Vitamin E And Coronary Heart Disease

In this essay, I will write about Vitamin E and how the lack of it might affect coronary heart disease. Epidemiologic studies can be controversial, as highlighted when the National Research Council spent several years delaying the 10th revision of the recommended dietary allowance. The Council was weary of their new recommendation to decrease the RDAs for Vitamins A and C as epidemiologic research suggested that these nutrients played a vital role in preventing diseases, like cancer. In recent years, epidemiological research has focused on another vitamin, Vitamin E, and its prevention of coronary heart disease. This article aims to use two criterias, the Hill and the US Preventive Services Task Force criteria, to investigate the current evidence that suggests that we should consume more Vitamin E to reduce the risk of coronary heart disease.

The Hill criteria is based on six categories. The first category, strength of association, is simple; the stronger the association, the higher the correlation. In the studies presented in the table, women who consumed lower amounts of Vitamin E had higher risks of mortality due to heart disease. Another study showed that those who took Vitamin E supplements had half the risk of coronary heart disease compared to their counterparts. None of the studies showed a significant dose-response relationship (second category) of Vitamin E intake and coronary disease, although some showed that the consumption of any amount of Vitamin E correlated with lower risk of coronary disease. The next criterion, temporally correct association, is fulfilled, as almost all of the diets in the studies were assessed before diagnosis of disease and are therefore directly related to whether Vitamin E influences risk of the disease. In examining consistency of association, all six studies showed some sort of inverse relationship between Vitamin E intake and coronary heart disease. For the specificity of association category, the author acknowledges that many other confounding factors, like cholesterol levels, affect coronary heart disease. However, he also acknowledges that not meeting this Hill category does not necessarily mean that there is no correlation between Vitamin E and coronary heart disease. Although the last criterion, biological factors, might affect the risk of coronary disease, these factors do not imply a causal association.

For the US Preventive Services Task Force Criteria, criterion one is met as there is at least one properly designed controlled study that shows evidence of a correlation. However, this evidence is modest in showing the protective effect of Vitamin E on coronary disease. Although the part one of the second criterion is not met, part two is met because many well designed cohort studies have come to the same conclusion that Vitamin E has an inverse relationship with coronary disease. Part three of the third criterion is also met as there has been at least one study that was international, and it included 24 developed countries. This widespread study showed that Vitamin E has a strong inverse association with coronary disease, as an increase in Vitamin E availability led to fewer coronary heart disease moralities. The last criterion is not met as no expert committee can confirm the positive effects of Vitamin E on coronary disease. Looking at the Hill criteria, there is some consistency in the data showing a relationship between Vitamin E and coronary disease, but looking at the US Preventive Service Task criteria, there is far less evidence to prove this. Overall, we can conclude that there is sufficient evidence to support an inverse relationship between Vitamin E and coronary disease; however, it is still uncertain whether this modest evidence should impact RDAs.