Vitamin E Supplementation Improves Insulin Action and Reduces Heart Disease in Elderly People
James Meschino DC, MS, ROHP
Narrowed blood vessels in the heart (coronary heart disease) is the leading cause of death in adult life and in elderly people. With aging many people also develop resistance to insulin, forcing the pancreas to secrete higher levels of this hormone to maintain blood sugar within a normal range. A high blood level of insulin is considered a risk factor for coronary heart disease. In fact high blood insulin (hyperinsulinemia) plays a pivotal role in the genesis, development, and progression of artery narrowing.
Most researchers agree that a decline in fasting blood insulin levels and improved insulin action would have favorable effects on heart disease risk.
Several observational studies have demonstrated that vitamin E may play a protective role against coronary heart disease. Vitamin E protects cholesterol in the bloodstream from free radical damage (oxidative damage). Studies reveal that cholesterol that is damaged by free radicals is much more inclined to narrow arteries than cholesterol that is not modified in this way. By protecting cholesterol from free radical damage vitamin E and other antioxidant vitamins have been linked to a reduction in heart disease risk.
Additionally, long-term administration of vitamin E supplementation has been shown to decrease fasting blood insulin levels.
Based upon these findings Paolisso et al. set out to investigate if vitamin E supplementation would improve risk factors for heart disease in elderly patients. They included thirty elderly non-diabetic, moderately overweight patients with stable angina in a vitamin E supplementation study lasting 4 months.
Each subject ingested 900 mg of vitamin E each day during the study. The results of the study revealed a decrease in fasting blood sugar (glucose), insulin and triglycerides (blood fats). There was also an improvement in the LDL to HDL ratio. All of these findings suggest that chronic intake of pharmacological doses of vitamin E might be useful in the therapy of elderly insulin-resistant patients with coronary heart disease. Of course, preventing coronary heart disease in the first place has also been shown to be attainable by taking a vitamin E supplement throughout life.
Many studies have demonstrated that vitamin E helps ward off the development of narrowed arteries. An elderly cross-cultural study by Gey et al. demonstrated that higher blood levels of vitamin E were associated with a decreased risk of heart disease death. In the study by Kaardinal et al. the authors concluded that only vitamin E supplements in the diet might have beneficial effects in the prevention of coronary heart disease. Vitamin E from food alone was not shown to offer protection.
Originally researchers believed that the exclusive mechanism by which vitamin E could reduce heart disease risk was by reducing free radical damage to blood cholesterol. This antioxidant effect has been shown to be an important anti-heart disease property of vitamin E.
However, vitamin E appears to be involved in other metabolic processes that also reduce coronary heart disease risk. Vitamin E decreases the stickiness of blood platelets, which reduces the tendency for abnormal clotting inside blood vessels. Clumping together of platelets is often the final event that precipitates a heart attack. Decreasing platelet stickiness is a significant factor in reducing heart disease. This is the principle mechanism through which aspirin reduces heart attack risk.
The study by Paolisso et al. provides evidence for the first time that in elderly patients with coronary heart disease long term supplementation of vitamin E (900 mg/day) is a useful tool not only in improving blood triglycerides (fats) and LDL:HDL ratio, but also in lowering blood insulin concentrations.
Other antioxidant agents have also been shown to lower blood insulin levels. In previous studies Paolisso et al. demonstrated that vitamin C and glutathione have a similar effect to vitamin E on lowering insulin levels in the bloodstream.
With respect to vitamin E and elderly individuals Paolisso et al. conclude that chronic pharmacological vitamin E administration may contribute to lower fasting plasma LDL-cholesterol and insulin concentrations and therefore might be useful in the therapy of elderly patients with coronary heart disease.
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