Is salt restriction necessary in high blood pressure?

Dr Md Abedur Rahman
Patients often ask, what changes in lifestyle can improve their blood pressure controlled. In response, we doctors often recommend that reducing body weight, decreasing intake of dietary salt and limiting consumption of alcohol can be beneficial.Many people with high blood pressure see salt as a villain. According to conventional wisdom, just a few shakes can send blood pressure high. But is salt really so dangerous?After decades of studies, scientists finally have answer to the question: Yes and no. For many people, extra salt really does raise blood pressure. In a few cases, however, it seems to lower pressure. And for some people, it does not really matter.Nobody knows why some people are sensitive to salt and others are not. But researchers have some clear-cut advice — to be on the safe side, everyone should keep a lid on salt intake. The amount of salt that we eat has a direct effect on our blood pressure.The more salt we take, the higher our blood pressure goes. This is true, not only in people with high blood pressure, but also in people with normal blood pressure. A high salt intake also causes other health damage such as greater retention of water in your body, which leads to swelling of the ankles.How much salt should I consume each day?The Food and Nutrition Board (of America) recommends a daily intake of no more than 2,300 mg. And as one study shows, reducing salt to 1,500 mg a day may be even better. The study published in the December 18, 2001 issue of the Annals of Internal Medicine, examined six diets and found that a low-sodium regimen could make a healthy diet even healthier.Half of the study subjects ate a typical diet but were divided into three groups, each consuming different levels of sodium: high (3,300 mg each day), intermediate (2,400 mg per day), and low (1,500 mg each day). The participants in the other half of the study ate meals rich in fruits and vegetables but low in fat and cholesterol (also known as the Dietary Approaches to Stop Hypertension or DASH diet).Their diets also were subdivided into three different levels of salt consumption. The one-sixth of the subjects who ate the lowest-sodium DASH diet enjoyed the greatest reduction in blood pressure, even among people who did not have high blood pressure (also called hypertension) to start with. This group lost an average of 9 points from their systolic pressure (the top number in a blood pressure reading) — the biggest drop in any group.Weinberger's findings highlight two important points. First, some people can significantly reduce their blood pressure by cutting back on salt. Second, salt is just a start. You can give your heart extra protection by getting plenty of fruits and vegetables every day and going easy on fats. Not only will you lower your blood pressure, you will reduce your risk of atherosclerosis (a form of hardening of the arteries) and heart disease.If I do not have high blood pressure, do I still need to watch my salt?Another recent NHLBI study suggests that salt sensitivity can be a dangerous condition — even among people who do not have high blood pressure. Researchers followed up on a group of 708 people who had been evaluated for salt sensitivity and hypertension 25 years ago and were surprised by their findings.Subjects who had normal blood pressure but were sensitive to salt were just as likely as subjects with hypertension to have died of heart disease.Since there is no blood test or other quick way to measure salt sensitivity, it is best not to take any chances.How can I cut back on salt?You can start by going easy on the saltshaker. It is important to understand, however, that the average person gets 90 percent of his or her salt from other sources. Many "convenience" foods such as frozen dinners, restaurant meals, luncheon meats, fast foods, and canned soups are extremely high in salt.The best way to protect yourself is to prepare meals at home. If you do eat processed foods, check the labels carefully — and aim for a daily dose of 2,300 mg of sodium or less from all your food sources.

The writer is a teacher in Dhaka Medical College