Stress leads to people retaining as much as 500 milligram of extra salt per day, a new research suggests.

Excess salt has been associated with an increase in blood pressure that leads to many complications like heart failure and diabetes.

Researchers say that in response to stress African Americans or dark skinned people hold on to about 160 milligram of salt every time. This along with a high blood pressure that goes up about 7 points in stressful situation adds a lot of burden on the heart. Research found that a salt increase like this adds up to 500 milligrams of salt per day and that this salt elevation remains even at night.

The study was conducted on African Americans or dark skinned people who were identified as salt retainers. Researchers found that salt levels can be controlled through angiotensin receptor blockers, a common drug used to lower blood pressure. But this treatment is rarely used by these people.

Angiotensin receptor gene raises blood pressure levels by telling the kidneys to retain salt.

"This response pattern puts you under a greater blood pressure load over the course of the day and probably throughout the night as well, increasing your risk of cardiovascular disease," said Dr. Gregory Harshfield, hypertension researcher at the Institute of Public and Preventive Health at Georgia Health Sciences University.

"Everybody knows stress is bad for you and everybody has the perception that a high-salt diet is bad for you, and both are particularly bad for these individuals. Every time they are stressed, they hold onto as much salt as you get eating a small order of French fries and this can occur many times over the course of even a good day," said Dr. Harshfield.

The findings were presented on Sept. 7 during the Behavioural Economics, Hypertension Session of the Psychogenic Cardiovascular Disease Conference in Prato, Italy.

A recent research found that people consuming 4,000 milligrams of sodium were three times more likely to suffer from a stroke than people who consumed less than 1,500 milligrams of sodium.

According to Institute of Medicine (IOM), reducing salt intake alone can save up to 100,000 lives annually in the U.S.

IOM recommends a salt intake of less than 2,300 milligrams, that's about a teaspoon of table salt a day (including cooking and extra salt added to food).