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."