Eating oats can lower cholesterol as measured by a variety of markers
Researchers have known for more than 50 years that eating oats can lower cholesterol levels and thus reduce a person's risk of developing cardiovascular disease.
Studies during that time have focused on the impact of oats on levels of LDL (or "lousy") cholesterol, which collects in the walls of blood vessels where it can cause blockages or blood clots.
But there is growing evidence that two other markers provide an even more accurate assessment of cardiovascular risk -- non-HDL cholesterol (total cholesterol minus the "H" or "healthy cholesterol") and apolipoprotein B, or apoB, a lipoprotein that carries bad cholesterol through the blood. This is especially true for people with metabolic syndrome and Type 2 diabetes, since they typically do not have elevated LDL cholesterol levels.
A new systematic review and meta-analysis of randomized controlled trials has concluded that eating oat fibre can reduce all three markers. The study, led by Dr. Vladimir Vuksan, a research scientist and associate director of the Risk Factor Modification Centre of St. Michael's Hospital, was published online today in the British Journal of Nutrition.
Dr. Vuksan said oats are a rich source of beta-glucan, a viscous soluble fibre, which seems to be responsible for the beneficial effects. The first study of its kind, published in 1963, found that substituting white bread with oat bread containing 140g of rolled oats lowered LDL cholesterol.
Dr. Vuksan's group looked at 58 clinical trials involving almost 4,000 people from around the world that assessed the effect of diets enriched with oat beta-glucan compared with controlled diets on LDL cholesterol, and, for the first time, on non-HDL cholesterol and apoB as well.
"Diets enriched with about 3.5 grams a day of beta-glucan fiber from oats were found to modestly improve LDL cholesterol, but also non-HDC and apoB compared to control diets," Dr. Vuksan said.
The review found that overall, LDL cholesterol was reduced by 4.2 per cent, non-HDL cholesterol by 4.8 per cent and apoB by 2.3 per cent.
Dr. Vuksan said it could be difficult for people to consume the recommended amount of oat fiber by eating oat meal alone so he recommends people increase their consumption of oat bran. For example, one cup of cooked oat bran (88 calories) contains the same quantity of beta-glucan as double the amount of cooked oat meal (166 calories). Oat bran can also be eaten as a cereal, used in some baked goods (although since it is low in gluten, the texture may be tough) or sprinkled on other foods.
Eating whole instead of refined grains reduces the risk for cardiovascular disease
The Nutrition Source, from the Harvard Scholl
of Public Health, reports that eating whole instead of refined grains
substantially lowers total cholesterol, low-density lipoprotein (LDL, or bad)
cholesterol, triglycerides, and insulin levels. Any of these changes would be
expected to reduce the risk for cardiovascular disease.
In
the Harvard-based Nurses’ Health Study, women who ate 2 to 3 servings of
whole-grain products (mostly bread and breakfast cereals) each day were 30
percent less likely to have a heart attack or die from heart disease over a
10-year period than women who ate less than 1 serving per week. (1)
A
recent meta-analysis of seven major studies showed that cardiovascular disease
(heart attack, stroke, or the need for a procedure to bypass or open a clogged
artery) was 21 percent less likely in people who ate 2.5 or more servings of
whole-grain foods a day compared with those who ate less than 2 servings a
week. (2)
1.
Liu S, Stampfer MJ, Hu FB, et al. Whole-grain consumption and risk of coronary
heart disease: results from the Nurses’ Health Study. American Journal of
Clinical Nutrition. 1999; 70:412-9.
2.
Mellen PB, Walsh TF, Herrington DM. Whole grain intake and cardiovascular
disease: A meta-analysis. Nutr Metab Cardiovasc Dis. 2007.
New reason to eat oats for heart health
Eleven
top scientists from around the globe presented the latest findings on the
powerful compounds found in oats in a scientific session titled,
Physicochemical Properties and Biological Functionality of Oats, at the 247th
Annual Conference of the American Chemical Society in Dallas, TX. Scientists
described research on the diverse health benefits of oats and emphasized the
growing evidence that the type of phenolic compound avenanthramide (AVE) –
found only in oats – may possess antioxidant, anti-inflammatory, anti-itch and
anti-cancer properties. The culmination of the studies suggests that oat AVEs
may play an important role in protecting the heart.
Eating
whole grains is consistently associated with a reduced risk of chronic disease,
including cardiovascular disease. Most of the benefits have been attributed to
the relatively high fiber, vitamin, mineral and phytochemical content of whole
grains. Notably, the soluble fiber beta-glucan found in oats has been
recognized for its ability to lower both total and low-density lipoprotein
cholesterol (LDL-C).
"While
the data to support the importance of oat beta-glucan remains, these studies
reveal that the heart health benefit of eating oats may go beyond fiber,"
explains the session's presiding co-officer, Dr. Shengmin Sang of the Center
for Excellence in Post-Harvest Technologies at North Carolina Agricultural and
Technical State University. "As the scientific investigators dig deeper,
we have discovered that the bioactive compounds found in oats – AVEs – may
provide additional cardio-protective benefits."
New
research shows that oat AVEs may be partly responsible for the positive
association between oats and heart health. Oliver Chen, Ph.D., of the Jean
Mayer USDA Human Nutrition Research Center on Aging at Tufts University,
presented mechanistic data that demonstrated that the antioxidant and
anti-inflammatory properties of AVEs likely contribute to the atheroprotection
of oats.
Similarly,
Mohsen Meydani, Ph.D., from the Vascular Biology Laboratory at the Jean Mayer
USDA Human Nutrition Research Center on Aging at Tufts University, provided
evidence that oat AVEs suppress the production of inflammatory cytokines
associated with fatty streak formation in the arteries. In addition, oat AVEs
appear to repress the process associated with the development of
atherosclerosis.
Whole-grain
breakfast cereal associated with reduced heart failure risk
Eating
whole-grain breakfast cereals seven or more times per week was associated with
a lower risk of heart failure, according to an analysis of the observational
Physicians’ Health Study. Researchers presented findings of the study today at
the American Heart Association’s 2007 Annual Conference on Cardiovascular
Disease Epidemiology and Prevention. For the present study, breakfast cereals
that contain at least 25 percent oat or bran content were classified as whole
grain cereals.
The
analysis shows that those who ate a whole-grain breakfast cereal seven or more
times per week were less likely (by 28 percent) to develop heart failure over
the course of the study than those who never ate such cereal. The risk of heart
failure decreased by 22 percent in those who ate a whole-grain breakfast cereal
from two to six times per week and by 14 percent in those who ate a whole-grain
breakfast cereal up to once per week.
According
to researchers, if this data is confirmed by other studies, a healthy diet
including whole-grain breakfast cereals along with other measures may help
reduce the risk of heart failure.
"There
are good and powerful arguments for eating a whole-grain cereal for
breakfast," said Luc Djoussé, M.D., M.P.H., D.Sc., lead author of the
study and assistant professor of medicine in the Division of Aging at Brigham
& Women’s Hospital and Harvard Medical School in Boston, Mass. "The
significant health benefits of whole-grain cereal are not just for kids, but
also for adults. A whole-grain, high-fiber breakfast may lower blood pressure
and bad cholesterol and prevent heart attacks."
Djoussé
urges the general public to consider eating a regular whole-grain, high fiber
breakfast for its overall health benefits.
In
the Physicians’ Health Study, the majority of the physicians in the study ate
whole-grain cereals rather than refined cereals. Whole grains are rich in
vitamins, minerals, and anti-oxidants and have a high fiber content. Of 10,469
physicians reporting cereal consumption at baseline, 8,266 (79 percent) ate
whole-grain cereals compared to 2,203 (21 percent) who ate refined cereals.
Among
the physicians who ate whole-grain breakfast cereals, 2,873 (35 percent) said
they ate them seven or more times per week; 3,240 (39 percent) said two to six
times per week; and 2,153 (26 percent) said they ate up to one cereal serving
per week.
The
findings reported here were based on annual detailed questionnaires about major
heart events and reported breakfast cereal consumption at baseline. However,
the results did not change when possible changes in cereal consumption over
time (assessed at 18 weeks; two years; four years; six years; eight years; and
ten years) were taken into account. Researchers conducted the study from 1982
to 2006. The average age of physicians in the study at baseline was 53.7 years.
Djoussé hopes the findings of the Physicians’ Health Study will encourage the
general population to eat heart-healthy diets.
In
the United States, foods considered "whole grain" contain 51 percent
or more whole grain ingredients by weight per reference amount customarily
consumed.
Health benefits of
whole grain oats
According to a new, wide-reaching collection of scientific
reviews published in the October 2014 supplement issue of the British
Journal of Nutrition, oats may play an important role in improving satiety,
diet quality and digestive, cardiovascular and general metabolic health. In the
supplement issue, entitled "Oats, More Than Just a Whole Grain,"
scientists from around the world explore the oat from agriculture and
sustainability to nutrition policy and opportunity and new insights in
nutritional science that go beyond cardiovascular health.
"The British Journal of Nutrition oats
supplement is a comprehensive compilation of scientific reviews written by a
diverse group of international experts that showcase the remarkable role the
oat plays in human health and agriculture," explains Jan-Willem van Klinken,
MD, PhD, MSc, of the Quaker Oats Center of Excellence. "Not only does it
enhance the understanding of the role of oats in health promotion from satiety
to chronic disease, but the authors also identified future areas of research in
agriculture and health that will help provide greater health benefits and
increase availability worldwide."
While oats have been the focus of scientific investigation
for decades, the supplement uniquely summarizes the developing science and
technology around oats. In the supplement, new evidence is presented, while
well-established benefits are further supported, in relation to human health,
agriculture and food processing. Here are some of the noteworthy takeaways from
the supplement:
Calorie-for-Calorie,
Oatmeal is More Filling than Ready-to-Eat, Oat-Based Cereals
·
According to the supplement, epidemiological
evidence suggests that regular consumption of whole-grain foods is correlated
with lower body mass index (BMI).
·
Several studies outlined in the review suggested
that eating oats helps reduce hunger and increase feelings of fullness.
·
Similarly, recent evidence can be found in a
study from the May 28, 2014 issue of Nutrition Journal. In this study,
Rebello, et al., found that subjects who ate 217.5-calorie breakfasts of
oatmeal with nonfat milk for their first meal reported less hunger, increased
fullness and a reduced desire to eat more, compared to subjects given an equal
calorie serving of ready-to-eat, oat-based cereal with nonfat milk.
·
According to the aforementioned study and the
supplement, satiety appears to be enhanced by the higher viscosity of the
oatmeal beta-glucan compared to a ready-to-eat, oat-based cereal.
·
Subsequently, researchers are looking into oat
varieties with higher levels of beta-glucan to potentially amplify the fullness
effects of oats.
Oats: A Unique Whole
Grain That May Contribute to Digestive Health
·
Whole grains are often recommended for their
beneficial effects on the gastrointestinal tract.
·
The role that beneficial bacteria in the human
digestive tract play in human health is an area of great interest, with
potential health effects ranging from immune health to reducing risk for
obesity and chronic disease.
·
Author Devin Rose, PhD, of the University of
Nebraska, summarized emerging research regarding oats and the digestive tract.
·
Rose concluded that the beta-glucan, resistant
starch, and the unique polyphenols, avenanthramides, may benefit gut health and
that resistant starch present in oats may specifically boost the beneficial
bacteria Bifidobacteria in the lower GI tract.
·
A review of 29 studies concluded that oats and
oat bran might provide benefits in some cases of bowel disease (one of two
studies on ulcerative colitis) and constipation (14 studies).
·
The review authors note that oat products not
crossed with other cereal grains that contain gluten (such as wheat) may be
consumed by patients with celiac disease (11 studies).
Oats Improve
Cardiovascular Health
·
Review authors remind us that the evidence
supporting the impact of beta-glucan fiber in oats on low-density
lipoprotein-cholesterol (LDL-C) and cardiovascular disease is so convincing
that authorities in the United States, Europe, Canada and Japan have issued formal
health claims about the role of oats in heart health. For example, the European
Food Safety Authority (EFSA) support the claim that oat beta-glucan has been
shown to lower/reduce blood cholesterol.
·
A review of the most recent and compelling
studies on oats and oat bran and cardiovascular disease risk factors concluded
that oats and oat bran lower total cholesterol and LDL-C by respectively 2-19
percent and 4-23 percent; the effects are particularly prominent among people
with high cholesterol levels.
·
The study's lead author, Frank Thies, PhD, of
the University of Aberdeen, wrote that eating a 60-gram serving of oatmeal
might lower cholesterol significantly.
·
To put it in perspective, an LDL-C reduction of
4-6 percent is estimated to reduce coronary heart disease risk by 6-18 percent.
·
What's more, all forms of oats—oat bran, oatmeal
or other oat-containing foods—appear to be beneficial.
Eating more whole grains appears to be associated with reduced
mortality, especially deaths due to cardiovascular disease (CVD), but not
cancer deaths, according to a report published online Januaray 5 2015 by JAMA
Internal Medicine.
Whole grains are widely recommended in many dietary guidelines
as healthful food. However, data regarding how much whole grains people eat and
mortality were not entirely consistent.
Hongyu Wu, Ph.D., of the Harvard School of Public Health,
Boston, and coauthors examined the association between eating whole grains and
the risk of death using data from two large studies: 74,341 women from the
Nurses' Health Study (1984-2010) and 43,744 men from the Health Professionals
Follow-Up Study (1986-2010). All the participants were free of cancer and CVD
when the studies began.
The authors documented 26,920 deaths. After the data were
adjusted for potential confounding factors including age, smoking and body mass
index, the study found that eating more whole grains was associated with lower
total mortality and lower CVD mortality but not cancer deaths. The authors further
estimated that every serving (28 grams/per day) of whole grains was associated
with 5 percent lower total mortality or 9 percent lower CVD mortality.
"These
findings further support current dietary guidelines that recommend increasing
whole grain consumption to facilitate primary and secondary prevention of
chronic disease and also provide promising evidence that suggests a diet
enriched with whole grains may confer benefits toward extended life
expectancy," the study concludes.
Oats may deserve the well-earned status of
"super grain"
Oats
may deserve the well-earned status of "super grain", according to
research presented at the American Association of Cereal Chemists International
2013 annual meeting. World-renowned grain researchers presented compelling data
to support the important role that oats can play in improving diet quality and
supporting human health.
YiFang
Chu, Ph.D., PepsiCo R&D Nutrition, shared new data about antioxidants in
oats (Avena sativa L.) and their role in human health. In the session,
"Antioxidants in Grains and Health: Is there a Linkage?" Chu
emphasized that oats are a nutritious whole grain with evidence to show that
oats are even more complex than previously thought. They possess a wide
spectrum of biologically active compounds including carotenoids, tocols
(Vitamin E), flavonoids and avenanthramides – a class of polyphenols.
"The
polyphenols, avenanthramides, are unique to oats and have been widely used in
skincare products because of their anti-inflammatory and anti-itching
effects," says Chu. "As scientists continue to link inflammation to
chronic diseases, they are also investigating whether bioactivities produced by
the polyphenols in oats can be as beneficial from within the body as they are
on the skin." There are over 25 different biologically active
avenanthramides in oats that look similar chemically, but behave differently.
Therefore, adds Chu, "compared to the bioactive compounds identified in
other grains—like wheat and rye—oats may be more bioavailable and possess more
anti-inflammatory properties."
In
addition to avenanthramides, oats and oat products have many bioactive
compounds that may provide health benefits. Oats and oat-containing products
that meet a minimum level of oat beta-glucan are allowed to bear a Food and
Drug Administration-approved health claim for cholesterol-lowering benefits.
Studies also suggest oats can enhance satiety and may also help reduce the risk
of other chronic conditions.
Oatmeal for breakfast results in greater fullness and lower calorie intake at lunch
A new study suggests that your breakfast cereal choice may affect how full you feel and how much you eat for lunch, especially if you're overweight. According to new research published January 2015 the Annals of Nutrition and Metabolism, scientists found that having oatmeal (Quaker Oats Quick 1-minute™) for breakfast resulted in greater fullness, lower hunger ratings and fewer calories eaten at the next meal compared to a calorie-matched breakfast of a ready-to-eat cereal (RTEC) - sugared corn flakes.
Scientists from the New York Obesity Nutrition Research Center at Mount Sinai St. Luke's Hospital randomly assigned 36 subjects (18 normal weight and 18 overweight) to each receive three different breakfasts. The breakfasts consisted of 350 calories of similar amounts of carbohydrates, fat and liquid from either quick-cook oatmeal or sugared corn flakes. A third control breakfast was only 1.5 cups of water. To evaluate appetite, ratings of hunger and fullness were obtained at frequent intervals before and after the breakfast until a lunch test meal 3 hours later. Researchers measured the calorie intake of the lunch meal consumed to compare the effects of the corn flakes, oatmeal or water breakfasts. Blood samples were collected just after each of the appetite ratings to assess levels of glucose, insulin, acetaminophen (a marker for how quickly the breakfast emptied from the stomach into the intestine) and various hormones related to appetite, in response to each breakfast.
"Our results show that despite eating the same number of calories at breakfast, satiety values were significantly greater after consuming oatmeal compared to sugared corn flakes. After three hours, subjects reported the same level of hunger after having a corn flakes breakfast as they did when they consumed only water," explained lead researcher Allan Geliebter, PhD, research psychologist in the Department of Psychiatry at Mount Sinai St. Luke's Hospital. "Interestingly, the results were more pronounced for the participants who were overweight, suggesting that overweight individuals may be more responsive to the satiety effects of the dietary fiber in oatmeal."
The results showed statistically significant higher ratings of fullness, lower ratings of hunger, and 31% fewer calories consumed at lunch after consuming oatmeal compared to sugared corn flakes or water. The overall satiety effect was greater among overweight subjects, who consumed 50% fewer calories at lunch after eating oatmeal.
The study authors suggested that the greater satiety effect of oatmeal cereal compared to sugared corn flakes or water might be due to a slower gastric emptying (oatmeal took longer to leave the stomach). Given that the results were more pronounced in overweight subjects, researchers suggested that a longer-term weight control study testing daily oatmeal for breakfast is warranted.
"Consumers choose oatmeal for its great taste, well-established health benefits and convenience, but scientists are finding that eating oatmeal for breakfast may also be one of the easiest ways to improve satiety after breakfast," adds Marianne O'Shea, PhD, Director, Quaker Oats Center of Excellence. "We are encouraged by the potential for future investigations that could have a positive impact on public health and give people more reasons to enjoy oat-based breakfasts and snacks."
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