Inflammation and free radical damage have been linked with virtually every disease plaguing the modern world. Whether you are talking about cancer, Alzheimer’s, heart disease, arthritis, and even diabetes, rampant inflammation and/or oxidation are likely playing large roles in either the cause or worsening of the condition.
Given this, it’s no surprise that there are dozens of prescription and over-the-counter drugs aimed at reducing inflammation and protecting your body from free radical damage. However, they have also been known to do a little damage themselves, with side effects ranging in severity from mild nausea and diarrhea to liver damage, kidney failure and congestive heart failure.
In an effort to avoid the dangerous consequences of these medications, yet still offer some sort of solution for reducing inflammation and oxidation, researchers have looked to the natural world for answers. And there, they have found berries. Blueberries to be exact.
Fight Back With Blueberries
While several animal studies have shown that blueberries can prevent oxidative stress as well as inflammation, very little has been done in humans. To learn if blueberries would have the same effect in people, researchers recruited 25 athletes (you’ll see why in a minute) and divided them into two groups. They were both tested for heart rate, body composition and training protocols, and asked to avoid all supplements and anti-inflammatory medication for the duration of the study. They were also asked to abstain from foods high in vitamins C and E.
Next, one group was told to continue training and following their usual diet for six weeks. The other group was told to do the same, but to also add in 250 grams of blueberries (just under two cups) every day for six weeks.
At the end of the study period, participants returned to the lab. All subjects had blood drawn and a muscle biopsy taken at that time. The blueberry group was then asked to consume 375 grams of blueberries (just over 2 1/2 cups).
One hour later, both groups completed a fairly strenuous 2.5-hour run on a treadmill. (This is why the researchers needed to recruit athletes.) Exercise this intense often increases oxidative stress and inflammation, making it a great way to simulate and test these effects in the body.
Immediately after they finished the run, participants had a second blood sample taken, as well as another muscle biopsy. Finally, one hour after they finished the run, the subjects had a third blood sample taken.
With the blood samples and muscle biopsies, researchers were looking for several markers of oxidative stress, inflammation and antioxidant activity, including:
- F2-isoprostanes (oxidation)
- Ferric reducing antioxidant potential
- Interleukin-6, -8 and -10 (inflammation)
- Natural killer cells (inflammation/immune response)
- T-cells and B-cells (inflammation/immune response)
Blueberries to the Rescue
Researchers found that F2-isoprostanes increased 129 percent in the control group immediately after exercise, but only 55 percent in the blueberry group. This indicates that the blueberries offered protection against oxidation.
They also found that the blueberry group had greater natural killer cell activity in all three blood draws, with levels being 96 percent, 122 percent and 76 percent greater than the control group for the same blood draws.
That’s nearly twice the levels before exercise and throughout the exercise for the blueberry groups as compared to the control group. This shows that the blueberries helped to reduce inflammation, particularly when consumed immediately before stressing the body with exercise.
There was also a significant increase in interleukin-10 in the blueberry group immediately following the exercise as compared to the control group. This also indicates anti-inflammation benefits.
All other markers were not statistically or significantly different between the groups.
While researcher do acknowledge that it may have been helpful to have taken a baseline reading of all participants to determine their status of these various markers prior to blueberry consumption, they felt that the similarities in the participants, as well as the fact that they were randomized into their respective groups makes it unlikely that some outside factor other than the blueberry consumption is responsible for their results.
Therefore, they concluded, “Daily blueberry consumption for six weeks increases [natural killer] cell counts and acute ingestion reduces oxidative stress and increases anti-inflammatory cytokines.” Or, more directly, eating blueberries every day protects you from inflammation and free radical damage.
A Delicious Alternative to Medication
Now there’s a recommendation I can get behind! And here are a few novel ways to incorporate blueberries into your diet:
- Toss them into a salad with a little goat cheese and sliced almonds.
- Blend with coconut yogurt, flaxseed, fresh spinach and a bit of water for a nutrient-packed smoothie.
- Place frozen berries in high-speed blender with water and a touch of powdered stevia for instant sorbet.
- Make a delicious chutney or sauce and serve with chicken or beef.
- Crush and add to mineral water for a healthy, alcohol-free cocktail.
Whether you get inventive or simply pop them into your mouth au natural, ask yourself, did you get your two cups of blueberries today? Check. And did you lower your risk for oxidation and inflammation? Check again.
 McAnuity, LS et al. Effect of blueberry ingestion on natural killer cell counts, oxidative stress, and inflammation prior to and after 2.5 h of running. App Physiol Nutr Metab. 2011 Dec;36(6):976-84.