Let’s be honest. There are a million reasons to exercise and not many acceptable reasons to avoid it. People who exercise are happier, less stressed, more well rested, leaner, and overall healthier than couch potatoes. But recently, researchers at the University of North Carolina in Chapel Hill added another reason for women to exercise to an already impressive list.
After studying more than 3,000 women between the ages of 20 and 98 years old, some of whom had breast cancer and some who did not, the team found a startling commonality. Women who exercised were less likely to develop breast cancer, regardless of the period of their lives when they start. The data held true for women who exercised throughout their lives and also for women who started exercising after menopause. The bottom line, it’s never too late to start.
These findings add to a growing body of research that tie regular moderate exercise to lower rates of breast cancer. The results can’t lead to a definitive conclusion that it is exercise that lowers the risk of breast cancer. People who exercise may have other things in common, like a diet lower in saturated fat and higher in vegetables and fruits. However, the evidence is compelling, regardless of the reason for the results.
One possible reason for the lower breast cancer rates is lower body fat. Excess body fat has been linked to overproduction of hormones, including estrogen, and growth hormones that aid in tumor development. Exercise also boosts the immune system and helps prevent cell damage from free radicals.
The study interviewed 1,504 women with breast cancer and 1,550 women without cancer. Each was asked for details about lifetime exercise habits and other health factors, including smoking and alcohol intake.
It’s not exactly a catch, but the correlation between lower incidence of breast cancer and exercise was notable only in post-menopausal women. Pre-menopausal women had a much lower statistical edge of 6%, perhaps because the risk factors are more determinate by genetic and other factors for younger cancer victims.
Post menopausal women who reported exercising for 10-19 hours a week during their reproductive years were 30% less likely to have breast cancer than women who did not exercise during the same stage of life.
In addition, women who started exercising after the onset of menopause and averaged 9 to 17 hours per week were 30% less likely to develop breast cancer than sedentary women of the same age. The benefits extended well into old age. Women well into elder years enjoyed the same benefits as younger women.
Quantifying the numbers
As mentioned before, women who exercise regularly often have very different lifestyles than women who do not exercise. After accounting for such factors as disparity of education and income, smoking, drinking, and other life and health details, exercise still rose to the top of the commonality list.
Of course, women who exercise can be different from sedentary women in many ways. Active women are often better educated, more financially secure and more inclined to eat a healthy diet. By contrast, low income results in poor nutrition, overwork (and underpay), and the stress that goes hand-in-hand with living in poverty. Lower cancer rates could be a result of any combination of factors, so the researchers accounted for differences in education, income, smoking and other lifestyle and health factors. Regardless of these influences, exercise was still linked to lower breast cancer risk.
Another factor the researchers took into consideration was body weight. Women who weighed less had lower breast cancer rates. For obese women, exercise may have played a role in mitigating the increased risk of cancer. Either way, exercise offered benefits for all women. If the benefit from exercise turns out to be due to lower body fat, it’s a moot point. Exercise still accounts for the difference. Active women have lower body fat.
Any study like this that relies on the memories of respondents has certain limitations and can only be examined for broad patterns, but the trend is clear and impressive. The questions were very specific about the amount of time spent exercising and the intensity of the exercise. The researchers used the information to assign a lifetime composite score to each participant, then compared the scores with incidence of cancer.
Perhaps the most significant finding in the study is this: The intensity of exercise did not matter. Women who engaged in moderate physical activity for 2 hours a day, five days a week, benefited. Activities ranged from typical daily gardening, cleaning house, or walking to more intense activities like running or cycling. More intense activity did not increase the benefit. The lesson is simple. Anything women do at any age or stage in life that does not involve being motionless, results in lower risk of breast cancer.
Exercise has many benefits for elderly people. Studies show that Â elderly people who exercise regularly Â have more cognitive brain functions and are less inclined to mental deterioration. Minimizing the risk of breast cancer is just another big, fluffy feather in the exercise cap.
A great way to encourage seniors to start reaping the benefits is to advocate gentle activities like tai chi or yoga, gardening, bird watching, or simply a morning walk.
Cindy Johnson is a freelance writer with a new passion for healthy eating and a healthy lifestyle. Read her blog forÂ healthy eating and lifestyle tips. When she’s not writing, Cindy loves to hike in the mountains of North Carolina, where she lives with her husband, son, and a small assortment of dogs.