Reducing your salt intake is a bigger challenge than you may think with an estimated 80 per cent of our daily salt intake coming from processed food. Susan Calnan reports
The Greek poet, Homer, referred to it as a divine substance and Plato said it was particularly dear to the gods: for thousands of years salt has been regarded as a valuable commodity, which was once of vital economic importance and even the cause of bitter warfare.
Although salt continues to be an essential substance for life, its consumption today, however, is thought to greatly exceed acceptable levels and, as a result, may be detrimental to our health. In particular, a growing number of studies indicate a strong correlation between excessive salt consumption and high blood pressure.
"The link between a high-salt diet and high blood pressure has been highlighted for many years," says chief executive of the Irish Heart Foundation (IHF), Michael O'Shea. "However, the recent obesity epidemic has placed the spotlight on the salt issue again, in particular in relation to the need to reduce high levels of salt in processed foods."
As part of the IHF's annual Irish Heart Week, which will run from September 26th to October 2nd, the organisation is focusing on the salt issue and on the need to increase public awareness about the potential dangers of high salt consumption. In particular, the IHF will highlight the role that food manufacturers can play in helping to reduce the high levels of salt in processed foods, which account for about 80 per cent of the salt consumed in the daily diet.
"We need a national nutritional policy that sets out clear guidelines on salt consumption for the Irish consumer and that policy needs to involve all of the relevant shareholders, including the food manufacturers and retailers. The salt issue and the role it plays in heart health is an issue that is not going to go away," says O'Shea.
In Ireland, like the majority of developed countries, daily consumption of salt is significantly high. The current average salt intake is about 8.7g per day and there is growing evidence to suggest that children are consuming as much salt as adults, even though they require far less salt.
The World Health Organisation (WHO) recommends that daily salt consumption is restricted to 5g per day, while the IHF recommends that daily salt consumption in Ireland is reduced to 6g, the equivalent of a teaspoon of salt, per day.
There is now convincing evidence that high sodium intake, mainly through dietary salt (sodium chloride), is directly associated with high blood pressure which, in turn, is a major risk factor for cardiovascular disease - the single largest cause of death in Ireland.
Additional research suggests that high dietary salt intake may be a factor in osteoporosis and it may also have a direct effect on increasing a person's risk of stroke, independent of its effect on blood pressure.
Although the adverse health effects of high salt intake are now more widely accepted, the solution to reducing daily salt consumption has sparked a certain degree of controversy.
It is estimated that about 80 per cent of salt consumed every day comes from the processed foods we eat, that 5 per cent occurs naturally in food and that only about 10 to 15 per cent comes from the salt we add ourselves at the table or in cooking.
Because the majority of salt we consume in our diet is already hidden in the foods we eat, reducing the amount of salt we add at the table, therefore, will have only a marginal impact on reducing our daily salt intake.
Increasingly, scientists and health researchers are calling for "population-wide strategies" to reduce salt consumption, namely by encouraging food manufacturers and catering companies to significantly reduce the amount of salt they add to our foods.
Until recently, such an approach was challenged because of lack of evidence that population-wide strategies would lower blood pressure.
However, evidence is growing that such an approach would have beneficial effects on blood pressure, both in people with high blood pressure (hypertensive individuals) and in people with normal blood pressure (normotensive individuals). For example, it is estimated that a reduction in salt consumption of 3g per day (a half teaspoon) would reduce the incidence of stroke by 13 per cent and of coronary heart disease by 10 per cent.
"Ultimately, hypertension, cardiovascular disease and related conditions are population-level problems that require population-level solutions," insists Dr Ivan Perry, professor of public health at University College Cork and a leading expert on salt consumption in Ireland.
"A reduction in the salt concentration of processed food represents a potentially feasible and important population-level measure in the control of essential hypertension."
Perry, who is also a member of the IHF's Blood Pressure Council and the Food Safety Authority's Nutritional Sub-Committee, cites a number of studies, which argue the case for "population-level solutions". Results of the DASH (Dietary Approaches to Stopping Hypertension)-Sodium study, published in the New England Journal of Medicine in the US, for example, demonstrates substantial falls in blood pressure associated with reducing salt intake in both hypertensives and normotensives and highlights how everyone can benefit from a diet that limits excess sodium.
In a recent study carried out by Perry's department at UCC, the daily salt intake of Type II diabetes patients was examined. Although the patients were already following a healthy diet and were reducing the amount of salt they added to their food, results showed that patients were still consuming on average 9 to 10g of salt per day, almost twice the daily level recommended by WHO.
"This highlights the fact that salt consumption is not something that the individual can do that much about," adds Perry. "At the end of the day, reducing salt levels is really an issue for the food sector."
Chief specialist in food science with the Food Safety Authority (FSA), Dr Wayne Anderson, agrees the escalating level of dietary salt consumption is an issue that needs to be addressed by the food sector.
He adds that the FSA is currently in negotiations with some of the major food manufacturers to encourage them to reduce the level of salt in processed foods, in particular, in three of the major staple foodstuffs that people eat everyday in significant quantities - bread, cereals andmeat products.
"Because these products are eaten in much larger quantities than other foodstuffs, they contribute the highest to the intake of salt in the population as a whole," says Anderson.
"Our main focus at the moment, therefore, is to try to get the manufacturers of these three products to reduce the level of salt on an incremental basis over a number of years."
Since January of this year, the FSA secured a 5 per cent reduction in the amount of salt added to bread products by the main bread manufacturers in Ireland. Taste trials are also currently underway to assess how salt levels can be reduced even further in bread products.
The FSA also plans to enter into negotiations with the meat industry in Ireland and is optimistic that producers will acknowledge the need for salt reduction in their products.
Because the majority of breakfast cereals consumed in Ireland are produced in the UK, Anderson says that reducing salt levels in cereals is more of an issue for UK manufacturers.
However, he points to the fact that the UK has been committed to reducing salt levels in their products for the past three years.
The FSA, he adds, is also working with the Retail Forum in Ireland, which will be adopting a similar approach by encouraging food manufacturers to reduce the amount of salt in the products they sell.
Given the significantly high level of dietary salt consumption, matched with worrying rates of cardiovascular disease in Ireland, however, are the FSA's current measures hard-hitting enough?
Anderson argues that although it's early days, the food sector is moving in the right direction in relation to the salt issue.
"You don't start campaigns by going in very hard, particularly when the industry is very willing to change," he adds. "So far, we've been getting a lot of co-operation from the food sector and, although there's still a lot to be done, we are confident that we are making progress."
Perry agrees that it's important to work with the food manufacturers and that an incremental reduction of salt in processed foods over time is the best approach. He adds, however, that it's important not to get too cosy with the food sector over this issue.
"In public health, inevitably there will be tensions between the needs of health and the needs of shareholders," he stresses. "Our role is to try to argue the case for health as opposed to profit."
Perry adds that although the salt issue needs to be addressed as an important dietary contributor to high blood pressure and to other health problems, we shouldn't lose sight of the other contributory factors."Salt isn't the only factor that is important in reducing blood pressure; there are other dietary factors that influence blood pressure, including the extent to which people are overweight and the amount of fresh fruit and vegetables they consume as part of their daily diet," insists Perry.
"Although salt isn't the only factor, however, it is a factor we can do something about, provided we can persuade the food sector to gradually reduce salt levels over the next five to 10 years and as long as we continue to target the major sources of salt in the diet," he says.
For further information on Irish Heart Week, contact the Irish Heart Foundation on 01 6685001 or visit www.irishheart.ie
Ways to reduce salt intake
1. Gradually reduce the amount of salt you add at the table and during cooking, aiming over time to cut out added salt completely.
2. Learn to enjoy the natural flavours of food again.
3. Use alternative flavourings such as black pepper, herbs, spices and lemon juice.
4. Limit the use of stock cubes, gravy granules and ready-made sauces, which are all high in salt. Try making homemade stock and freeze it in ice cube trays, so you can use a few cubes at a time.
5. Choose fresh vegetables and lean meat more often than tinned or processed varieties.
6. Try to make home-cooked meals the norm during the week. If you do need to use ready meals on occasion, look for reduced salt options.
7. Get out of the habit of having instant salty foods at home, scuh as cuppa soups, instant noodles and savoury snack foods such as crisps. In fact, do not even put them in your shopping basket.
8. Reduce the amount of salty meats in your diet.
9. When eating out, always taste the food first before you add seasoning and ask if the sauce or dressing of your dish can be served on the side so you can control how much you use.
10. Remember, the more salty foods you eat, the more salty foods your taste buds will like. Gradually reduce the amount of salt you use and the number of salty foods you buy to give your taste buds time to get accustomed to the reduction in salt.
As recommended by Ursula O'Dwyer, consultant dietician to the Department of Health and Children and the Irish Heart Foundation.