Studies Under Way to Confirm Health Benefit of Rice Bran
A number of research projects under way hope to confirm earlier federal studies that indicate rice bran has the same cholesterol-lowering properties as oat bran.
Any such association is a potential boon for the nation’s rice growers--including the sizable industry in California--because rice bran is generally considered a waste product of the milling process.
There has been an explosion in the introduction of foods containing oat bran after research indicated that the compound could help lower blood cholesterol levels.
Although there have been recent claims to the contrary, people with high cholesterol levels are considered at increased risk for atherosclerosis, or hardening of the arteries.
Studies on laboratory animals, conducted by the federal government, indicated that rice bran may prove to be a powerful cholesterol fighter.
The initial work, conducted by U.S. Department of Agriculture researchers in Albany, Calif., studied the effects of a rice-bran-rich diet on hamsters. A second group of animals was fed similar amounts of oat bran.
Both animal groups in the study experienced reductions in cholesterol of about 20%, or significantly more than a third control group that was fed a more innocuous substance. The findings were successfully duplicated in subsequent USDA tests.
Studies by Two Groups
Now, however, there are at least two studies that are examining rice bran’s effect on humans’ cholesterol levels. The work is being conducted at Louisiana State University and at the University of Texas Medical Center in Houston. A third study is reportedly being conducted by a private firm in Northern California, where this state’s rice industry is based. The earliest results from any of these projects are not expected until next month.
At present, most rice bran is diverted into animal feed. The compound is actually the thin brown hull that is milled off the grain to achieve a white kernel.
Soon after milling, though, oil in the hull degrades and becomes rancid. The change renders the byproduct inedible for humans. Technology has been developed recently that prevents the rancidity from occurring, thus stabilizing the compound sufficiently for inclusion in food products or as a stand-alone item.
‘Lo and Behold’
“We wanted to see if rice bran could be treated so that it could be utilized as a human food and not just as animal feed,” said Robin Saunders, an USDA researcher who worked on the study. “We looked at rice bran to check out its cholesterol effects because of its high-fiber content. And, lo and behold, we found this result.”
Saunders sees several commercial possibilities for rice bran such as in breakfast cereals, bakery products, snack foods and as a supplement that can be mixed with anything from yogurts to juices. An added bonus is that rice bran’s fiber content is also higher than that of oat bran.
Also promising is that the oil extracted from rice bran is highly unsaturated and it is thought to be the compound likely to contain most of the cholesterol-lowering properties, Saunders said. The oil may have promise as a processed food ingredient or as a cooking medium.
Several manufacturers already offer rice bran in processed foods. Health Valley Foods in Irwindale has introduced both a cereal and a granola bar containing the compound.
Two rice bran supplements are also available: Vitafiber Rice Bran from Pacific Rice Products Inc., of Woodland, Calif., and CalBran from California Rice Bran Inc., in Redondo Beach.
Rice bran can be obtained, though in a less concentrated form, from simple brown rice.
Rice Bran Review--A health newsletter, while lauding rice bran’s nutritional profile, gave it a mixed review as a food ingredient.
“Rice bran has been available in health-food stores for some time without arousing much enthusiasm: in its natural state, it (has a texture) like sawdust,” the UC Berkeley Wellness Letter reported. “It tastes OK and, unlike oat bran, doesn’t turn gummy when cooked.”
Though rice bran, if proven an effective cholesterol fighter, certainly has potential, some believe that there are limits to the public’s enthusiasm for other bran-related products.
“Manufacturers are tripping over themselves to find oat bran’s successor,” according to Nutrition Action Newsletter. “Rice bran, corn bran and psyllium (the plant used in some laxatives) are all contenders. But judging by the flood of new oat bran products, its going to take something pretty spectacular to displace the No. 1 cholesterol-lowering food.”
The newsletter, which is published by the Center for Science in the Public Interest, also cautions consumers that “oat bran won’t turn (an otherwise) fatty, salty or sugary food into a health food.”
Cautious Fiber Advice--While conclusive cholesterol data is still unavailable on rice bran, a recent medical report endorses diets that regularly include a variety of fiber-rich foods.
Though stopping short of making any specific recommendations, the Journal of the American Medical Assn. stated that the “full range of health benefits from dietary fiber” are only possible from eating a wide selection of plant foods.
In reviewing almost two decades of scientific research, the journal found conflicting information on the role of fiber in preventing illness.
“During the past 18 years, considerable research has been conducted on the role of dietary fiber in preventing colon cancer, heart disease, diabetes and other diseases. However, for most of these benefits, the evidence from scientific studies remains inconclusive or equivocal,” the journal reported.
The review was conducted by the AMA’s Council on Scientific Affairs.
Further complicating the fiber issue is that the compound is a mixture of substances and not a single entity. For instance, there are both soluble and insoluble dietary fibers, according to the report.
Soluble fibers, when consumed in large quantities, have been shown to reduce cholesterol levels and decrease heart disease risk in some individuals. But the foods high in soluble fibers, such as produce, oat bran and barley, are also low in fat. Therefore, the fiber may play only a part in the benefits achieved with such an eating regimen.
While recommending a diet that includes such fiber-rich foods such as whole-grain breads and cereals, produce, legumes and nuts, the journal did not endorse fiber supplements nor purified fibers.
