaign.
Jeffery
also found that if you do eat well-cooked broccoli, you can still get
sulforaphane to form by adding raw foods containing myrosinase to your meal.
Study participants ate a broccoli supplement with no active myrosinase. When
some of them ate a second food with myrosinase, their blood and urine levels of
sulforaphane were significantly higher than those who did not eat the second
food with myrosinase.
The
findings were presented at the November, 2013 annual meeting of the American
Institute for Cancer Research in Bethesda, Md. Findings presented at medical
meetings should be viewed as preliminary until published in a peer-reviewed
journal.
"Mustard,
radish, arugula, wasabi and other uncooked cruciferous vegetables such as
coleslaw all contain myrosinase, and we've seen this can restore the formation
of sulforaphane," Jeffery said in an institute news release.
Previous
research has found that:
*
Crushing or chopping garlic, and then waiting 10 to 15 minutes before exposing
it to heat allows its inactive compounds to convert into the active, protective
phytochemical known as allicin.
*
Cooking tomatoes and other foods that contain lycopene allows our body to more
easily absorb the beneficial phytochemical.
*
Boiling vegetables for a long time means you lose water-soluble vitamins, such
as vitamin C, folate and niacin that leach into the water.
"As
we're learning, food processing isn't just what happens to food before it
reaches the grocery shelves," AICR associate director of nutrition
programs Alice Bender said in the news release. "This research highlights
that what you do in your kitchen can make those fruits and vegetables on your
plate even more cancer-protective."
Cruciferous vegetables give cancer-fighting help
Chemicals
in cruciferous vegetables, such as broccoli, watercress, cabbage and
cauliflower, appear to not only stop human prostate cancer cells from growing
in mice but also may cut off the formation of blood vessels that
"feed" tumors, says a University of Pittsburgh Cancer Institute
study.
"The
contribution of diet and nutrition to cancer risk, prevention and treatment has
been a major focus of research in recent years because certain nutrients in
vegetables and dietary agents appear to protect the body against diseases such
as cancer," said Shivendra Singh, Ph.D., lead investigator and professor
of pharmacology and urology at the University of Pittsburgh School of Medicine.
"From epidemiologic data, we know that increased consumption of vegetables
reduces the risk for certain types of cancer, but now we are beginning to
understand the mechanisms by which certain vegetables like broccoli may help
our bodies fight cancer and other diseases."
Dr.
Singh’s study is based on phytochemicals, called isothiocyanates (ITCs), found
in several cruciferous vegetables and generated when vegetables are either cut
or chewed. His laboratory has found that phenethyl-ITC, or PEITC, is highly
effective in suppressing the growth of human prostate cancer cells at
concentrations achievable through dietary intake.
The
current study follows previous research in which Dr. Singh’s laboratory found
that mice grafted with human prostate tumors that received a small amount of
PEITC daily for 31 days had significantly reduced tumor size when compared to a
control group of mice. Now the researchers have shown that treating cells in
culture with PEITC inhibits angiogenesis, a process that plays an important
role in the growth and spread of cancer by forming new blood vessels that pass
oxygen and nutrients to tumor cells.
"Angiogenesis
is a major issue in cancer metastases," said Dr. Singh. "Our results
provide promising preliminary evidence that constituents of many edible
cruciferous vegetables may slow down, or even halt, this process."
Broccoli, Cauliflower, and Cabbage Combat Breast Cancer
Women
should go for the broccoli when the relish tray comes around during holiday
celebrations this season.
While
it has been known for some time that eating cruciferous vegetables, such as
broccoli, cauliflower, and cabbage, can help prevent breast cancer, the
mechanism by which the active substances in these vegetables inhibit cell
proliferation was unknown - until now.
Scientists
in the UC Santa Barbara laboratories of Leslie Wilson, professor of
biochemistry and pharmacology, and Mary Ann Jordan, adjunct professor in the
Department of Molecular, Cellular, and Developmental Biology, have shown how
the healing power of these vegetables works at the cellular level. Their
research is published in the journal Carcinogenesis
(December, 2008).
"Breast
cancer, the second leading cause of cancer deaths in women, can be protected
against by eating cruciferous vegetables such as cabbage and near relatives of
cabbage such as broccoli and cauliflower," said first author Olga
Azarenko, who is a graduate student at UCSB. "These vegetables contain
compounds called isothiocyanates which we believe to be responsible for the
cancer-preventive and anti-carcinogenic activities in these vegetables.
Broccoli and broccoli sprouts have the highest amount of the isothiocyanates.
"Our
paper focuses on the anti-cancer activity of one of these compounds, called
sulforaphane, or SFN," Azarenko added. "It has already been shown to
reduce the incidence and rate of chemically induced mammary tumors in animals.
It inhibits the growth of cultured human breast cancer cells, leading to cell
death."
Azarenko
made the surprising discovery that SFN inhibits the proliferation of human
tumor cells by a mechanism similar to the way that the anticancer drugs taxol
and vincristine inhibit cell division during mitosis. Mitosis is the process in
which the duplicated DNA in the form of chromosomes is accurately distributed
to the two daughter cells when a cell divides.
Hundreds
of tiny tube-like structures, called microtubules, make up the machinery that
cells use to separate the chromosomes. SFN, like the more powerful anticancer
agents, interferes with microtubule functioning during mitosis in a similar
manner to the more powerful anticancer drugs. However SFN is much weaker than
these other plant-based drugs, and thus much less toxic.
"SFN
may be an effective cancer preventive agent because it inhibits the
proliferation and kills precancerous cells," said Wilson. It is also
possible that it could be used as an addition to taxol and other similar drugs
to increase effective killing of tumor cells without increased toxicity.
Eating Cruciferous Vegetables May Improve Breast Cancer Survival
A study by Vanderbilt-Ingram Cancer
Center and Shanghai Center for Disease Control and Prevention investigators
reveals that breast cancer survivors who eat more cruciferous vegetables may
have improved survival. The study of women in China was presented by
postdoctoral fellow Sarah J. Nechuta, Ph.D., M.P.H., at the American
Association for Cancer Research Annual Meeting in Chicago, Ill. (April, 2012)
"Breast cancer survivors can
follow the general nutritional guidelines of eating vegetables daily and may
consider increasing intake of cruciferous vegetables, such as greens, cabbage,
cauliflower and broccoli, as part of a healthy diet," said Nechuta.
Nechuta, Xiao Ou Shu, M.D., Ph.D.,
and colleagues investigated the role of cruciferous vegetables in breast cancer
survival among women in the Shanghai Breast Cancer Survival Study, a
prospective study of 4,886 Chinese breast cancer survivors who were diagnosed
with stage 1 to stage 4 breast cancer from 2002 to 2006. Shu, Ingram Professor
of Cancer Research, is the principal investigator of the Shanghai Breast Cancer
Survival Study.
After adjusting for demographics,
clinical characteristics and lifestyle factors, the researchers found
cruciferous vegetable intake during the first 36 months after breast cancer
diagnosis was associated with a reduced risk for total mortality, breast
cancer-specific mortality and disease recurrence.
Survival rates were influenced by
vegetable consumption in a dose-response pattern. As women ate more of these
vegetables, their risk of death or cancer recurrence decreased.
Women who were in the highest
quartiles of intake of vegetables per day had a 62 percent reduced risk of
total mortality, 62 percent reduced risk of breast cancer mortality, and 35
percent reduced risk of breast cancer recurrence, compared to women with the
lowest quartile of intake."
Nechuta noted that cruciferous
vegetable consumption habits differ between China and the United States and
suggested this fact be considered when generalizing these results to U.S.
breast cancer survivors.
"Commonly consumed cruciferous
vegetables in China include turnips, Chinese cabbage/bok choy and greens, while
broccoli and Brussels sprouts are the more commonly consumed cruciferous
vegetables in the United States and other Western countries," she said.
"The amount of intake among Chinese women is also much higher than that of
U.S. women."
Cruciferous vegetables contain
phytochemicals known as isothiocyanates and indoles which appear to have a
protective effect against some types of cancer.
Nechuta said the level of these
bioactive compounds, proposed to play a role in the anticancer effects of
cruciferous vegetables, depends on both the amount and type of cruciferous
vegetables consumed.
She said there is a need for future
studies that measure the bioactive compounds in these vegetables and the host
factors that may influence the effects of these compounds to improve the
understanding of the association between cruciferous vegetable consumption and
breast cancer outcomes.
Broccoli, cabbage and cauliflower fight breast cancer
When
your mother told you to eat your vegetables it appears that maternal wisdom had
a scientific basis. Researchers have discovered a possible link between a diet
rich in certain vegetables and a decreased risk for breast cancer. The study
appears in the American Journal of
Clinical Nutrition.
Cruciferous
vegetables contain some compounds that may have a cancer-inhibitory effect.
While
there was only a small positive relationship between a diet high in these
vegetables and a reduction in breast cancer risk for the overall study
population, there was a striking risk reduction – 50 percent – among women with
a certain genetic profile. Researchers identified three forms of the GSTP1
genotype among the cancer patients: Ille/Ile, Ile/Val and Val/Val.
“Women
who consumed more of these cruciferous vegetables and who also had the Val/Val
genetic polymorphism had a lower breast cancer risk. So we cautiously
interpreted this as diet being a factor that may reduce the impact of genetic
susceptibility in overall breast cancer risk,” said Fowke.
Studies
by other researchers have suggested cruciferous vegetables may reduce the risk
of lung, stomach, colorectal and bladder cancers.
Cruciferous vegetables & soy vs breast/ ovarian cancers
We all know that eating fruits,
vegetables and soy products provides essential nutrition for a healthy
lifestyle, while obesity leads to the opposite. Yet proving the effect of
nutrition, or obesity, on cancer is an experimental challenge and a focus for
scientists. According to emerging evidence being presented at the 2007 Annual Meeting
of the American Association for Cancer Research, eating well might still be one
of the more pleasurable ways to prevent cancer and promote good health.
Eating such foods as broccoli and
soy are believed to offer some protection against cancer, but how this occurs
is not well-understood. Now, in laboratory experiments, researchers at the
University of California, Los Angeles, have discovered a biological mechanism
whereby two compounds in these foods might lower the invasive and metastatic
potential of breast and ovarian cancer cells.
They found that diindolylmethane
(DIM), a compound resulting from digestion of cruciferous vegetables, and
genistein, a major isoflavone in soy, reduce production of two proteins whose
chemotactic attraction to each other is necessary for the spread of breast and
ovarian cancers.
When applying purified versions of
DIM and genistein to motile cancer cells, the researchers could literally watch
these cells come to a near halt. When either compound was applied, migration and
invasion were substantially reduced.
"We think these compounds might
slow or prevent the metastasis of breast and ovarian cancer, which would
greatly increase the effectiveness of current treatments," said Erin Hsu,
a graduate student in molecular toxicology. "But we need to test that
notion in animals before we can be more definitive."
Both DIM and genistein are already
being developed for use as a preventive and a chemotherapy treatment for breast
cancer, although more extensive toxicological studies are necessary, the
researchers say.
The researchers looked at the
potential of DIM and genistein to interfere with the "CXCR4/CXCL12
axis," which is known to play a central role in the metastasis of breast
cancer and is also thought to play a role in the development of ovarian cancer.
Primary cancer cells express very high levels of the CXCR4 chemokine receptor
on the surface of their cells, and the organs to which these cancers
metastasize secrete high levels of the CXCL12 chemokine ligand. This attraction
stimulates the invasive properties of cancer cells and acts like a homing
device, drawing the cancer cells to the organs they metastasize to.
When breast and ovarian cancer cell
lines are exposed to purified DIM or genistein, levels of CXCR4 and CXCL12
messenger RNAs and proteins decrease in a dose-dependent manner, compared to
untreated cells, according to Hsu.
To assess whether the compounds had
any effect on the metastatic potential of the cells, the researchers placed the
cells in one end of a compartment and watched how they moved toward CXCL12 at
the other end. "The cells degrade the extracellular matrix in the upper
compartment in order to move toward CXCL12 in the lower compartment, a system
that represents a cell culture model for invasiveness," she said.
But if the cells are treated with
either DIM or genistein, movement toward CXCL12 is reduced by at least 80
percent compared to untreated cells, the researchers say.
Hsu says that this same chemotactic
attraction is thought to play a role in the development of more than 23
different types of cancer, and, so far, they have found that messenger RNA
expression of CXCR4 and CXCL12 is substantially reduced when melanoma and
prostate cancer cells are treated with the two compounds.
"We have also tested other
phytochemicals and seen similar effects, indicating that this mechanism may
mediate protective effects of other vegetable products as well," Hsu said.
The amount of DIM and genistein used
in this study is probably comparable to use of a high dose of supplements, and
is likely not achievable through consumption of food alone, the researchers
say.
Sulforaphane –
from broccoli, cauliflower and cabbage – may improve some symptoms of autism
spectrum disorders
According
to an article in Anti-Cancer Agents in Medicinal Chemistry sulforaphane also has huge
cancer chemopreventive potential.
A
small study led by investigators at MassGeneral Hospital for Children (MGHfC)
and Johns Hopkins University School of Medicine has found evidence that daily
treatment with sulforaphane – a molecule found in foods such as broccoli,
cauliflower and cabbage – may improve some symptoms of autism spectrum
disorders. In their report being published online in PNAS Early
Edition, the investigators describe how participants receiving a daily dose of
sulforaphane showed improvement in both behavioral and communication
assessments in as little as four weeks. The authors stress that the results of
this pilot study – conducted at the MGHfC-affiliated Lurie Center for Autism –
must be confirmed in larger investigations before any conclusions can be drawn
about sulforaphane's therapeutic benefit.
"Over
the years there have been several anecdotal reports that children with autism
can have improvements in social interaction and sometimes language skills when
they have a fever," explains Andrew Zimmerman, MD, a co-corresponding
author of the current report who also published a 2007 paper documenting the
fever effect. "We investigated what might be behind that on a cellular
level and postulated that it results from fever's activation of the cellular
stress response, in which protective cellular mechanisms that are usually held
in reserve are turned on through activation of gene transcription."
Affiliated with the MGHfC Department of Neurology, Zimmerman is now based at
UMass Memorial Medical Center.
Sulforaphane
was first isolated in the 1990s by Paul Talalay, MD – co-corresponding author
of the PNAS Early Edition paper and now a professor of
Pharmacology and Molecular Sciences at Johns Hopkins – and his group also found
that the chemical supports key aspects of the cell stress response. Zimmerman,
who was based at Hopkins when he published the fever paper, approached members
of Talalay's team to propose investigating sulforaphane's possible benefits for
treating autism. While the mechanism underlying autism and other disorders on
the autism spectrum remain largely unknown, several molecular abnormalities –
including some related to the cellular stress response – have been identified.
After Zimmerman moved to MGHfC in 2010, the trial was initiated at the Lurie
Center in Lexington, Mass.
The
study enrolled 44 young men, ages 13 to 27, who had been diagnosed with
moderate to severe autism spectrum disorder. Participants were randomly
assigned to a daily dose of either sulforaphane – extracted from broccoli
sprouts – or a placebo, with neither investigators, participants nor their
caregivers knowing who was receiving the study drug. Participants were assessed
using standardized measurements of behavior and social interaction – some
completed by caregivers, some by study staff – at the outset of the study and
at 4, 10 and 18 weeks after treatment began. Treatment was discontinued after
18 weeks, and additional assessments of 22 participants were conducted 4 weeks
later.
Study
lead author Kanwaljit Singh, MD, MPH – of MGHfC, the Lurie Center and UMass –
says that among the 40 participants who returned for at least one evaluation,
the average scores for each of the assessments were significantly better for
the 26 participants receiving sulforaphane than for the 14 who received a
placebo. Even at the 4-week visit, some caregivers reported a noticeable
behavioral improvement, and by the end of the study period, both study staff
and family members correctly guessed the assignments of many participants.
Overall, 17 of the 26 participants who received sulforaphane were judged by
their caregivers to have improvements in behavior, social interaction and
calmness while on active treatment.
After
18 weeks of treatment, the average scores on two assessments – the Aberrant
Behavior Checklist and Social Responsiveness Scale – of those who received
sulforaphane had decreased 34 and 17 percent, respectively – indicating
improvement in factors such as irritability, lethargy, repetitive movements,
hyperactivity, communication, motivation and mannerisms. Assessments using the
Clinical Global Impression scale indicated that 46 percent of sulforaphane
recipients exhibited noticeable improvement in social interaction, 54 percent
in aberrant behaviors, and 42 percent in verbal communication. Most but not all
of the improvements had disappeared by the 22-week reassessment, supporting the
probability that changes had been the result of sulforaphane treatment.
"When
we broke the code that revealed who was receiving sulforaphane and who got the
placebo, the results weren't surprising to us, since the improvements were so
noticeable," says Zimmerman, now a professor of Pediatric Neurology at
UMass. "The improvements seen on the Social Responsiveness Scale were
particularly remarkable, and I've been told this is the first time that any
statistically significant improvement on the SRS has been seen for a drug study
in autism spectrum disorder.
"But
it's important to note that the improvements didn't affect everyone – about one
third had no improvement – and the study must be repeated in a larger group of
adults and in children, something we're hoping to organize soon," he adds.
"Ultimately we need to get at the biology underlying the effects we have
seen and study it at a cellular level. I think that will be done, and I hope it
will teach us a lot about this still poorly understood disorder."
Broccoli may help
protect against respiratory conditions like asthma
Here's another reason to eat your broccoli: UCLA researchers
report that a naturally occurring compound found in broccoli and other
cruciferous vegetables may help protect against respiratory inflammation that
causes conditions like asthma, allergic rhinitis and chronic obstructive
pulmonary disease.
Published in the journal Clinical
Immunology, the research shows that sulforaphane, a chemical in broccoli,
triggers an increase of antioxidant enzymes in the human airway that offers
protection against the onslaught of free radicals that we breathe in every day
in polluted air, pollen, diesel exhaust and tobacco smoke. A supercharged form
of oxygen, free radicals can cause oxidative tissue damage, which leads to inflammation
and respiratory conditions like asthma.
"This is one of the first studies showing that broccoli
sprouts — a readily available food source — offered potent biologic effects in
stimulating an antioxidant response in humans," said Dr. Marc Riedl, the
study's principal investigator and an assistant professor of clinical
immunology and allergy at the David Geffen School of Medicine at UCLA.
"We found a two- to three-fold increase in antioxidant
enzymes in the nasal airway cells of study participants who had eaten a
preparation of broccoli sprouts," Riedl said. "This strategy may
offer protection against inflammatory processes and could lead to potential
treatments for a variety of respiratory conditions."
The UCLA team worked with 65 volunteers who were given varying
oral doses of either broccoli or alfalfa sprout preparations for three days.
Broccoli sprouts are the richest natural source of sulforaphane; the alfalfa
sprouts, which do not contain the compound, served as a placebo.
Rinses of nasal passages were collected at the beginning and end
of the study to assess the gene expression of antioxidant enzymes in cells of
the upper airways. Researchers found significant increases of antioxidant
enzymes at broccoli sprout doses of 100 grams and higher, compared with the
placebo group.
The maximum broccoli sprout dosage of 200 grams generated a
101-percent increase of an antioxidant enzyme called GSTP1 and a 199-percent
increase of another key enzyme called NQO1.
"A major advantage of sulforaphane is that it appears to
increase a broad array of antioxidant enzymes, which may help the compound's
effectiveness in blocking the harmful effects of air pollution," Riedl
said.
According to the authors, no serious side effects occurred in
study participants receiving broccoli sprouts, demonstrating that this may be
an effective, safe antioxidant strategy to help reduce the inflammatory impact
of free radicals.
Riedl notes that more research needs to be done to examine the
benefits of sulforaphane for specific respiratory conditions. It is too early
to recommend a particular dosage.
Riedl recommends including broccoli and other cruciferous
vegetables as part of a healthy diet.
Broccoli may help boost the aging immune system
UCLA
researchers have found that a chemical in broccoli and other cruciferous
vegetables may hold a key to restoring the body's immunity, which declines as
we age.
Published
in the Journal of Allergy and Clinical
Immunology, the study findings show that sulforaphane, a chemical in
broccoli, switches on a set of antioxidant genes and enzymes in specific immune
cells, which then combat the injurious effects of molecules known as free
radicals that can damage cells and lead to disease.
Free
radicals are byproducts of normal body processes, such as the metabolic
conversion of food into energy, and can also enter the body through small
particles present in polluted air. A supercharged form of oxygen, these
molecules can cause oxidative tissue damage, leading to disease — for example,
triggering the inflammation process that causes clogged arteries. Oxidative
damage to body tissues and organs is thought to be one of the major causes of
aging.
"The
mysteries of aging have always intrigued man," said Dr. Andre Nel, the
study's principal investigator and chief of nanomedicine at the David Geffen
School of Medicine at UCLA. "While we have known for some time that free
radicals are important in aging, most of the past attention has focused on the
mechanisms that produce free radicals rather than addressing the pathways used
by the body to suppress their production."
A
dynamic equilibrium exists in the body between the mechanisms that lead to
increased free radical production and those antioxidant pathways that help
combat free radicals.
"Our
study contributes to the growing understanding of the importance of these
antioxidant defense pathways that the body uses to fight free radicals,"
said Nel, a practicing clinical allergist and immunologist at the Geffen
School. "Insight into these processes points to ways in which we may be
able to alleviate the effects of aging."
The
delicate balance between pro-oxidant and antioxidant forces in the body could
determine the outcome of many disease processes that are associated with aging,
including cardiovascular disease, degenerative joint diseases and diabetes, as
well as the decline in efficiency of the immune system's ability to protect
against infectious agents.
"As
we age, the ability of the immune system to fight disease and infections and
protect against cancer wears down as a result of the impact of oxygen radicals
on the immune system," Nel said.
According
to the UCLA study, the ability of aged tissues to reinvigorate their
antioxidant defense can play an important role in reversing much of the
negative impact of free radicals on the immune system. However, until this
current study, the extent to which antioxidant defense can impact the aging
process in the immune system was not properly understood.
"Our
defense against oxidative stress damage may determine at what rate we age, how
it will manifest and how to interfere in those processes," Nel said.
"In particular, our study shows that a chemical present in broccoli is
capable of stimulating a wide range of antioxidant defense pathways and may be
able to interfere with the age-related decline in immune function."
"Dietary
antioxidants have been shown to have important effects on immune function, and
with further study, we may be adding broccoli and other cruciferous vegetables
to that list," Nel said.
For
now, Nel suggests including these vegetables as part of a healthy diet.
Nel
said that these findings offer a window into how the immune system ages.
"We
may find that combating free radicals is only part of the answer. It may prove
to be a more multifaceted process and interplay between pro- and antioxidant
forces," he said.
Consumption of
raw, but not cooked, cruciferous vegetables and reduction of bladder cancer
risk
While
researchers have long known that cruciferous vegetables are chock full of isothiocyanates
(ITCs), which are a well-known class of cancer prevention agents especially
promising in bladder cancer chemoprevention, they didn’t know how much one
needed to eat to reap the protective benefits.
Researchers
from Roswell Park Cancer Institute report that three or more servings a month
of raw cruciferous vegetables like broccoli, cabbage and cauliflower, may
reduce bladder cancer risk by approximately 40 percent, overall.
The
Roswell Park team surveyed the dietary habits of 275 individuals with incident,
primary bladder cancer and 825 individuals without cancer. The researchers
surveyed patients about their pre-diagnostic intake of raw and cooked
cruciferous vegetables, their smoking habits and other cancer risk factors.
They observed a strong and statistically significant inverse association
between bladder cancer risk and raw cruciferous vegetable consumption. When
compared to smokers who ate less than three servings of raw vegetables,
non-smokers who ate at least three servings a month were almost 73 percent less
likely to develop bladder cancer, the researchers say.
A
key factor in the research was that it’s a survey of raw cruciferous
vegetables. Previous research had surveyed intake of any cruciferous vegetables
– cooked or not – and results proved inconsistent. Cooking significantly
reduces the availability of ITCs for absorption into the body, according to
researchers.
“Cooking
can reduce 60 to 90 percent of ITCs,” says Li Tang, M.D., Ph.D. of Roswell Park
Cancer Institute and lead researcher on this study. “Heating destroys the
enzyme that converts the precursor glucosinolates into ITCs, and also destroys
ITCs already formed, which is why you need to eat raw cruciferous vegetables to
receive the food’s maximum benefit.”
Broccoli Sprouts: protection against gastritis, ulcers and even stomach cancer
A
small, pilot study in 50 people in Japan suggests that eating two and a half
ounces of broccoli sprouts daily for two months may confer some protection
against a rampant stomach bug that causes gastritis, ulcers and even stomach
cancer.
Citing
their new "demonstration of principle" study, a Johns Hopkins
researcher and an international team of scientists caution that eating sprouts
containing sulforaphane did not cure infection by the bacterium Helicobacter
pylori (H. pylori). They do not suggest that eating this or any amount of
broccoli sprouts will protect anyone from stomach cancer or cure GI diseases.
However,
the study does show that eating a daily dose of broccoli sprouts reduced by
more than 40 percent the level of HpSA, a highly specific measure of the
presence of components of H. pylori shed into the stool of infected people.
There was no HpSA level change in control subjects who ate alfalfa sprouts. The
HpSA levels returned to pretreatment levels eight weeks after people stopped
eating the broccoli sprouts, suggesting that although they reduce H. pylori
colonization, they do not eradicate it.
"The
highlight of the study is that we identified a food that, if eaten regularly,
might potentially have an effect on the cause of a lot of gastric problems and
perhaps even ultimately help prevent stomach cancer," says Jed W. Fahey,
M.S., Sc.D., an author of the paper who is a nutritional biochemist in the
Lewis B. and Dorothy Cullman Cancer Chemoprotection Center at the Johns Hopkins
University School of Medicine.
The
discovery that sulforaphane is a potent antibiotic against H. pylori was
reported in 2002 by Fahey and colleagues at Johns Hopkins. "Broccoli
sprouts have a much higher concentration of sulforaphane than mature
heads," Fahey explains, adding that further investigation is needed to
affirm the results of this clinical trial and move the research forward. The
study, published April 6 in Cancer Prevention Research, builds on earlier
test-tube and mouse studies at Johns Hopkins and elsewhere about the potential
value of sulforaphane, a naturally occurring biochemical found in relative
abundance in fresh broccoli sprouts. Sulforaphane appears to trigger cells in
the body, including in the gastrointestinal tract, to produce enzymes that
protect against oxygen radicals, DNA-damaging chemicals, and inflammation.
In
the new report, the team also shows that when H. pylori-infected mice sipped
broccoli-sprout smoothies for eight weeks, there was up to a fourfold increase
in the activity of two of these key enzymes that protect cells against
oxidative damage. In addition, the number of Helicobacter bacteria in the
mice's stomachs decreased by almost a hundredfold it did not change in infected
control animals that drank plain water. The researchers also noted a greater
than 50 percent reduction in inflammation of the primary target of this
bacterium - the body of the stomach - in treated mice but not in controls.
In
a related experiment, the team fed the same dose of broccoli sprouts for the
same amount of time to H. pylori-infected mice that had been genetically
engineered to lack the Nrf2 gene that activates protective enzymes. "These
knock-out mice didn't respond," Fahey says, which confirms previous
findings for a role of Nrf2 in protection against H. pylori-induced
inflammation and gastritis.
Classified
a carcinogen by the World Health Organization, H. pylori is a gastrointestinal
tract germ that manages to thrive in the lining of the stomach despite the
strength of natural acids there that rival that of car batteries. Afflicting
several billion people - roughly half of the world's population - this
corkscrew-shaped bacterium has long been associated with stomach ulcers, which
now are frequently cured by antibiotics. Research strongly suggests that the
bacteria also are linked to high rates of stomach cancer in some countries,
that strains resistant to standard antibiotics are prevalent, and that multiple
courses of standard antibiotics do not always eliminate the infection.
Working
in Japan where there is high incidence of chronic H. pylori-infection, the
research team gave 25 H. pylori-infected subjects two and a half ounces (70
grams) per day of broccoli sprouts for two months. Another 25 infected people
consumed an equivalent amount of alfalfa sprouts which, although rich in
phytochemicals, don't contain sulforaphane.
The
researchers assessed the severity of Helicobacter infection at the start of the
study, after four and eight weeks of treatment, and again eight weeks after
intervention was stopped. They used breath tests to assess colonization by H.
pylori bacteria and blood tests to judge the severity of inflammation in the
stomach lining; in addition, they looked for antigens in stool samples to help
determine the extent of the infections.
"We
know that a dose of a couple ounces a day of broccoli sprouts is enough to
elevate the body's protective enzymes," Fahey says. "That is the
mechanism by which we think a lot of the chemoprotective effects are
occurring."
"What
we don't know is whether it's going to prevent people from getting stomach
cancer. But the fact that the levels of infection and inflammation were reduced
suggests the likelihood of getting gastritis and ulcers and cancer is probably
reduced."
"It's
exciting that a chronic bacterial infection that poses great hazards to
hundreds of millions of people globally can be ameliorated by a specific
dietary strategy," says Paul Talalay, M.D., John Jacob Abel Distinguished
Service Professor of Pharmacology and Experimental Therapeutics and director of
the Lewis B. and Dorothy Cullman Cancer Chemoprotection Center at Johns
Hopkins' Institute for Basic Biomedical Sciences.
Talalay
directs the lab where, in 1992, his team discovered the health-promoting
properties of sulforaphane. A longtime proponent of cancer prevention and
chemoprotection, Talalay eats fresh broccoli sprouts regularly, as does Fahey.
Broccoli and cauliflower protect cells from damage
Scientists
at the University of Pennsylvania School of Medicine discovered that a dietary
antioxidant found in such vegetables as broccoli and cauliflower protects cells
from damage caused by chemicals generated during the body’s inflammatory
response to infection and injury. The finding has implications for such
inflammation-based disorders as cystic fibrosis (CF), diabetes, heart disease,
and neurodegeneration.
Through
cell-culture studies and a synthesis of known antioxidant biochemistry, Zhe Lu,
MD, PhD , Professor of Physiology, Yanping Xu , MD, PhD , Senior Research
Investigator, and Szilvia Szép , PhD, postdoctoral researcher, showed that the
antioxidant thiocyanate normally existing in the body protects lung cells from
injuries caused by accumulations of hydrogen peroxide and hypochlorite, the
active ingredient in household bleach. These potentially harmful chemicals are
made by the body as a reaction to infection and injury. In addition,
thiocyanate also protects cells from hypochlorite produced in reactions
involving MPO, an enzyme released from germ-fighting white blood cells during
inflammation. They published their finding November 2009 in the Proceedings of the National Academy of
Sciences. Lu is also an Investigator of the Howard Hughes Medical
Institute.
“Dr.
Lu’s work throws new light on how the genetic defect underlying CF leads to the
lung illnesses that are the leading cause of death,” said Bert Shapiro, Ph.D.,
who oversees membrane structure grants at the National Institutes of Health’s
National Institute of General Medical Sciences (NIGMS). “His team’s findings
suggest that the lungs of people with the disease are more susceptible to the
damaging effects of cellular oxidants. While the idea is tantalizing and
creative, further testing is needed to confirm it.”
The
research team demonstrated that in three additional cell types used to extend
their ideas to other inflammation-related conditions – cardiovascular disease,
neurodegeneration, and diabetes – thiocyanate at blood concentrations of at
least 100 micromolar (micromoles per liter) greatly reduces the toxicity of MPO
in cells, including those lining blood vessels. Humans naturally derive
thiocyanate from some vegetables and blood levels of thiocyanate in the general
population vary from 10 to 140 micromolar.
This
comparison raises the possibility, the authors point out, that without an
adequate dietary supply of thiocyanate, hypochlorite produced by the body
during inflammation would cause additional collateral damage to cells, thus
worsening inflammatory diseases, and predisposing humans to diseases linked to
MPO activity, including atherosclerosis.
Connection
to CF
For
over a decade Lu and colleagues have been exploring the inner workings of ion
channels and how this knowledge relates to the pathology of such diseases as
CF. The CF disease originates from mutations in the CF transmembrane
conductance regulator (CFTR) protein, an ion channel protein in the cell
membrane commonly thought to transport mainly chloride ions. It has, however,
remained a mystery why a defect in a chloride-transporting channel leads to
cystic fibrosis, a disease with exaggerated inflammation in both the lungs and
the digestive system.
Lung
injuries inflicted by excessive inflammation and recurring infection cause
about ninety percent of CF patients’ symptoms and mortality. Although known as
a chloride channel, CFTR also conducts thiocyanate ions, important because, in
several ways, they can limit potentially harmful accumulations of hydrogen
peroxide and hypochlorite, chemicals produced by the body to fight germs.
In
CF patients, there is also a high incidence of diabetes, partly caused by
damage to the pancreas. Type 2 diabetes is also associated with higher levels
of MPO in the blood. The researchers found that the MPO-caused injuries to
pancreas cells and endothelial cells used in their experiments can be greatly
reduced by as little as 100 micromolar thiocyanate. Their finding raises the
possibility that MPO, in the absence of adequate thiocyanate, contributes to
diabetes.
In
the cell-based experiments, thiocyanate at concentrations below 100 micromolar
did not eliminate hypochlorite accumulation and did not fully protect against
MPO toxicity. Conceivably, inadequate thiocyanate levels would aggravate
MPO-produced injuries in patients suffering from inflammatory diseases, surmise
the authors.
Links
to Other Diseases
In
other studies, MPO activity has been linked to lung cancers among smokers and
also implicated in neurodegenerative diseases. Intriguingly, people with
congenital MPO deficiency are less likely to develop cardiovascular diseases.
The research team found that MPO-caused injuries to nerve cells, as well as to
blood vessel-lining endothelial cells, can be greatly reduced by 100 micromolar
thiocyanate.
Genetic
defects in the CFTR predispose CF patients’ lungs to excessive inflammation
entangled with recurring lung infection. Defective CFTR channels would be
expected to result in lower thiocyanate concentrations in the affected regions
within the respiratory, as well as the digestive systems, leaving tissues
inadequately protected from accumulated hydrogen peroxide and overproduced
hypochlorite.
Conceptually,
delivering thiocyanate directly to the digestive and respiratory systems might
be a therapy for CF disease, propose the researchers. As for the general
population, individuals with low blood levels of thiocyanate may be at risk for
chronic injuries by MPO, predisposing them to inflammatory or
inflammation-mediated diseases.
Many
investigators have proposed developing drugs that specifically inhibit
MPO-catalyzed hypochlorite production to combat these diseases, but natural
thiocyanate not only decreases MPO-catalyzed formation of hypochlorite but also
rapidly, once it is made, neutralizes it.
“In
light of the obvious implications of this protective action of thiocyanate
against the cell-damaging effect of MPO activity with regard to both CF disease
and general population health, my colleagues and I will vigorously investigate
the potential health benefit of thiocyanate,” says Lu. He emphasizes though,
“until the research community acquires a better understanding of both positive
and negative impacts of thiocyanate on human health, it would be unwise for
anyone to self-administer thiocyanate because like many other chemicals,
thiocyanate has adverse side effects at improper doses and/or under
inappropriate conditions.
Health
benefits of broccoli require the whole food, not supplements
New
research has found that if you want some of the many health benefits associated
with eating broccoli or other cruciferous vegetables, you need to eat the real
thing – a key phytochemical in these vegetables is poorly absorbed and of far
less value if taken as a supplement.
The
study, published by scientists in the Linus Pauling Institute at Oregon State
University, is one of the first of its type to determine whether some of the
healthy compounds found in cruciferous vegetables can be just as easily
obtained through supplements.
The
answer is no. And not only do you need to eat the whole foods, you have to go
easy on cooking them.
"The
issue of whether important nutrients can be obtained through whole foods or
with supplements is never simple," said Emily Ho, an OSU associate
professor in the OSU School of Biological and Population Health Sciences, and
principal investigator with the Linus Pauling Institute.
"Some
vitamins and nutrients, like the folic acid often recommended for pregnant
women, are actually better-absorbed as a supplement than through food," Ho
said. "Adequate levels of nutrients like vitamin D are often difficult to
obtain in most diets. But the particular compounds that we believe give
broccoli and related vegetables their health value need to come from the
complete food."
The
reason, researchers concluded, is that a necessary enzyme called myrosinase is
missing from most of the supplement forms of glucosinolates, a valuable
phytochemical in cruciferous vegetables. Without this enzyme found in the whole
food, the study found that the body actually absorbs five times less of one
important compound and eight times less of another.
Intensive
cooking does pretty much the same thing, Ho said. If broccoli is cooked until
it's soft and mushy, its health value plummets. However, it can still be
lightly cooked for two or three minutes, or steamed until it's still a little
crunchy, and retain adequate levels of the necessary enzyme.
The
study was published October 2011 in the Journal
of Agricultural and Food Chemistry.
Broccoli
has been of particular interest to scientists because it contains the highest
levels of certain glucosinolates, a class of phytochemicals that many believe
may reduce the risk of prostate, breast, lung and colorectal cancer. When eaten
as a raw or lightly-cooked food, enzymes in the broccoli help to break down the
glucosinolates into two valuable compounds of intensive research interest –
sulforaphane and erucin.
Studies
have indicated that sulforaphane, in particular, may help to detoxify
carcinogens, and also activate tumor suppressor genes so they can perform their
proper function.
Most
supplements designed to provide these glucosinolates have the enzyme
inactivated, so the sulforaphane is not released as efficiently. There are a
few supplements available with active myrosinase, and whose function more
closely resembles that of the whole food, but they are still being tested and
not widely available, Ho said.
Small
amounts of the myrosinase enzyme needed to break down glucosinolates are found
in the human gut, but the new research showed they accomplish that task far
less effectively than does whole food consumption.
Although
broccoli has the highest levels of glucosinolates, they are also found in
cauliflower, cabbage, kale and other cruciferous vegetables. The same cooking
recommendations would apply to those foods to best retain their health
benefits, Ho said.
Many
people take a variety of vitamins, minerals and phytochemicals as supplements,
and many of them are efficacious in that form, researchers say. Higher and
optimal levels of popular supplements such as vitamins C, E, and fish oil, for
instance, can be difficult to obtain through diet alone. Some researchers
believe that millions of people around the world have deficient levels of
vitamin D, because they don't get enough in their diet or through sun exposure.
But
for now, if people want the real health benefits of broccoli, there's a simple
guideline: Eat your vegetables.
Eat Your Broccoli: Sulforaphane Prevents Cancer
Researchers
in the Linus Pauling Institute at Oregon State University have discovered yet
another reason why the "sulforaphane"compound in broccoli and other
cruciferous vegetables is so good for you -- it provides not just one, but two
ways to prevent cancer through the complex mechanism of epigenetics.
Epigenetics,
an increasing focus of research around the world, refers not just to our
genetic code, but also to the way that diet, toxins and other forces can change
which genes get activated, or "expressed." This can play a powerful
role in everything from cancer to heart disease and other health issues.
Sulforaphane
was identified years ago as one of the most critical compounds that provide
much of the health benefits in cruciferous vegetables, and scientists also knew
that a mechanism involved was histone deacetylases, or HDACs. This family of
enzymes can interfere with the normal function of genes that suppress tumors.
HDAC
inhibitors, such as sulforaphane, can help restore proper balance and prevent
the development of cancer. This is one of the most promising areas of much
cancer research. But the new OSU studies have found a second epigenetic
mechanism, DNA methylation, which plays a similar role.
"It
appears that DNA methylation and HDAC inhibition, both of which can be
influenced by sulforaphane, work in concert with each other to maintain proper
cell function," said Emily Ho, an associate professor in the Linus Pauling
Institute and the OSU College of Public Health and Human Sciences. "They
sort of work as partners and talk to each other."
This
one-two punch, Ho said, is important to cell function and the control of cell
division -- which, when disrupted, is a hallmark of cancer.
"Cancer
is very complex and it's usually not just one thing that has gone wrong,"
Ho said. "It's increasingly clear that sulforaphane is a real
multi-tasker. The more we find out about it, the more benefits it appears to
have."
DNA
methylation, Ho said, is a normal process of turning off genes, and it helps
control what DNA material gets read as part of genetic communication within
cells. In cancer that process gets mixed up. And of considerable interest to
researchers is that these same disrupted processes appear to play a role in
other neurodegenerative diseases, including cardiovascular disease, immune
function, neurodegenerative disease and even aging.
The
influence of sulforaphane on DNA methylation was explored by examining
methylation of the gene cyclinD2.
This
research, which was published February, 2012 in the journal Clinical Epigenetics, primarily studied
the effect on prostate cancer cells. But the same processes are probably
relevant to many other cancers as well, researchers said, including colon and
breast cancer.
"With
these processes, the key is balance," Ho said. "DNA methylation is a
natural process, and when properly controlled is helpful. But when the balance
gets mixed up it can cause havoc, and that's where some of these critical
nutrients are involved. They help restore the balance."
Sulforaphane
is particularly abundant in broccoli, but also found in other cruciferous
vegetables such as cauliflower and kale. Both laboratory and clinical studies
have shown that higher intake of cruciferous vegetables can aid in cancer
prevention.
Magnesium In Green Leaves and Broccoli Helps You Remember
Those
who live in industrialized countries have easy access to healthy food and
nutritional supplements, but magnesium deficiencies are still common. That's a
problem because new research from Tel Aviv University suggests that magnesium,
a key nutrient for the functioning of memory, may be even more critical than
previously thought for the neurons of children and healthy brain cells in
adults.
Begun
at MIT, the research started as a part of a post-doctoral project by Dr. Inna
Slutsky of TAU's Sackler School of Medicine and evolved to become a
multi-center experiment focused on a new magnesium supplement,
magnesium-L-theronate (MgT), that effectively crosses the blood-brain barrier
to inhibit calcium flux in brain neurons.
Published
recently in the scientific journal Neuron, the new study found that the
synthetic magnesium compound works on both young and aging animals to enhance
memory or prevent its impairment. The research was carried out over a five-year
period and has significant implications for the use of over-the-counter magnesium
supplements.
In
the study, two groups of rats ate normal diets containing a healthy amount of
magnesium from natural sources. The first group was given a supplement of MgT,
while the control group had only its regular diet. Behavioral tests showed that
cognitive functioning improved in the rats in the first group and also
demonstrated an increase of synapses in the brain — connective nerve endings
that carry memories in the form of electrical impulses from one part of the
brain to the other.
"We
are really pleased with the positive results of our studies," says Dr.
Slutsky. "But on the negative side, we've also been able to show that
today's over-the-counter magnesium supplements don't really work. They do not
get into the brain.
"We've
developed a promising new compound which has now taken the first important step
towards clinical trials by Prof. Guosong Liu, Director of the Center for
Learning and Memory at Tsinghua University and cofounder of Magceutics
company," she says.
While
the effects were not immediate, the researchers in the study — from Tel Aviv
University, MIT, the University of Toronto, and Tsighua University in Beijing —
were able to assess that the new compound shows improved permeability of the
blood-brain barrier. After two weeks of oral administration of the compound in
mice, magnesium levels in the cerebral-spinal fluid increased.
"It
seems counterintuitive to use magnesium for memory improvement because
magnesium is a natural blocker of the NMDA receptor, a molecule critical for
memory function. But our compound blocks the receptor only during background
neuronal activity. As a result, it enhances the brain's 'plasticity' and
increases the number of brain synapses that can be switched on," says Dr.
Slutsky.
"Our
results suggest that commercially available magnesium supplements are not
effective in boosting magnesium in cerebro-spinal fluid," she says.
"Magnesium is the fourth most abundant mineral in the body, but today half
of all people in industrialized countries are living with magnesium
deficiencies that may generally impair human health, including cognitive
functioning."
Before
the new compound becomes commercially available, Dr. Slutsky advises people to
get their magnesium the old-fashioned way — by eating lots of green leaves,
broccoli, almonds, cashews and fruit. The effects on memory won't appear
overnight, she cautions, but with this persistent change in diet, memory should
improve, and the effects of dementia and other cognitive impairment diseases
related to aging may be considerably delayed.
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