Research shows that exercise is an important step in the prevention of breast cancer! There are many studies that show strong evidence that exercise lowers the risk of breast cancer (along with colon cancer, kidney cancer, bladder cancer, esophageal and stomach cancers!).
There is also strong evidence that exercise reduces anxiety, depressive symptoms, and fatigue in cancer patients. Studies show that regular exercise reduces your risk of breast cancer by 20 – 30% with a 38% reduced risk of invasive breast cancers.
Studies also show that breast cancer patients with higher exercise levels have 29 – 41% lower risk of dying from breast cancer.
How Exercise Fights Cancer
Exercise has direct and powerful effects on human physiology that directly lower cancer risk including:
Improved insulin sensitivity – insulin resistance is directly linked to cancer growth and spread!
Improved blood circulation driving more oxygen into cells and helps the liver detoxify cancer causing substances.
Improved mitochondrial function – mitochondria are the energy factories of the cells and healthy mitochondria are key to prevention of many chronic diseases including cancer.
Decreased bodyfat levels – excess bodyfat produces copious amounts of estrogen and being overweight is an independent risk factor for breast cancer for this reason.
Improved immune function – a strong immune system is primed to recognize and destroy cancer cells before they form tumors!
Time Restricted Eating and Breast Cancer Prevention
Time restricted eating is exactly what it sounds like: restricting your intake of food to a certain period of time each day. Most Americans eat something every two hours for 16 – 18 hours per day. Time restricted eating involves shortening this “feeding window” to somewhere between 8 and 12 hours per day.
In the course of our evolution humans spent hundreds of thousands of years without constant access to food, and even as recently as the 50’s most people only ate two times per day. Our bodies were not designed to have constant food intake all day, every day and doing so causes problems.
Every time we eat we secrete insulin which is necessary to absorb nutrients into our cells. However frequent insulin secretion is one of the reasons so many Americans develop insulin resistance which frequently progresses to adult onset diabetes aka type 2 diabetes. Woman with type 2 diabetes have a 23% higher risk for developing breast cancer and a 30.8% higher risk of breast cancer mortality
There is considerable research linking high evening/night-time calorie intake to elevated insulin resistance and inflammation both which drive breast cancer.
Enter Time-Restricted Eating where you simply restrict calorie intake to 11 – 12 hours per day – ideally having your first meal early in the day and finishing your last meal 11 hours later. For example, an eating window of 7am – 6pm or 8am – 7pm. Research has shown that this simple step can dramatically improve insulin sensitivity and inflammation and lower breast cancer risk.
A recent study analyzed data from the Women’s Healthy Eating and Living study and found that breast cancer survivors who didn’t eat for at least 13 hours overnight had a 36% reduction in the risk of recurrence and were 21% less likely to experience breast cancer related mortality.
The proposed mechanism is reduced insulin levels and improved insulin sensitivity, and this makes perfect sense because elevated insulin levels and decreased insulin levels are directly linked to cancer growth. Each 2-hour increase in nightly fasting was linked to progressively lower hemoglobin A1C levels which is a sign of improved insulin sensitivity.
An advantage of time-restricted eating versus other dietary interventions like reduced calorie intake is that it is very simple to perform. To learn more about time-restricted eating (which is also referred to as “intermittent fasting”) check out this previous blogpost on this subject: http://workoutanytime.blogspot.com/2020/06/the-benefits-of-intermittent-fasting.html