After being diagnosed with breast cancer, many women make diet and other lifestyle changes to improve their health as they recover from treatment. Eating a healthy diet that’s rich in fresh, unprocessed foods and low in trans fats after being diagnosed can give you more energy as you recover and improve your quality of life.
Researchers have wondered if eating a low-fat diet after being diagnosed improves survival. A study suggests that postmenopausal women who eat a low-fat diet after a breast cancer diagnosis are less likely to die from breast cancer.
The study was presented at the American Association for Cancer Research Annual Meeting on April 18, 2016. Read the abstract of “Low-fat dietary pattern and breast cancer mortality in the Women’s Health Initiative (WHI) randomized trial.”
The research is part of the very large Women’s Health Initiative Clinical Trial and the Women’s Health Initiative Observational Study. Both studies are commonly called the WHI. Together, the two studies include information from more than 161,608 postmenopausal women who were ages 50 to 79 when they joined from 1993 to 1998. The WHI wants to find any links between health, diet, and lifestyle factors and health problems such as cancer.
In this part of the study, called the Women’s Health Initiative Dietary Modification Trial, 48,835 postmenopausal women, ages 50 to 79, who had no history of breast cancer and who ate a diet that was more than 32% fat, were randomly assigned to one of two diet plans:
- 19,541 women were told to eat a low-fat diet (fat intake was supposed to be only 20% of the diet); these women also participated in group sessions led by a nutritionist to teach the women how to reduce their fat intake
- 29,294 women were told to eat their usual diet and received educational materials on healthy eating
After the women had followed the diet plans for about 8 years, 1,767 women had been diagnosed with breast cancer.
Survival after a breast cancer diagnosis was better among with women in the low-fat group:
- 82% of the women in the low-fat diet group were alive about 11 years after diagnosis
- 78% of the women in the usual diet group were alive about 11 years after diagnosis
"This was the first time we had examined the deaths after breast cancer among this group, and we found that a sustained low-fat diet increased the survival rates among postmenopausal women after a breast cancer diagnosis," said Rowan Chlebowski, M.D., Ph.D. of the Los Angeles Biomedical Research Institute, who presented the findings at the conference. "The study also suggests that women would need to remain on the low-fat diets to maintain the benefits of the dietary intervention."
While these results are encouraging, it’s important to keep several things in mind:
- The study relied on the women accurately reporting what they ate and then estimating the fat content in the food. Sometimes people don’t remember everything they eat or how much of something they eat, which would affect the results of the study.
- The study didn’t look to see if the women stuck to their breast cancer treatment plans completely. Stopping a treatment, such as hormonal therapy, early would affect the study results.
- The study only looked at postmenopausal women diagnosed with breast cancer. The results can’t be applied to premenopausal women with breast cancer.
- While the women in the study had no history of breast cancer, it’s not clear if any of the women had a family history of breast cancer. This could possibly affect the results of the study.
If you’re a postmenopausal woman who’s been diagnosed with breast cancer, it makes sense to make healthy diet and lifestyle choices to keep your risk of recurrence as low as it can be and your overall health the best it can be, including:
- eating a diet low in added sugar and processed foods
- eating a diet rich in unprocessed, nutrient-dense foods (foods that have the most vitamins, minerals, and healthy compounds)
- exercising regularly at the highest intensity level you’re comfortable with
- avoiding alcohol
- not smoking
It also makes sense to stick to your treatment plan. Treatments such as chemotherapy and radiation therapy can require trips to the hospital or doctor’s office for several months. You also may need to take medicines for 5 or 10 years after surgery. You get the best results when you follow your plan completely and on schedule.
For tips on how to overcome common problems with following a treatment plan, visit the Breastcancer.org Staying on Track With Treatment pages.