Are oats safe to eat if I?m on a gluten-free diet?
It partly depends why you are on that diet. Many people seem to react to gluten-containing grains such as wheat, rye, barely and triticale. However, there is a difference between a gluten allergy (an immune reaction mediated by immunoglobulin E or immunoglobulin G antibodies) and celiac disease (a genetic autoimmune disease that interferes with digestion). When a celiac person eats foods containing gluten, the immune system responds by damaging the small intestine?s villi (tiny hair-like projections that increase the mucosal surface area for greater nutrient absorption). While both are associated with immune system dysfunction, the person with gluten allergies may be able to tolerate small amounts of gluten, while celiac disease necessitates absolute avoidance of gluten.
So where do oats come in? Oats do not appear to contain the offending gluten subfraction found in other gluten-containing grains. Therefore oats seem safe to eat if someone has gluten sensitivity. In fact, a well-designed 1995 study concluded that the consumption of oats was safe for adults with celiac disease, and the issue seemed to be settled.1 It?s not quite that simple, though. Oats may be contaminated with other gluten-containing grains. Contamination may occur through sharing equipment during grain processing or crop rotation—for example, where wheat was grown prior to oats and then regrows from residual seeds left in the field. The latter may explain why one recent report suggested that oats processed in an oats-only facility may not be completely free of contamination.2
A recent study tried to determine whether challenging celiac patients with 50 g of oats per day for 12 weeks caused problems. Of the 19 patients, one did show villous atrophy, the gold standard of damage from gluten; five others showed positive blood tests to gluten, suggesting that they had some reaction but not enough to cause any damage.3 With this in mind, Finnish researchers found that many celiac patients ate oats without apparent problems, but 15 percent stopped eating them because they feared adverse effects or contamination.4 So some trepidation remains.
My bottom line is that if you have a gluten allergy (not celiac disease), you can probably tolerate oats, even if contaminated. The potential amounts of gluten are so minuscule they shouldn?t be of concern. However, if you are celiac-intolerant, take caution. It does seem that many who are celiac-intolerant can tolerate oats, but you should protect yourself from possible gluten contamination.
I know I should take calcium, folic acid and iron when I?m pregnant, but how about other vitamins or nutrients?
It is clear that a pregnant woman?s diet affects the health of her child, but research is suggesting that nutrients other than just the ?big three? listed above are also important. An oft-reported study that gave either probiotics or placebo to pregnant women (and then to their infants for six months) showed that the frequency of eczema was half in the probiotic versus the placebo group.5
A recent Scottish study adds to the growing body of literature showing that what a pregnant woman eats can affect her developing child?s risk for health problems. In this study, researchers had pregnant women record their food intake during pregnancy and then followed their health patterns for two years after the birth of their children. They found that total maternal vitamin C intake during pregnancy was not statistically significant when associated with wheezing during the first year of life; however, in the second year it was.6 Wheezing can be associated with possible allergic reactions, and it is known that vitamin C may have an effect on allergies. Certainly, additional research should be done to assess, for instance, whether this reported association persists into later childhood, but this study suggests that what a mother eats during pregnancy can have an effect even two years later. This is another good reason a woman should take a high-quality multiple or supplemental through the full course of her pregnancy.
Should I take vitamin E to decrease my risk of prostate cancer?
That?s a hard question to answer. Epidemiologic studies suggest that vitamin E may hinder the development of prostate cancer. It?s thought that vitamin E might fight cancer through activity that combats the oxidative stress involved in cancer development. In the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study, a double-blind, placebo-controlled trial, male smokers showed a 32 percent decreased risk of prostate cancer after taking alpha-tocopherol (50 mg/day) versus placebo.7 A recent follow-up of this study confirmed that higher levels of vitamin E in the blood were associated with lower risk. Specifically, participants with higher circulating concentrations of the major vitamin E fractions, alpha-tocopherol and gamma-tocopherol, had similarly lower prostate cancer risk.8
But one must remember this trial was conducted with heavy smokers. Nonsmokers may not gain the same benefit. A new study, named the Selenium and Vitamin E Cancer Prevention Trial, has recently finished recruiting. It is designed to see if one or both of these dietary supplements prevent prostate cancer in relatively healthy older men. More than 35,000 men are participating in SELECT, and the study will continue for seven years. So all the data is not in. But given the cost, the previous research and the other positive findings with vitamin E, it seems reasonable to include that nutrient in a good antioxidant supplement mixture.
Dan Lukaczer, N.D., is director of clinical research at the Functional Medicine Research Center, a division of Metagenics Inc., in Gig Harbor, Wash.
1. Janatuinen EK, et al. A comparison of diets with and without oats in adults with celiac disease. N Engl J Med 1995;333(16):1033-7.
2. Thompson T. Gluten contamination of commercial oat products in the United States. N Engl J Med 2004;351(19):2021-2.
3. Lundin KE, et al. Oats induced villous atrophy in coeliac disease. Gut 2003;52(11):1649-52.
4. Peraaho M, et al. Oats can diversify a gluten-free diet in celiac disease and dermatitis herpetiformis. J Am Diet Assoc 2004;104(7):1148-50.
5. Kalliomaki M, et al. Probiotics in primary prevention of atopic disease: a randomised placebo-controlled trial. Lancet 2001;357(9262):1076-9.
6. Martindale S, et al. Antioxidant intake in pregnancy in relation to wheeze and eczema in the first two years of life. Am J Respir Crit Care Med 2005;171(2):121-8.
7. Heinonen OP, et al. Prostate cancer and supplementation with alpha-tocopherol and beta-carotene: incidence and mortality in a controlled trial. J Natl Cancer Inst 1998;90(6):440-6.
8. Weinstein SJ, et al. Serum alpha-tocopherol and gamma-tocopherol in relation to prostate cancer risk in a prospective study. J Natl Cancer Inst 2005;97(5):396-9.
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