More and more scientific studies are highlighting that dietary habits and lifestyle may play a pivotal role on the health of the body and mind. This is good news since it means that we have several tools that we can use to guarantee to us a long and healthy life. Exactly to demonstrate that diet may influence the functioning of the brain a study was published a few days ago on the prestigious journal Nature by a team of the Weill Cornell Medicine, New York (Faraco et al, Oct 2019). The study has observed that a low intake of salt from diet may contribute to keep healthy the blood vessels and to reduce the risk of developing dementia.
The scientists have observed, indeed, that a diet characterized by a high intake of salt causes the cells of the intestine to release a molecule, the interleukin-17, or IL-17 that is pro inflammatory. IL-17 enters the bloodstream and prevents the cells of the blood vessels from producing nitric oxide. Nitric oxide regulates blood flow since it acts by relaxing and widening the vessels. On the contrary, lower amounts of nitric oxide, as happens in a high salt diet, restrict the blood vessels thus causing also less blood to the brain. But scientists have also observed that the mechanism is even more complex and doesn’t just involve a lower blood flow. In fact, in case of a lower production of nitric oxide, the stability of tau proteins is altered. Tau proteins form paths to bring the nutrients to the neurons. As a consequence of a decrease of nitric oxide, the tau proteins don’t work anymore and accumulate in the brain causing cognitive problems and opening the way to dementia. The accumulation of tau protein in the brain is also implicated in the development of Alzheimer’s disease.
Further studies are needed, this work in fact is at its very beginning, but, despite this, the authors of the research give a piece of advice. According to their experiment, regulating the salt in the diet is for sure a healthy choice. And the salt isn’t just that contained in a saltshaker but a lot, or even more, attention should be given to processed or ready meals that are a rich source of added salt.