It is established that a regular exercise program is associated with reduced incidence of heart attacks and some types of cancers. Several recent studies show that you don’t have to have a formal exercise program to gain these benefits. Just being active is also associated with reduced likelihood for certain cancers. You can stay active by climbing stairs, mowing your own lawn, washing your dishes and so forth, Just keep on moving — don’t sit in a chair or lie in bed all day long.
A recent study from Australia included 22,398 cancer-free adults, average age 62 years, who had no formal exercise program and took at most one walk per week. The participants wore heart rate monitors for seven days to measure their average daily activity levels, and were then followed for seven years (JAMA Oncology, July 27, 2023). The study found that:
• Increased activity that raised heart rates for a total of 4.5 minutes per day was associated with a 20 percent reduction in total cancer risk and a 31 percent reduction in risk for cancers specifically associated with lack of physical activity (such as cancers of the breast, colon, prostate, lung or endometrium)
• Actively moving about for at least 3.4 minutes per day was associated with a 17 percent reduced risk for all cancers, and moving for 3.7 minutes per day was associated with a 28 percent reduced risk of cancers specifically related to inactivity
• 92.3 percent of vigorous activity occurred in intervals of one minute or less, and results were the same with two-minute intervals
The accompanying editorial noted that increased physical activity can also improve physical fitness, muscle strength, cancer-related fatigue and quality of life among cancer survivors.
Studies Showing How Physical Activity May Help to Prevent Cancer
• A review of almost 170 human and animal studies showed that regular exercise is associated with reduced cancer risk, particularly for the types of cancers that are believed to be related to unhealthful lifestyles (J Nutr, 2002 Nov;132(11 Suppl):3456S-3464S).
• Exercise appears to help prevent cancers by reducing causes of inflammation: overweight, excess calorie intake, high blood sugar, high insulin and insulin-like growth factor-1, high estrogen, and overactive or suppressed immune function (Exerc Sport Sci Rev, 2015;43(3):134-142); and by reducing markers of an overactive immune system that are also necessary for cancer growth (interleukin-6, tumor necrosis factor-alpha, and monocyte chemoattractant protein 1).
• Exercise has been shown to reduce inflammation that causes mice to develop colon cancer (Int J Oncol, 2014; 45(2):861–8), and breast cancer (Cytokine, 2011; 55(2):274–9).
• Exercise reduces inflammation in humans to increase survival from colon cancer (Gut, 2006; 55(1):62–7), and is associated with reduced precancerous polyps in humans (BMC Res Notes, 2012; 5: 312).
• Physical activity reduces sex hormones such as estrogen, and growth factors associated with cancer development and progression (Cancer Causes and Control, 2011; 22(6):811-826).
• Physical activity reduces blood levels of insulin which, at high levels, is a known cancer stimulant (Cancer Causes and Control, 2011; 22(6):811-826).
• Physical activity improves the immune system’s ability to search out and destroy cancer cells (Scientific Reports, April 21, 2023;13:6561).
• Physical activity improves quality of bile acids, to remove carcinogens from the intestinal tract (Cancer Epidemiology, Biomarkers & Prevention 2009; 18(5):1591-1598).
• Physical activity reduces the time it takes for food to travel through the digestive system, and helps to prevent obesity, a major cancer risk factor for cancer. Sedentary behavior is itself a risk factor for cancer (Annals of Internal Medicine, 2015;162(2):123-132; Annals of Oncology, 2014; 25(7):1293-1311; Cancer Epidemiology, Biomarkers & Prevention, 2015; 24(9):1350-1359).
My Recommendations
An exercise program significantly helps to prevent certain cancers, but if you can’t exercise, you can still benefit from short bouts of increased activity lasting less than a minute each throughout the day. You can check your activity by buying an inexpensive wrist pedometer that measures your heart rate, and doing your own house cleaning, dishwashing, yard mowing and dusting or whatever keeps you moving. See Keep On Moving to Prolong Your Life
Being Physically Active Helps to Prevent Heart Attacks and Some Cancers
Caution: Be aware that exercise can cause heart attacks in people who already have blocked arteries. Check with your doctor, particularly if you have any markers for arteriosclerosis: high blood pressure, cholesterol or blood sugar, or being able to pinch more than two inches of fat over your belly.
