positive co-relation between exercise and cancer

In wake of ‘World cancer day’ marked on 4th Feb here we are creating more awareness to keep the cancer away.

We have already spoken about co-relation between Obesity & Cancer. How Obesity increases risk of cancer? in our previous blogs.

So today let’s look at Positive co-relation between Exercise & Cancer risk reduction.

There is strong evidence that higher levels of physical activity are linked to lower risk of several types of cancer.

What is Physical activity?

Physical activity is defined as any movement that uses skeletal muscles and requires more energy than resting. Physical activity can include walking, running, dancing, biking, swimming, performing household chores, exercising, and engaging in sports activities.

Light-intensity activities expend less than 3 METs, moderate-intensity activities expend 3 to 6 METs, and vigorous activities expend 6 or more METs. One MET [metabolic equivalent of task] is the rate of energy expended by a person sitting at rest.

What is the evidence ?

• Studies that follow large groups of people over time show that individuals who exercise regularly appear to have a lower risk of developing colon cancer. Although we do not know for sure that exercise itself is lowering the cancer risk, people who exercise regularly have a 40% to 50% lower risk of colon cancer, compared with those who don’t exercise regularly. 
• Similar large, long-term studies show that women who engage in moderate to vigorous exercise for more than 3 hours per week have a 30% to 40% lower risk of breast cancer. This applies to all women, regardless of family history or risk of breast cancer.

A new study from Tel Aviv University analysed the impact of exercise, and in particular HIIT exercises, such as high knees, burpees, jumping jacks etc , on the cancer:

Around 3000 cancer-free individuals were followed for 20 years. 10% of these individuals developed cancer over time.

Those who exercised, especially HIIT, had 72% less metastatic cancer growth compared to those who didn’t exercise at all.

• Similarly many meta-analysis of cohort studies and case-control studies have shown, large % reduced risk of cancer as follows

Bladder cancer 13% lower risk

Breast cancer 12-21% lower risk

Colon cancer 19% lower risk

Endometrial cancer (cancer of the lining of the uterus) 20% lower risk

Oesophageal cancer 21% lower risk

Kidney (renal cell) cancer 12% lower risk

Stomach (gastric) cancer 19% lower risk

• For several other cancers, there is more limited evidence of an association and the research is still on. These include certain cancers of the blood, as well as cancers of the lungs, pancreas, prostate, ovaries, thyroid, liver, and rectum.

How does it work?

• High intensity exercise gets its energy mainly from glucose. Intense exercise causes our internal organs to need and absorb more glucose, removing it from circulation. This deprives highly metastatic tumours of glucose, which can help reduce the tumour size and even prevent cancer from spreading to other parts of the body.
• Exercise helps you maintain a healthy weight. Being overweight or obese is linked to 13 different types of cancer.
• Physical activity  helps regulate your hormones. Increased levels of some hormones can increase your cancer risk.
• It supports healthy digestion and may reduce the number of toxins in your body.

Key Points

Exercise reprograms our organs to absorb more glucose, making it less available to the growing tumour and thus helping reduce the spread of cancer through the body.

The effect was greater with high- intensity exercise, defined in this study as 75% or more of maximum heart rate.

Major Conclusions

It is still unknown how long this effect lasts, so it is necessary to continue research. Exercise is the best thing you can do for your health.