|
From The July 2001 Issue of Nutrition Science News
At the Counter with Dan Lukaczer, N.D.
The Sugar Source
Q:What is the biggest dietary sugar source in the United States?
A: You're probably asking about simple sugars or monosaccharides, such as fructose and glucose, and disaccharides such as sucrose, or common table sugar. The winner might surprise you. Soft drinks account for one-third of all simple sugars consumed in the United States. Drinking one soda pop is comparable to eating seven teaspoons of sugar. Men and women ages 18 to 34 get almost 20 percent of their calories from simple sugars—refined sugar, honey, corn syrup, and fructose.1
Update: Folic Acid for Heart Disease
Q:How much folic acid should I take to reduce my risk of heart disease?
A few months ago I gave my best estimate for the amount of folic acid necessary to lower homocysteine levels, and the risk of heart disease associated with hyperhomocysteinemia. A new study in the Archives of Internal Medicine supports my estimate that 800 mcg/day folic acid would produce the maximum reduction in serum homocysteine.2
The researchers conducted a double-blind, randomized, placebo-controlled trial of 151 patients with ischemic heart disease. Participants were split into groups: five folic acid supplementation groups (200, 400, 600, 800 and 1,000 mcg/day) and one placebo. Subjects took the supplements for three months. Fasting blood samples of serum homocysteine were obtained at baseline, after three months of supplementation, and three months after supplementation was discontinued.
Serum homocysteine levels decreased with increased folic acid dosage up to 800 mcg/day; the median serum homocysteine reduction was 2.7 mcmol/L (a 23 percent reduction). That decrease in serum homocysteine levels is expected to lower ischemic heart disease mortality rates by about 15 percent.
Serum homocysteine concentrations returned to baseline levels for all groups after they stopped supplementation, indicating that folic acid supplementation must be sustained to maintain lowered homocysteine levels. This raises doubts about the current recommended daily allowances for folic acid.
The level of fortification mandated by the U.S. government (140 mcg folic acid per 100 grams of cereal grain, intended to supplement an individual's diet by about 100 mcg folic acid per day) will achieve only a fraction of this maximum homocysteine-lowering effect. To ingest a sufficient dose of folic acid, supplementation is necessary; both single supplements and many multivitamins provide the proper amount. My only added caveat is that for some individuals, other vitamins—B6 and B12—also play a critical role in lowering homocysteine. Therefore, additional supplementation might be indicated.
EFAs And Arthritis
Q: Do essential fatty acids (EFAs) help improve rheumatoid arthritis?
People get confused about EFAs and arthritis and with good reason. Considerable research has been conducted on EFAs and rheumatoid arthritis (RA). Both omega-6 oils in the form of gamma linolenic acid (GLA), omega-3 oils in the form of eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) have been used with some positive results. A fairly high dose of GLA seems to be indicated (1.5-2.8 grams),3 while studies generally suggest using 3-6 grams of a combination EPA with DHA, of which the higher dose appears more effective.4,5
Although using these essential fats separately has produced positive results, I know of no human trials using both oils in combination. This is unfortunate, because some in vitro studies suggest that they may be even more efficacious when combined.6
My recommendation is to start with the omega-3 oils because Americans are more likely to be deficient in these essential fatty acids. However, I've also recommended taking both oils, but at slightly lower amounts. I suggest three grams combined EPA/DHA with one gram GLA. Using concentrated oils in capsule form may make it easier to take regular, large doses. It takes at least 12 weeks to experience benefits of fatty acid supplementation.
Dan Lukaczer, N.D., is director of clinical research at the Functional Medicine Research Center, a division of Metagenics Inc., in Gig Harbor, Wash.
References
1. Tufts University Health and Nutrition Letter; March 2000:3.
2. Wald D, et al. Randomized trial of folic acid supplementation and serum homocysteine levels. Arch Intern Med 2000:161(5):695-700.
3. Leventhal LJ, et al. Treatment of rheumatoid arthritis with gammalinolenic acid. Ann Intern Med 1993;119(9):867-73.
4. Kremer JM, et al. Dietary fish oil and olive oil supplementation in patients with rheumatoid arthritis. Clinical and immunologic effects. Arthritis Rheum 1990;33(6):810-20.
5. Nielsen GL, et al. The effects of dietary supplementation with n-3 polyunsaturated fatty acids in patients with rheumatoid arthritis: a randomized, double blind trial. Eur J Clin Invest 1992;687-91.
6. Barham JB, et al. Addition of eicosapentaenoic acid to gamma-linolenic acid-supplemented diets prevents serum arachidonic acid accumulation in humans. J Nutr 2000:130(8);1925-31.
|
