NAPLES, ITALY. People with type 2 diabetes have elevated oxidative stress and decreased antioxidant defenses. They also have an imbalance in the autonomic nervous system, which manifests itself in the form of a more pronounced sympathetic (adrenergic) activity in the heart. This sympathetic over-activity is linked to oxidative stress and is believed to be responsible for many cases of sudden death even in the absence of documented heart disease.
Researchers at the Second University of Naples reasoned that if oxidative stress and sympathetic over- activity were related then antioxidant supplementation should reduce both. Their double-blind, randomized, controlled clinical trial involved 50 patients with type 2 diabetes with an average age of 65 years. The patients were assigned to receive either a daily supplement of 600 mg of alpha-tocopherol acetate (synthetic) corresponding to 300 IU of natural vitamin E or a placebo. Blood samples and heart rate recordings (Holter) were taken at the beginning and end of the four-month study.
At the end of the study the researchers noted significant decreases in oxidative stress, fasting insulin level,
norepinephrine level and epinephrine (adrenalin) level, and a tripling of plasma vitamin E level. They also
noted a considerable decline in the low frequency (adrenergic) component of the heart rate variability
spectrum and a doubling of the high frequency (parasympathetic, vagal) component. The ratio between the
low and high frequency components (LF:HF) was cut in half. The researchers conclude that long-term
vitamin E supplementation reduces oxidative stress and cardiac sympathetic activity in type 2 diabetes