Thursday, June 29, 2006

Multivitamin use before pregnancy reduces risk of preterm births

Pre-term birth is associated with many health risks as well as a lower rate of infant survival during the first year of life. Women who take a multivitamin before conception have only half the risk of preterm delivery than those who wait until after becoming pregnant to start taking nutritional supplements.

A study published in the November 2004 issue of the American Journal of Epidemiology showed that the use of multivitamin supplements by women prior to becoming pregnant was associated with fewer preterm deliveries. Preterm birth is defined as birth at less than 37 weeks of gestation and is associated with a lower rate of infant survival during the first year of life. Researchers utilized data from the Pregnancy, Infection and Nutrition Study which recruited 2,010 women during their 24th to 29th week of pregnancy. They compared the incidence of preterm delivery among women who took multivitamins prior to conception, before conception and during pregnancy, during pregnancy only, or not at all. Women who took a multivitamin supplement before conception had half the risk of early and late preterm delivery than those who took no vitamins. Women used multivitamins during pregnancy only had approximately the same amount of preterm births than women who took none at all. This study, as well as many previous studies, reinforces the concern that waiting until pregnancy is diagnosed may be too late for nutritional intervention to benefit many pregnancy outcomes.

Source: Multivitamin Use and the Risk of Preterm Birth, Anjel Vahratian, Anna Maria Siega-Riz, David A. Savitz, and John M. Thorp Jr, Am J Epidemiol. 2004 Nov 1;160(9):886-92.

Friday, June 23, 2006

Soy isoflavones from supplements and soymilk benefit the immune system of postmenopausal women

The hormone estrogen has positive benefits on the immune system of women. During menopause, the effects of aging and diminishing concentrations of estrogen may negatively impact the immune system. Soy isoflavones have both estrogenic and antioxidant properties so they may be beneficial to women during this stage of life.

A recent study evaluated the effects of soy isoflavones, both in soymilk and supplement form, on immunity and oxidative stress in postmenopausal women. Results from this placebo-controlled double blind study showed that soy isoflavones from either the soymilk or supplements were beneficial. Isoflavones increased the population of B-cells, important cells in the immune system, and decreased the plasma concentration of a compound whose high levels are an indicator of DNA damage. Soymilk and supplemental isoflavones may therefore be protective against DNA damage and improve immune function in postmenopausal women.

Source: Soy isoflavones modulate immune function in healthy postmenopausal women, Tracy A Ryan-Borchers, Jean Soon Park, Boon P Chew, Michelle K McGuire, Lisa R Fournier and Kathy A Beerman, American Journal of Clinical Nutrition, Vol. 83, No. 5, 1118-1125, May 2006

Wednesday, June 14, 2006

Take steps now to protect your vision later

High dietary intakes of the antioxidants beta-carotene, vitamin C, vitamin E, and zinc may reduce the risk of developing age-related macular degeneration (AMD) the most common cause of permanent blindness in the developed world.

AMD is a retinal degenerative disease that causes progressive loss of central vision, and the most common cause of vision loss in individuals over the age of 55 in the developed world. Although it rarely causes total blindness, AMD destroys the central vision necessary for performing many of the daily tasks we take for granted such as: recognizing faces, colors, watching television, reading, driving, performing finely detailed work, and safely navigating stairs. The risk of developing macular degeneration increases with age. A report published in the Journal of the American Medical Association has found that individuals whose diets contain high amounts of the antioxidants beta-carotene, vitamin C, vitamin E and zinc have a significantly lower risk of developing AMD than people whose diets contain lower levels of the nutrients. This study included 4,176 men and women at risk of AMD who were participants in the Rotterdam Study, which enrolled 7,983 men and women aged 55 or older. Nutrient intake was assessed via food frequency questionnaires completed by all subjects. Participants underwent eye examinations upon enrollment, and three times during the eight year follow-up. 560 subjects were diagnosed with new macular degeneration during the follow-up period. Participants with an above-median intake of all four nutrients including beta carotene, vitamin C, vitamin E, and zinc, had a 35 percent reduced risk of AMD compared to those whose intake of any of the nutrients was below average. This study suggests that the risk of developing AMD can be modified by diet; in particular, by the dietary antioxidants beta carotene, vitamin C, vitamin E, and zinc.

Source: Dietary Intake of Antioxidants and Risk of Age-Related Macular Degeneration, Redmer van Leeuwen, Sharmila Boekhoorn, Johannes R. Vingerling, Jacqueline C. M. Witteman, Caroline C. W. Klaver, Albert Hofman, Paulus T. V. M. de Jong, JAMA 2005;294:3101-3107

Thursday, June 01, 2006

Media Bias, Conflicts of Interest Distort Study Findings on Supplements

News media spinning out of control

Recent reporting of scientific studies completely misses the mark, says Comparative Guide to Nutritional Supplements author Lyle MacWilliam. Not only are journalists misunderstanding the results of many new studies, he says, but they are being pointed in the wrong direction by pharmaceutical giants with patented products that are threatened by natural health alternatives to the drugs they peddle.

The issue is much deeper than a simple misunderstanding of scientific processes. Studies are being completely misrepresented, deluding the public into believing that the herbal and micronutrient treatments they believe will help them are actually harming them, or even just a waste of their time. But is that true?

Probably not. The vast majority of news reports about the dangers and inefficacy of supplements are based on misunderstandings of the results or even complete denial of the results.

READ MORE by Lyle MacWilliam MSc FP

by Lyle MacWilliam, MSc, FP

Meal replacements effective as medications for weight maintenance

The most difficult part of any weight loss program is not losing the weight, but keeping it off. As a result, many people opt for medications to help maintain weight loss. Results from a new study now show that meal replacement drinks can be as effective as medications at helping dieters maintain weight. Researchers compared the benefit of using meal replacement drinks to Orlistat in two groups of people that had lost significant amounts of weight. A year after their weight loss, the group using meal replacement drinks had maintained their weight even better than the group using the medication. For many people, meal replacements drinks may be an effective, simple and safe method to maintaining a healthy weight.

Meal replacement drinks were recently shown to be as effective as medications for maintaining weight loss according to a study published in the Journal of the American College of Nutrition. In this study, participants followed a very low calorie liquid diet (VLCD) for 12 weeks followed by 4 weeks of re-introduction to solid food. Then the subjects were randomly selected to receive either meal replacements or Orlistat (a medication that blocks fat absorption in the intestines), both combined with a structured meal plan calculated to maintain weight loss. For one year, all subjects followed a weight management program that included topics such as lifestyle, physical activity, and nutrition. During weight maintenance, there were no significant differences in physical activity, fruit and vegetable intake and pedometer steps between the groups. After one year, the meal replacement group had regained only 5.9 lbs while the Orlistat group had regained 6.2 lbs. Meal replacements and Orlistat were both effective in maintaining weight significantly below baseline levels over a year period of time. However, the group using meal replacement drinks maintained their weight even better than the group using the medication without the side effects. For many people, meal replacements drinks may be an effective, simple and safe method to maintaining a healthy weight.

Source: A Comparison of Meal Replacements and Medication in Weight Maintenance after Weight Loss, James D. LeCheminant, Dennis J. Jacobsen, Matthew A. Hall and Joseph E. Donnelly, Journal of the American College of Nutrition, Vol. 24, No. 5, 347-353 (2005)