Our bodies need salt. Salt also adds taste to our food. However, too much salt in your diet may lead to high blood pressure. The World Health Organization recommends 5 grams of salt in your diet every day. But the world average is 10.8 grams. A recent report, a part of the national non-communicable disease monitoring survey, states that Indian men consume 8.9 grams, and Indian women take in 7.1 grams of salt on a daily basis (Prashant Mathur et al., Scientific Reports, 2023)
Studies in animals, as well as surveys in humans have consistently shown that high salt intake causes disease in the kidney, brain, vasculature, and immune system. High levels of sodium in the diet are also associated with conditions ranging from kidney stones to osteoporosis. It is estimated that excessive salt contribution contributes to around five million deaths worldwide every year.
The Yanomami people of the Amazon rainforest live a foraging lifestyle and eat a diet consisting of the root vegetable Cassava, plantains, fruit, fish and an occasional tapir. They use peppers for flavour, and no salt. They consume less than one gram of salt a day yet stay supremely fit.
High salt and obesity
While our bodies need a certain amount of salt for vital functions, excessive salt intake can lead to health problems such as high blood pressure and heart disease. It’s always best to consume salt in moderation. India faces a rapidly escalating burden of non-communicable diseases (NCDs), nutritional diseases such as diabetes and obesity, in particular childhood obesity. For many young Indians, the “hidden” salt in processed foods is a big danger.
High salt impairs metabolism and increases the size of adipocytes, which are cells in our body that store energy in the form of fat. These two factors together lead to obesity. The preference for high-fat and for salty food may be related. In one experiment, pregnant mice were fed a standard diet (4.6% fat) during the first week of their three-week gestation period. At this point some of them were switched to a high-fat diet (32% fat). The off-spring of the high-fat fed mice preferred salty water to plain or sweetened water.
In population studies, reducing salt intake by five to eight grams daily led to a 4 mmHg fall in systolic blood pressure, and an overall reduction in risk of cardiovascular disease. Data from several clinical trials of antihypertensive drugs show an average reduction in blood pressure of 5mmHg by this class of drugs. Similar results were also seen in a Chinese population study in which dietary sodium was lowered by replacing normal salt with a mixture of 75% sodium chloride and 25% potassium chloride: systolic blood pressure came down by 3.3 mmHg. Oral rehydration solutions recommended by UNICEF contain 60:40 ratios of the two salts.
Lastly, salt reduction may be dangerous for some. Elderly adults must be extremely cautious of hypotension since it might lead to falls. This is especially true if they are taking medication to reduce their high blood pressure.
(The article was written in collaboration with Sushil Chandani, who works in molecular modelling)
