Salt Consumption and Myocardial Infarction: Is Limited Salt Intake Beneficial?

Introduction: Sodium is an essential mineral that plays a crucial role in the maintenance of normal cellular homeostasis, regulation of fluid and electrolytes, and blood pressure (BP). Due to the presence of sodium in a variety of regularly consumed food products, the deficiency of sodium is extremely unlikely. On the other hand, excess intake of dietary sodium is observed in many populations as it is generally used in most food products. Existing guidelines recommend lowering salt consumption for better cardiovascular health; these dietary sodium intake recommendations are not reassuring as the evolving studies show evidence that there is a higher risk of cardiovascular disease (CVD) with low sodium consumption. The aim of this study was to identify the association between salt consumption and myocardial infarction (MI).

Methods: The National Health and Nutrition Examination Survey (NHANES) data between 2017- 2018 was analyzed to examine the association between sodium intake (use in daily meal preparation) and reported history of MI. Logistic regression was used to assess for significant differences between the groups and calculated odds ratios while adjusting for confounders.

Results: A total of 4626 participants were included in the study, with a mean age of 66 ± 11 years in those with a history of MI (n = 212). Amongst these participants, those with salt consumption "Occasionally used" or "Very often used" were less likely to have suffered from MI than those who "Never used" salt in meal preparation. Multivariable logistic regression was performed to control for confounders. "Occasionally used" compared to "Never used" odds ratio was 0.5227 (95% confidence interval (CI); 0.3053-0.9009 p = 0.0184) and "Very often used" compared to "Never used" odds ratio was 0.5033 (95% CI; 0.2892-0.8799 p = 0.0152).

Conclusion: After adjusting for confounders, the participants that used salt more liberally during meal preparation were less likely to have MI than those who minimally or never used salt in meal preparation.