For almost 50 years, public health experts have recommended that we limit our salt intake by linking it to high blood pressure and coronary heart disease.
Salt contains 40 % sodium and 60 % chloride so salt = sodium x 2.5. The Recommended Nutrient Intake for sodium is 1.6g which therefore equates to 4g of salt.
As if the common interchange of the terms ‘sodium’ and ‘salt’ isn’t enough to confuse us, research and recommended health guidelines appear to be at odds.
So, what are we to believe?
The importance of salt
Salt plays a key role in maintaining optimal health. Sodium helps:
- our muscles to contract
- our nerves to function effectively
- regulate blood-pressure and blood-volume regulation
- maintain Acid-Base balance
- maintain fluid balance
- the absorption of Vitamin C.
Furthermore, chloride aids digestion and can help reduce bacterial overgrowth which means a healthier gut.
What public health recommendations fail to highlight is how not enough salt can lead to:
- an increase of cholesterol and triglycerides in the blood
- a hormonal disruption that has been linked to mortality.
So not getting adequate amounts really can be detrimental to our health.
The UK Reference Nutrient Intake (RNI) is 1.6g which many believe to be too low. Not only can not enough be an issue, each person’s requirements will differ based on their lifestyle, activity level, genetics, water intake etc.
The key message here is that blanket guidelines that have been developed to with a large population in mind are a ‘blanket’ approach; they do not take individual needs or requirements in to consideration so should always be taken ‘with a pinch of salt’ – pun intended!
The real issue
The fact is that if you eat a healthy, balanced diet that comprises mainly of fresh, whole foods then you do not need to worry about your salt intake!
I will never forget when I suggested that my Nonna, my Italian Grandmother, cut back on the amount of salt she puts in her sauces and salads (before I became a Nutritionist of course…). It was as if I was blaspheming….
‘It will taste like dirt’ she yelled irately in her local dialect.
Of course, my Nonna follows a Mediterranean diet that is pretty devoid of processed foods so has no need to consider such minute, inconsequential details when preparing food – and she is almost 90 now may I add!
The issue we face is that processed foods are MUCH higher in salt that any we would add to improve taste. It is even found in raw chicken to help preserve it for longer.
In addition, they lack potassium and other essential minerals that help to protect our cardiovascular health. And, when we consume a high level of processed foods, we are more likely to reduce our consumption of the whole foods that contain the vital nutrients we require.
Not eating enough fruit and vegetables means that our Sodium:Potassium ratio is unbalanced which is actually a greater indicator of Cardiovascular disease than our salt intake alone.
So, instead of stressing about how much salt you add to your food, it would be more prudent to processed food consumption and increase fruit and veg intake. Add as much salt as you need to your whole foods, it may just increase the amount you eat. For example, greens contain potassium, magnesium and other vital nutrients and adding salt to them makes them taste nicer so we eat more.
Does salt really raise blood pressure and cause heart disease?
The research in this area is incredibly nuanced and the evidence to suggest that salt is the cause of high blood pressure and cardiovascular disease is weak.
In one study, increasing salt intake from 4g to 15g for 6 days did not significantly increase blood pressure in males with normal blood pressure (Foo et al. 1998).
Yet in another study, increasing salt intake to 5.5g per day for 4 weeks significantly increased blood pressure.
And in another study, reducing salt intake by ~4.4g/day for over 4 weeks significantly reduced systolic & diastolic blood pressure (He at al.2013).
Whilst it is important to note that statistical significance does not equate to real life significance, the jury really is still out on this one. Are high salt intakes really causing issues or is it an unhealthy lifestyle in general?
One study concluded:
“Both low sodium intakes and high sodium intakes are associated with increased mortality, consistent with a U –shaped association between sodium intake and health outcomes” – Graudal et al. (2014)
Furthermore, a look in to ancestral diets is somewhat revealing. The Kuna of Panama have a very high salt intake yet are free from hypertension (raised blood pressure) and Cardio Vascular Disease (CVD). One may think that this is because they have a protective, genetic predisposition but Kuna’s who have moved to more urban areas, where they consume less added salt but more processed foods, have been observed to experience higher rates of CVD and blood pressure.
It is true that genetics can play a part in the development of disease but do not underestimate the power of environment and lifestyle.
To conclude, what seems to suit a majority does not necessarily apply to an individual. We are all different; no two people share the exact same genetics, lifestyle or environment so a salt intake that is healthy for me may not be for you.
One thing is clear, however, a shift towards a more traditional, less processed diet would be a good move for anyone!