Extra salt at dinner could reduce life expectancy by two years: study


Extra salt from the salt shaker everyday at dinner time could end up contributing more than flavor to your life — according to a new study, those who always add extra salt to cooked food are more likely to die prematurely than those who rarely do.

Researchers looked at data on more than 500,000 people, and found that those who were always adding extra salt to their meals at the dinner table had a 28 per cent increased risk of dying prematurely compared to those who never added extra.

This meant that by the age of 50, women and men had 1.5 and 2.28 years, respectively, shaved off of their life expectancy, the study suggests.

“To my knowledge, our study is the first to assess the relation between adding salt to foods and premature death,” Lu Qi, a professor with Tulane University and lead author of the study, said in a press release.

“It provides novel evidence to support recommendations to modify eating behaviors for improving health. Even a modest reduction in sodium intake, by adding less or no salt to food at the table, is likely to result in substantial health benefits, especially when it is achieved in the general population.”

The study, published Monday in the European Heart Journal, aimed to investigate the impacts of extra sodium in a person’s diet.

Because salt is an important part of a meal’s flavor and can vary widely between foods, researchers chose to focus exclusively on the impact of adding extra salt from a salt shaker right before consuming a meal, as opposed to measuring salt added in the cooking process or already present in processed foods.

Researchers used data from the UK Biobank, a research cohort of more than 501,000 people from the UK When joining the study between 2006 and 2010, participants were asked to assess how often they added extra salt to their food, with four potential answers: never/ rarely, sometimes, usually, or always.

Participants were followed for nine years on average, and during this study period, 18,474 premature deaths — defined as those who died before reaching 75 years of age — were recorded among participants.

Researchers then looked at how much extra salt those who had died prematurely had reported adding versus those who did not die prematurely, in order to assess what impact this added sodium may have had on the risk of a shortened life expectancy.

Urinary samples were also collected at baseline for 481,000 participants to measured sodium levels, and 189,000 participants completed dietary recall surveys with more detail on their eating habits and diet.

The study adjusted for possible mitigating factors such as age, sex, smoking, alcohol intake, diet, physical activity levels and existing medical conditions.

They found that the risk of premature death increased as the frequency of adding extra salt did. By age 60, women who always added extra salt to their food had 1.37 years knocked off their life expectancy and men who always added extra salt had 2.04 years knocked off.

These risks were slightly reduced in those who consumed a lot of fruits and vegetables, researchers noted, although this association was not significant.

“Adding salt to foods at the table is a common eating behavior that is directly related to an individual’s long-term preference for salty-tasting foods and habitual salt intake,” Qi said. “In the Western diet, adding salt at the table accounts for 6-20 per cent of total salt intake and provides a unique way to evaluate the association between habitual sodium intake and the risk of death.”

In an editorial that accompanied the research, Annika Rosengren, a senior researcher and professor of medicine at the University of Gothenburg in Sweden, stressed that these findings don’t mean that we should all strive to eat bland, saltless food, as the relationship between salt and health is complex.

“Given the various indications that a very low intake of sodium may not be beneficial, or even harmful, it is important to distinguish between recommendations on an individual basis and actions on a population level,” she stated in the editorial. Rosengren was not involved in the work of the new study.

“So far, what the collective evidence about salt seems to indicate is that healthy people consuming what constitutes normal levels of ordinary salt need not worry too much about their salt intake. Instead, to counterbalance potentially harmful effects of salt, and for many other reasons, a diet rich in fruit and vegetables should be a priority on the individual, as well as the population, level.”

However, those who have been identified by their doctor as being at a high risk for issues such as cardiovascular disease and have a high salt intake already should maybe consider cutting down the amount of salt they add on top of the amount in their food already, she stated.

“At the individual level, the optimal salt consumption range, or the ‘sweet spot’ remains to be determined,” Rosengren wrote.

The study does have limitations, including that participants did not indicate the exact amount of salt that they were adding when surveyed on how often they added extra quantities.

“Because our study is the first to report a relation between adding salt to foods and mortality, further studies are needed to validate the findings before making recommendations,” Qi noted.