Salt and high blood pressure

Salt - it’s one of the staples of the British diet. Our fish and chips don’t taste half as good without it and it’s the most common form of seasoning used in cooking in homes and restaurants up and down the country. But unfortunately, high dietary sodium intake is associated with high blood pressure, significantly increasing the risk of cardiovascular disease, so while we might all love the taste, it’s a good idea to put the salt shaker to the back of the cupboard, to avoid serious heart problems.

You might be surprised to know, however, that limiting the amount you eat may not help everyone to lower their blood pressure as some of us are more sensitive to salt than others¹.

What is salt sensitivity?

It is a measure of how your blood pressure responds to salt intake. People can either be salt-sensitive or salt-resistant. Around a quarter of the population has a sensitivity to salt, meaning that their blood pressure rises as soon as the amount of sodium chloride in their diet increases².

These elevated levels put these people at a higher risk of cardiovascular disease, while those who are salt resistant will not see an increase in blood pressure, even if they eat a diet that is high in salt.

What causes salt sensitivity?

Salt sensitivity - or sodium homeostasis - is regulated by a system that happens in the kidney and in vascular smooth muscle cells. Depending on their genetic profile, race, age, gender and medical history, people can have variations in this system, which cause the kidney in salt sensitive individuals to handle excess sodium less efficiently than others.

It is more common in females, African and Asian people, and the likelihood of having a salt sensitivity increases with age³.

However, whether or not you are likely to have a sodium sensitivity can often be determined by your genes. About 38% of the general population carries an ACE gene variant that increases activity in the renin-angiotensin-aldosterone system. This leads to greater blood pressure increase when there are increased levels of sodium in the blood.

What should you do if you are salt-sensitive?

To reduce your risk of high blood pressure and cardiovascular disease, you should pay more attention to how much salt you are consuming as many foods that you might not expect to contain salt have extremely high levels. Try to limit your intake of foods that are high in sodium while eating more foods that are rich in potassium. Here are some tips:

Eat more vegetables and fruit
Eat more fresh foods and fewer processed foods
Avoid eating lots of baked goods, as bicarbonate of soda or baking powder contains high levels of sodium.
Get into the habit of looking at the labels in supermarkets. Most processed foods now have low-sodium versions available.
When eating out, ask for them not to add salt to your food and never add salt to food when it’s been prepared.

What are the other benefits of cutting back on salt?

In addition to helping to prevent high blood pressure, cutting back on salt also reduces stiff arteries, a condition associated with heart attack and stroke⁴.

How can I tell if I have a sensitivity to salt?

The MyHealthChecked Intolerances & Sensitivities DNA Test will help you find out if your genetic profile makes you more at risk of having a sensitivity to salt, as well as a range of other foods and drinks including caffeine and alcohol.

All you need to do is take a quick cheek swab and send it off to our UK-based laboratory. Our medical experts will then analyse your genetic profile and indicate whether you are likely to experience blood pressure changes when your sodium intake is high. If so, you’ll get clear, actionable advice on diet and lifestyle changes that are tailored to your genetic makeup.

References

National Center for Biotechnology Information. (n.d.). Salt Sensitivity and Hypertension: A Paradigm Shift. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4144382/
Pilic, L., Pedlar, C. R., & Mavrommatis, Y. (2016). Salt-sensitive hypertension: mechanisms and effects of dietary and other lifestyle factors. Available from: https://doi.org/10.1093/nutrit/nuw028
GB HealthWatch. (n.d.). Salt Sensitivity. Available from: https://www.gbhealthwatch.com/Trait-Salt-Sensitivity.php
American Heart Association. (n.d.). Salt Sensitivity May Increase Risk of High Blood Pressure. Available from: https://www.heart.org/en/news/2021/04/26/salt-sensitivity-may-increase-risk-of-high-blood-pressure