High-salt diet ‘increases risk of cognitive decline and dementia’

A diet rich in salt is linked to an increased risk of cerebrovascular diseases and dementia, according to new research published in the journal Nature Neuroscience.

Experiments carried out on human and mice cells suggest that salty foods trigger an inflammatory immune response that deprives the brain of oxygen, which damages neurons and leads to cognitive impairments.

The mice also struggled to identify new objects in recognition tests, which shows that their non-spatial memory had deteriorated. These effects were reversed when a normal amount of salt was consumed.

During the study, researchers fed mice a diet high in salt (roughly comparable to more than one teaspoonful a day in humans). The mice on a high salt diet struggled to navigate a maze that tested their ability to find an escape hole. They were also less capable of building a nest.

This could be partly explained by the gut’s immune response to salt. This includes an increase in the number of TH17 cells, They release a pro-inflammatory chemical called IL-17, which cause damage to endothelial cells and a reduction in blood flow to the brain.

This chemical reaction suppresses nitric oxide, which is essential in the process that allows the hippocampus  to form new memories, and is important to cognitive function. In Alzheimer’s patients the flow of blood to the brain is believed to be reduced.

The effects of a salty diet were reversed in mice after four weeks. Brain scans showed blood flow and endothelial function were healthy again by this point. The head of research at Alzheimer’s Research UK says this demonstrates that a change in lifestyle – or new prescription drugs – could help reverse or prevent these effects.

‘This research not only highlights the importance of the immune system for brain health but also suggests that changes in the gut can play a role.’

‘The findings highlight the importance of cutting out excess salt in our diets, as well as identifying possible new avenues in the search for treatments to help those with memory problems or dementia.’

  • AlfTupperDarlin

    “The findings highlight the importance of cutting out excess salt in our diets”


    It highlights the importance of not eating more than a teaspoonful of salt a day. That is a massive amount. A teaspoonful a week would be going some.

    • gnostic

      The Reference Daily Amount you see on food labelling is 7 grams which is about a teaspoon or so. A pizza is about 3 grams. Bacon and supermarket ready meals have similar amounts. Any savoury manufactured food has had salt added; sausages, pate, stock cubes. Little salt is found in fresh fruit, veg or grains. Almost all salt you eat is added by someone, like sugar, to improve taste and sales.

  • approveds

    I do not think this research has any merit as we are not told what type of salt was used. Most salt has chemicals added to it to make it flow, and bleach to make it white. real salt is damp, and grey. There are dozens of different salts, pink salt has all the minerals you need. Unless we are told which salt was used, research on salt becomes meaningless. If you go out to a restaurant, always ask for the salt menu, or take your own salt with you as we used to in the middle ages.