IHN Database

Timing of antioxidant supplementation is important

ALBUQUERQUE, NEW MEXICO. It is estimated that over 70% of patients with type 2 diabetes eventually die of cardiovascular disease. The development of cardiovascular disease, in turn, involves oxidative stress leading to the release of inflammatory mediators, oxidation of low-density cholesterol lipoprotein (LDL), and the creation of an environment favourable to blood clotting (prothrombotic state). The presence of inflammatory mediators can be determined through measurement of blood levels of CRP (C-reactive protein) and a tendency to increased blood clotting is indicated by an increased level of PAI-1 (plasminogen activator inhibitor-1).

Several studies have shown that high fat meals raise LDL levels, create inflammation, and increase blood clotting tendency in diabetics. Researchers at the New Mexico School of Medicine reasoned that if oxidative stress is the underlying cause of the inflammation and increased blood clotting tendency then antioxidants taken before meals should be beneficial. Their clinical trial involved 11 patients with type 2 diabetes who were exposed to four different test conditions over four 2-day periods. The first day involved consuming a standard dinner at 6 pm and a snack at 10 pm. The next day the participants consumed a standardized breakfast at 8 am and a standardized lunch at 1 pm. At 6 pm the participants were fed a high-fat test dinner equivalent to a McDonald's "Big Mac" meal (70 g fat). The four test periods differed in that in period 1 no antioxidants were given, in period 2 800 IU of natural vitamin E and 1000 mg of vitamin C were taken at the beginning of breakfast, and in period 3 800 IU of natural vitamin E and 1000 mg of vitamin C were taken at the beginning of dinner. Period 4 was a control with no high-fat dinner and no vitamins.

The researchers found that vitamin E levels rose substantially after taking vitamin E at breakfast and stayed high during the day. Vitamin C levels, on the other hand, increased after breakfast, but had decreased by supper time. Both pre-breakfast and pre-supper vitamins C and E supplementation prevented the increase in CRP caused by the high-fat meal with pre-supper vitamins being the most protective. The high-fat evening meal also caused a marked increase in PAI-1 levels; however, this increase was totally avoided if vitamins C and E were given at breakfast, but remained if the vitamins were only taken at supper time.

The researchers conclude that morning supplementation with vitamin E combined with slow-release vitamin C may be the optimum protocol for preventing high-fat evening meal induced inflammation and blood clotting.
Carroll, Mary F. and Schade, David S. Timing of antioxidant vitamin ingestion alters postprandial proatherogenic serum markers. Circulation, Vol. 108, July 8, 2003, pp. 24-31

Editor's Comment: Although this study was limited to diabetes patients there is no reason why taking vitamins E and C with breakfast and vitamin C with supper (or use a timed release vitamin C formulation at breakfast) should not be equally protective for healthy individuals against the inflammatory and blood clotting effects of high-fat meals.

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