Walnuts

A Nut With the Power to Protect the Brain

WalnutsLiving up to their name, essential fatty acids (EFAs) are essential to your health. These nutrients perform a range of important functions to promote superior health and wellness. EFAs are best known for fighting inflammation in the body and supporting healthy levels of C-reactive protein, a marker of inflammation.

There are several types of EFAs, but omega-3s get the most attention… and for good reason. Along with their anti-inflammatory properties, omega-3 fatty acids have been shown to lubricate your joints and prevent arthritis, promote normal cholesterol levels and blood pressure (and, therefore, healthy heart function), prevent cancer, and protect your brain against degenerative diseases like dementia, Alzheimer’s disease and Parkinson’s disease.

It’s this last benefit — brain protection — where many scientists focus their attention.

Alzheimer’s disease remains one of the most dreaded conditions that affect us as we age. And the scariest part is that there is no cure, and still so little is understood about its development. But since omega-3s show so much promise in protecting the brain, a lot of research is focused on this nutrient’s potential in preventing and even treating Alzheimer’s disease.

In one such study, researchers at Tufts University in Boston wanted to examine the effects of walnuts — a nut rich in omega-3s — on the accumulation of polyubiquitinated proteins in the brain.[1] This substance is the hallmark of many age-related neurodegenerative diseases like Alzheimer’s, and it accumulates in our brains as we age.

In this study, researchers used 45 male rats, aged 19 months, and divided them equally into three diet groups: control, 6 percent walnut and 9 percent walnut. (They noted that the 6 percent walnut diet fed to the rats is equivalent to 1 oz. of walnuts per day for humans.) The animals were fed their diets for 15 weeks, then a sample size of five rats per group were euthanized and had their brains autopsied.

The researchers found that the 6 percent and 9 percent walnut diets both significantly reduced the accumulation of polyubiquitinated proteins.

Even better, the walnut diets seemed to activate a process called autophagy, which the researchers described as “a neuronal housekeeping function,” in the striatum and hippocampus areas of the brain. This process was more profound in the hippocampus, though, which is the region of the brain involved in memory and cognitive performance. The discovery of the autophagy in the walnut-eating groups was particularly exciting because as we age, this process slows down.

In addition to these physical changes in the brain, researchers found that both groups fed the walnut diets performed better than the control group in cognitive and motor tests. All this, and the walnut-eating rats did not gain any weight compared to the rats in the control group.

Go Nuts for Walnuts

Obviously, further research needs to be conducted to achieve more definitive results on the effects of walnuts on human brain health. But in the meantime, it doesn’t hurt one bit to add these healthy EFA-rich nuts to your diet.

It doesn’t take a lot of walnuts to equal the amount eaten by the rats in this study. Eating 1-1.5 oz. of raw, unsalted walnuts per day (which is about 14-20 shelled walnut halves) is all it takes to reap these potential brain protective benefits — and all the other advantages that come from consuming EFA-rich foods.

There are many ways you can enjoy walnuts:

  • Add them to a salad, oatmeal, pancakes, muffins or even a smoothie.
  • Crush them and use them to coat chicken or fish before sautéing or baking.
  • Stir them into yogurt or cottage cheese.
  • Grind them up and add them to meatloaf.
  • Simply eat them raw.

[1] Poulose SM, Bielinski DF and Shukitt-Hale B. Walnut diet reduces accumulation of polyubiquitinated proteins and inflammation in the brain of aged rats. J Nutr Biochem. 2012 Aug 20. [Epub ahead of print.]