Studies of colon and breast cancer patients link healthy habits to better outcomes amid slew of research on lifestyle and cancer
A healthy diet and exercise could reduce colon cancer patients’ chance of death and simply walking could improve survival rates for breast cancer survivors, studies presented at the world’s largest cancer conference have found.
A study of nearly 1,000 colon cancer patients found that those who exercised regularly, ate more fruits and vegetables and avoided refined grains and meats had a 42% lower chance of death after seven years.
Similarly, a study of more than 300 Australian breast cancer survivors who aimed to exercise for 180 minutes per week – most by simply walking – had far better rates of survival than those who were not part of an exercise program.
The studies were presented amidst a slew of research on the impact of a healthy lifestyle on cancer, presented at the American Society of Clinical Oncology (ASCO) in Chicago.
“Most of what we know about the importance of exercise post-cancer comes from studying women with breast cancer,” said Sandra Hayes, an epidemiologist studying cancer and exercise at Queensland University of Technology in Australia.
Studies conducted on the relationship between exercise and other types of cancer, she said, held up a general set of findings.
“Engaging in some activity [or] exercise is better than none, and doing more is generally better than less,” Hayes said.
Researchers acknowledged that studies on the effects of exercise and cancer recurrence remain epidemiological, and that causal links are yet to be established. Further, the mechanisms through which exercise may influence cancer survival remain “unclear”.
In one study, researchers at the University of California San Francisco and colleagues aimed to test whether American Cancer Society (ACS) nutrition and exercise guidelines for cancer survivors could impact survival among colon cancer patients.
In general, the guidelines recommend moderate exercise of 150 minutes per week, eating a diet rich in whole grains, fruits and vegetables, and keeping a healthy body weight. The ACS has detailed guidelines for nutritional and exercise standards for cancer survivors, addressing everything from exercise to eating recommendations forthose who have little appetite.
Researchers found that even colon cancer survivors who drank moderately while following other guidelines had a 42% lower chance of dying than those that did not.
“I would recommend that patients build up to exercising for at least 150 minutes per week,” said the senior author, Erin Van Blarigan, an epidemiologist at University of California San Francisco. “Brisk walking is a great exercise for everyone. I would also recommend that patients aim to eat at least five servings of vegetables every day, not counting potatoes, and choose whole grains over refined grains.”
Van Blarigan said she was surprised by the strong correlation between healthy diet, exercise and lowered mortality.
“These recommendations can be applied within whatever diet type an individual prefers,” she said. “The key is finding foods that fit the recommendations that you enjoy, so you can continue this pattern of eating for the long term.”
In a smaller study, Hayes and colleagues in Australia randomly assigned more than 300 breast cancer survivors to groups that received exercise counseling or to a control group.
All patients were six weeks out of surgery, and lived in both rural and urban settings. The exercise program lasted eight months. The goal was to exercise 180 minutes per week. Most of the participants, researchers said, chose simply to walk.
After a median follow-up of roughly eight years, researchers found 5.3% of the women who had received exercise counseling had died, versus 11.5% of those who had not received counseling. Similarly, 12.1% of women in the group that received exercise counseling had a recurrence of cancer, versus 17.7% of those who did not.
The researchers said an exercise program after treatment “has clear potential to influence survival”.