Salt and High Blood Pressure - What are the Facts?

Salt and high blood pressure: is there really a link?

What is the truth about salt? Does it cause high blood pressure? Does the free use of the salt cellar inevitably lead to health problems? If we continue to eat salt in a free and easy way as we get older are we risking our health?

Here are some thoughts on salt as a necessary and healthy part of our diets and in particular about salt and high blood pressure.

Why do I think this question of salt and health is important? This site is about green living, after all. The main reason I think this is important from a green living stand point is that the world is full of beautiful, natural salts that we could all (well, most of us) be enjoying! And mostly they can be produced in an eco-friendly sustainable manner. (It is also important to "junk the junk" - a lot of our salt intake is hidden in junk foods. Read on below for more on the role of junk foods and excessive salt consumption.)

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Salt and health - the good news

So, here's the good news. If you do not already have high blood pressure and you are living a healthy lifestyle you do not need to be excessively concerned about your salt intake, no matter what your age. Note the provisos: If you are living a healthy lifestyle! And if you do not already have a high blood pressure or a heart condition.

Some recent research has shown that people who are otherwise healthy need not fear salt and need not restrict it in their daily diet. Just how true this is will become more evident with further research. Here's a brief round-up of the arguments for a healthy intake of salt as part of a healthy lifestyle.

Salt and high blood pressure: is there really a link?
Why do we need salt?

Salt (sodium) is an essential part of a healthy diet because it is part of our body's cells. Salts maintain the electrolyte balance inside and outside of our cells. The electrolyte enables cells to do their work - producing energy, for example. Potassium and sodium salts are the main salts involved, (i.e sodium chloride and potassium chloride). When electrolyte levels are depleted one of the symptoms is exhaustion.

If you want to understand the role of potassium in preserving a healthy blood pressure, you can't do better than to read The High Blood Pressure Solution: Natural Prevention and Cure With the K Factor

by Richard D Moore, MD. It has had 5 star reviews and helped many people rid themselves of the curse of high blood pressure.

Salt is constantly lost from our bodies as we go about our daily activities. Exercise, in particular, depletes our salt levels. Salt is lost in urine and sweat. If not enough salt is taken to compensate for what is being lost actual illness can result. This is even more important when illness causes salt loss: one of the standard medical responses to diarrhoea and vomiting is to replace lost salts. This speeds recovery and in extreme cases prevents death.

People in hot, tropical climates particularly need salt (because heat makes you sweat). The human body cannot store salt for long, so adequate supplies from food and drinks are essential. In hot countries as much as 20 grams of salt may be lost per day by people engaged in strenuous activities.

Salt and high blood pressure: is there really a link?
How much salt do we need?

We do not need much if any added salt as many foods will supply us with some. Natural foods contain enough salt (sodium and potassium) for our needs for the most part, especially in temperate parts of the world.

The US National Academy of Sciences recommends that Americans consume at least 500 mg. of salt per day. Left to their own devices, many people consume far, far more. The kidneys will cope with excessive salt intake up to a point by excreting it.

Adults in good health are able to cope with excessive amounts of salt - at least in the short term. Babies and young children are a different matter. Babies need less than one gram total salt per day which is why it should never be added to food for very young babies. (There was a tragic case in Britain in 1999 of a 3 month old baby who died from being fed adult food. The high salt levels overwhelmed his kidneys resulting in brain damage.)

The UK government recommends that 6 grams of salt per day is enough for an adult.

About 3/4 of the salt consumed comes as hidden salt in preserved and packaged foods.

Salt and high blood pressure: is there really a link?

Salt and high blood pressure: 
Hidden salts

One source of excess salt in the western diet is "junk food". Many processed foods contain astonishingly high amounts of sodium. This may not be present as sodium chloride (table salt) but rather as sodium nitrate and sodium nitrite.

Sodium nitrite is used to preserve and colour some foods. Some studies have found a link between high processed meat consumption and colon cancer - processed meats are very often preserved with sodium nitrite because it prevents botulism.

Sodium nitrate is also sometimes used as a preservative in foods. It also occurs naturally in leafy green vegetables. However, as an additive, it may cause some foods to be unduly high in sodium.

Salt and high blood pressure: is there really a link?

Salt and high blood pressure:
Calculating your hidden salt intake

You can do a rough-and-ready calculation to tell you the total amount of salt in packaged food. Just read off the amounts of sodium and multiply their total by 2.5. This gives you the equivalent of actual grams of salt present.

If you are interested in keeping within the government guidelines for salt intake, it is also worth doing a little pinch test. Measure out a 6 grams of salt. Weigh it if you want reasonable accuracy; otherwise a level teaspoonful should be around 5 or 6 grams in weight.

Now take a normal pinch of this salt and remove it from the heap. Count the number of times you can remove a pinch from the heap before it is all gone. This gives you a rough and ready idea of how much salt you can add to your food - assuming of course that you have eliminated most packaged and ready salted foods from your diet. (Remember, 3/4 of most people's salt comes from packaged food.)

It's interesting to see that usually you can get more pinches of gourmet salt than conventional salt from a 6 grams heap. This is because gourmet salts usually have a looser structure and therefore weigh less by volume compared to conventional table salts.

This little test needs to be done by the individual who wants to control their salt levels. You can't rely on other peoples' ideas of a pinch as people obviously have very different sized fingers and different ways of gripping the salt.

It's only a rough and ready way of measuring, so don't be too reliant on it, especially if you do have health problems. (The point of this article is that salt intake is not too crucial for people who are in good health and who are taking steps to maintain their health - in particular, eating a good diet and taking plenty of exercise.)

Salt and high blood pressure:
How are salt and high blood pressure linked?

An excessive salt intake can be a contributory cause in high blood pressure. This has been a fairly well-understood and accepted fact in medicine for many years.

Eating too much salt can lead to "hardening of the arteries" (arteriosclerosis) which in turn may be one cause of high blood pressure. The artery walls thicken and become less flexible, resulting in increased pressure as the blood pumps against the resistance of the thickened, toughened artery walls.

The main causes of hardening of the arteries are: smoking, high cholesterol levels, diabetes, and inadequate exercise. Atherosclerosis is commonly a co-factor - i.e. the build up of fatty deposits on the artery walls. Eating a diet which is routinely too high in salt is also a contributory cause.

If you already have hypertension (high blood pressure) then it's still very important to control your salt intake to within reasonable limits.

However, recent research has shown that a long-term low-salt diet may not be such a healthy choice. The study showed that the lower your salt intake the higher your risk of death from coronary heart disease. This is because low salt levels increase artery damage from certain hormones.

If you want to read about the report and judge for yourself see here .

There is also some evidence that the modern high fat/sugar and processed food diet is just too low in other essential minerals such as potassium, calcium and magnesium. These imbalances may play a role in high blood pressure and heart disease. Vegetarians generally have fewer problems with raised blood pressure than meat eaters, probably because they eat relatively more vegetable-based foods which are rich in these minerals.

These minerals are thought to play an important role in preserving the elasticity of the arteries.

Salt and high blood pressure

This is an important health issue: about 1/3 of adults in the US, Canada and Britain have some raised blood pressure.

According to the Salt Institute, (who, of course, have a vested interested in promoting salt!) people who reduce their intake of salt get only a limited and decreasing effect upon their blood pressure. There are however, some individuals who are salt sensitive - but even they may benefit more from other dietary adjustments rather than just going down the low salt route.

The DASH "Dietary Approaches to Stop Hypertension" is a diet plan based on scientific research that shows eating mainly certain types of foods can reduce high blood pressure. The DASH plan focuses on fruits and vegetables, and is low in saturated fat, total fat & cholesterol. It also emphasises food rich in heart-healthy minerals, like magnesium, potassium, and calcium.

Here's a link to someone who was part of a scientific inquiry into the effects of salt - which apparently revealed no link between salt intake and hypertension.

However, there are other problems that may arise from excessive salt use. Salt (sodium) has been linked to other serious illnesses such as strokes, asthma, osteoporosis and kidney disease.

The scientific debate about the exact relation of salt and high blood pressure will doubtless roll on for many years to come!

Nevertheless, it certainly makes sense for anyone suffering from hypertension to review their diet carefully, especially as regard to the amount of salt and fat they consume. Anyone who is overweight, on HRT or steroids should be especially careful, as should anyone with a family history of high blood pressure or heart disease.

This is an important health issue: about 1/3 of adults in the US, Canada and Britain have some raised blood pressure.

There is also an on-going problem with children's commercial foods. A Food Commission report in 2003 (the Food Commission is a British organisation which monitors food quality) noted that many children's foods contained as much as twice the recommended daily salt provision in one serving.

The recommended amount for children between 5 and 10 is no more than 4 grams per day. One bag of crisps may supply more than 0.5 gram - so it's quite easy for snack-loving youngsters to be getting a high proportion of their daily allowance without eating any real food!

Salt and high blood pressure:
A healthy lifestyle

For the rest of us, the important thing is to find a balanced, agreeable and enjoyable diet and lifestyle which contribute to our long term health and well being. If we mainly avoid packaged and factory prepared foods with hidden salt we'll be helping ourselves to good health. And if we avoid excessive amounts of saturated fats and sugars and enjoy a reasonable exercise routine, then salt can then still be an enjoyable part our food.

It's also worth taking a good look at the types of salt we include in our diet. Here is a page about gourmet salts which some health experts believe play a more positive role in promoting health than conventional table salt.

The link between excessive dietary salt and high blood pressure is fairly clear but one of the less explored aspects is the fact that the modern western diet is sadly deficient in potassium-rich foods. So whether you measure your salt intake or not, make sure you are eating plenty of vegetables!