A study published by the Elsevier journal Medical Hypotheses in 2006 found that a person who goes without salt experiences similar withdrawal symptoms as a drug addict. And the higher a person's sodium consumption is, the greater will be his or her tolerance for more.
A person who switches from a high- to low-salt diet probably will consider the food bland and flavourless at first. But after a few weeks, the taste buds adjust, making the reduction less noticeable. A person who follows a low-sodium diet is likely to find the taste of high-sodium food excessively salty.
Salt in your system
Sodium The body needs a certain amount of sodium every day to function; it is an electrolyte that helps regulate fluids and blood pressure and helps nerves transmit signals. Salt is also iodized in Canada to help prevent iodine deficiency, which can lead to mental impairment. (In many developing countries, this is a major cause of mental retardation.)
High blood pressure or hypertension Blood exerts pressure on the walls of the arteries as the heart pumps it around the body. But if excess water in the blood vessels or increased rigidity in the artery walls force the organ to work harder, it can cause it to become enlarged, with the risk of heart attack, failure and other cardiac events.
Damage to blood vessels can cause them to burst or become blocked by a clot - if this occurs in the brain, it can cause a stroke.
Obesity, inactivity and excessive alcohol intake have been linked to high blood pressure, also known as hypertension. But high sodium intake has been shown to be the most significant factor.
Fatalities In 2005, the latest year for which figures are available, heart disease and stroke accounted for 22.4 per cent and 6.1 per cent of deaths in this country respectively, according to Statistics Canada - more than any other cause of death except cancer.
The link The correlation between increased sodium consumption and rising blood pressure is still not completely understood. It is known that excess sodium can cause the body to retain water. Extra water and sodium in the blood vessels means that the heart has to work harder to pump blood around the body.
Emerging research also suggests that a high-salt diet can stiffen the aorta and other central arteries, which could put increased pressure on blood flow.
Kidneys are vital to controlling blood-pressure levels because they remove extra sodium from the body and work to maintain a proper balance of sodium. Consuming excess sodium makes the kidneys work harder, and, in simple terms, can make them function less efficiently.
A safe solution Most medical experts agree that government- and industry-led efforts to reduce sodium in packaged and processed foods won't cause Canadians to become sodium- or iodine-deficient, because the mineral is ubiquitous in the food supply.
Our sodium levels
The average Canadian consumes twice the recommended amount of sodium per day - men more than women, with teenaged boys by far the worst offenders.
Recommended daily intake (amount of sodium adequate to good health), by age group:
- Ages 1-3: 1,000 milligrams (less than half a teaspoon of salt)
- Ages 4-8: 1,200 mg
- Ages 9-50: 1,500 mg
- Ages 51-70: 1,300 mg
- Over age 70: 1,200 mg
Daily tolerable-consumption limit (highest amount of sodium before significant risk of compromising health), by age group:
- Ages 1-3: 1,500 mg
- Ages 4-8: 1,900 mg
- Ages 9-13: 2,200 mg
- Ages 14 and older: 2,300 mg (roughly one teaspoon)
Actual average daily sodium intake in Canada, excluding salt added while cooking or at table:
- 3,092 mg
Actual average daily sodium intake in Canada by age group and gender, excluding added salt:
- Ages 1-3: males, 1,918 mg; females, 1,918 mg
- Ages 4-8: males, 2,677 mg; females, 2,677 mg
- Ages 9-13: males, 3,513 mg; females, 2,959 mg
- Ages 14-18: males, 4,130 mg; females, 2,938 mg
- Ages 19-30: males, 4,066 mg; females, 2,793 mg
- Ages 31-50: males, 3,607 mg; females, 2,806 mg
- Ages 51-70: males, 3,334 mg; females, 2,573 mg
- Seniors over age 70: males, 2,882 mg; females, 2,300 mg
Source: Statistics Canada's Canadian Community Health Survey
Carly Weeks is a reporter for Globe Life.