Diets low in salt aren't just 'good for health' – they keep life-threatening conditions at bay

Did you grow up eating low-salt food because someone in your family had high blood pressure (BP)? If yes, you’re probably luckier than you realise. One in four Indian adults has hypertension. Increasingly people in the 25-34 age group are falling prey to this disease that increases wear and tear in the blood vessels. Though there are many reasons for this, a high-salt diet is not blameless. Here’s how it affects your health:

Thirsty for more

Ever noticed how you feel thirsty after going through a bag of chips? Regular salt contains roughly 40% sodium (the rest is chlorine). When we consume a lot of salt in a short time, the body tries to dilute the sodium in our blood with water. When the amount of water in the blood rises, the overall volume of blood increases. Now the heart has to pump more. Hardworking as it is, the heart likes to work just the right amount. Too much strain on the heart can weaken the heart muscle, or even lead to heart failure. [caption id=“attachment_7821141” align=“alignnone” width=“1280”] Salt poisoning isn’t only real, it’s already affecting public health in evident ways. Image: WWW[/caption] Research has also linked high-salt diets to increased risk of kidney disease, brain stroke, diabetes, dementia and poorer bone health.

A vicious cycle

High BP affects every organ in the body, especially the heart. BP is measured in millimetres of mercury - any reading over 140/90 is considered high. This reading means that blood vessels withstand at least 140 mm of pressure every time the heart contracts and 90 mm when it relaxes. Over time, the blood vessels become rigid as a result of high pressure. This sets off a vicious cycle. High BP makes the blood vessels rigid, and rigid blood vessels increase BP further and high BP also increases the chances of cholesterol plaque buildup in the arteries which can become choked. This, in turn, can lead to a host of problems like heart attack and brain stroke.

Mission to Mars

Between 2009 and 2011, German scientists ran a bunch of tests on astronauts on two simulated missions to Mars over 105 days and 205 days, respectively (the second mission was for 520 days, but the scientists studied the astronauts for a little less than half that duration). Every 30-60 days, the scientists changed the amount of salt in the astronauts’ diet. The variations were 12 grams of salt a day, 9 grams daily or 6 grams per day.   At the end of the period, they found a connection between high salt intake and water retention in the kidneys – not only did the test subjects have less water in their pee for days when they ate more salt, but they also started drinking less water because their kidneys were retaining water already.   The scientists found one more thing: changing the amount of salt in the daily diet also triggered a change in the production of two hormones – aldosterone, which cleans the sodium out of the kidneys, and glucocorticoids, which keeps the metabolism ship-shape. This hormonal imbalance, they said, can cause a range of metabolic disorders, from diabetes to metabolic syndrome.

Other niggles

Salt affects the excretion of calcium through our pee. More salt equals more calcium loss equals loss of bone density, and potentially, the formation of kidney stones. It’s fitting that the way to pass the smaller kidney stones is to drink lots of water, which also improves the overall salt-water balance in the blood.

Head in the game

Scientists at New York’s Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, and the Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer’s Disease Research Center, Washington University, have found that the more salt you eat, the more tau proteins build up in your brain. Usually, tau proteins help the brain cells get nutrition. But when there’s an imbalance of tau proteins, it can lead to a decline in brainpower. The scientists published their research in  Nature Neuroscience  - a peer-reviewed journal - in October 2019.

Things to consider the next time you’re buying groceries

• The next time you’re in the snacks section at a supermarket or your local mom-and-pop shop, ask about snacks with lower salt content. Read the food labels - they should tell you how much salt they contain per serving. Weigh that against the World Health Organization’s recommendation to eat no more than 5 grams of salt daily before buying.
• Check the sodium content in packaged foods, separately. Many plant-based meat alternatives actually have higher sodium than meat!
• Ask the shopkeeper about low-sodium salt options. (Make sure the salt you buy is fortified with iodine, or start taking iodine supplements separately). Remember, though, that low-sodium salt may still contain small quantities of potassium chloride. In minuscule quantities, it can lower blood pressure. But an excess of potassium chloride can be bad for your health.
• Check if your medicines and vitamins have salt as a filler. If yes, ask your doctor to recommend an alternative that doesn’t.

For more information, please read our article on   Rock Salt: Benefits and Side-effects_._ Health articles in Firstpost are written by myUpchar.com, India’s first and biggest resource for verified medical information. At myUpchar, researchers and journalists work with doctors to bring you information on all things health.