'Apple a day' advice rooted in science
Everyone has heard the old adage, "an apple a day keeps the doctor away." We all know we should eat more fruit. But why apples? Do they contain specific benefits?
According to Dr. Bahram H. Arjmandi, PhD, RD, Margaret A. Sitton Professor and Chair, Department of Nutrition, Food and Exercise Sciences at The Florida State University, apples are truly a "miracle fruit" that convey benefits beyond fiber content. Animal studies have shown that apple pectin and polyphenols in apple improve lipid metabolism and lower the production of pro-inflammatory molecules. Arjmandi's most recent research is the first to evaluate the long-term cardioprotective effects of daily consumption of apple in postmenopausal women. The results of this USDA-funded study will be presented at Experimental Biology 2011 on Tuesday, April 12, at 12:45 pm in Washington, DC.
This study randomly assigned 160 women ages 45-65 to one of two dietary intervention groups: one received dried apples daily (75g/day for 1 year) and the other group ate dried prunes every day for a year. Blood samples were taken at 3, 6 and 12-months. The results surprised Dr. Arjmandi, who stated that "incredible changes in the apple-eating women happened by 6 months- they experienced a 23% decrease in LDL cholesterol," which is known as the "bad cholesterol." The daily apple consumption also led to a lowering of lipid hydroperoxide levels and C-reactive protein in those women.
"I never expected apple consumption to reduce bad cholesterol to this extent while increasing HDL cholesterol or good cholesterol by about 4%," Arjmandi said. Yet another advantage is that the extra 240 calories per day consumed from the dried apple did not lead to weight gain in the women; in fact, they lost on average 3.3 lbs. "Reducing body weight is an added benefit to daily apple intake" he said. Part of the reason for the weight loss could be the fruit's pectin, which is known to have a satiety effect. The next step in confirming the results of this study is a multi-investigator nationwide study.
There is frequently some truth behind our common expressions, and in the case of 'an apple a day,' Dr. Arjmandi has shown that nutrition science backs up the expression. "Everyone can benefit from consuming apples," he said.
An Apple Peel a Day Could Keep Cancer at Bay
An apple peel a day might help keep cancer at bay, according to Rui Hai Liu, Cornell associate professor of food science, who has identified a dozen compounds -- triterpenoids -- in apple peel that either inhibit or kill cancer cells in laboratory cultures. Three of the compounds have not previously been described in the literature.
"We found that several compounds have potent anti-proliferative activities against human liver, colon and breast cancer cells and may be partially responsible for the anti-cancer activities of whole apples," says Liu, who is affiliated with Cornell's Institute of Comparative and Environmental Toxicology and is senior author of the study, which is online and published in the Journal of Agricultural and Food Chemistry.
In previous Cornell studies, apples had been found not only to fight cancer cells in the laboratory but also to reduce the number and size of mammary tumors in rats. The Cornell researchers now think that the triterpenoids may be doing much of the anti-cancer work.
"Some compounds were more potent and acted differently against the various cancer cell lines, but they all show very potent anti-cancer activities and should be studied further," says Liu.
With co-author Xiangjiu He, a Cornell postdoctoral researcher, Liu analyzed the peel from 230 pounds of red delicious apples from the Cornell Orchard and isolated their individual compounds. After identifying the structures of the promising compounds in the peel, the researchers tested the pure compounds against cancer cell growth in the laboratory. In the past, Liu has also identified compounds called phytochemicals -- mainly flavonoids and phenolic acids -- in apples and other foods that appear to be have anti-cancer properties as well, including inhibiting tumor growth in human breast cancer cells.
"We believe that a recommendation that consumers to eat five to 12 servings of a wide variety of fruits and vegetables daily is appropriate to reduce the risks of chronic diseases, including cancer, and to meet nutrient requirements for optimum health," said Liu.
The study online: http://pubs.acs.org/cgi-bin/abstract.cgi/jafcau/2007/55/i11/abs/jf063563o.html
Adults who eat apples, drink apple juice have lower risk for metabolic syndrome
Apple product consumers likely to have lower blood pressure, trimmer waistlines, and more nutrient dense diets
Not eating your apple a day" Perhaps you should be. Adults who eat apples, apple juice and applesauce have a significantly reduced risk of metabolic syndrome, a cluster of health problems that are linked to numerous chronic diseases such as diabetes and cardiovascular disease.
The study results, presented at the Experimental Biology 2008 meeting this week, were derived from an analysis of adult food consumption data collected in the 1999-2004 National Health and Nutrition Examination Survey (NHANES), the government’s largest food consumption and health database.
Dr. Victor Fulgoni analyzed the data, specifically looking at the association between consumption of apples and apple products, nutrient intake and various physiological parameters related to metabolic syndrome. When compared to non-consumers, adult apple product consumers had a 27% decreased likelihood of being diagnosed with metabolic syndrome.
Fulgoni notes, “We found that adults who eat apples and apple products have smaller waistlines that indicate less abdominal fat, lower blood pressure and a reduced risk for developing what is known as the metabolic syndrome.”
In addition to having a 30% decreased likelihood for elevated diastolic blood pressure and a 36% decreased likelihood for elevated systolic blood pressure, apple product consumers also had a 21% reduced risk of increased waist circumference – all predictors of cardiovascular disease and an increased likelihood of metabolic syndrome. Additionally, adult apple product consumers had significantly reduced C-reactive protein levels, another measurable marker related to cardiovascular risk.
Furthermore, apple product consumers’ diets were healthier than non-consumers – they had an overall greater intake of fruit and key nutrients, including dietary fiber, vitamins A and C, calcium and potassium. These consumers also ate less total fat, saturated fat, discretionary fat and added sugars.
Apple pectin, apple juice extracts shown to have anticarcinogenic effects on colon
The apples and apple juice you consume may have positive effects in one of the most unlikely places in the body – in the colon. New research has demonstrated that both apple pectin and polyphenol-rich apple juice components actually enhance biological mechanisms that produce anticarcinogenic compounds during the fermentation process.
Using human fecal matter as the test substance, German researchers Dr. Dieter Schrenk, M.D. and his colleagues hypothesized that the compound butyrate could be increased in the presence of apple pectin and apple juice extracts.
Butyrate has been suggested to be a chemopreventative metabolite that might prevent the occurrence of colorectal cancer, which is very common in Western industrialized countries. It is a short chain fatty acid which is seen as a major factor contributing to healthy colon mucosa. The research notes, “Butyrate not only serves as a major nutrient for the colon epithelia but is also thought to play an important role in the protective effect of natural fiber against colorectal cancer.”
So how do apple pectin and apple juice extracts play a role in increasing amounts of butyrate? The laboratory tests performed by Schrenk found that by the increased production of butyrate via the addition of apple components, histone deacetlyases (HDAC) were inhibited. With slowed production of HDAC, there would be significantly less growth of precancerous and tumor cells.
The research, published in the April 2008 issue of Nutrition, notes, “apples are a major source of natural fiber and of low molecular weight plan polyphenols in the Western diet.” The researchers conclude, “Pectin-rich apple products can thus be expected to exert anticarginogenic effects in the colon.”
Apple consumers reap heart-health benefits
Apple consumers reap heart-health benefits thanks to flavonoid content, says new research
American Heart Association new recommendations support increased fruit, vegetable consumption
Apples may prove to be a winner when it comes to reducing the risk of heart disease, says a new study of more than 34,000 women. In this study, flavonoid-rich apples were found to be one of three foods (along with red wine and pears) that decrease the risk of mortality for both coronary heart disease (CHD) and cardiovascular disease (CVD) among post-menopausal women, The findings were published in the March 2007 American Journal of Clinical Nutrition.
Women of all ages are encouraged to consume more fruit and vegetables, including apples and apple products, for heart health. However, this study focused on postmenopausal woman, a group becoming more aware of the risk for heart disease. Using a government database that assesses the flavonoid-compound content of foods, the researchers hypothesized that flavonoid intake (in general and from specific foods), might be inversely associated with mortality from CVD and CHD among the women in the study groupSubjects selected for this research analysis were postmenopausal and part of the ongoing Iowa Women's Health Study, each of which has been monitored for dietary intake and various health outcomes for nearly 20 years.
As a result of the extensive analysis that considered what the women ate, the types of cardiovascular-related diseases they experienced, and the overall flavonoid content of an extensive list of foods, the researchers concluded that consumption of apples, pears and red wine were linked with the lowest risk for mortality related to both CHD and CVD (not just one or the other).
"Flavonoids are compounds found in small quantities in numerous plant foods, including fruits and vegetables, tea, wine, nuts and seeds, and herbs and spices," say the university researchers from the University of Minnesota and the University of Oslo (Norway) Earlier research has indicated that flavonoids also have antioxidant properties that are linked to the reduction of oxidation of the bad (LDL - low density lipoprotein) cholesterol which have been linked in various ways with the development of CVD. According to the government database cited in this paper, apples contain a wide variety of flavonoid compounds.
The researchers also believe this is the first prospective study of postmenopausal women to report on the intake and impact of total and specific flavonoid subclasses. They conclude, "Dietary intakes of flavanones, anthocyanins, and certain foods rich in flavonoids were associated with reduced risk of death due to CHD, CVD and all causes."_
The publication of this positive study for apples comes on the heels of updated heart disease prevention guidelines for women just released by the American Heart Association in the February 20 issue of Circulation. As part of their guidelines, AHA emphasizes that women increase their intake of fruits and vegetables to help prevent heart disease over their lifetime, not just to reduce short-term risk. Worldwide, cardiovascular disease is the largest single cause of mortality among women, accounting for one third of all deaths.
Can an apple a day keep asthma away?
Poor diets show increased respiratory symptoms in teens
Teenagers who forego a healthy and balanced diet may have a harder time catching their breath. A new study, published in the July issue of CHEST, the peer-reviewed journal of the American College of Chest Physicians (ACCP), shows that a low dietary intake of certain nutrients increases the likelihood of respiratory symptoms such as asthma, especially in teens who smoke. Furthermore, a lack of these nutrients may also lead to lower lung function.
“Our study, as well as other research, suggests that higher intakes of antioxidant and anti-inflammatory micronutrients are associated with lower reports of cough, respiratory infections, and less severe asthma-related symptoms,” said lead study author Jane Burns, ScD, Harvard School of Public Health. “Teenagers who have low dietary intakes of fruit, vitamin E, and omega-3 fatty acids are at greater risk of having asthma, emphasizing the importance of a balanced diet, composed of whole foods.”
While observing 12th-grade students from 12 communities around the US and Canada, Dr. Burns and her colleagues from the Harvard School of Public Health, Health Canada, Brigham and Women’s Hospital, and the Environmental Protection Agency (EPA), examined the associations of low dietary nutrient intake with low pulmonary function and respiratory symptoms. Over the period of one school year, 2,112 students completed a standardized respiratory questionnaire and a dietary questionnaire. They also answered questions about medication use, smoking habits, and recent exercise, before participating in lung function testing. Dr. Burns explained that the researchers focused on teens because it is the ideal age at which to test lung capacity and eating habits.
“During late adolescence, physical stature has, on average, been attained and lung growth closely parallels this growth. Therefore we were observing a time when lung function was close to its optimal capacity,” she said. “Also, although our diet survey targeted eating habits only during the past year, it did give us some idea of the teens’ general past diet. However, their current respiratory health may be a reflection of diet during childhood, as well as during the past year.”
The majority of adolescents in the study were white, one third was overweight, and 72% did not consume multivitamins. Also, nearly 25% reported smoking on a daily basis. Researchers also found that at least one third of the students’ diets were below the recommended levels of fruit, vegetable, vitamins A and E, beta-carotene, and omega-3 fatty acid intake.
“Vitamin supplements can help teens meet their daily recommended levels,” said Dr. Burns, “and surprisingly, even relatively low levels of omega-3 fatty acids appeared to protect teens from higher reported respiratory symptoms.”
Results showed that low dietary intakes of fruit, vitamins C and E, and omega-3 fatty acids were associated with decreased lung function and a greater risk of chronic bronchitic symptoms, wheeze, and asthma. These risks were further increased among students with the lowest intakes and who also smoked.
“I wish we could say that an apple a day can keep asthma away, but it’s a complex disease with a genetic component. However, it may be that certain foods can lessen or prevent asthma symptoms,” said Dr. Burns. “The most important thing to remember is that diet can have a significant impact on teens’ respiratory health. I would encourage them to make healthy eating a part of their daily routine, and stress to them that smoking is bad.” Researchers emphasized that fresh fruits make for convenient snacks. They also suggest preparing a simple, daily family meal, as a method to promote both communication and good nutrition.
“A balanced diet is not only good for lung health, but for general health,” said Mark J. Rosen, MD, FCCP, President of the American College of Chest Physicians. “Parents and physicians should work together to monitor and maintain healthy diets and lifestyles for children of all ages.”
Apples, apple juice shown to prevent early atherosclerosis
A new study shows that apples and apple juice are playing the same health league as the often-touted purple grapes and grape juice. The study was published in the April 2008 issue of Molecular Nutrition and Food Research.
Researcher Kelly Decorde from the Universite Montpelier in France was part of the European research team that found apples have similar cardiovascular protective properties to grapes. The researchers also observed that processing the fruit into juice has the potential to increase the bioavailability of the naturally-occurring compounds and antioxidants found in the whole fruit.
Using a variety of established analytical techniques, aortic plaque was evaluated to determine the effectiveness in decreasing plaque that is associated with atherosclerosis.
According to the research, “This study demonstrates that processing apples and purple grapes into juice modifies the protective effect of their phenolics against diet induced oxidative stress and early atherosclerosis in hypercholesterolemic hamsters.”
Researchers also noted, “These results show for the first time that long-term consumption of antioxidants supplied by apples and purple grapes, especially phenolic compounds, prevents the development of atherosclerosis in hamsters, and that the processing can have a major impact on the potential health effects of a product.”
In summary, the researchers stated that their work would help provide encouragement that fruit and fruit juices may have significant clinical and public health relevance.
Apples, Apple Juice Lower Wheezing and Asthma Risk in Children
Published in the September 2007 issue of Thorax, the latest study finds that when women ate apples during pregnancy, researchers found a significant decrease in asthma and wheezing among their children when the children were followed over five years and reached five years of age.
This unique longitudinal study tracked dietary intake by 1253 mother-child pairs. According to the researchers that conducted medical evaluations for asthma and related symptoms (i.e., wheezing) in the children, they found no other association with decreased risk other than for apple consumption. The only other positive association found between prenatal food intake and risk reduction in the children was with fish intake by the mothers, for which the researchers found that children of mothers who ate fish had a lowered incidence of doctor-confirmed eczema.
A similar but different study published June 2007 also showed a link between apple juice consumption and a reduction in wheezing among children. That study was published in June’s European Respiratory Journal.
Among children who experienced what was characterized as “current wheeze” (where the child had wheezing or whistling in the chest in the last 12 months), there was a significant, dose response association between consumption of apple juice and a reduced incidence of the wheezing. The researchers found that drinking apple juice made from concentrate and consumption of bananas one or more times a day (compared to drinking apple juice or eating bananas less than once a month) was directly associated with improvement of wheezing occurences.
According to the authors of the Thorax paper, the protective effect from apples is attributable to their powerful phytochemical content, which includes flavonoids, isoflavonoids, and phenolic acids. Apples and apple products combined are the largest source of free phenolics in people’s diet in the US and in Europe.
The American Lung Association states that asthma remains a major public health concern. In 2003, approximately 20 million Americans had asthma and the condition accounted for an estimated 12.8 million lost school days in children. Asthma ranks within the top ten prevalent conditions causing limitation of activity and costs our nation $16.1 billion in health care costs annually.
Apple's benefits reach into the womb to fight asthma
Eating apples while pregnant may give new meaning to an apple a day keeping the doctor away. Compelling new research has concluded that mothers who eat apples during pregnancy may protect their children from developing asthma later in life. The study was published in Thorax online.
This unique longitudinal study tracked dietary intake by nearly 2000 pregnant women, then examined the effects of the maternal diet on airway development in more than 1200 of their children five years later. Among a wide variety of foods consumed and recorded by the pregnant women, the researchers concluded that the children of mothers who ate apples had a significantly reduced risk for the development of asthma and childhood wheezing.
This study focuses on medical evaluations for asthma and related symptoms (i.e., wheezing) when the children were five years old. As a result of the evaluations cited in this research, other than apples, there were no consistent associations found between prenatal consumption of a range of healthful foods and asthma in the 1253 children who were evaluated.
Children of mothers who ate apples during pregnancy were much less likely to exhibit symptoms of asthma (including wheezing), say the researchers who hail from institutions in The Netherlands and Scotland. These same researchers previously reported positive associations between maternal consumption of vitamins A, E, D and zinc with reduced risk of asthma, wheeze and eczema in children.
The only other positive association found between prenatal food intake and risk reduction in the children was with fish, for which the researchers found that children of mothers who ate fish had a lowered incidence of doctor-confirmed eczema.
According to the research, "The present study suggests beneficial associations between maternal apple intake during pregnancy and wheeze and asthma at age five years." They add that their findings "suggest an apple specific effect, possibly because of its phytochemical content, such as flavonoids." The research paper cites other related studies on apples, including those which found that "intake of apples as a significant source of flavonoids and other polyphenols has been beneficially associated with asthma, bronchial hypersensitivity, and lung function in adults."
In 2004, the National Center for Health Statistics reported that nine million U.S. children have been diagnosed with asthma at one point in their lives and four million children suffered from asthma attacks that year. Others suffer from "hidden asthma" – undetected or undiagnosed asthma, according the American Lung Association. The cost of this disease is great – statistics show asthma to be the third-ranking cause of hospitalization among children under 15 and is among the leading causes of school absenteeism.
Eating apples/fish helps vs asthma/allergies
Women who eat apples and fish during pregnancy may reduce the risk of their children developing asthma or allergic disease, suggests a new study presented at the American Thoracic Society 2007 International Conference, on Sunday, May 20.
The SEATON study, conducted at the University of Aberdeen, UK, found that the children of mothers who ate the most apples were less likely to ever have wheezed or have doctor-confirmed asthma at the age of 5 years, compared to children of mothers who had the lowest apple consumption. Children of mothers who ate fish once or more a week were less likely to have had eczema than children of mothers who never ate fish.
The study did not find any protective effect against asthma or allergic diseases from many other foods, including vegetables, fruit juice, citrus or kiwi fruit, whole grain products, fat from dairy products or margarine or other low-fat spreads.
The researchers studied 1212 children born to women who had filled out food questionnaires during their pregnancy. When the children were 5 years old, the mothers filled out a questionnaire about the children’s respiratory symptoms and allergies, as well as a questionnaire about their child’s food consumption.
The children were also given lung function and allergy tests. Previous studies in the same children have found evidence for protective effects of vitamin E and D and zinc during pregnancy in reducing the risk of children’s wheeze and asthma, notes researcher Saskia Willers, M.Sc. of Utrecht University in the Netherlands. If the new results are confirmed, she says, "recommendations on dietary modification during pregnancy may help to prevent childhood asthma and allergy."
Willers concludes that at least until age 5, a mother’s diet during pregnancy might be more influential on a child’s respiratory health than the child’s own diet. She notes that further study of this group of children will be needed to see whether the association with the mothers’ diet declines in older children, and if mothers’ and their childrens’ diets interact in older children.
Willers suggests that the beneficial effect of apples may come from powerful antioxidants called flavonoids, while fish’s protective effect may come from omega-3 fatty acids, which other studies have suggested have a protective effect on the heart and may have a protective effect in asthma. "Other studies have looked at individual nutrients’ effect on asthma in pregnancy, but our study looked at specific foods during pregnancy and the subsequent development of childhood asthma and allergies, which is quite new," Willers says. "Foods contain mixtures of nutrients that may contribute more than the sum of their parts."
Naturally-occurring apple compounds reduce risk of pancreatic cancer
Smokers benefit most from intake of 'hidden' plant nutrients
Eating flavonol-rich foods like apples may help reduce the risk of pancreatic cancer, says a team of international researchers. Quercetin, which is found naturally in apples and onions, has been identified as one of the most beneficial flavonols in preventing and reducing the risk of pancreatic cancer. Although the overall risk was reduced among the study participants, smokers who consumed foods rich in flavonols had a significantly greater risk reduction.
This study, published in the October 15 issue of the American Journal of Epidemiology, is the first of its kind to evaluate the effect of flavonols – compounds found specifically in plants – on developing pancreatic cancer. According to the research paper, “only a few prospective studies have investigated flavonols as risk factors for cancer, none of which has included pancreatic cancer. “
Researchers from Germany, the Univ. of Hawaii and Univ. of Southern California tracked food intake and health outcomes of 183,518 participants in the Multiethnic Cohort Study for eight years. The study evaluated the participants’ food consumption and calculated the intake of the three flavonols quercetin, kaempferol, and myricetin. The analyses determined that flavonol intake does have an impact on the risk for developing pancreatic cancer.
The most significant finding was among smokers. Smokers with the lowest intake of flavonols presented with the most pancreatic cancer. Smoking is an established risk factor for the often fatal pancreatic cancer, notes the research.
Among the other findings were that women had the highest intake of total flavonols and seventy percent of the flavonol intake came from quercetin, linked to apple and onion consumption.
It is believed that these compounds may have anticancer effects due to their ability to reduce oxidative stress and alter other cellular functions related to cancer development.
“Unlike many of the dietary components, flavonols are concentrated in specific foods rather than in broader food groups, for example, in apples rather than in all fruit,” notes the research study. Previously, the most consistent inverse association was found between flavonols, especially quercetin in apples and lung cancer, as pointed out in this study. No other epidemiological flavonol studies have included evaluation of pancreatic cancer.
While found in many plants, flavonols are found in high concentrations in apples, onions, tea, berries, kale, and broccoli. Quercetin is most plentiful in apples and onions.
Compound in Apples Inhibits E. coli
A compound that is abundant in apples and strawberries inhibits the highly pathogenic E. coli O157:H7 biofilms while sparing a beneficial strain of E. coli that also forms biofilms in the human gut, according to a paper in the December 2011 issue of the journal Infection and Immunology.
Transcriptome analysis revealed that the compound, called phloretin, suppresses toxin and other genes involved in O157:H7 pathology and biofilm formation. And in a rat model of colitis, phloretin, reduced colon inflammation and body weight loss. "Phloretin has a triple biological activity as an antioxidant compound, a biofilm inhibitor, and an anti-inflammatory agent," says corresponding author Jintae Lee of Yeungnam University, Gyeongsan, Korea.
E. coli O157:H7 causes hemorrhages in the intestine. To date, no effective therapy for O157:H7 biofilms has been found. Biofilms generally are notoriously resistant to antimicrobial therapy. So in the study, Lee screened a dozen flavonoids, including phloretin, for their ability to inhibit these biofilms. "We found that phloretin markedly reduced E. coli O157:H7 biofilm formation on abiotic surface and human colon epithelial cells, while phloretin did not harm commensal E. coli K-12 biofilms," says Lee. Commensal E. coli can actually fortify the human immune system, he says.
In addition to its anti- E. coli O157:H7 biofilm activity, phloretin "accounts in part for the antioxidant capacity of apples, and it also shows anti-inflammatory activity," says Lee. "This study suggests that phloretin in apples could reduce the risk of E. coli O157:H7 infection and intestinal inflammation."
"This study demonstrated for the first time that phloretin, a natural flavonoid, is a nontoxic inhibitor of enterohemorrhagic E. coli O157:H7 biofilms, but does not harm commensal E. coli K-12 biofilms," Lee writes. "Also, importantly, our results confirmed that phloretin shows anti-inflammatory properties in both the in vitro and in vivo inflammatory colitis models. The effect of phloretin was noticeably more pronounced than that of the conventional [inflammatory bowel disease] drug 5-aminosalicylic acid."