Study Finds Multi-Vitamin Use Associated With Reduced Risk Of Heart Attacks
A recent study published in the Journal of Nutrition showed that individuals taking a daily multi-vitamin supplement experienced fewer heart attacks than those who do not. The study showed that male multi-vitamin supplement users had 22% fewer heart attacks and females had 33% fewer heart attacks than men and women who were non-users of multi-vitamins. These findings may be explained by the fact that several vitamins and minerals are known to affect risk factors for atherosclerosis and heart disease.
Folic acid, vitamin B12, and vitamin B6 are required to prevent the build- up of homocysteine in the bloodstream. High blood levels of homocysteine is associated with an increase of heart attacks, as homocysteine increases platelet aggregation, vasoconstriction, encourages oxidation of LDL-cholesterol and initiates other changes that promote atherosclerosis. Folic acid and vitamin B12 work synergistically to provide a methyl group to homocysteine, which converts it into the amino acid methionine within the cells of the body. The average intake of folic acid across the population is only 190-210 mcg per day, whereas the amount required to ensure that homocysteine is recycled back to methionine is in the range of 400-600 mcg per day. Thus, the use of a daily multiple vitamin, most of which provide 400 mcg per day, provides insurance against a build-up of homocysteine, and in turn, is associated with reduced heart disease risk. Some individuals have a resistance to the conversion of homocysteine to methionine due to genetic factors (faulty enzyme structure) and may require levels of folic acid and vitamin B12 at levels that exceed those found in most multi-vitamin supplements. In these cases folic acid supplementation of 1,000 mcg per day may be required to bring blood levels of homocysteine into a safer range. Vitamin B6 is required by the enzyme cystathionine synthase, which converts homocysteine into cystathionine (cystathionine can then be converted to serine and cysteine with the help of other B6-dependent enzymes. Studies show that more than 30% of the U.S. population does not attain the RDA level for vitamin B6 each day from food alone. A sub-optimal intake of vitamin B6 has also been shown to encourage the build of homocysteine, which in turn contributes to heart disease risk. As such, the daily use of a multi-vitamin may help to keep homocysteine within a safer range by providing more optimal levels of vitamin B6.
Antioxidants found in multi-vitamin supplements may also be protective against heart attacks. Antioxidants such as vitamin E, vitamin C, and beta-carotene, are known to reduce free radical damage to LDL-cholesterol in the bloodstream. In turn, this makes LDL-cholesterol less inclined to participate in the atherosclerosis process. In the event that LDL-cholesterol becomes damaged by free radicals (oxidized), it is picked up more rapidly by macrophage cells within the atherosclerotic plaque of the blood vessel wall. In this instance LDL-cholesterol will thicken the plaque and narrow the blood vessel, restricting blood flow to vital organs such as the heart. Studies have shown that individuals and populations with higher blood levels of vitamin E and/or vitamin C have an associated lower risk of heart attack. Most experts believe it is due to the protection these antioxidants provide to LDL-cholesterol as it circulates through the bloodstream, as non oxidized LDL-cholesterol displays a significantly lower propensity to get picked up by macrophages within the arterial plaque, and is thereby less atherogenic.
The Journal of Nutrition (2003; vol. 133:2650-2654)