Too much of this can kill you – and your brain: study

New study finds everyday item can increase risk of dementia.

The ‘poison’ we all eat

Heart failure, stroke, kidney problems, osteoporosis. oedema – all are conditions linked to high salt intake. According to a new study, you should now add an increased risk of dementia to that list.

Researchers from Weill Cornell Medicine in New York have found that a high salt diet can lead to a drop in nitric oxide, which is vital for brain health.

When nitric oxide levels are too low, chemical changes to the protein tau occur in the brain, contributing to dementia, the researchers reported in an article published in Nature this week.

In the study, the investigators sought to understand the series of events that occur between salt consumption and poor cognition in mice and concluded that lowering salt intake and maintaining healthy blood vessels in the brain may “stave off” dementia.

Accumulation of tau deposits has been implicated in the development of Alzheimer's disease in humans.

“Our study proposes a new mechanism by which salt mediates cognitive impairment and also provides further evidence of a link between dietary habits and cognitive function,” said lead study author Dr Giuseppe Faraco, an assistant professor of research in neuroscience in the Feil Family Brain and Mind Research Institute at Weill Cornell Medicine.

The new study builds on research published last year in Nature Neuroscience by Dr Faraco and senior author Dr Costantino Iadecola.

The 2018 study found that a high-salt diet caused dementia in mice. The rodents became unable to complete daily living tasks such as building their nests and had problems passing memory tests. The research team determined that the high-salt diet was causing cells in the small intestine to release the molecule interleukin-17 (IL-17), which promotes inflammation as part of the body’s immune response.

IL-17 then entered the bloodstream and prevented the cells in the walls of blood vessels feeding the brain from producing nitric oxide. This compound works by relaxing and widening the blood vessels, allowing blood to flow. Conversely, a shortage of nitric oxide can restrict blood flow.

In their new Nature study, the investigators found that decreased nitric oxide production in blood vessels affected the stability of tau proteins in neurons. Tau provides structure for the scaffolding of neurons. This scaffolding helps to transport materials and nutrients across neurons to support their function and health.

The current mouse study was a reminder for people to regulate salt consumption, Dr Iadecola said. “And the stuff that is bad for us doesn't come from a salt shaker, it comes from processed food and restaurant food. We’ve got to keep salt in check. It can alter the blood vessels of the brain and do so in a vicious way.”

The Heart Foundation says the average Australian should aim to consume fewer than five grams of salt a day, which is less than one teaspoon. It says most of us are exceeding this with the average Australian consuming about nine grams daily.

Are you mindful of your salt consumption? Did you know the recommended daily limits?

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    25th Oct 2019
    I use lots of salt as it raises my blood pressure.
    25th Oct 2019
    Living can kill you
    25th Oct 2019
    Almost correct, turtle.
    Living WILL kill you.

    Everyone and everything that has ever lived is now either dead or dying.
    Polly Esther
    25th Oct 2019
    yes, it is a certainty and thank goodness for that; don't want to run into any zombies :)
    25th Oct 2019
    A recent blood test revealed only one problem. No salt (sodium) in my blood!! Had done as I was instructed several years ago by a GP, to cut out salt as it raised blood pressure! Now, I must eat salt each day and no, my blood pressure is still low for my age!
    25th Oct 2019
    I have never liked adding salt to my food, it was not done in my family so I just grew used to it. When I joined the military at age 17 I was surprised at the number of my messmates who covered their food with salt (also had the same reaction to peanut butter as it was the first time I was acquainted with it). Still avoid salt although we do use minimal salt in our cooking. By the way I always had good blood pressure until a few years ago, now I have to take pills.
    25th Oct 2019
    ps. looks like YLC have at last fixed the double entry issue, no longer have to 'remove' a repeated post. Good
    25th Oct 2019
    We usualy use salt reduced buttsr but recently bought the 'ordinary' version of the same brand. It tastes awful, bitter, takes over the taste of everything. Shows what you get used too and why the gravy you get eating out often tastes awful too.

    They should tell all the TV chefs who mostly dose everything with salt.
    25th Oct 2019
    Good to see there's no added salt in today's recipe.
    25th Oct 2019
    A better 'Headline' would be appropriate, why not be reflect the message of the article and say 'salt can kill you". A household staple, that could be anything, even water in excess can be fatal. Please get away from the 'Womans Day"/"New Idea" methodology of having headlines to emphasise the scandalous and not the fact
    25th Oct 2019
    Ok - before we carried away with the "salt" bit.
    We need some salt - especially iodised salt for the thyroid. The thyroid hormones control body temperature, regulate the metabolism and promote proper growth and development. Salt helps with balancing fluid balance, nerve transmission and muscle function.

    Have a balanced diet and just don't over do it.
    25th Oct 2019
    The salt thing has been around for decades.

    Too much of anything is bad for something.
    Too much oxygen can kill. Same as water.

    Be Zen, everything in moderation. Ommmm... except for moderation.
    Ted Wards
    25th Oct 2019
    Actually if you read most of the newest research it tells you, all our health problems are related to dairy, any meat consumption and processed food. Bet you that research will never make iot on here!
    25th Oct 2019
    Ask a starving person about dairy and meat. I doubt they would agree.
    25th Oct 2019
    A starving person would eat dirt if need be...might be healthier.
    25th Oct 2019
    As a diabetic type 2 I do not add salt to anything except fresh tomatoes on a sandwich and that is purely my choice as I like it
    25th Oct 2019
    I wish they would provide more detail re the mice study. My question is how much salt did they feed the mice? Was it equivalent to what the average human eats per day or was it 50% of their diet? These studies can be very misleading when you look into them.

    25th Oct 2019
    As Rosret posted we do need iodine, only small amounts. In large doses iodine can be detrimental to thyroid glands, it's in certain types of seaweed which is tasty sprinkled over soups etc.
    Commercial salt is in nearly every processed product, even in 'healthy' canned beans etc. Adding more salt to your meal is overdoing it.
    Up there with salt is processed sugar, same deal.
    25th Oct 2019
    My mother refused to take heed the repeated warnings to cut down her way above average salt intake. "It will kill you!" the medics said. Well perhaps it did, but as she was 102 at the time and in generally good health I don't think she should have changed her ways. What I hope is that individual physiology is passed on in the genes because I like salt, too.
    25th Oct 2019
    Make sure its iodized salt, at least there's some benefit.
    Those fancy expensive salts handmade by a Tibetan monk and only found 1 mile down under a sacred mountain have no iodine.
    Check the label.
    25th Oct 2019
    How do you control salt, its in everything... You will starve to death or spend all day shopping to have everything home cooked... Go to Mcdonalds one day and there's enough to complain about, another day its normal. They add it whilly nilly same with chile , maybe chile salt.? My blood pressure is high enough to use medication, but when I go to sleep it crashes, giving my blood vessels a break

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