One question I keep being asked is ‘how much salt can we eat?’
Firstly it’s probably useful to know that our bodies do need salt to function properly and our own, Dr Claire Maguire has answered most of this question in her Dear Doctor question (reproduced below):
“Don’t be confused as in my heart of hearts I do not believe salt or rather sodium chloride to be bad! It is a necessary chemical for the body to work in that sodium is required for the maintenance of extracellular fluid volume (I’m talking blood here!!!) so sodium regulates blood pressure. It is also necessary for the generation and transmission of electrical impulses in nerves and muscles and for the uptake of nutrients from the small intestine. So as you can see sodium is important for our bodies to works.
So, why the bad press about salt? Well, our bodies need very little sodium for the above functioning of our bodies, about 4.2g salt a day. And this is where the problem regarding salt arises as the majority of the salt consumed in the standard UK (or American) diet comes from processed, pre-packed foods ie breads, cereals, sauces etc. On the whole the average consumer does not know where their salt is coming from as most people do not spend time reading labels and calculating their salt intake. As much as 75% of salt is consumed this way, leading to an average salt consumption of around 10g. Therefore, nutritionists recommend as a way of reducing your overall salt consumption the easy ways to cut it back are to not add salt to your food when you are cooking and to not add salt on your meal at the table.”
The history of salt is fascinating, especially the importance to trade over the centuries and a short summary can be found in the UK government archives. Apparently our highest salt intake at 18g/day was during the 1800s when we ate lots of cured meats and fish, since this was before the days of refrigerators and salt was the only way to preserve our fresh food. The UK government guidelines now recommend our daily salt intake to be 6g per day which is about 1 heaped teaspoon full.
So sodium regulates blood pressure and high salt intake is claimed to produce high blood pressure. The other problem with eating too much salt is that your body automatically wants to regulate to the right concentration of electrolytes, so it retains water to make that balance right – hence you put on weight!
But too little salt is also dangerous for us. Too little sodium can be the cause of muscle cramps, dizziness and drinking too much water, without enough salt, can cause water intoxication which can be fatal.
So the problem with salt is twofold; firstly we eat so much processed food and this always has salt added (even ‘reduced salt’ items). Plus even raw unprocessed food has natural salt, so if you were to add up all the salt contents from everything you ate in a day you’d be amazed at how high the total salt content was! In the UK, about 75% of the salt in the diet comes from processed foods. The salt added when cooking or at the table contributes a further 10-15% and naturally occurring salt (it is found naturally in most foods) represents the remaining 10-15% (ref: Medical News Today)
Remember if you try to read the food labels then you need to calculate the salt (sodium) amount on the ‘actual’ amount you’ll eat, not on the very small serving size the nutritional values are based on! Who eats only 10 potato crisps at one time from a whole packet?
Secondly the type of salt is also important. According to the pH diet philosophy, the body functions best when its pH is at a specific alkaline level and our diet is what affects this level. By eating a diet high in acid producing foods we disrupt the efficient functioning of our body system. One of these food items is salt – but not all salt is bad… Table salt is the bad one as its acid forming (& hence bad for you) whereas sea salt or rock salt alkalinizes the body so it’s ok. And the reason? As expected the answer is that table salt is highly processed and the refining process removes nearly all of the additional trace minerals which would normally neutralise the acids that sodium chloride make. Hence table salt is about 95% sodium chloride and therefore acidic to your body. Plus it has additives such as anti-caking agents to stop it clumping.
One last theory to contemplate is this: The UK government guidelines recommend limiting your daily salt intake to 6g per day which equates to 2.4 g for sodium per day (since salt is sodium & chloride) & it seems your body needs 1.6g of sodium (or 4g of salt) per day to function. A study in 2009 found that the sodium consumption of 19,151 individuals from 33 countries fit into the narrow range of 2.7 to 4.9 g/day. The small range across many cultures, together with animal studies, suggest that sodium intake is tightly controlled by feedback loops in the body, making recommendations to reduce sodium consumption below 2.7 g/day potentially futile…
So I suggest you take all this information with a pinch of salt – rock salt that is.