Recently, there has been a flurry of debates on whether a low-salt diet is harmful or helpful. A recent study found that low-salt diets increase the risk of death from heart attacks and strokes and do not prevent high blood pressure. Many feel this research is flawed, so the debate will continue. Researchers at the Centers for Disease Control and Prevention pointed out that the study was small; the subjects were relatively young and had very few cardiovascular events that made it difficult to draw any firm conclusions.
All the sodium consumed in a 24-hour period is excreted in the urine. So if you measure this amount it becomes the most accurate way to determine sodium consumption. Using this method, it was found that the less salt people ate, the more likely they were to die of heart disease- 50 people in the lowest third of salt consumption (2.5 grams of sodium per day) died during the study compared with 24 in the medium group (3.9 grams of sodium per day) and 10 in the highest salt consumption (6.0 grams of sodium a day). The people eating the most salt were also no more likely to develop high blood pressure.
Many health experts consider this study to be flawed and should not be the basis for any public health decisions. Often media headlines reflect misguided conclusions as well as the salt industry promoting these headlines to discount any adverse information about their product. Additionally, one or two studies do not make a very sound basis for health conclusions – but in this case there have been other studies that support these conclusions including one study by Dr. Michael Alderman, a blood pressure researcher and editor of the American Journal of Hypertension. He noted that lower salt consumption increases insulin resistance, which can increase the risk of heart disease.
Dr. Alderman further points out that most all the studies about salt consumption are inadequate – either short-term or are observational and the population characteristics are varied. It is unlikely that a large, randomly controlled study for a long period of time can be done. It would be impossible to keep people on a low-sodium diet for years with salt being so ubiquitous in the food supply.
Nevertheless, the debate will continue. Before you reach for the saltshaker, please note that a major study of more than 12,000 American adults compared diets with little sodium relative to potassium with diets with a high sodium-to potassium ratio. People eating the higher sodium, less potassium diet were 50% more likely to die from any cause and more than twice as likely to die from ischemic heart disease.
In other words, more potassium in the diet relative to sodium may help to modify any harmful effects of sodium in some people. Sodium in excess had been thought to stiffen arteries and block nitric oxide that relaxes arteries. Potassium on the other hand does the opposite – activates nitric oxide which reduces pressure in the arteries and thus lowers blood pressure.
Blood pressure increases with age and if you live long enough, you will be at risk at some point in your life.
So what should you do? Lets’ look at the facts (we know).
- The body’s requirement for sodium is small – only 220 milligrams a day; we eat on average more than 3400 milligrams a day mainly form processed and restaurant foods.
- The major sources of sodium in the U.S. diet come from:
Processed foods (77%)
Fresh foods (12%)
Salt added at the table (6%)
Salt added during cooking (5%)
- The current recommendation is to consume no more than 2300 milligrams a day (about a teaspoon of salt) for most people; 1500 milligrams for people older than 50, all African-Americans, and everyone with high blood pressure, diabetes or chronic kidney diseas
- Our intake has increased significantly since the early 1970’s due to more processed and restaurant foods. Salt is included on the FDA’s GRAS list – Generally Recognized as Safe, so there is no limit to its use by food companies.
- Potassium is lost in food processing, so as the sodium rises in processed foods, potassium content is decreased.
- New York City’s Department of Health and Mental Hygiene is leading a national effort to get food producers and restaurants to gradually reduce the salt in their products. So far, some have made a voluntary commitment (Kraft, Subway, Target) to comply by cutting the sodium in their products by 25% by 2014.
- Interestingly, Finland has promoted a government effort to reduce sodium intake by one-third and this has resulted in a decrease in hypertension and premature deaths from stroke and heart disease. In addition, Finland has made a concerted effort to increase the heart health of their population. The North Karelia Project was launched in Finland in 1972 in response to the local petition to get urgent and effective help to reduce the great burden of exceptionally high coronary heart disease mortality rates in the area.
Practical ways to lower sodium and increase potassium in your diet.
- Eat fewer processed foods and more whole foods such as fruits, leafy greens, potatoes and yogurt. Follow a DASH (Dietary Approach to Prevent Hypertension) by eating 4-5 servings each of fruits and vegetables a day. Avoid potassium supplements.
- Order vegetables steamed, salad dressing on the side, and split large portions in restaurants with someone else.
- Eat less at fast-food restaurants – some entrees can have a single day’s worth of sodium.
- Read food labels for sodium content and be careful of serving sizes. The amount of sodium is for one serving and eating the whole package just increases the amount of sodium consumed.
- Visit the American Heart Association Web site at www.heart.org/sodium to comment on sodium consumption.