Lower risk of many cancers with more exercise

Exercise is well known for helping lower and protect our risk of many chronic conditions such as heart disease, type 2 diabetes, and depression and now it looks definitive that the risk of cancer is one more disease to be added to this list.

A huge study of 1.44 million participants from the United States and Europe ranging in age from 19-98 showed an association of leisure-time activities lowering the risks of 13 different types of cancer.  The May 2016 study featured in JAMA Internal Medicine emphasized that most of the associations were evident regardless of body size or smoking history. 

Researchers found that participants who got in the most moderate to intense exercise reduced their risk of seven out of the 13 cancers by at least 20 percent or more.

It has been known for a long time from previous studies that being physically active can help reduce the risk of colon, breast, and endometrial cancers.  What was not conclusive was whether increased exercise was considered a strong predictor of reducing risk of other types of cancer due to small numbers of participants in past studies. 

The study sought out to answer the question of what cancers were associated with leisure time physical activity and whether associations varied by excess body-weight and smoking.  A total of 26 different types of cancers were looked at in this study.  Participants were followed for a median of 11 years during which 187,000 new cases of cancer occurred.  Because of the high number of study participants, it is believed to be the largest ever conducted on physical activity and cancer risk.

What was found was that those who were physically active the most had an overall lower risk of 13 cancers including a 42 percent lower risk of esophageal cancer, 27 percent lower risk of liver cancer, and a 26 percent lower risk of lung cancer. 

Why does exercise appear to have such a strong role in helping reduce the incidence of many different types of cancer?  It appears to lower cancer by directly affecting the growth of new tumors.  In the case for breast and endometrial cancers, exercise lowers levels of the hormone estrogen decreasing their risk.  In addition, physical activity uses up excess blood glucose helping to better regulate insulin and exercise appears to lower inflammation. 

Participants in this study reported their physical activity in many ways but to standardize them and to rank them in duration and intensity, the participants were given a score between zero and 100. 

The median was considered the point at which 50 percent did more exercise and 50 percent did less, which was the equivalent of 150 minutes of moderate-intensity exercise such as walking per week.  The greater the intensity of the workout, the more the cancer rates dropped.  Basically, those who worked out longer and put in more effort saw better improvement of lower cancer rates. 

The takeaway from this study does indeed point to the necessity of getting and remaining physically active over a lifetime in order to help reduce the risk of many types of cancer.  The problem is how to help the average individual determine what exercise is best for them, how to get started and what about if they have physical limitations preventing them from being very physically active. 

Many individuals have limitations on what they can do for exercise. For instance, a person with osteoarthritis in the knees or hips, or someone with neuropathy causing pain in their feet, how do they develop an exercise plan?  Some suggestions could be instead of walking, try using a stationary bike.  Water aerobics or water walking can be another viable option that challenges a person physically yet is easy on their joints or feet.  Lifting weights is another physical activity to be considered and can be done in a seated position for those who are unable to stand for long periods of time.  Working with a personal trainer to develop an appropriate, individualized exercise program is a worthwhile investment. 

The more individuals can be helped to come up with ideas on becoming and staying physically active, the healthier of a society we will be and the less cancer diagnoses will be made.