The Impressive Anti-Cancer Power of Berries

Image Credit: Stein Lauritsen / Flickr. This image has been modified.

Boosting Anticancer Immunity with Berries

For disease prevention and health maintenance, berries of all colors have “emerged as champions.” Research has focused mainly on cancer prevention and treatment. Studies show 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. Berries may also have many other positive effects, such as boosting detoxifying enzymes.

One of the more remarkable effects is that of blueberries on natural killer cell counts. Natural killer cells are part of our immune system’s rapid response team against cancer cells, eliminating cancer cells through the activation of cancer cell suicide via death receptors. They’re called natural killers because they don’t require activation by prior exposure. We don’t want to wait until our second tumor before our immune system starts fighting.

We have about two billion of these soldiers circulating in our blood stream at any one time, but we may be able to get a troop surge with blueberries. Researchers had athletes eat about a cup and a half of blueberries a day for six weeks to see if that would reduce the oxidative stress of long-distance running. They indeed saw a blunting of the spike in oxidant stress. But that’s not what sets that 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—that is, unless we’ve been eating lots of blueberries. In the video, Boosting Natural Killer Cell Activity,  you can see a graph comparing natural killer cell numbers with and without blueberries.  Those who ate blueberries retained close to the standard two billion cells. This is because six weeks of blueberries had doubled the resting number of natural killer cells up to over four billion. This has never before been demonstrated in humans. There was a study on goji berries, but despite a cup a day for a month, there was no significant change in the number of natural killers.

Another study, though, showed a significant increase in natural killer cell activity thanks to the spice cardamom. (Cardamom and blueberries—I never thought we’d be fighting cancer with blueberry muffins!) When researchers took some lymphoma cells in a petri dish and added cardamom, nothing happened. However, if we add some natural killer cells, about 5% of the cancer cells are wiped out. Add a little more cardamom, and our troops do better still. And then if we add more and more spice, then all of a sudden the natural killer cells are killing cancer like crazy—the same number of natural killer cells, but they’re now able to kill off ten times more cancer cells. While cardamom alone had no effect on cancer cells even at the highest dose, it seemed to enhance our natural killer cells’ killer instincts.

The same thing was found for black pepper: Black pepper alone, nothing, but when combined with natural killer cells, there seemed to be a boosting effect up to around 30 or 40% cancer cell clearance. If cardamom and black pepper are combined, they synergize and their individual effects are doubled. The researchers conclude that “Taken together, these data strongly suggest that black pepper and cardamom have the potential to markedly enhance the anti-cancer activity of natural killer cells.”

Exercise itself can improve immune function in general (See Preserving Immune Function in Athletes With Nutritional Yeast), but the blueberry finding, so far, is unique. The oxidative stress part of the story is told in Reducing Muscle Soreness With Berries.

It is true that the blueberry study was funded by the North American Blueberry Council and the North Carolina High-bush Blueberry Council. However, just because the study was funded by blueberry councils doesn’t necessarily mean the science is suspect, but we would want to see the study independently verified, especially one so dramatic.

What else can berries do? Check out:

You can check also out my blueberry smoothie recipe here in A Better Breakfast.

-Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my videos for free by clicking here and watch my full 2012 – 2015 presentations Uprooting the Leading Causes of Death, More than an Apple a Day, From Table to Able, and Food as Medicine.


Michael Greger M.D., FACLM

Michael Greger, M.D. FACLM, is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous "meat defamation" trial.

31 responses to “Boosting Anticancer Immunity with Berries

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  1. How much blueberries would need to be consumed to have these effects. I think it’s premature to emphasize the benefits if quantity of blueberry consumption is unrealistic

    1. Dr. Greger recommends one cup a day and the book “Super Foods, Fourteen Foods That WIll Change Your Life<" by Steven Pratt and Kathy Matthews recommends one to two cups a day. Raisins and dried fruit do count. Juice is evidently too filtered and canning damages the phytonutrients. Eating this many berries can make your brain two years younger. This amount of berries could be expensive, as alluded to by Ariel, and not always available, so considered dried.

  2. Cardamom and black pepper … That’s in the recipe for chai tea! (plus cinnamon, ginger and cloves). Does it get any better than that!?

  3. Adding berries is a great way to fight cancer. It just takes a cup to a cup and a half a day. Even Golden raisins or grapes count. There are dried berries packs on the internet, like this one on Amazon. I thinking a cup of blueberries a day is very healthy way to find health. To get berries, you could buy frozen or dried as said below. A cup of berries a day can make your brain two years younger. I wish fresh berries were always available. One cup of Chai Tea has many of the spices listed here.

      1. Hello! I saw it right here on this site in the video “How to slow brain aging by two years.: “In other words, women with higher intake of berries appeared to have delayed cognitive aging by as much as 2.5 years.”
        In this study he cites this report,
        “These findings suggest that, in addition to their known beneficial effects on cancer and heart disease, phytochemicals present in antioxidant-rich foods may be beneficial in reversing the course of neuronal and behavioral aging.”
        In the abstract of this report:
        J. A. Joseph, B. Shukitt-Hale, N. A. Denisova, D. Bielinski, A. Martin, J. J. McEwen, P. C. Bickford. Reversals of age-related declines in neuronal signal transduction, cognitive, and motor behavioral deficits with blueberry, spinach, or strawberry dietary supplementation. J. Neurosci. 1999 19(18):8114 – 8121.

        Thank you,

          1. Happy Holidays! Thank you very much! I can’t wait to read Dr. Greger’s book on how to add life through nutrition. This diet can bring youth to hundreds of thousands of people. I am glad you are one of them!

  4. I would love to eat all these berries, but I have diverticular disease. I cannot eat them because of the seeds. This is especially true of blueberries because the seeds are sharp. They are of particular risk to me. Does anyone have any idea how I could process blueberries to ingest them without any seeds? Thanks and Merry Christmas all!

    1. I, too wish seedless jam had all the health benefits of the fresh fruit. Evidently, cooking it is bad for the phytonutrients. Trader Joes sells whole pure blueberry juice, if it helps.

    2. first off, fix your epithelial cell issue inside intestional channel.
      start with researching naturopathic approaches because my understanding of how I reversed mine is by focusing on high fiber only, multiple daily movements, increased motility and bulk, and most important of all: years of very concentrated (expensive) daily supplementation of probiotics and increase of food-delivered probiotics, in addition to multiple herbal capsules known to cure colorectal issues. It is a matter of getting to the cause of DV, not bandage solutions which fail to address the underlying systems which are not working properly. I cured multiple GI cancers in CR, IBS, Colitis, and sensitivity to everything to the point of not being able to handle any food. After a year of concentrated effort and throwing every penny I could into the problem, and a lot of self-discipline in what I buy and consume, I totally reversed my colon function to closer to normal. Now have almost no GI symptoms ever – you can do it too. Think independently, do your own research, have a plan, be critical in terms of what you read, and exercise the courage to do things differently. Einstein: Insanity is doing the same things over and over, expecting different results. Change everything from the ground up, heal from the beginning of it all, and take your mind and effort off of relieving symptoms.

    3. Eat your berries! Here’s a large cohort showing that people with diverticular disease were able to consume foods like nuts, seeds and popcorn without complications ( There isn’t any research to back up the dated recommendation to avoid these foods. In fact, these high fiber foods have been shown to reduce the risk of developing diverticulosis/itis disease in the first place. Check out Dr. Greger’s video on the matter:

  5. There are so many more berries to consider than blueberries, acai, etc., which are over-studied, over-discussed, and over-marketed. The main issue is that they are also more often not the most cost-effective delivery package for a given nutrient or medicinal component desired. The typically more therapeutic berries, which so often give a far greater ROI – Return on Investment, than blueberries, can be added to smoothies, encapsulized, sprinkled/stirred into foods, made into poultices, teas,”candies,” jellies, etc. Of course we have to vet their source identity and safety, figure out appropriate dosages for our bodies and needs and budget, and develop our ability to know how to read our body’s reaction to every new introduction. How long did it take for us to adopt blueberries as a goal for daily consumption? Too long. Berries you can grow, purchase, or wild-harvest, which you might want to begin learning about and experimenting with include: Hawthorn, Elder, Marqui, Acerola, Schisandra, Saw Palmetto, Bilberry, Sea Buckthorn, Gogi, Aronia, Camu Camu, Amla, Lingonberry, Yumberry. The list is huge as to what you and I can locate and safely purchase, grow in our yard, wild-harvest on a nature walk, and then learn to incorporate into our daily diet. The potential impact of these lesser known berries far outweigh the importance of remembering to budget and buy blueberries. When you get around to comparing the phytonutrient content of the marginalized or forgotten but readily available more medicinal berries, you can prove to your self that the habit you wish to cultivate is researching what is not being sold to you every time you log on to the Internet to read another re-hashed story about blueberries or the other so-called superfruit. Berries as a category is so much more than the Big Three – Blueberries, Strawberries, Black/Raspberries and it it time to bring the lesser promoted ones into the light. In the end, it is simply one of cost-effectiveness. The rest of this century will be about cost-effective eating….eating for longevity and prevention means we need to ask the question of ROI.

    1. You have done great research to condense so long a list of super berries! I was using the list of berries from the Republic of Tea for that, Acai, Pomegrante, Goji, Cherry Acerola, Blueberry, Black Raspberry, and Sea Buckthorn. Your list will help a lot of people. Dr. Greger has some videos on this topic:

      Links at this link:

      Eating healthy on a budget
      Eating Healthy on the Cheap
      Biggest Nutrition Bang for Your Buck
      Cheapest Source of Vitamin B12
      The Effect of Canned Tuna on Future Wages
      Are Goji Berries Good for You?
      Superfood Bargains

      He said that purple cabbage, cinnamon, and cloves are the best antioxidant bargain. According to him, the most powerful berry is amla, followed by rose hips or dog rose. To get antioxidants cheaply, he recommends oregano sprinkles or ground flax seed powder or cloves. A single cup of Chai tea has three days worth of antioxidants (maybe because of the cloves). One cup of green rooibos may have many more according to another site, but he has not tested this. The healthiest berry, between alma or dog rose or rose hips.

      He ranks berries in this site:

      “we can get more than twice the bang for our buck choosing blackberries, for example, over strawberries.”

      I am also interested in the healthiest super berry. Is it dragon wood blood bark? Chris Kilham has a list of some of the super berries here:

      From your list, Hawthorn, Elder, Marqui, Acerola, Schisandra, Saw Palmetto, Bilberry, Sea Buckthorn, Gogi, Aronia, Camu Camu, Amla, Lingonberry, Yumberry, what do you eat the most of? What is the best? Maybe we could test this list for what is the cheapest and the best. How do you get the most of these berries knowing that they are different? Dr. Greger has said he likes pomegrante juice for this purpose in part. Have you heard of Jiaogulan? It is evidently the most adaptagenic (stress relieving) plant we know of.

      Thank you!

    2. This is a wonderful list of commercially unavailable, nutritionally dense berries, some native or naturalized and possible to forage, others really easy to grow. If you live in the western US, Raintree Nursery has a wonderful catalog of bare-root mailable “unusual” berry plants including elder, bilberry, gogi, aronia, lingonberry, huckleberry and black currant. Some of these make handsome, fairly carefree “foundation” plants. I grow blueberries, blackberries and european black currants in a fairly small space. They come ripe over a fairly short season and are easy to freeze and store. They’re one of the most successful parts of my food garden. Give it a try!

        1. Thanks, Toxins. These berries are so interesting. The “whortleberry” comprises several species of Vacciniums, including V myrtillus, the bilberry or European blueberry, and V vitus-idaea, the lingonberry. They’re closely related to our American blueberry, V cyanococcus. All far northern hemisphere (is that paleoarctic?) northern US, Scandinavia, Scotland, Russia, Siberia. I wouldn’t be surprised if whortleberries outrank our blueberries only because ours have been domesticated–bred for large size, sweetness, resistance to disease/pests, etc.
          Rowanberries are even more interesting–magical, mythical, druidic trees in Scotland, Sorbus aucuparia, producing a fairly inedible berry that persists on the trees thru freezing winters and are thus available in the hunger times of the year. (Reputed to taste better at the end of the winter too.) Their seeds, like many rose family plants, are reputed to contain cyanide. The birds must not eat them. They’re mountain ash trees–there are a lot of Sorbus species in North America too.

            1. Hi Toxins–I like your name–it feels strange to be addressing Toxins!
              I didn’t forget the Indian gooseberry–I just can’t grow it, here in the very rainy Pacific Northwest–very sad. Wrong climate so I don’t know very much about it. I actually have high blood glucose, so I’ve tried dried amla powder but I didn’t see much of an effect. Maybe I should try again.

    1. Ideally organic. But otherwise get what you can. Brands wise? Just do a search on the interwebz to find suppliers; some health food shops buy in bulk from importers and repackage into smaller amounts to sell.

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