Dementia and Alzheimer’s add to the many diseases caused by excessive salt intake. A team of researchers from Weill Cornell Medicine in New York explains the mechanism, in a study published in Nature.(1)
Too much salt and Alzheimer’s
The authors of the research had already demonstrated, in a previous study published in Nature Neuroscience, the causal relationship between excess salt consumption and cognitive decline in mice. The attribution of this phenomenon to stiffening of the vascular walls-whence a reduction in blood flow to the brain results-has been further explored, with new evidence to the contrary.
The harmful effects of excess sodium-as this study shows-are in fact brought about by reduced nitroxide production by endothelial cells in brain vessels. With two consequences:
– Reduced blood flow (hypoperfusion) to the brain and
– alteration with pathological deposits in a protein (tau) linked to the onset of Alzheimer’s disease.
The evidence was also confirmed by administering an antibody that promotes tau protein stability to the researched mice. The protective mechanism of the antibody deactivated the effects of the salt-rich diet, preventing the development of dementia.
The responsibility of the food industry
Reducing salt consumption is extremely difficult for those who consume a lot of packaged foods. As the food industry continues to add excessive amounts of sodium to foods, thereby endangering the health of consumers. The latest alarm comes from research by the Joint Research Center (JRC) on behalf of the European Commission. Where it has been shown that more than half of the foods intended for children and young people contain too much salt.
In addition to ready meals and snacks, which are notoriously too salty, the threat also lurks in ‘special’ foods. As shown in market surveys conducted by GIFT(Great Italian Food Trade) on foods for vegans and vegetarians and gluten-free foods, particularly baked goods and breadcrumbs.
Notes
(1) Faraco, G., Hochrainer, K., Segarra, S.G. et al. Dietary salt promotes cognitive impairment through tau phosphorylation. Nature 574, 686-690 (2019) doi:10.1038/s41586-019-1688-z
https://doi.org/10.1038/s41586-019-1688-z
Professional journalist since January 1995, he has worked for newspapers (Il Messaggero, Paese Sera, La Stampa) and periodicals (NumeroUno, Il Salvagente). She is the author of journalistic surveys on food, she has published the book "Reading labels to know what we eat".