Nuts and dried fruit, but not peanut butter, protect brain, kidney, lung and heart health
Walnuts, hazelnuts, almonds, cashew and peanuts, dried fruit is a tasty snack, capable of recharging energy and also providing important minerals, vitamins, antioxidants and fatty acids. Not only that, a daily intake of dried fruit is linked to a reduction in the risk of developing heart disease, cancer, infections, diseases of lung, liver and kidney and neurodegenerative illnesses such as Alzheimer's and Parkinson's. These beneficial effects, however, have not been observed for peanut butter that, although containing at least 90% of dried fruit, does not preserve its properties. All that is the result of several scientific studies published in recent months, such as the research that appeared in the journal Nutrients thanks to the work of an American team (Amba et al, Nutrients, 2019) or the research published by a Canadian and Spanish team in the American Journal of Clinical Nutrition (Sala Vila et al, Am J Clin Nutr, 2020).
In the study published in Nutrients, the researchers drew on the data relating to the health and diet of more than 500,000 people, recruited in a previous study that began in 1995 and ended in 2003. In particular, study participants were asked to indicate the frequency with which they had consumed nuts and other dried fruit in the previous twelve months and, in a separate question, also the amount of peanut butter. What emerged is that the consumption of walnuts is generally associated with a lower risk of developing cancer, cardiovascular diseases, illnesses of the respiratory tract, infections, kidney and liver diseases. However, the same protective effect on health was not observed with the consumption of peanut butter. A possible explanation offered by the study authors is that the peanut butter production process can impact the beneficial properties of the food. Not only that, it is also possible that peanuts alone do not guarantee all the healthy properties offered by the intake of dried fruit in general, walnuts, hazelnuts, almonds, cashews, capable of providing a wider range of nutrients.
Finally, as regards walnuts, it was possible to observe that their consumption, about 30 grams per day, in the long term, the Canadian and Spanish study considered a period of two years, also has a protective action on the brain, delaying the onset of cognitive decline in older and higher-risk people, such as smokers.