Perhaps a very important piece of the great and complicated puzzle that represents the fight against Alzheimer's has been added. As evidenced by a very recent scientific research published a few days ago in the journal Science Advances by a Japanese team, diet influences, for better or for worse, the health of our brain (Sato et al, Science Advances, 2021). What we eat or, as we will see, also what we don't eat can pave the way for dementia and Alzheimer's. At the same time, this discovery also allows us to understand how to intervene to block neurodegeneration, but let's explore these very important results.
A protein deficiency paves the way for Alzheimer's
Japanese researchers started from the observation, which emerged thanks to other very recent studies, that the supply of proteins is essential for maintaining brain function as we age. Unfortunately, many elderly people, due to lack of appetite or chewing problems, follow a low-protein diet. Reduced protein intake has been observed to be associated with an increased risk of cognitive impairment and the development of Alzheimer's disease. However, the mechanism underlying this impairment of cognitive function was not yet well understood. Precisely to shed light on this aspect and to understand whether the integration of essential amino acids, the building blocks of proteins, can inhibit the neurodegeneration process, the Japanese scientists have developed the study we are talking about today.
Essential amino acids protect the brain
The research was carried out on mice and it was observed that, in the case of a low-protein diet, there was an acceleration of neurodegeneration but also poor connectivity between neurons. Instead, these conditions were reversed with the intake of a supplement consisting of 7 essential amino acids, which, as mentioned, are precisely the building blocks of proteins. This supplement, in particular, was able to inhibit neuronal death and neuroinflammation, although the accumulations of tau proteins, a hallmark of Alzheimer's, remained unchanged. This observation, however, is understood in the light of the most recent discoveries that have observed that aggregates of proteins and neuroinflammation must coexist for the development of Alzheimer's, by turning off neuroinflammation one of the two conditions necessary for the progression of Alzheimer's is eliminated. Then, the supplement was also able to improve neuronal connectivity. Finally, the supplement taken by healthy people and without neurodegeneration has improved cognitive function. The supplement is composed of the amino acids leucine, phenylananine, lysine, isoleucine, valine, histidine, and tryptophan. These amino acids are contained in some foods, such as some processed foods such as bresaola and raw ham, in chicken, but also in some cheeses such as parmesan, emmental, robiola and gruyere, tuna, anchovies, salmon, mackerel and cod, beans, chickpeas and peas, some cereals such as millet and spelt, nuts such as cashews, pine nuts, almonds, pistachios, walnuts, hazelnuts, pumpkin and sunflower seeds, cocoa powder, peanut butter, eggs and soy (Rondanelli et al, Front Nutr, 2020).
Other studies will follow to verify the beneficial action of this supplement in people with neurodegeneration and to understand its ability to prevent dementia. At the moment, waiting for science to take further steps on this fascinating and highly promising path, surely we can do a lot for the health of our brain even at the table. Ensuring a healthy and varied diet, which includes proteins, such as legumes, nuts and soy for those who have chosen a vegan diet, but also poultry, eggs and fish in other cases, is certainly a good choice for our future health.