Being a health writer, I have a good grasp of how our immune system works.

I’ve written about it often, including how to know if your immune system isn’t working properly, how to slow immune system aging and how inflammation can turn your immune system harmful.

And when it comes to the involvement of blood cells, I’m quite familiar with the immune system’s first line of defense: white blood cells that help fight infection and disease, including “killer T cells” that help fight cancer.

However, there are more kinds of white blood cells than I’d known about. And not all of them are “good guys.”

In fact, some of them support the growth of cancer — but you’re not helpless to take them down…

Just 30 minutes can destroy cancer-causing cells

Tiia Koivula is a doctoral researcher at the University of Turku in Finland. She is the lead author of a study that alerted me to the fact that, while some white blood cells support our immune system and fight disease, just as many are busy promoting disease.

Including cancer.

“The balance of different types of white blood cells determines whether the immune system works to destroy cancer or to support it. If there are more cancer-destroying cells than cancer-promoting cells in the tumor area, the body is more capable of fighting cancer.”

Her study looked at twenty newly diagnosed breast cancer patients who had not yet started treatments.

During the study, these patients pedaled a stationary bicycle for 30 minutes. Three different blood samples were taken: before they started pedaling, during the exercise, and after they’d finished the exercise.

The blood samples showed that cancer-killing cytotoxic T cells and natural killer cells increased the most. On the other hand, the number of cancer-promoting regulatory T cells and myeloid-derived suppressor cells did not change.

The researchers also looked at the proportion of different types of white blood cells relative to the total white blood cell count. The proportion of natural killer cells increased significantly, while the proportion of myeloid-derived suppressor cells decreased.

But you might be wondering: do those new cancer-killing cells stick around?

“In this study, it was seen that the number of almost all white blood cell types decreased back to resting values one hour after the exercise,” says Koivula.

“With the current knowledge, we cannot say where the white blood cells go after the exercise, but in preclinical studies, cancer-destroying cells have been seen to migrate into the tumor area.”

The evidence for cancer-slaying exercise piles up

Exercise fighting cancer? It’s not nearly as farfetched as it seems…

Edith Cowan University showed that men with advanced prostate cancer could increase levels of proteins called myokines by engaging in six months of exercise training. Myokines suppress tumor growth and fight the growth of new cancer cells.

Even better, in a follow-up study of a similar group of men, those same anti-cancer molecules increased in a single bout of vigorous exercise.

But exercise shouldn’t be something we only turn to after a cancer diagnosis…

When researchers in Tel Aviv found high-intensity exercise starves cancer cells of glucose preventing spread or metastasis, they suggested regular exercise could provide permanent cancer protection because it changes the tissue of internal organs to become similar to muscle tissue.

That means exercise will make your organs burn glucose like muscles do leaving less fuel for glucose-loving cancer cells.

And it doesn’t end there…

A team of scientists from The MD Anderson Cancer Center pitted exercise against a genetic cancer predisposition known as Lynch Syndrome — and found it resulted in statistically significant changes in gene expression. That’s epigenetics at work!

So the Finnish study isn’t really that much of a leap.

It’s just the latest in a growing collection of data pointing to the importance of regular exercise to avoid or beat cancer.

Sources:

Already 30 minutes of exercise increases the proportion of tumor-killing white blood cells in blood — Eureka Alert

The effect of exercise and disease status on mobilization of anti-tumorigenic and pro-tumorigenic immune cells in women with breast cancer — Frontiers