9 May, 2013

How aerobic exercise helps lower breast cancer risk

Aerobic exercise influences the way our bodies break down estrogens to produce more of the `good` metabolites that lower breast cancer risk, according to a new research.

Observational studies suggest physical activity lowers breast cancer risk, but there are no clinical studies that explain the mechanism behind this, said Mindy S. Kurzer, Ph.D., professor in the Department of Food Science and Nutrition at the University of Minnesota in Saint Paul.

Kurzer and her colleagues conducted the Women in Steady Exercise Research (WISER) clinical trial, which involved 391 sedentary, healthy, young, premenopausal women. They randomly assigned the women to two age-matched, body mass index-matched groups: a control group of 179 women and an intervention group of 212 women.

While women in the control group continued a sedentary lifestyle for the entire study period, women in the intervention group performed 30 minutes of moderate-to-vigorous aerobic exercise five times a week for 16 weeks. Aerobic exercises included the treadmill, stair stepper or elliptical machine.

Using a state-of-the-art technique called liquid chromatography/tandem mass spectroscopy, they measured the amount of three parent estrogens, E1, E2 and E3, and nine of their breakdown products called metabolites, in the participants` urine samples.

According to Kurzer, estrogen metabolism favoring the production of a metabolite called 2-hydroxyestrone (2-OHE1) over one called 16alpha-hydroxyestrone (16alpha-OHE1), which results in an increase in the 2-OHE1/16alpha-OHE1 ratio, has been linked with a reduction in breast cancer risk.

She and her colleagues found that aerobic exercise led to an increase in the amount of 2-OHE1 and a decrease in the amount of 16alpha-OHE1, which led to a significant increase in the 2-OHE1/16alpha-OHE1 ratio. There were no changes in the 2-OHE1/16alpha-OHE1 ratio in the urine of control group participants.  "Exercise, known to favor fitness and improve heart health, is also likely to help prevent breast cancer by altering estrogen metabolism," said Kurzer.

In collaboration with researchers at the University of Pennsylvania in Philadelphia, Kurzer is conducting similar studies in women with a high risk for breast cancer.

The study results were published in Cancer Epidemiology, Biomarkers and Prevention, a journal of the American Association for Cancer Research.

Source: www.timesofindia.com

09.05.2013

Sunshine could be `elixir of life`

A new study has suggested that exposing skin to sunlight may help reduce blood pressure, cut the risk of heart attack and stroke - and even prolong life.

Researchers from the University of Edinburgh have shown that when our skin is exposed to the sun`s rays, a compound is released in our blood vessels that helps lower blood pressure.

The findings suggest that exposure to sunlight improves health overall, because the benefits of reducing blood pressure far outweigh the risk of developing skin cancer.

Production of this pressure-reducing compound - called nitric oxide - is separate from the body`s manufacture of vitamin D, which rises after exposure to sunshine. Until now it had been thought to solely explain the sun`s benefit to human health, the scientists added.

Researchers studied the blood pressure of 24 volunteers who sat beneath tanning lamps for two sessions of 20 minutes each. In one session, the volunteers were exposed to both the UV rays and the heat of the lamps. In the other, the UV rays were blocked so that only the heat of the lamps affected the skin.

The results showed that blood pressure dropped significantly for one hour following exposure to UV rays, but not after the heat-only sessions. Scientists said that this shows that it is the sun`s UV rays that lead to health benefits. The volunteers` vitamin D levels remained unaffected in both sessions.

"We suspect that the benefits to heart health of sunlight will outweigh the risk of skin cancer. The work we have done provides a mechanism that might account for this, and also explains why dietary vitamin D supplements alone will not be able to compensate for lack of sunlight," said Dr Richard Weller, Senior Lecturer in Dermatology at the University of Edinburgh.

The landmark proof-of-principle study will be presented on Friday in Edinburgh at the world`s largest gathering of skin experts.

Source: www.timesofindia.com

09.05.2013

When inspiration does not come to you, you go to meet it

SIGMUND FREUD