Healthy heart may help men battle cancer, study finds

Cardiovascular exercise may be an important component to battling cancer, a new study finds.

Published in "JAMA Oncology," doctors concluded middle-age men with high cardiovascular respiratory fitness (CRF) cut their risk of cancer death, if they were diagnosed at age 65 or older, by over one-third.

"Pretty amazing that a decade-and-a-half before the event, your cardio fitness predicted what was going to happen with cancer," CBS News medical contributor Dr. David Agus said Friday on "CBS This Morning."

Remarkably, even a minor adjustment in CRF can produce significant outcomes. Results were gathered from men running on treadmills and found that those who developed cancer and ran an 11.5-minute mile, compared to those just a half a minute slower, were 10 percent less likely to die of cancer.

Participants who had high CRF at age 50 also demonstrated a lower risk of developing lung cancer by over half, and colon cancer by over 40 percent, compared to men who had low levels of CRF.

Two studies reflected similar results.

A recent publication in "The Journal of the National Cancer Institute" described the effect of exercise on breast cancer in mice. Researchers observed that mice with hypoxic cancer cells, those with a reduced supply of oxygen, actually fared worse than mice with cells containing healthy supplies of oxygen. Chemotherapy drugs and radiation, the study notes, are more effective with oxygen.

In 2009, the "Annals of Epidemiology" journal published a study of nearly 1,000 Finnish men who were observed for an over 12-year period. That study suggested "higher circulating concentrations of lycopene" could contribute to lower risk of certain cancers.

Agus said exercise changes the body's environment, which can lessen the threat of cancer.

"If I drop a match in a field of grass after it rains, nothing happens. If I drop a match in Los Angeles, it goes up in flames; so you need a receptive environment," he said.

While this study only tested men, Agus said, "there shouldn't be a major physiologic difference" for women.