Can Exercise Reduce the Risk of Cancer?
If you have a reasonable network of family and friends, chances are that you know of someone or your network knows of someone who has had or still does have a battle with cancer. This year, in the U.S, Canada, Australia and in fact all around the world, many will be diagnosed or pass away from cancer. The most common being skin, breast, lung, colorectal and prostate.
Around 1 in 8 women will develop invasive breast cancer over her lifetime in the US.
It is expected that there will be over 228,000 cases of lung cancer diagnosed in the US this year.
Over 191,900 new cases of prostate cancer this year in the US are expected.
Up to 10,000 men in the US will be diagnosed with testicular cancer.
It is expected that around 53,000 people will die from colorectal cancer in the US this year.
The National Cancer Institute recently published an article that identified higher levels of physical activity linked with a decrease in cancer risk. Several cancers in fact. Whilst observational studies do not prove a causal relationship, there is enough evidence across different populations of a common causal relationship identifying a consistent mechanism - Physical Activity.
The simple take away from this is that those who participate in physical activity ARE noted as having a reduced risk to many cancers, compared to those who do not participate in physical activity or minimal levels of physical activity.
Bladder Cancer - 2014 - The risk of bladder cancer was noted as being 15% lower for individuals who fell into the highest category of physical activity (occupational and recreational) than those in the lowest level. Those that participated in physical activity for recreation only appeared to have a 13% reduced risk.
Breast Cancer - 2016 - Most women who participated in physical activity had a 12-21% reduced risk of breast cancer than those who are not physically active. Positive outcomes also apply to women who are pre/postmenopausal. In fact, women who adopt physical activity may also have a lower risk than those who do not.
Colon Cancer - 2016 - Those who fell into the highest level of physical activity had a 19% lower risk than those who were least physically active.
Endometrial Cancer - A 20% reduced risk applied to those who were highly physically active compared to those who were considered as low. The catch here is that it appears to be connected to obesity. Obesity has a strong relationship with endometrial cancer and physical activity is a proven way to keep in shape.
Esophageal Cancer - 2014 - A 14% reduced risk applies to those who participate in high levels of physical activity in comparison to those who are considered to be in the low category when comparing esophageal adenocarcinoma.
Kidney Cancer - 2013 - A 12% reduced risk applies to those who were engaged in high levels of physical activity in comparison to those who were engaged in low levels of physical activity.
Stomach Cancer - 2016 - Those who were in the high category for physical activity were 19% better off than those who were least active.
Help each other to stay accountable.
Over the decades, the volume of physical activity data has increased immensely. There are a number of likely ways that physical activity attributes to the above statistics.
It is thought that exercise lowers growth factors and hormones such as estrogen linked to breast and colon cancer.
Prevents high blood levels of insulin also related to breast and colon cancer.
It can reduce inflammation and improve the immune system.
Promotes gastrointestinal tract peristalsis, thus reducing gastrointestinal tissue exposure to possible carcinogens.
It alters the metabolism of bile acids, decreasing gastrointestinal exposure to possible carcinogens.
It helps to prevent obesity which is related to a number of cancers.
Improved Recovery
Evidence also suggests that individuals who are engaging in physical activity and do have an unfortunate health event such as cancer set themselves up for improved outcomes. The simple act of participating in physical activity pays dividends when they need it the most.
There is strong evidence that moderate-intensity aerobic training and/or resistance exercise during and after cancer treatment can reduce anxiety, depressive symptoms, and fatigue and improve health-related quality of life and physical function.
There is also strong evidence that exercise training is safe in persons who have or might develop breast-cancer-related lymphedema.
Breast cancer: In a 2019 systematic review and meta-analysis of observational studies, breast cancer survivors who were the most physically active had a 42% lower risk of death from any cause and a 40% lower risk of death from breast cancer than those who were the least physically active.
Colorectal cancer: Evidence from multiple epidemiologic studies suggests that physical activity after a colorectal cancer diagnosis is associated with a 30% lower risk of death from colorectal cancer and a 38% lower risk of death from any cause.
Prostate cancer: Limited evidence from a few epidemiologic studies suggests that physical activity after a prostate cancer diagnosis is associated with a 33% lower risk of death from prostate cancer and a 45% lower risk of death from any cause.
Participating in Physical Activity, at levels that meet or exceed the recommended guidelines as stated recently by The U.S. Department of Health and Human Services Physical Activity Guidelines for Americans, 2nd edition, released in 2018, will have substantial health benefits and help to reduce the risk of chronic diseases, including cancer, adults engage in:
150 to 300 minutes of moderate-intensity aerobic activity,
75 to 100 minutes of vigorous aerobic activity, or an equivalent combination of each intensity each week. This physical activity can be done in episodes of any length.
Muscle-strengthening activities at least 2 days a week.
Balance training, in addition to aerobic and muscle-strengthening activity.
Setting yourself up for success is important. Yes, it can be difficult to remain engaged in physical activity especially in the dark cold winter, but it can be easier if you have accountability to friends, a coach or even a pet. It is not only you that suffers when cancer is present, it is your whole family that will be impacted.
Original Article Credit:
National Cancer Institute - Physical Activity and Cancer - Feb, 2020
https://www.cancer.gov/about-cancer/causes-prevention/risk/obesity/physical-activity-fact-sheet