A pinch too much: The silent weight of salt on a beating heart

Most people consume way too much sodium. The American Heart Association recommends no more than 2,300 milligrams per day, basically a teaspoon. But the average person? Way over that. The CDC reports that Americans eat roughly 3,400 milligrams daily, which is about 50% more than recommended. And it's not because you're salting your eggs at breakfast. About 70% of the sodium in our diets comes from processed foods and restaurant meals.

The UK's food standards agency found something similar—Brits are consuming around 8.4 grams of salt daily, well above the recommended 6 grams. Australia's health department reported comparable numbers, with most adults exceeding daily limits. So this isn't just an American problem.

India's got a salt problem too. As per a study published in the Indian Journal of Medical Research (IJMR), the average Indian consumes somewhere between 9 to 10 grams of salt daily. That's way more than the World Health Organization's recommendation of 5 grams, and it's significantly higher than what most health organizations say your body actually needs. What's particularly concerning is that high salt consumption is directly linked to hypertension, and India's already dealing with a massive hypertension epidemic.

Why does it matter? Salt makes your blood vessels stiffer and forces your heart to work harder. Over time, that damages your heart and increases blood pressure. Harvard researchers have linked high sodium intake to increased risk of heart disease and stroke. The CDC estimates that reducing sodium could prevent hundreds of thousands of heart attacks and strokes annually in the US alone.

TOI Health spoke to Dr. Rushikesh Patil, Associate Director- Cardiologist, Dr L H Hiranandani Hospital Powai, Mumbai on how that extra pinch of salt on your dinner plate affects your heart without you knowing about it.

Dr. Rushikesh Patil: Yes, salt has been a significant part of India in the past as well as in today’s time, from Dandi march to loyalty to it, and to being a means of micronutrients fortification. But increased salt consumption is a risk factor for hypertension and cardiovascular diseases. According to the population survey of Indians, the daily consumption of salt by them is twice the limit set by WHO of less than five grams a day. It is estimated that cardiovascular diseases account for about one-third of all the deaths in India, and hypertension is the highest risk factor for cardiovascular diseases. There is a proven correlation between an increase in consumption of salt and increase in blood pressure and, therefore, an increased risk of stroke and stroke mortality according to results obtained from randomized clinical trials. The link between salt consumption and heart diseases stems from high blood pressure. Excess consumption of salt causes water retention within the body and increases pressure in the blood vessels. This causes hypertension, which has been widely regarded as the major cause of heart attacks and strokes. There is evidence that a lower level of salt consumption results in a lower level of CVDs. In a study conducted over a period of 10-15 years, known as Trials of Hypertension Prevention, there was a 30% decrease in CVDs and a 20% decrease in mortality among patients randomly assigned to consume less sodium.

Dr. Rushikesh Patil: Considering the difficulties encountered in implementing mass media campaigns and behaviour change strategies to target home-cooked sources of sodium, the promotion of low sodium salt (LSS) instead of regular salt (sodium chloride) may prove to be a useful technique in bringing down the sodium content in the population, especially since very little behavioural change is needed on the consumer’s part.

Low sodium salts involve the replacement of a portion of sodium chloride with another mineral, usually potassium chloride. The amount of sodium chloride used varies between zero percent (no sodium) and 88% sodium in LSS.

Potassium consumption in large quantities is known to reduce blood pressure. It seems that the ratio of sodium to potassium is what matters in the reduction of blood pressure and cardiovascular disease.

Salt substitution has been proven to lower blood pressure and reduce CVD. 7 villages in the Siddipet district of the Indian state of Telangana 502 hypertensive rural residents in a randomized double blind placebo-controlled clinical trial carried out in India revealed that salt substitution (using 30% potassium) over a period of 3 months was linked to a significant lowering of SBP by 4.6mmHg and DBP by 1.1mmHg.

In addition, salt substitutes can also lower the chances of suffering from CVD and premature death. In a study involving Chinese people (who had suffered from a previous stroke or were at least 60 years old and had high blood pressure) called the "Salt Substitute and Stroke Study" (SSaSS), the results revealed that people receiving a salt substitute experienced 14% less chance of getting a stroke, 13% fewer chances of developing CVD and 12% fewer chances of dying.

However, one of the major fears when it comes to salt substitutes is the risk of developing hyperkalaemia due to an increased intake of potassium.

Although there is very little knowledge about LSS, many other varieties of salts like Himalayan pink salt, black salt, and sea salt are gaining popularity. The marketing of non-iodized specialty salts is aggressive, and their supposed health benefits without any scientific basis are heavily promoted. These types of salts contain sodium content just like ordinary salt but only trace amounts of other minerals. There is very little scientific proof that they are healthier.

Dr. Rushikesh Patil: Three primary sources of sodium in an individual’s diet in India include
The salt used in foods at the time of preparation or consumption in the household
Foods prepared outside the household, such as restaurants, street vendors, school foods, and other foods available from government establishments
Processed or packaged foods like instant noodles, chips, and other snacks. Very few studies in India have found that sodium consumption through household salt is one of the largest sources of dietary sodium, contributing about 80 percent of total salt intake among adults. Nevertheless, considering the varied diet of India, sources can differ across states. For example, in Ladakh and tea gardens in Assam, adding salt in tea is a significant contributor to dietary sodium. Therefore, unlike several Western nations where salt consumption is in the form of processed food, Indians consume more salt by way of addition in their meals at home or via traditional accompaniments such as pickles and papads. Hence, the kitchen becomes an ideal place for intervention. Even a slight decrease in the amount of salt in cooking could make a lot of difference to families.

Dr. Rushikesh Patil: To tackle the rising problem of hypertension and other CVDs, sodium reduction interventions should become mainstream in our country. This will help to involve the people in adopting an integrated approach focusing on the main sources of sodium consumption. Initiatives like front-of-pack labelling, food reformulation (such as establishing salt reduction goals or motivating food producers to manufacture low-sodium, low-fat, and low-sugar content foods), taxation of HFSS foods, and limiting HFSS advertising directed at children can lower the quantity of sodium found in packaged foods available around us. Moreover, the policymakers should also take steps in implementing such initiatives which will help in promoting the accessibility and recognition of low-sodium salt that can assist consumers in making better decisions. However, this strategy will not only be seen as a one-size-fits-all intervention. People with kidney disease or using particular drugs could be at risk due to elevated potassium levels.

Dr. Rushikesh Patil: A considerable number of heart attacks and strokes are associated with the high consumption of salt. Therefore, the additional amounts of salt become one of the most preventable causes of cardiovascular diseases in India. Even cutting down by 20-30%, the overall impact would be huge. Recent modelling research assessing the advantages and disadvantages of LSS and thus decreasing the amount of salt in the diet of Indians showed that in conservative estimates, the application of LSS will save 214,000 cardiovascular-related deaths per year in the country. But the increasing prevalence of heart diseases among Indians is also connected with contemporary way of life and work.