Thanks to the Cancer Society, the Tobacco Control Act was passed here in December 2009. It is designed not only to protect individuals from exposure to tobacco smoke (secondary smoking), but (hopefully) also to prevent people from the habit. Fortunately, the smoking prevalence here (30 per cent in males and seven per cent in females) is lower than in North America. However, many people here believe that heavy smoking only causes lung cancer. In fact, in a research study on 100 consecutive patients with heart attacks in the Port of Spain General Hospital done in collaboration with my colleague Dr Keith Aleong, we showed that heavy smoking is significantly associated with angina and heart attacks, even in young people.

High blood pressure, on the other hand, is directly associated with the early stages of atherosclerotic disease and causes strokes and heart disease. In fact, while HIV is by far the leading cause of death in the 15–34 age group, heart and cerebrovascular diseases are the highest-ranking causes of death in T&T and hypertension is a major contributing factor.

Now, there is an indisputable relationship between salt and blood pressure. China, for example, has 160 million patients with high blood pressure (28 per cent of the population) largely because they add a lot of salt in their cooking. For example, those different types of Chinese salt prunes. Indeed, hypertension is the leading preventable cause of death in China causing 2.3 million deaths a year (almost twice the population of Trinidad and Tobago)!

According to the World Health Organisation (WHO), 62 per cent of all strokes and 49 per cent of coronary heart disease events are attributable to high blood pressure. In other words, excess salt is one of the leading causes of death worldwide. But a host of problems can also crop up if you have salt deficiency, say, from too many diuretics. You may then experience headaches, palpitations, fatigue, dizziness, muscle cramps and may even collapse and die.

Salt is cheap and adds flavour. As the ancient American hymn says, "the Bible tells me so." Unfortunately many food producers take advantage of this and add a lot of salt to their food. Some of the major sources of sodium are processed foods, luncheon meats, yeast, pizza, pasta dishes, condiments, sausages, frankfurters, salt fish, bacon, regular cheese, especially soft cheeses, canned soups and even breads. In fact, 75 per cent of dietary salt comes from these processed foods and only ten per cent comes from the salt added to food at the table.

All people, especially, of course, those with high blood pressures, should therefore always check the food labels in the supermarkets. They may then be surprised to see that sodium has the highest percentage of the ingredients in most items, sometimes as much as 50 per cent. And so, the first step towards reducing sodium is not so much stopping the use of the salt shaker but to check the labels of processed foods.

Now, salt sensitivity is defined as the tendency for blood pressure to fall with salt reduction and rise with salt supplementation and those who are salt sensitive are more likely to develop high blood pressure as they age. African-Americans tend to be more salt-sensitive and they have a higher rate of hypertension than other racial and ethnic groups in the United States. Studies in T&T have also shown that hypertension is more common in Afro-Trinidadians than in Indo-Trinidadians. Indeed, some of us (like myself) are "saltaholics" and many doctors need to know that a cheap salt-excreting diuretic and a salt-reducing diet are quite effective to achieve normotensive levels and there may be no need for more expensive new-fangled drugs.

Both the American Medical Association and the American Heart Association have recommended that a healthy adult should not exceed an intake of 2300mg of sodium per day. That is about one teaspoon of salt. They propose that food manufacturers should reduce levels of salt in processed and prepared foods. Indeed, several studies have documented that a population-wide effort to reduce dietary salt could be as beneficial as interventions aimed at smoking cessation. But what I am saying is that in T&T it will be even more beneficial than the Tobacco Control Act in saving lives. This is the main point I wish to emphasise today.

In a paper entitled Compelling Evidence for Public Health Action to Reduce Salt Intake, researchers from Johns Hopkins University proposed that a US national effort to reduce daily salt intake could reduce the annual number of new cases of coronary heart disease by 60,000–120,000, stroke by 32,000–66,000 and myocardial infarction by 54,000–99,000. This intervention, it is said, could also save between $10 billion to $24 billion in healthcare costs annually. In fact, 11 countries of the European Union have recently implemented aggressive public health programmes to reduce salt intake, and several US manufacturers are also reducing the salt content of certain foods. Why not in T&T?

Interestingly, in an editorial in The Lancet, it stated: "The international health community remains easily distracted by exotic microbes such as swine flu (and dengue) and seems to find focusing on things as mundane as high blood pressure difficult, despite the catastrophic human and financial consequences of excess salt." Attention Madam, Minister of Health. Salt is killing us.

• Prof Courtenay Bartholomew is UWI's first Trinidadian professor of medicine and director of the

Medical Research Centre