Inside that hard shell, walnuts are packed with beneficial components such as antioxidants, omega-3 fatty acids, vitamins, protein, and fiber.1 According to the Prevención con Dieta Mediterránea, or PREDIMED, clinical trial, the long-term adoption of a Mediterranean diet, which consists of healthy foods like whole grains, fruits, vegetables and beans, with mixed nuts is linked to a 30% decreased risk of developing cardiovascular disease in high-risk individuals.2 But, can this superfood offer other advantages? Are walnuts good for brain health?
Long-term walnut consumption may improve memory
Using a smaller group of participants from the PREDIMED clinical trial, researchers looked at whether a Mediterranean diet supplemented with nuts may delay the decline in cognition that is observed in the aging population.2 People in this study were randomly separated into one of three diet plans that included a Mediterranean diet with olive oil, a Mediterranean diet with mixed nuts (30 grams), and a control diet that simply encouraged a decrease in dietary fat intake.2 The mixed nuts portion consisted of 15 grams of walnuts, 7.5 grams of hazelnuts, and 7.5 grams of almonds.2After about 5 years, the results of this study indicated that nut consumption, in combination with a Mediterranean diet, is associated with improved memory.2 In contrast, the control diet was associated with a significant decline in memory, which is an outcome that is generally a by-product of aging.2 Other studies have also reported that eating 1 to 2 ounces of walnuts each day may improve cognitive function and may prevent the progression of mild cognitive impairment.1
Antioxidant and anti-inflammatory effects of walnuts
Overall, various studies suggest that consuming walnuts may delay the onset of neurodegenerative conditions linked to memory problems such as Alzheimer’s disease and dementia.2 This is largely attributed to the antioxidant and anti-inflammatory effects of walnuts.1 Antioxidants found in walnuts include flavonoids, phenolic acids, melatonin, and vitamin E.1 Walnuts are also abundant in omega-3 fatty acids, particularly linolenic acid and linoleic acid, that work to reduce inflammation.1
Reducing oxidative stress and inflammation is important when it comes to preventing cognitive decline.3 This is due to the fact that aging disrupts the balance between free radicals and antioxidants, ultimately leading to the development of oxidative stress in the body.3 Oxidative stress, in turn, can trigger inflammation.3 Brain cells can die as a consequence, and this ultimately leads to problems with learning, decision making, and memory.3 Therefore, increasing the amount of antioxidant and anti-inflammatory mediators in the body, which can be done using dietary measures such as consuming walnuts on a regular basis, may confer neuroprotective benefits.2,3
Walnuts and the brain: Are walnuts good for brain health?
In addition to improving oxidative stress and inflammation, walnuts can counteract the loss of polyunsaturated fatty acids – particularly linolenic acid and linoleic acid – observed in the aging brain.3 Walnuts are also a source of melatonin and may therefore benefit people with a melatonin deficiency.3 In terms of brain health, regulating melatonin levels is important as a decrease is associated with the aggregation of proteins such as amyloid beta peptides, which is one of the hallmarks of Alzheimer’s disease.3
So, are walnuts good for brain health? The existing research suggests that – when eaten in moderation as a part of a healthy diet – they may be good for your brain. Walnuts contain beneficial antioxidants and anti-inflammatory compounds that are linked to an improvement in different brain functions, especially memory.1 This does not imply that walnut consumption can treat neurodegenerative diseases such as Alzheimer’s, only that it may contribute to a decreased risk. Please consult your healthcare provider to learn more about how a healthy diet may help you improve your brain health.
1. Chauhan A, Chauhan V. Beneficial effects of walnuts on cognition and brain health. Nutrients. 2020;12(2):1-10. doi:10.3390/nu12020550
2. Valls-Pedret C, Sala-Vila A, Serra-Mir M, et al. Mediterranean diet and age-related cognitive decline: A randomized clinical trial. JAMA Intern Med. 2015;175(7):1094-1103. doi:10.1001/jamainternmed.2015.1668
3. Poulose SM, Miller MG, Shukitt-Hale B. Role of walnuts inmaintaining brain health with Age. J Nutr. 2014;144(4):561-566. doi:10.3945/jn.113.184838
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