July 12, 2023 | 6 minute read

AICR research explores links between physical activity, nutrition and breast cancer survivorship.

Maxine Bergman, a breast cancer survivor and a grandmother of five, relies on breast cancer research and advice from AICR to help guide her lifestyle choices. Bergman’s motto is “take care of your body. It’s the only one you’ve got.”

Bergman, a retired nurse, was excited to read AICR’s new research on breast cancer survivors as it relates to:

• Body weight and outcomes after a breast cancer diagnosis.
• Physical activity and outcomes after a breast cancer diagnosis.
• Diet and outcomes after a breast cancer diagnosis.
• Whether being physically active improves the quality of life in women living with and beyond breast cancer.

The new research about breast cancer was conducted as part of the World Cancer Research Fund International (of which AICR is a member) Global Cancer Update Program, or CUP Global (formerly called the Continuous Update Project, or CUP). Research for breast cancer and lifestyle factors is ongoing.

Why is Our Research So Important?

Breast cancer is the most common type of cancer among women worldwide (approximately one percent of men develop breast cancer). In the US, one in eight women will develop breast cancer in their lifetime. It’s expected that there will be 297,790 breast cancer cases in the US in 2023. Around 90 percent of those diagnosed with breast cancer now survive five years after diagnosis.

Breast Cancer and Body Weight

Researchers looked at 226 studies from around the world, comprising more than 456,000 women with breast cancer. The review found strong evidence that having a higher body weight after diagnosis increases the risk of death.

Maintaining a healthy body weight can help prevent breast cancer and help improve the chances of survival if someone is diagnosed with the disease. If you struggle with maintaining a healthy body weight or need advice about nutrition, find a dietitian through your oncology team.

Breast Cancer and Physical Activity

Researchers analyzed 23 studies from around the world, comprising more than 39,000 women with breast cancer. Most of the studies looked at aerobics, walking and running, with limited studies on other types of physical activity.

The review found some evidence that physical activity for breast cancer patients could reduce the risk of death after a breast cancer diagnosis. There was also some evidence that physical activity could reduce the risk of getting breast cancer again.

The evidence on breast cancer and exercise was judged as “limited-suggestive.” That means that despite some evidence for benefit, there are limitations in the type and quality of studies that have been conducted to-date.

So, although the evidence was not considered strong enough to make specific recommendations for physical activity in women diagnosed with breast cancer, being physically active remains part of our overall recommendations for cancer survivors. 

Breast Cancer and Diet

Researchers looked at 108 studies from around the world, comprising more than 151,000 women with breast cancer. The review showed some evidence that eating more dietary fiber from whole grains, pulses, vegetables and fruits could improve survival.

There was also some evidence that eating soy could reduce the risk of death and the risk of breast cancer recurrence. Soy foods include tofu, tempeh, edamame and soy beverages.

There is also some evidence from breast cancer and diet research that people with healthy eating patterns have a reduced risk of death from breast cancer. No single kind of diet was best. The consistent thread is that diets should be high in fiber, fruits and vegetables. A good model is AICR’s New American Plate.

As with physical activity, this evidence is considered “limited” due to the amount, type or quality of the research available. However, we do still recommend that people follow AICR Cancer Prevention Recommendations for a healthy diet after a breast cancer diagnosis.

Breast cancer research helps with survivorship. As part of her cancer recovery, Bergman found the energy to go for a short walk each day and make nutritious food choices that included lots of vegetables and fruits. Before long, her five-minute walks got longer and longer, and now she takes over 10,000 steps most days. She has also picked up pickleball to add a social and fun element to her regular physical activity.

Exercise and Quality of Life

In a separate set of analyses, the CUP Global team looked at how exercise can improve quality of life for women with breast cancer. They analyzed 79 studies from around the world comprising 14,554 women with breast cancer. The review found that women living with and beyond breast cancer who do more physical activity see improvements in their overall quality of life.

People with breast cancer should talk to their health-care provider about the recommended exercise guidelines and seek the help of a rehab or exercise specialist to develop an individualized plan.

If no guidelines are provided, follow national guidelines for physical activity. In the US, the CDC recommends:

• At least 150 minutes per week of moderate intensity physical activity such as brisk walking, cycling and swimming.
• Two days of muscle-strengthening activity such as using free weights or resistance bands.

Future Breast Cancer Research

Dr Nigel Brockton, Vice President of Research at AICR, says that through many years of extensive research, AICR has developed Cancer Prevention Recommendations to help support individuals to make healthier choices to reduce cancer risk.

“We want to be able to do the same for those living with and beyond cancer, so that alongside their health-care team, they have the latest evidence-based information about healthy eating, physical activity and weight,” says Brockton. “These analyses are an important contribution toward that goal.

AICR will continue to fund this important research on cancer and lifestyle.

 – Reviewed by Nigel Brockton, PhD, Vice President of Research, AICR