SALTING FOOD PRIOR TO TASTING: DANGEROUS OR NOT?

Even if you don’t do it yourself, we often see those who add salt to foods even before tasting. So what are the health effects, if any, of such a habit? A possible answer to this question has recently come to light: In a study of 501,379 participants in the UK, a dose-dependent increased risk of all-cause mortality was observed with increasing frequency of adding salt to food. Compared with participants who reported to never or rarely adding salt to foods, those who always added salt to foods had a 1.50- and 2.28-year lower life expectancy at the age of 50 years in women and men, respectively. These findings suggest that addition of salt to food is associated with a dose-dependent increase in premature mortality. To counter this danger, however, is that increased intake of fruits and vegetables significantly attenuated the hazard of premature mortality also in a dose-dependent fashion.

Adding salt to food at the table is a common eating behavior directly related to an individual’s long-term preference for salty tasting foods and habitual salt intake. According to the study noted above, the researchers followed study subjects for a median of 9 years. These participants were classified according to their salt addition at the table into 4 groups: never/rarely, sometimes, usually, and always.

These findings documented an increasing risk of all-cause premature mortality with increasing frequency of adding salt at the table, after adjustment for sex, age, race, smoking history, moderate drinking habit, body mass index (BMI), physical activity, high cholesterol, chronic kidney disease, diabetes, cardiovascular disease, and cancer. An analysis of cause-specific premature mortality showed that adding salt at the table was associated with an increased risk of both cardiovascular and, surprisingly, cancer mortality, but not of dementia or respiratory mortality. Unexpectantly, the increased risk of premature mortality diminished with increasing intakes of food high in potassium, such as fruits and vegetables.

The authors concluded that their study “indicates that the higher frequency of adding salt to foods is associated with a higher hazard of all-cause premature mortality and lower life expectancy” and extrapolated from this conclusion “our findings also support the notion that even a modest reduction in sodium intake is likely to result in substantial health benefits, especially when it is achieved in the general population.”

Unfortunately, the issue is not quite as straightforward as the authors let us believe. The difference in 24-hour sodium intake between those who never/rarely added salt and those who always did is a minuscule 0.16 g or less than 4%. It is highly unlikely that such negligible quantity has any impact on blood pressure, not to speak on cardiovascular mortality or life expectancy. This suggests that people who routinely add salt to their food exhibit a complete disregard to any health measures in their diet. In the study, they consistently consumed more red meat, processed meat, less fish, and less fruits and vegetables than those who did not salt their food. Not surprisingly, most, if not all, cardiovascular risk factors were significantly higher in those who always added salt compared with those who never/rarely did. Thus they were less likely to have a healthy lifestyle. but more likely to be male, not of White race, and to have a higher weight index as well as a higher prevalence of diabetes and cardiovascular diseases.

Thus, the bad habit of mindlessly adding salt at the table might simply be a marker for an unhealthy diet and lifestyle. The study noted above is a thorough and sophisticated statistical exercise in adjusting for multiple confounders, but, in my opinion, may not clearly be related with salt intake.

CONCLUSION

Based on many studies, salt intake should be curtailed, and certainly adding salt mindlessly to foods is inadvisable. But beyond consideration of salt intake per se, all the other lifestyle changes that I have covered in previous notes should be respected. Statistical studies based upon population trends are always beset by confounding variables, usually indicating the need to perform additional studies to confirm initial conclusions. Sorry folks, but that’s how science usually works!