According to Science, 5 Hours of Exercise Per Week Could Lower Your Cancer Risk

May 15, 2022

by Cathe Friedrich

Did you know that 90% of cancers are related to environmental exposures and lifestyle habits rather than genetic susceptibilities? This news comes directly from the World Health Organization. (WHO) That means lifestyle plays an important role in preventing cancer. Maintaining a healthy body weight and eating a healthful diet are two factors that can lower your risk of developing cancer. Studies show that at least 13 types of cancer are related to obesity.

But there’s another lifestyle habit that is linked with a lower risk of cancer and it’s regular physical activity. In fact, a study reveals that 46,000 cases of cancer could be prevented each year in the USA if people did only 5 hours of moderate-intensity exercise per week. Plus, if physical activity prevents obesity, the protective benefits would be even greater.

Based on these findings, here’s the percentage of various cancer types and what percentage of cancer cases could be prevented with only 5 hours of exercise weekly:

Stomach cancer 16.9%
Cancer of the uterus 11.9%
Kidney cancer 11%
Colon cancer 9.3%
Esophageal cancer 8.1%
Breast cancer 6.5%
Bladder cancer 3.9%

Five hours of exercise per week isn’t a huge outlay of time when you consider the positive impact it could have on your health and well-being. Although it’s unclear how exercise lowers the risk of some types of cancer, there are theories as to how staying physically active protects against this leading cause of death in Western countries.

By Protecting Against Obesity

Physical activity helps reduce body weight and body fat. One of the most dangerous kinds of fat from a health standpoint is deep belly fat, called visceral fat. Visceral fat cells produce inflammatory chemicals that increase the risk of some health problems, including type 2 diabetes and cardiovascular disease. The inflammation that visceral fat cells create damages cells and tissues in a way that increases susceptibility to cancer. For example, a study that used imaging to measure visceral fat found that women with more visceral fat were more likely to develop breast cancer than those with less deep abdominal fat.

By Exercise’s Effect on Hormones

Another way in which exercise lowers the risk of certain types of cancer is by its effect on sex hormones. For example, one study found that regular physical activity reduced estradiol, the most potent estrogen, by 13.7% and estrone by 11.9%. Another study showed that as little as 3 hours of exercise weekly lowers estrogen in post-menopausal women. In turn, lowering estrogen reduces the risk of estrogen-receptor-positive breast cancers in post-menopausal women. Less estrogen also lowers the likelihood of developing cancer of the uterus.

By Improving Insulin Sensitivity

Research shows physical activity improves insulin sensitivity. So, physical activity reduces fasting insulin. That’s important since insulin and its close cousin insulin-like growth factor (IGF) are growth factors for malignant cells, particularly breast cancer. Studies link higher IGF-1 with a greater risk of breast cancer. IGF-1 likely stimulates the growth of prostate and colon cancer too. So, improving insulin sensitivity has multiple benefits; it improves blood sugar control, helps with weight control, and may lower your risk of certain types of cancer.

The good news is that physical activity can help prevent insulin resistance before it starts. Studies show regular exercise reduces insulin resistance even if you’re already at high risk for CVD or diabetes because you’ve got extra belly fat or are overweight. Better insulin sensitivity also places you at lower risk of cardiovascular disease and type 2 diabetes.

By Its Effect on the Immune System

Exercise may fight cancer through its effect on your immune system too. When you work out, especially at a high intensity, it increases stress hormones like epinephrine and norepinephrine. That might sound negative for your health, but these hormones recruit natural killer cells (NK) that fight tumors and viruses. Each time you work out, these tumor-fighting cells mobilize and enter your bloodstream, where they give cancer a run for its money. A compelling reason to exercise, right? You might catch fewer colds if you stay physically active, but don’t overdo it. You also need recovery time for optimal immune health.

The Bottom Line

If you can spend at least 5 hours per week moving your body, you can lower your risk of developing at least 7 types of cancer. That sounds like a wise investment of time, doesn’t it? Plus, you’ll get the other health and fitness benefits that exercise offers:

Better bone health
Healthier body composition
Greater endurance
Greater functional strength
Better mobility
Improvements in sleep quality
Stress reduction
Improvements in mood and brain function

Combine exercise with a healthy diet, along with sleep and stress management, and the returns will be even greater. Ready to get started?

References:

American Cancer Society. “Data continues to show that American’s need at least 5 hours per week of physical activity to prevent some cancers.” ScienceDaily. ScienceDaily, 14 October 2021. <.sciencedaily.com/releases/2021/10/211014102027.htm>.
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