We know it’s bad for us, but it gives food more flavor. We know it contributes to hypertension, but still, it gives food more flavor. And we know hypertension can lead to stroke, heart disease, kidney failure, and other chronic diseases, but adding salt gives food more flavor.
Although some sodium is necessary to control blood volume and to help cells function properly, too much salt definitely increases our health risks.
Most sodium consumed comes from sodium chloride, commonly called table salt. But most of the salt we consume is hidden from view. It is estimated that 77% of our daily average sodium intake comes from prepared and processed foods such as canned soups, muffins, bottled dressings, condiments, snack food, luncheon meats, pizza, and fast food. Another 12% occurs naturally in food, and the remaining 11% is salt that’s added during cooking or sprinkled on our plates at the table.
According to the Institute of Medicine (Washington, DC), the adequate intake of sodium each day is:
• Age 1 to 3: 1000 mg
• Age 4 to 8: 1200 mg
• Age 9 to 50: 1500 mg
• Age 51 to 70: 1300 mg
• Age 71 and older: 1200 mg
However, for those people who have been diagnosed with hypertension, heart disease, or any other chronic disease, sodium intake levels should be lower.
Most Canadians consume two or even three times the adequate intake level of sodium because it is so easy to do. According to Health Canada, 90% of men and 65% of women exceed the upper daily limit (2300 mg) of sodium.
A British Medical Journal study published in April 2007 determined that people who ate a salt-reduced diet were 25% to 30% less likely to develop cardiovascular disease and had a 20% lower risk of dying during the 10- to 15-year follow-up.
According to a May 2007 study published in the Canadian Journal of Cardiology, reducing our intake of sodium could lead to 1 million fewer Canadians with hypertension. That, in turn, has direct savings to the health care system of approximately $430 million annually because of fewer physician visits and lab tests, lower medication use, and the prevention of disabling and fatal salt-related heart attack and stroke.
Lowering our intake of salt can be done immediately or gradually over a period of a few weeks. Sodium is an acquired taste, so most people will need to be weaned off it. It takes 6 to 12 weeks for our palates to become accustomed to the reduction of salt in our food—and chances are, if we then attempt to eat something salty, we probably won’t enjoy it. Please see the Box for some suggestions for salt reduction that you can photocopy and pass on to patients.
Although obesity and other factors contribute to hypertension, excessive sodium intake is one of the most important causes and is also the cause most amenable to a public health solution. In Finland and the United Kingdom, manufacturers have gradually reduced the salt content in packaged foods and they are clearly labeled—a method approved by the World Health Organization.
The CMA adopted COHP’s resolution at last year’s General Council that calls on the federal government to work with industry to reduce the level of sodium chloride or salt in processed foods. Combining forces with the Heart and Stroke Foundation of Canada, the CMA has already requested that Health Canada monitor and report on sodium food targets beginning in 2012.
In February the Council on Health Promotion began a 3-month advertising campaign on Vancouver buses suggesting that everyone pay attention to their salt consumption. For more information about the health risks of excessive salt use, check the BCMA web site at www.bcma.org [2] under the Patient Advocacy/Health and Wellness section.
—Bill Mackie, MD
Chair, Council on Health Promotion