|
|
|
|
The Physicians’ Health Study II Randomized Controlled Trial, which will be published in the November 12 issue of the Journal of the American Medical Association (JAMA), examines the effects of Vitamins E and C supplementation on cardiovascular events in male physicians. Jamieson Laboratories has prepared this statement in response to the study’s findings:
Earlier observational trials indicated that there were positive cardiovascular results associated with the two antioxidant Vitamins E and C. While this important follow-up prevention trial failed to confirm these earlier observations, its results do not discount previous epidemiological data indicating that people taking higher doses of Vitamins E and C may have a lower risk of cardiovascular disease.
The reason for the different outcomes has yet to be clarified, but a number of potentially relevant factors — including dose, duration and the combinations of nutrients studied — has been suggested by the study’s authors.
For example, the authors note that a previous pool of nine studies indicated that 700 mg/day of Vitamin C showed a 25 percent reduction in the occurrence of cardiovascular disease. Knowing this, the study was designed using only 500 mg/day. It raises an obvious question about their method: In attempting to understand the role of these vitamins in preventing heart disease, why didn't they use the dose previously correlated with a benefit?
Another confounding detail is the authors failure to control data for dietary sources of Vitamin C and E. At the very least, this oversight clouds any precise measurement of each subject's Vitamin C and E intake and confounds the study's conclusions.
Nutrition research is extremely complex and doesn’t always provide clear-cut answers. To date, there haven’t been any conclusive randomized, controlled studies that demonstrate exactly how to prevent cardiovascular disease. The factors that influence heart health are largely practical: not smoking, maintaining a healthy weight, eating a healthy, balanced diet, enjoying regular exercise, monitoring overall health in consultation with a health-care practitioner and using vitamin supplements responsibly.
Vitamins alone will not prevent cardiovascular disease. But the results of this study have no negative impact on all the other evidence that demonstrates the benefits of these two nutrients in supporting overall health. While Vitamin E has not yet been directly associated with the function of any enzyme system, it has a firmly established role as an antioxidant and a scavenger of free radicals, making it effective as a protector of the integrity of fats and the membranes of fatty acids. As an antioxidant, Vitamin E is strongly interactive with other dietary antioxidants, such as Vitamin C and glutathione. There is growing evidence suggesting that Vitamin E may have several other functions, including the modulation of gene expression and the suppression of inflammatory responses within the body.
Vitamin C (ascorbic acid) famously protects against scurvy. In addition to supporting the formation of collagen, Vitamin C has other important biological functions that include increasing copper and iron absorption, carnitine biosynthsesis, neurotransmitter biosynthesis, protection of folic acid and the regeneration of Vitamin E. Much of the current interest in Vitamin C is focused on its ability to devour free radicals. All of these effects may promote optimal health through support for the immune system and defence of tissues against the oxidative challenges associated with chronic disease, including cardiovascular disease and cancer.*
Therefore, despite the findings of this new study, the overwhelmingly beneficial effects of Vitamins C and E indicate that consumers can experience better health through the responsible use of supplements. Jamieson Laboratories is Canada’s leading manufacturer of advanced health products. Our premium formulations are manufactured in Windsor, Ontario, according to a minimum of 360 quality-assurance tests that guarantee each product’s safety, full potency and absolute clinical purity.
* Frei 1991; Niki 1991; Stadtman 1991; Sevanian et al 1991; Sies and Stahl 1995, Council for Responsible Nutrition, Vitamin and Mineral Safety, 2004, (Second Edition)
|
|
|