Eating too much salt over a long period of time may bring on several health issues.
May raise blood pressure
Research suggests that salt-rich diets significantly increase blood pressure and that lowering the salt content of a person’s diet can help lower their blood pressure levels.
For instance, two large reviews report that a reduction in salt intake of 4.4 grams per day may lower systolic and diastolic blood pressure (the top and bottom numbers of a reading) by up to 4.18 mm Hg and 2.06 mm Hg respectively.
However, the observed reductions were close to two times larger in individuals with high blood pressure, compared with those with blood pressure in the normal range.
Moreover, these effects are thought to be significantly stronger in salt-sensitive individuals than in those who are not salt-sensitive. Obesity and aging are also though to amplify the blood pressure-raising effects of salt-rich diets.
May increase stomach cancer risk
Several studies link a high salt diet to a higher risk of stomach cancer.
A review including more than 268,000 participants suggests that those with median salt intakes of 3 grams per day may have up to a 68% higher risk of stomach cancer than those with median salt intakes of 1 gram per day.
Another study further suggests that people with high salt intakes may have a two times higher risk of stomach cancer than those with lower intakes. Still, this study doesn’t clearly define what is considered high or low salt intake.
The mechanism behind salt’s effect on stomach cancer isn’t fully understood.
However, experts believe that salt-rich diets may make a person more vulnerable to stomach cancer by causing ulcers or inflammation of the stomach lining.
Effect on risks of heart disease and premature death
The link between salt-rich diets, heart disease, and premature death is still somewhat controversial.
Some studies suggest that high salt intakes cause a rise in blood pressure and a stiffening of blood vessels and arteries. In turn, these changes may result in a higher risk of heart disease and premature death.
For instance, one 20-year study notes that participants who consumed less than 5.8 grams of salt per day had the lowest mortality rates, while those who consumed more than 15 grams of salt per day had the highest.
However, others suggest that high salt diets have no effects on heart health or longevity and that low salt diets may actually increase the risk of heart disease and death.
These differing study results may be explained by differences in study design, methods used to estimate sodium intake, and participant factors, such as weight, salt sensitivity.
While it’s possible that eating too much salt doesn’t increase the risk of heart disease or premature death for everyone, more studies are needed before strong conclusions can be made.
Eating too much salt in the long term may raise your blood pressure and increase your risk of stomach cancer. It may also increase the risk of heart disease and premature death, although more research is needed to confirm this.