Cancer-Fighting Weapon: Is It in Your Arsenal?

Nearly 50% of Americans will be diagnosed with cancer of any site at some point during their lifetime, based on 2012-2014 data.  Would you like to reduce your risk for cancer-related death by 31%? Engage regularly in aerobic and strength building exercise. Evidence, please!

A study of 80,000 people found that people who did strength-based exercise had a 23 percent reduction in the risk of premature death by any means, and a 31 percent reduction in cancer-related death.¹

Animal and human studies indicate that regular exercise can inhibit tumor promotion and progression in animals and humans who have cancer. ²

Exercise & Cancer Stats

Now, from an even larger study: Pooled data from a dozen studies, totaling 1.4 million participants, reveal higher levels of leisure-time physical activity are linked to lower risks for 13 types of cancers. Which cancers? By how much?³

• esophageal adenocarcinoma (42 percent lower risk)
• liver (27 percent lower risk)
• lung (26 percent lower risk)
• kidney (23 percent lower risk)
• gastric cardia (22 percent lower risk)
• endometrial (21 percent lower risk)
• myeloid leukemia (20 percent lower risk)
• myeloma (17 percent lower risk)
• colon (16 percent lower risk)
• head and neck (15 percent lower risk)
• rectal (13 percent lower risk)
• bladder (13 percent lower risk)
• breast (10 percent lower risk).

Exercise Balances Hormones.

Engaging regularly in physical activity may reduce breast cancer risk by altering estrogen metabolism. Women who did aerobic exercises had an increased ratio of “good” to “bad” metabolites of estrogen.⁴

Regular exercise also helps to balance insulin levels. We all need insulin to facilitate the entry of glucose into the cells so that the cellular powerhouses can burn it for insulin. Obesity and consumption of saturated fats are the usual villains that cause the cells to respond ineffectively to insulin or to become resistant to it. Insulin resistance causes the insulin levels to rise. High levels of insulin encourage chronic inflammation and boost the risk for cancer. Regular exercise improves the sensitivity of insulin receptors on our cells to respond to insulin more effectively.

Exercise Focuses the Immune System on the Tumor.

During exercise, the adrenal glands release epinephrine. Vigorous exercise drives cancer-destroying natural killer cells to the tumor site.⁵ Skeletal muscles produce proteins called myokines. Once released into the blood, myokines perform several functions. Myokines exert several cancer-fighting mechanisms, including suppression of tumor growth. Exercise also increases the number and efficiency of circulating natural killer cells that destroy cancer cells and viruses.⁶

Men who have prostate cancer who exercise exhibit slower disease progression and survive for longer. A single bout of vigorous exercise can boost the level of myokines in men with advanced prostate cancer for 30 minutes.⁷  The number of natural killer cells increases within minutes of starting moderate to vigorous exercise.⁸ Moderate-intensity exercise shows greater benefits to the immune system by stimulating NK cell activity, improving their ability to detect danger, reducing inflammation, and preventing cellular ageing. In contrast, the high-intensity, long-duration exercise decreases the proliferation of another type of cancer-fighting immune cells called killer T lymphocytes and reduces their ability to kill.⁹

Outdoor Exercise is Superior If You Have a Green Space.

Spending time in a forest helps to decrease stress, improves moods, reduces anger and aggressiveness, and improves one’s happiness. Forest visits also strengthen our immune system by increasing the activity and number of natural killer cells that destroy viruses and cancer cells.¹⁰

Plants emit phytoncides that protect them from insects and rotting. When people breathe phytoncides in, there is an increase in the level of natural killer cells. Walking in the woods or where there are trees improves the number and efficiency of natural killer cells.¹¹ Additionally, walking in the woods helps to lower elevated levels of cortisol which suppress the immune system. Then, too, sunshine can boost the vitamin D hormone levels. This hormone engages in several cancer-fighting activities.

Exercise Lowers the Risks for Recurrences.

Of all lifestyle factors, physical activity has the most robust effect on breast cancer outcomes.¹² Regular exercise also benefits individuals who have colon cancer. A person’s risk of having a cancer recurrence or dying was lowered by 40 to 50 percent in the 2 1/3 to 3 years following surgery and chemotherapy for stage III colon cancer if they walked briskly for one hour, six days a week.¹³ Ideally, a person should engage in at least 30 minutes of moderate exercise a day, five days a week, or 75 minutes of vigorous exercise per a week. Two to three sessions of strength training per a week for large muscle groups are also recommended. However, certain cancers like lung, blood, pancreatic cancers, and myeloma increase the risk for cancer. Walking for 10 minutes for every two hours of sitting, and deep breathing exercises, help to reduce risk of clots.

Exercise is a Great Immune Motivator.

Early evidence suggests that exercise, after chemotherapy is completed, helps the immune system to remodel itself in such a way as to improve its efficiency. After chemotherapy the immune cells tend to become senescent. Regular exercise though, converts these cells into a form that is ready to fight cancer and infections.¹⁴

Exercise Improves how Cancer Patients Feel During and After Treatments.

Participating in regular exercise can reduce fatigue and pain, and improve cardiovascular health and quality of life in women being treated for advanced breast cancer. In one study,¹⁵

• Women who were exercising reported an average 21.4-point reduction in pain, compared to an average 2.6-point reduction for women who were not following the exercise program.
• For fatigue, there was a 14.4-point reduction in fatigue in women exercising compared with 2.2 points in women in the control group.
• For emotional well-being, there was an improvement of 16.6 points for those exercising compared to 11.0 points for those not exercising. For women’s ability to carry out normal daily tasks, there was an improvement of 14.9 points compared to 0.1-point deterioration in the control group.

Exercise may Offset Some of the Side-Effects of Cancer Treatment.

Certain types of chemotherapy give neuropathy—pain, tingling, or numbness in extremities. Walking and gentle resistant band exercises reduce the neuropathy symptoms. Other studies show exercise reduced chronic inflammation and cognitive impairment among people receiving chemotherapy.¹⁶

Caveats:

Two things to consider: First, the whole lifestyle is important in preventing cancer. A recent study suggests that regular physical activity can lower a woman’s overall risk of cancer — but only if she gets a good night’s sleep. Otherwise, lack of sleep can undermine exercise’s effect on cancer prevention.¹⁷ Secondly, use natural, herbal or mineral based sunscreen to minimize your chances of skin cancer if you are exercising outside for more than 10 minutes if the ultraviolet light is intense. If you use sunscreen, you need to be sure you are getting enough vitamin D, as sunscreen can substantially reduce vitamin D production.

Key Words: exercise and cancer prevention, exercise and cancer treatment, exercise and cancer recurrence, exercise and cancer survival, exercise and cancer statistics, exercise after cancer, exercise and breast cancer, exercise and cancer chemo, exercise decrease cancer risks, exercise fights cancer.

 

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11. Loyola University Health System. “Boost your immune system; shake off stress by walking in the woods.” ScienceDaily. 3 October 2013. www.sciencedaily.com/releases/2013/10/131003132112.htm[↩]
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