Take Chlorella to Boost Natural Killer Cell Activity?

Written by: Michael Greger M.D.

Multiple studies published over the last few decades suggest that exercise can mitigate the decline in immune function as we age. Exercising can boost the activity of natural killer cells, our immune soldiers that focus on eliminating both tumor cells and virus-infected cells.

In my video, Treating Hepatits C with Chlorella, you can see the clear difference in natural killer cell activity between women involved in athletic competitions and their sedentary counterparts. There is a growing consensus that natural killers appear to be the immune system component that is most responsive to the exercise across the board, in populations ranging from older women to younger men. Even just moderate exercise, such as daily walking, appears to significantly improve natural killer cell activity within six weeks. This may be why exercise helps protect against cancer.

On the other hand, sustained, vigorous exercise may actually impair natural killer cell immunity, which may be one reason endurance athletes like marathon runners appear more likely to get upper respiratory tract infections. But could there be a natural solution?

Petri dish and animal studies have suggested that the green algae chlorella can affect natural killer cell activity. However, there was no direct evidence for the effect of chlorella supplementation in humans, until a South Korean randomized double-blind placebo controlled trialgave subjects about two teaspoons of chlorella a day for eight weeks. Compared to placebo, those getting chlorella had a significant increase in natural killer cell activity.