Swimming can boost fight against cancer

New research suggests that regular swimming, fitness classes or jogging may protect women against invasive and early-stage breast cancer. A major study in the US found a significant correlation between taking regular physical exercise and lower rates of the disease.

Fitness fanatics appeared to benefit most. Women who spent more than five hours a week running, swimming, going to aerobics classes, or engaging in other forms of strenuous exercise reduced their risk of both early stage and invasive disease.  Moderate activity, such as brisk walking or playing golf, had some influence on invasive cancer.

Researchers also found exercise only protected against non-hormone sensitive invasive cancers - cancers which have spread beyond the milk ducts to invade the breast tissue.

In 80%-85% of cases, the female hormone oestrogen fuels breast cancer. These patients can successfully be treated with the drug tamoxifen, which blocks the hormone's activity.

However, up to 20% of cases are not hormone sensitive and are more difficult to treat.

"For these women, regular exercise may be part of the answer.”

The findings, published in the journal Archives of InternalMedicine, emerge from a study of 110,599 former teachers in California.Research leader Professor Leslie Bernstein said:

"This study confirms that breast cancer risk is influenced by consistent participation in strenuous forms of exercise activity. However, it may require substantial commitment of time to achieve this lower risk."

"Risk was lower for women who exercised at least five hours per week."