Cancer can be exacerbated by inflammation and exercise is known to cause inflammation. So shouldn’t exercise make cancer worse? On the contrary, it seems to make it better, but why?
It turns out that in studies they have found that people who regularly exercise and less likely to get cancer and if they have cancer, they are less likely to die.
Pumped Up Mice Have Clues
A recent study has noted that in mice who exercise changes take place including a raised level of insulin, and increases in specific chemicals and immune cells. It is thought that the combination of these can help prevent cancer or ameliorate its effects.
They injected a group of mice with melanoma cancer cells and gave half of them running wheels and the other half no wheel. After only 4 weeks there some stark differences between the two groups. Many more of the non-runners had developed melanoma in this time. In addition, they more lesions and larger lesions than the runners who had developed melanoma. Plus, they were more likely to have metastases.
Adrenaline & Interleukin-6
Adrenaline is produced as a response to stress, including exercise. It was found at higher levels in the runners not just after exercise but throughout the day. The runners also had higher levels of Interleukin-6 than the sedentary mice. IL-6 is a bit odd in that it can raise or lower inflammation based on where in the body and how it starts to work.
Natural Killer Cells
Natural Killer cells (NK cells) were also found at much higher levels in the blood stream of the runners and this might be most important of all because these potent fighters of cancer.
Adrenaline a Key to a Cascade of Effects
The scientists repeated the experiment with a twist. They injected some of the runners with a chemical that blocked adrenaline production and these runners developed cancer at the same rate as the sedentary mice.
They also gave some of the sedentary mice shots of adrenaline to raise their levels to near those of the runners. These mice developed much less cancer than other sedentary mice.
The scientists looked at how certain genes in the mice were working and found that the adrenaline was signaling the IL-6 cells. It was kind of a wake up call putting them at greater attention. The cells were then more responsive so that when cancer began to form they created a faster and larger response by activating the NK cells in the bloodstream.
Since the runners have more adrenaline, IL-6 and NK cells, they were able to combat the melanoma faster and better than the sedentary mice.
Get Some Exercise
There is no guarantee that the effect will be the same in people but it is known that exercise in people also increases adrenaline and NK cells. So it would be a good idea to make sure you get more exercise.