Heart disease is still Britain's biggest killer. One of the major culprits, often overlooked, is salt. Now, a new US study suggests an even greater need to cut back. iVillage nutritionist Dr Wynnie Chan tells you how

Recent research from Harvard Medical School and the National Heart, Lung and Blood Institute in America revealed that scaling back on salt has an even greater impact on lowering blood pressure than previously thought. This study found those who reduced their salt intake and followed a low fat diet lowered their blood pressure significantly more than another group who reduced their salt intake but continued with a high-fat diet and a third group who followed a low fat diet but did not cut down on salt.

The question of how much salt is too much is controversial because many studies have shown that reducing salt intake can also help lower high blood pressure, but it doesn't necessarily mean a habitual high salt intake causes high blood pressure. In 1994, the Department of Health recommended that people lower their salt intake from 9g to 6g a day based on studies that showed this could reduce blood pressure in older people and in people with high blood pressure. The 1999 Government White Paper, Our Healthier Nation, encouraged people to reduce the amount of salt in their diets to help minimise the number of strokes and heart disease.

We only need 1.6g of sodium a day (the total amount of salt in two bags of crisps, two slices of bread and two biscuits) to maintain normal bodily functions, but since most people are used to such a higher intake they find it difficult to cut back.

The average amount of sodium consumed by adults in the UK is 3.5g per day, or 9g salt (sodium chloride). This is equivalent to the total amount of salt in 4 rashers bacon, 2 bags crisps, 3 slices white bread, 1 large chunk cheese, 2 digestive biscuits and 1 large sausage. You should consider a reduction in salt intake if you have high blood pressure and are overweight or obese. Even if you have a healthy body weight and normal blood pressure it wouldn't hurt to cut back.

Recently, some retailers announced their intention to reduce salt content in many products but because it is a preservative, the food industry must first ensure they can reduce salt in foods without compromising safety.

Practical recommendations to lower blood pressure

• Avoid excessive amounts of salty foods like canned vegetables, butters, margarines and spreads, cheese, bread, pizzas, pies, crisps, some breakfast cereals, processed meats such as bacon, sausages, other types of meat products like luncheon meat, seasonings such as monosodium glutamate (MSG), sodium bicarbonate and some antacid medicines.
• Don't use salt at the table.
• Reduce the amount of salt in cooking by trying alternative seasonings such as herbs, lime and lemon juice.
• Buy low sodium versions of foods and condiments like Lo-salt, or Shoyu instead of soy sauce.
• Limit your alcohol intake.
• Maintain a healthy body weight.
• Exercise regularly.
• Include plenty of fruit and vegetables and low fat dairy products in your diet as they provide potassium and calcium respectively.