Can low levels of salt be as dangerous as high levels?

This study examined the association of sodium intake with health outcomes in populations with low, usual and high sodium intake.

The effect of sodium intake on population health remains controversial. Increasing evidence suggests that dietary patterns associated with high salt (mainly sodium) consumption contribute to higher levels of blood pressure. Based on this hypothesis sodium restriction is recommended for lowering blood pressure and preventing its adverse effects (heart attacks and strokes). Conversely, reduction in sodium consumption may produce unfavorable physiological effects, influencing health outcomes. Due to this contradiction researchers are trying to identify the optimal sodium intake range.

This analysis reviewed data from 25 studies containing 274,683 participants.

Researchers organized participants into 3 groups depending on their daily average sodium intake. A low sodium intake group (average daily sodium intake <115 mmol or <2.645g of sodium); a usual sodium intake group (average daily sodium intake of 115–215 mmol); and a high sodium intake group (average daily sodium intake >215 mmol or >4.945g of sodium).

During the follow up period any report of death or cardiovascular disease was noted.  In order for evaluation to be as accurate as possible adjustment for factors known to be associated with cardiovascular disease such as age, sex, educational level, weight, alcohol intake, and high blood pressure were performed.

Following analysis researchers concluded that mortality (death) and cardiovascular disease (such as strokes and heart diseases) rates were significantly lower in the usual sodium group than in the high and low sodium groups.

The usual sodium group showed a 9% decrease in mortality risk and a 10% decrease in cardiovascular disease risk when compared with the low sodium group. The high sodium group showed a 16% increase in mortality risk and a 12% increase in cardiovascular morbidity risk when compared with the usual sodium group.

This study concluded that both low sodium intakes and high sodium intakes are associated with increased mortality compared to a usual level of sodium intake. A specific range of sodium intake (2.645–4.945g) was associated with favorable health outcomes.

Although this article sets a “healthy range” for sodium intake, it is not specific for every subject, thus talk to your doctor or dietician before changing your diet.