Yum! Nuts come in so many varieties, macadamias, walnuts, pecans, Brazil nuts, hazelnuts, cashews, and the “nut” that’s actually a legume, the peanut. Whether you prefer a small handful of walnuts or a serving of almonds, they all have health benefits. Most of the health benefits you read about regarding nuts pertain to their heart health benefits. However, nuts are also a brain healthy snack and we should all be concerned about protecting our brains against aging.
Unfortunately, your brain ages along with the rest of your body. For example, as you grow older, your brain shrinks in size a bit, especially a region called the hippocampus, a portion of your brain involved in verbal memory and spatial orientation. Although you likely have more wisdom at age 70 than you had at age 20, you may have more problems remembering names of people you haven’t seen in a while and you may not process information as quickly. That doesn’t mean you have Alzheimer’s disease, just that your brain doesn’t retrieve the names of people and places as quickly as it once did.
Fortunately, diet and lifestyle have a big impact on the aging brain. We know that aerobic exercise and eating a healthy, whole foods diet benefits your brain more than devouring fast food and sugar-sweetened beverages on a regular basis. Certain foods also seem to be advantageous for the brain. As mentioned, nuts are one of these foods. There are several ways that nuts may benefit your brain. Let’s look at them.
The Anti-Inflammatory Effects of Nuts
Inflammation is the enemy of healthy cells, including healthy brain cells. Inflammation plays a role in a variety of chronic diseases and is a factor in brain aging as well. In fact, studies show the aging brain is marked by changes in the function of mitochondria, the energy producers of cells as well as inflammation. You also see these changes in Alzheimer’s disease.
What does this have to do with munching on nuts? Research shows that nuts reduce IL-6 and C-reactive protein, two markers of inflammation. Although all nuts offer these benefits including peanuts (actually a legume), peanut butter did not. This may be because some brands of peanut butter contain trans-fat, a type of fat that fuels inflammation. Nuts are also a component of the Mediterranean diet, a diet linked with a lower risk of cardiovascular disease and, possibly, Alzheimer’s disease.
Some Nuts Are Rich in Healthy Fats
We now know that fats are not to be feared, but the emphasis should be on consuming healthy fats. Macadamia nuts are highest in monounsaturated fats, a class of fats linked with a reduction in inflammation. Walnuts are also rich in omega-3s, a type of fat that also helps suppress inflammation. Plus, omega-3s are highly concentrated in the brain where they are incorporated into cell membranes to help them stay fluid. In fact, 8% of the brain’s volume is omega-3 fats. That means they’re important!
Some studies also link omega-3s with increased brain volume. As you know, the aging brain loses volume, and getting more dietary omega-3s may help slow loss of brain size, although more research is needed. Walnuts contain a short-chain form of omega-3, in contrast to the longer-chain forms you find in fatty fish. Some research suggests that the long-chain forms may be more beneficial than the short-chain variety. However, walnuts are rich in antioxidants as well, another way in which they may suppress brain-related inflammation and aging.
Lower Stroke Risk
Stroke is one of the most common causes of loss of brain function and it usually involves a portion of the brain. Strokes happen when a blood vessel that supplies blood and oxygen to the brain is blocked by a ruptured plaque or blood clot. Another less common type of stroke is a hemorrhagic stroke where a blood vessel ruptures. The portion of the brain that the affected blood vessel supplies is deprived of oxygen and it dies.
The good news? Research shows nut eaters enjoy a lower risk of stroke. Plus, some nuts, including walnuts and pistachios, improve endothelial function, the ability of blood vessels to relax and allow blood to flow more easily through the vessel. Improved endothelial function helps lower blood pressure too.
Healthier Body Composition
It’s true that nuts are high in calories but studies actually show that nut eaters tend to be lower in body weight and have a healthier body composition. Maybe it’s because nuts lovers eat fewer sugary snacks that are likely to promote weight gain or because nuts are high in fiber and protein and help to reign in appetite. Nevertheless, nuts are favorable for metabolic health and don’t cause a rapid rise in blood sugar or insulin. In fact, eating nuts may actually be protective against developing metabolic syndrome and type 2 diabetes – and that’s favorable for brain health and brain aging. Anything that helps reign in obesity likely slows brain aging. Don’t forget, body fat produces inflammatory cytokines that can damage cells and tissues, including the brain.
The Bottom Line
Nuts are a brain healthy snack and exert their benefits in a variety of ways. You can enjoy the benefits by consuming a handful of your favorite nuts daily. Although they all have health benefits, walnuts and pecans top the list in terms of antioxidant power. Plus, walnuts are the richest in omega-3s. No wonder walnuts are shaped like a brain! However, nuts should be part of an overall healthy diet of whole, unprocessed food to help keep your brain its healthiest. So, eat an anti-inflammatory diet rich in whole foods – but make sure you add nuts to the mix.
References:
Nature.com. “Nut intake and stroke risk: A dose-response meta-analysis of prospective cohort studies”
Free Radical Biology and Medicine Volume 100, November 2016, Pages 108-122
Asia Pac J Clin Nutr. 2008;17 Suppl 1:333-6.
The FASEB Journal vol. 30 no. 1 Supplement 296.5. April 2016.
Nutr Metab Cardiovasc Dis. 2011 Jun;21 Suppl 1:S40-5. doi: 10.1016/j.numecd.2010.11.005. Epub 2011 Jan 8.
Cochrane. “Mediterranean diet for the prevention of cardiovascular disease”
Scienceline.” Can a diet prevent Alzheimer’s Disease?”
Mayo Clinic. “Alzheimer’s: Can a Mediterranean diet lower my risk?”