0The New Complete Book of Food
water molecules, swell, and soften. When the temperature of the liquid reaches approxi-
mately 140°F, the amylose and amylopectin molecules inside the granules relax and
unfold, breaking some of their internal bonds (bonds between atoms on the same mol-
ecule) and forming new bonds between atoms on different molecules. The result is a net-
work that traps and holds water molecules, making the starch granules even more bulky
and thickening the liquid. Eventually the starch granules rupture, releasing the nutrients
inside so that they can be absorbed more easily by the body. Oatmeal also contains
hydrophilic (water-loving) gums and pectins, including beta-glucans, that attract and hold
water molecules, immobilizing them so that the liquid thickens. The beta-glucans give
oatmeal its characteristic sticky texture.
Ounce for ounce, cooked oatmeal has smaller amounts of vitamins and minerals than
dry oatmeal simply because so much of its weight is now water. The single exception is
sodium. Plain, uncooked oatmeal, with no additives, has no sodium; cooked oatmeal, made
with water or milk, does.How Other Kinds of Processing Affect This Food
* * *Medical Uses and/or Benefits
A lower risk of some kinds of cancer. In 1998, scientists at Wayne State University in Detroit
conducted a meta-analysis of data from more than 30 well-designed animal studies mea-
suring the anti-cancer effects of wheat bran, the part of grain with highest amount of the
insoluble dietary fibers cellulose and lignin. They found a 32 percent reduction in the risk
of colon cancer among animals fed wheat bran; now they plan to conduct a similar meta-
analysis of human studies. Like wheat bran, whole oats are a good source of insoluble dietary
fiber. NOTE: The amount of fiber per serving listed on a food package label shows the total
amount of fiber (insoluble and soluble).
Early in 1999, however, new data from the long-running Nurses Health Study at
Brigham Women’s Hospital/Harvard University School of Public Health showed that
women who ate a high-fiber diet had a risk of colon cancer similar to that of women who
ate a low fiber diet. Because this study contradicts literally hundreds of others conducted
over the past thirty years, researchers are awaiting confirming evidence before changing
dietary recommendations.
However, early the following year, new data from the long-running Nurses’ Health
Study at Harvard School of Public Health and Brigham and Women’s Hospital, in Boston,
showed no difference in the risk of colon cancer between women who ate a high-fiber diet
and those who did not. Nonetheless, many nutrition researchers remain wary of ruling
out a protective effect for dietary fiber. They note that there are different kinds of dietary
fiber that may have different effects, that most Americans do not consume a diet with the
recommended amount of dietary fiber, and that gender, genetics, and various personal
health issues may also affect the link between dietary fiber and the risk of colon cancer.