Boosting Natural Killer Cell Activity

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

For disease prevention and health maintenance, “berries of all colors have emerged as champions.” Most of the work has focused on cancer prevention and treatment. Studies have shown that “the anticancer effects of [berries] are partially mediated through their abilities to counteract, reduce, and also repair damage resulting from oxidative stress and inflammation.” They may also boost detoxifying enzymes, and a bunch of other things.

But, this is new. The effects of “blueberry ingestion on natural killer cell counts.” Natural killer cells are part of our immune system’s rapid-response team against cancer cells, taking them out through the activation of cancer cell suicide via “death receptors.” They’re called natural killers, because they don’t require activation by prior exposure. You don’t want to have to wait until your second tumor before your immune system starts fighting.

We have about two billion of these soldiers circulating in our bloodstream at any one time, but we may be able to get a troop surge with blueberries. They had athletes eat about a cup-and-a-half a day for six weeks, to see if blueberries could reduce the oxidative stress of long-distance running. And, indeed, that’s what they saw. No surprise; a blunting of the spike in oxidative stress.

But, that’s not what sets this study apart. The number of natural killer cells in the blood typically decreases after prolonged endurance exercise, dropping by half, to only about one billion—unless you’ve been eating lots of blueberries, in which case you end up here, because six weeks of blueberries doubled the number of natural killer cells up to over four billion. This “has never…been demonstrated in humans consuming blueberries.” Well, no one’s ever looked before. There was a study done on goji berries, and despite a cup a day for a month, there was no significant change in the number of natural killer cells.

There was a study, though, that showed a significant increase in natural killer cell activity, thanks to the spice cardamom. Hmm, cardamom and blueberries—I never thought we’d be fighting cancer with blueberry muffins. But, check this out. You take some lymphoma cells in a petri dish, and you add cardamom, and nothing happens. If, however, you add some natural killers, then about 5% of the cancer cells are wiped out. But, then you add a little cardamom, and your troops do a little better. And, if you add more and more, and all of a sudden, same number of natural killer cells, but they’re now able to kill off ten times more cancer cells. And, remember, cardamom alone, even at the highest dose, had no effect on cancer cells. But, it really seemed to enhance our NK cells’ killer instincts.

The same thing found for black pepper. Black pepper alone; nothing. Add a little black pepper; no effect. But, with enough, there seemed to be a boosting effect; up around 30 or 40% cancer cell clearance. And if you add them both together, they appear to synergize, and kind of work even better together. Taken together, these data strongly suggest that black pepper and cardamom have the potential to markedly enhance the anticancer activity of natural killer cells.

And, then imagine if you had twice as many in your bloodstream, thanks to this study, brought to you by, of course, “the North American Blueberry Council and the North Carolina Blueberry Council.” But then, the last sentence is my favorite: “There were no conflicts of interest.”

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Image thanks to VancityAllie via flickr. Thanks to Ellen Reid for her image-finding expertise, and Jeff Thomas for his Keynote help.

• berries
• blueberries
• cancer
• cancer survival
• detoxification
• exercise
• fruit
• goji berries
• immune function
• industry influence
• inflammation
• oxidative stress
• pepper