Significant Cardiovascular Benefits
 for Postmenopausal Women

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Eating a serving of whole grains, such as oats, at least 6 times each week is an especially good idea for postmenopausal women with high cholesterol, high blood pressure or other signs of cardiovascular disease (CAD).

A 3-year prospective study of 229 postmenopausal women with CAD, published in the July 2005 issue of the American Heart Journal, shows that those eating at least 6 servings of whole grains each week experienced both:

• Less progression in stenosis, the narrowing of the diameter of arterial passageways.

The women's intake of fiber from fruits, vegetables and refined grains was not associated with a lessening in CAD progression.

Enhance Immune Response to Infection

In laboratory studies reported in the August 2004 issue of <SURGERY< i>, a compound found in oats called beta-glucan significantly enhanced the human immune system's response to bacterial infection. Beta-glucan not only helps neutrophils (the most abundant type of non-specific immune cell) navigate to the site of an infection more quickly, it also enhances their ability to eliminate the bacteria they find there.

According to study leader Jonathan Reichner of the Department of Surgery at Rhode Island Hospital and Brown University, priming neutrophils with beta-glucan helps these immune defenders quickly locate the bacterial mother lode within infected tissue. And this more rapid response to infection results in faster microbial clearance and healing. Since our non-specific immune defenses are the body's first strike forces against invading pathogens, starting your day with a bowl of oatmeal may boost your immune response in addition to your morning energy levels.

Stabilize Blood Sugar

Studies also show that beta-glucan has beneficial effects in diabetes as well. Type 2 diabetes patients given foods high in this type of oat fiber or given oatmeal or oat-bran rich foods experienced much lower rises in blood sugar compared to those who were given white rice or bread. Starting out your day with a blood sugar stabilizing food such as oats may make it easier to keep blood sugar levels under control the rest of the day, especially when the rest of your day is also supported with nourishing fiber-rich foods.

Antioxidant and Anti-Cancer Benefits

In addition to its fiber benefits, oats are also a very good source of selenium. A necessary cofactor of the important antioxidant, glutathione peroxidase, selenium works with vitamin E in numerous vital antioxidant systems throughout the body. These powerful antioxidant actions make selenium helpful in decreasing asthma symptoms and in the prevention of heart disease. In addition, selenium is involved in DNA repair and is associated with a reduced risk for cancer, especially colon cancer.

Anti-Cancer Activity Equal to or Even Higher than that of Vegetables and Fruits

Research reported at the American Institute for Cancer Research (AICR) International Conference on Food, Nutrition and Cancer, by Rui Hai Liu, M.D., Ph.D., and his colleagues at Cornell University shows that whole grains, such as oats, contain many powerful phytonutrients whose activity has gone unrecognized because research methods have overlooked them.

Despite the fact that for years researchers have been measuring the antioxidant power of a wide array of phytochemicals, they have typically measured only the "free" forms of these substances, which dissolve quickly and are immediately absorbed into the bloodstream. They have not looked at the "bound" forms, which are attached to the walls of plant cells and must be released by intestinal bacteria during digestion before they can be absorbed.

Phenolics, powerful antioxidants that work in multiple ways to prevent disease, are one major class of phytochemicals that have been widely studied. Included in this broad category are such compounds as quercetin, curcumin, ellagic acid, catechins, and many others that appear frequently in the health news.

When Dr. Liu and his colleagues measured the relative amounts of phenolics, and whether they were present in bound or free form, in common fruits and vegetables like apples, red grapes, broccoli and spinach, they found that phenolics in the "free" form averaged 76% of the total number of phenolics in these foods. In whole grains, however, "free" phenolics accounted for less than 1% of the total, while the remaining 99% were in "bound" form.

In his presentation, Dr. Liu explained that because researchers have examined whole grains with the same process used to measure antioxidants in vegetables and fruits—looking for their content of "free" phenolics"—the amount and activity of antioxidants in whole grains has been vastly underestimated.

Despite the differences in fruits', vegetables' and whole grains' content of "free" and "bound" phenolics, the total antioxidant activity in all three types of whole foods is similar, according to Dr. Liu's research. His team measured the antioxidant activity of various foods, assigning each a rating based on a formula (micromoles of vitamin C equivalent per gram). Broccoli and spinach measured 80 and 81, respectively; apple and banana measured 98 and 65; and of the whole grains tested, corn measured 181, whole wheat 77, oats 75, and brown rice 56.

Dr. Liu's findings may help explain why studies have shown that populations eating diets high in fiber-rich whole grains consistently have lower risk for colon cancer, yet short-term clinical trials that have focused on fiber alone in lowering colon cancer risk, often to the point of giving subjects isolated fiber supplements, yield inconsistent results. The explanation is most likely that these studies have not taken into account the interactive effects of all the nutrients in whole grains—not just their fiber, but also their many phytonutrients. As far as whole grains are concerned, Dr. Liu believes that the key to their powerful cancer-fighting potential is precisely their wholeness. A grain of whole wheat consists of three parts—its endosperm (starch), bran and germ. When wheat—or any whole grain—is refined, its bran and germ are removed. Although these two parts make up only 15-17% of the grain's weight, they contain 83% of its phenolics. Dr. Liu says his recent findings on the antioxidant content of whole grains reinforce the message that a variety of foods should be eaten good health. "Different plant foods have different phytochemicals," he said. "These substances go to different organs, tissues and cells, where they perform different functions. What your body needs to ward off disease is this synergistic effect - this teamwork - that is produced by eating a wide variety of plant foods, including whole grains."

Lignans Protect against Cancers and Heart Disease

One type of phytochemical especially abundant in whole grains including oats are plant lignans, which are converted by friendly flora in our intestines into mammalian lignans, including one called enterolactone that is thought to protect against breast and other hormone-dependent cancers as well as heart disease. In addition to whole grains, nuts, seeds and berries are rich sources of plant lignans, and vegetables, fruits, and beverages such as coffee, tea and wine also contain some. When blood levels of enterolactone were measured in 857 postmenopausal women in a Danish study published in the October 2004 issue of the Journal of Nutrition, women eating the most whole grains were found to have significantly higher blood levels of this protective lignan. Women who ate more cabbage and leafy vegetables also had higher enterolactone levels.

A Well-tolerated Wheat Alternative for Children and Adults with Celiac Disease

Although treatment of celiac disease has been thought to require lifelong avoidance of the protein gluten, which is found in wheat, rye, barley and oats, recent studies of adults have shown that oats, despite the small amount of gluten they contain, are well-tolerated. Now, a double blind, multi-center study involving 8 clinics treating 116 children newly diagnosed celiac disease suggests oats are a good grain choice for children with celiac disease as well. The children were randomly assigned to receive either the standard gluten-free diet (no wheat, barley, rye or oats) or a gluten-free diet with some wheat-free oat products. At the end of the study, which ran for a year, all the children were doing well, and in both groups, the mucosal lining of the small bowel (which is damaged by wheat gluten in celiac disease) had healed and the immune system (which is excessively reactive in celiac patients) had returned to normal.
 

Meta-analysis Explains Whole Grains' Health Benefits

In many studies, eating whole grains, such as oats, has been linked to protection against atherosclerosis, ischemic stroke, diabetes, insulin resistance, obesity, and premature death. A new study and accompanying editorial, published in the December 2004 issue of the American Journal of Clinical Nutrition explains the likely reasons behind these findings and recommends at least 3 servings of whole grains should be eaten daily.

Whole grains are excellent sources of fiber. In this meta-analysis of 7 studies including more than150 000 persons, those whose diets provided the highest dietary fiber intake had a 29% lower risk of cardiovascular disease compared to those with the lowest fiber intake.

But it's not just fiber's ability to serve as a bulking agent that is responsible for its beneficial effects as a component of whole grains. Wheat bran, for example, which constitutes 15% of most whole-grain wheat kernels but is virtually non-existent in refined wheat flour, is rich in minerals, antioxidants, lignans, and other phytochemicals—as well as in fiber.

In addition to the matrix of nutrients in their dietary fibers, the whole-grain arsenal includes a wide variety of additional nutrients and phytochemicals that reduce the risk of cardiovascular disease. Compounds in whole grains that have cholesterol-lowering effects include polyunsaturated fatty acids, oligosaccharides, plant sterols and stanols, and saponins.

Whole grains are also important dietary sources of water-soluble, fat-soluble, and insoluble antioxidants. The long list of cereal antioxidants includes vitamin E, tocotrieonols, selenium, phenolic acids, and phytic acid. These multifunctional antioxidants come in immediate-release to slow-release forms and thus are available throughout the gastrointestinal tract over a long period after being consumed.

The high antioxidant capacity of wheat bran, for example, is 20-fold that of refined wheat flour (endosperm). Although the role of antioxidant supplements in protecting against cardiovascular disease has been questioned, prospective population studies consistently suggest that when consumed in whole foods, antioxidants are associated with significant protection against cardiovascular disease. Because free radical damage to cholesterol appears to contribute significantly to the development of atherosclerosis, the broad range of antioxidant activities from the phytochemicals abundant in whole-grains is thought to play a strong role in their cardio-protective effects.

Like soybeans, whole grains are good sources of phytoestrogens, plant compounds that may affect blood cholesterol levels, blood vessel elasticity, bone metabolism, and many other cellular metabolic processes.

Whole grains are rich sources of lignans that are converted by the human gut to enterolactone and enterodiole. In studies of Finnish men, blood levels of enterolactone have been found to have an inverse relation not just to cardiovascular-related death, but to all causes of death, which suggests that the plant lignans in whole grains may play an important role in their protective effects.

Lower insulin levels may also contribute to the protective effects of whole grains. In many persons, the risks of atherosclerotic cardiovascular disease, diabetes, and obesity are linked to insulin resistance. Higher intakes of whole grains are associated with increased sensitivity to insulin in population studies and clinical trials. Why? Because whole grains improve insulin sensitivity by lowering the glycemic index of the diet while increasing its content of fiber, magnesium, and vitamin E.

The whole kernel of truth: as part of your healthy way of eating, whole grains can significantly lower your risk of cardiovascular disease, obesity, and type 2 diabetes. Enjoy at least 3 servings a day. No idea how to cook whole grains? Just look at the "How to Enjoy" section in our profiles of the whole grains, or for quick, easy, delicious recipes, click on this link to our Recipe Assistant and select oats or whichever whole grain you would like to prepare.

Description

Oats, known scientifically as Avena sativa, are a hardy cereal grain able to withstand poor soil conditions in which other crops are unable to thrive. Their fortitude seems to be transferred to those who consume this nutrient-dense grain. After all, when we think of a satisfying and enriching way to start the day, one that gives us strength and lasting energy, we oftentimes relish the thought of a hot bowl of oatmeal.

Oats gain part of their distinctive flavor from the roasting process that they undergo after being harvested and cleaned. Although oats are then hulled, this process does not strip away their bran and their germ allowing them to retain a concentrated source of their fiber and nutrients. Different types of processing are then used to produce the various types of oat products, which are generally used to make breakfast cereals, baked goods and stuffings:

• Oat groats: unflattened kernels that are good for using as a breakfast cereal or for stuffing
• Steel-cut oats: featuring a dense and chewy texture they are produced by running the grain through steel blades which thinly slices them.
• Old-fashioned oats: have a flatter shape that is the result of their being steamed and then rolled.
• Quick-cooking oats: processed like old-fashioned oats, except they are cut finely before rolling
• Instant oatmeal: produced by partially cooking the grains and then rolling them very thin. Oftentimes, sugar, salt and other ingredients are added to make the finished product.
• Oat bran: the outer layer of the grain that resides under the hull. While oat bran is found in rolled oats and steel-cut oats, it may also be purchased as a separate product that can be added to recipes or cooked to make a hot cereal.
• Oat flour: used in baking, it is oftentimes combined with wheat or other gluten-containing flours when making leavened bread.

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