What are walnuts?
Walnuts are a wrinkly, globe-like nut that is the fruit of the walnut tree. They grow in a hard shell, which when opened reveals the walnut. This is then split in two and hence you will be familiar with seeing them as flat segments. Walnuts are usually eaten raw or roasted.
Nutritional value of walnuts
Like all nuts, walnuts contain good fats, such as monounsaturated and polyunsaturated fats (PUFAs), but they are also a valuable vegetarian source of the essential fatty acid omega-3. They also contain iron, selenium, calcium, zinc, vitamin E and some B vitamins.
Learn more about vitamins, minerals and different types of fat.
Are walnuts good for the brain?
Walnuts contain important phytochemicals as well as high amounts of polyunsaturated fats which do offer potential benefits for both brain health and brain function. Omega-3 plays a part by helping to reduce oxidative stress in the brain, but also by helping to improve brain signalling and neurogenesis, which is the creation of neurons.
Demand for macadamia nuts outpaces the current supply”
As well as the good fats, other important nutrients such as vitamin E, folate and ellagic acid are all found in walnuts and also contribute to neuroprotection and memory function.
The Walnuts and Healthy Aging Study found that walnut consumption by healthy, elderly adults had little effect on cognitive function over two years, but it had greater effect on elderly adults who had smoked more and had a lower baseline neuropsychological test scores.
The study examined nearly 640 free-living elders in Loma Linda, California, USA, and in Barcelona, Catalonia, Spain. For two years, the test group included walnuts in their daily diet, and the control group abstained from walnuts.
Walnuts contain omega-3 fatty acids and polyphenols, which have previously been found to counteract oxidative stress and inflammation, both of which are drivers of cognitive decline.
Joan Sabaté, MD, DrPH, professor of nutrition and epidemiology at Loma Linda University School of Public Health and the study's principal investigator, said this was the largest and most well-controlled trial ever conducted on the effects of nuts on cognition.
'While this was a minor result, it could lead to better outcomes when conducted over longer periods of time,' Sabaté said. 'Further investigation is definitely warranted based on our findings, especially for disadvantaged populations, who may have the most to gain from incorporating walnuts and other nuts into their diet.'
Sabaté and his research team at Loma Linda University were the first to discover the cholesterol-lowering effect of nut consumption - specifically walnuts - with lowering blood cholesterol.
Subsequently, findings from Loma Linda University researchers have linked nut consumption to lower risk of cardiovascular diseases.
