Does the longevity diet have to be a calorie-restricted diet?
Not necessarily, scientists explain. To live longer and counteract cognitive decline and the risk of Alzheimer’s it would be enough to eat a diet with more carbohydrates and less protein. 

After a study in mice that determined that a diet with more carbohydrates and less protein was ideal for living longer , a new study, also in mice, adds a little more detail.

Mice that ate a diet with more carbohydrates and less protein for years were shown to have healthier brains and a lower risk of cognitive decline, compared to those who ate more protein and fewer carbohydrates.

The results, conducted by a group of researchers from the University of Sydney , appear to be in line with the health parameters that the inhabitants of the so-called Blue Zones show. 
The diet that the mice followed is very similar to the famous Okinawan diet. 
That is: 65% carbohydrates, 15% protein, 20% fat.
Such a breakdown of macronutrients would be protective for our brains, explain the researchers, who say the results obtained with mice may be identical in this case also for humans.
The drugs on the market today to fight Alzheimer’s reduce the progression of the disease, but they do not cure or stop it, they explained. The study was in fact funded by the Ageing and Alzheimers Association.