Researchers at the Dana-Farber Cancer Institute in Boston say exercise helps combat breast cancer. Not the first time we've heard this fact. But these same researchers have something new to say -- about the reason physical activity lowers the risk of breast cancer recurrence.Jennifer Ligibel, MD, of Dana-Farber, reports that exercise lowers levels of the hormone insulin in the bloodstream. This is significant because there appears to be an association between relatively high levels of insulin, seen in obese and sedentary people, and an increased risk of breast cancer recurrence and breast cancer-related death.
"We know that women who are overweight at the time of breast cancer diagnosis have a higher risk of recurrence than lean women, but the reasons for this have not been clear," said Ligibel.
Now we know that study participants who took part in a 16-week program of cardiovascular and strength training were able to lower their insulin measurements by statistically-significant amounts.
"Our findings suggest that the effects of exercise on breast cancer prognosis may be mediated, at least in part, through changes in insulin levels and/or changes in fat mass or deposition," said Ligibel. "Exercise has benefits all through treatment and afterwards. It's an investment in a woman's health and hopefully will prove to lower her risk of dying from breast cancer."
