Taking vitamin E along with some regular exercise could help slow down the ageing process and improve health among the elderly, say researchers in the US.
Older men and women, asked to exercise regularly and take vitamin E supplements, significantly decreased their levels of a blood marker that signals free radical-induced oxidative stress, known to contribute to ageing and disease, report nurses in the latest issue of Biological Research for Nursing.
And study participants who did not exercise but still took vitamin E also showed significant decreases in oxidative stress and blood pressure, they said.
"The results of this study suggest that people who are over 40 can benefit from regular moderate exercise and vitamin E to protect against the destructive properties of free radicals and their effects on our ageing bodies," said James Jessup, the study's principal investigator and an associate professor at the University of Florida's College of Nursing.
Researchers have previously shown that antioxidants, such as beta-carotene and vitamins C and E, could help protect the body against free radicals, thought to also play a role in the development of cancer, Alzheimer's disease and several other age-related diseases. Evidence to support the role of antioxidants in specific disease outcome is however inconclusive.
Over a two-year period, Jessup and his team studied 59 healthy men and women, aged 60 to 75, who lived in a community retirement facility in North Central Florida. They did not take regular exercise. Half were randomly assigned to a group that exercised routinely and half to a control group that did not. Participants in each group were then randomly assigned to take daily vitamin E supplements or placebos.
All study participants maintained their usual eating habits. Those in the vitamin E groups took 800 international units of vitamin E, well over the recommended daily allowance of 30 international units. Exercise is thought to increase the production of free radicals and the requirements for dietary antioxidants such as vitamin E.
Both exercise groups completed 16 weeks of supervised endurance exercise for 60 minutes twice a week, with intensity and duration increasing in the fourth and fifth weeks of the regimen.
Free radical damage in the two groups taking vitamin E was cut in half, reported the researchers, measuring a key byproduct of the impact of free radicals. Those in the sedentary group taking vitamin E also showed a significant reduction in their systolic blood pressure (an average of almost seven points).
The group who exercised and took vitamin E had an average drop of about 15 points in their systolic blood pressure and about five points in their diastolic blood pressure, as well as increased weight loss and significant improvement in resting oxygen uptake, a measure of cardiovascular fitness and endurance. The sedentary group not taking vitamin E showed no significant changes.
The two groups taking vitamin E did not differ in their concentrations of a byproduct of free radical damage, but exercise produced extra, significant benefits such as weight loss, improved cardiovascular health and lower blood pressure.
However even adults who cannot exercise should take vitamin E because of its clear benefits to ageing and systolic blood pressure, added Jessup.
The study suggests that currently recommended intakes of vitamin E may not be enough for older adults.