August 9, 2005
Healthy women over 65 can lower their risk of serious consequences of arthrosclerosis by 25 %. This is confirmed by the world’s longest study of vitamin E, so far.
In 1997 44 % of all American cardiologists regularly used antioxidants, especially vitamin E, to prevent coronary thrombosis and strokes. The confidence in vitamin E was so strong that it surpassed the confidence in aspirin, which was only used by 42 %.
The cardiologists relied on the universal theory that arthrosclerosis arises when cholesterol is oxidized and that vitamin E, amongst other things, prevents this oxidization. Unfortunately solid evidence that vitamin E truly protects against arthrosclerosis, and thereby prevents thromboses, has been lacking. Large randomized studies have been disappointing, but also encumbered by obvious faults. Everything is shrouded in doubt. But if the doctors have stopped using vitamin E in disappointment, maybe they will begin using it again now.
The occasion is the largest and longest randomized study up until now with vitamin E. It showed that when healthy women over 65 received vitamin E as a supplement, their risk of suffering a coronary thrombosis or a stroke decreased by 26 %. And not only was the incidence lowered, the diseases also became less dangerous. The total mortality rate was approximately halved (to 51 %).
Other studies of vitamin E have been relatively short, and have had participants who suffered from serious arthrosclerosis. However this study lasted ten years, and the participants were healthy. Exactly because they did not suffer seriously from arthrosclerosis from the beginning, it was hoped that it was not too late to prevent it. A total of 20,000 women received 600 units of natural vitamin E (alpha-tokoferol) every other day for ten years. Just as many other women were given a placebo (fake pills).
The women who were over 65 benefited. However, the large majority was younger than 65. They had no obvious benefits from the treatment. 18,000 women under 65 received vitamin E. 352 of these suffered a coronary thrombosis or a stroke, some with a fatal outcome. That number was eleven higher than amongst the 18,000 who received placebos. A small and random difference. Apparently vitamin E did not benefit the younger women.
For comparison only 2 times 2000 women over 65 participated. In the group receiving vitamin E, there were 130 cases of either cardiac thrombosis or stroke. In the placebo group there were 46 cases more. This difference is relatively large, and statistically quite certain.
But why does vitamin E not benefit the younger? The obvious answer is that maybe it does, but younger women more seldom suffer cardiac thrombosis, and the potential effect is difficult to measure. In the course of the ten years the study ran, less than two percent of those under 65 suffered a cardiac thrombosis or a stroke. Those older, of course had a bigger risk (about eight percent). One can speculate that despite the neutral numbers, the younger group did in fact become less atherosclerotic because of the vitamin E supplement. No one knows, since a direct measurement of the blood vessels was not conducted. The only measurement for the degree of arthrosclerosis was the rough numbers for cardiac thrombosis and stroke.
If seen under the same light, statistically there was only tendency towards benefit from vitamin E. It is a natural consequence of the fact that there were nine times as many young participants, as there were older. The researchers did however choose to conclude on the basis of this result. They believe that the study does not warrant a general recommendation of vitamin E for the prevention of cardio-vascular disease. With regards to those over 65, it is being said that the result deviates from “the total knowledge” and should be investigated further.
This is a somewhat weak comment. A more direct comment came from Maret Taber who is professor at the Linus Pauling Institute in California and one of the World’s leading vitamin E experts:
“Vitamin E has its clear value in the fight against cardiac disease and other degenerative sufferings. It is most important for smokers, persons suffering from hypertension and those who eat an unhealthy diet.”
By: Vitality Council
Lee, I-Min. Vitamin E in the primary prevention of cardiovascular disease
and cancer. The Womens Health Study: A randomized controlled trial. JAMA