Did you know that official advice is to avoid effervescent paracetamol, vitamin C or other fizzy tablets? This is especially important if you have high blood pressure, as these formulations use sodium salts to achieve their characteristic fizz. As a result, effervescent medications and supplements can contain as much sodium as is found in 1g of salt which can have a significant blood pressure raising effect.
If you currently take fizzy medicines or vitamins, NHS Choices recommend you consider changing to a non-effervescent tablet, particularly if you have been advised to reduce your salt intake.
Fizzy tablets can cause high blood pressure
The advice to switch to non-effervescent tablets is based on a study, published in the British Medical Journal, which involved almost 1.3 million people.
The results showed that those who used sodium-containing soluble, effervescent or dispersible painkillers were seven times more likely to have high blood pressure than those using standard tablets. They were also between 16% and 28% more likely to experience a non-fatal heart attack or stroke.
These are scary figures and, not surprisingly, the researchers concluded that sodium-containing formulations should be prescribed with caution only if the perceived benefits outweigh these risks.
Given that non-fizzy alternatives are readily available, the only time the benefits are likely to outweigh the risks is if someone is physically unable to swallow a tablet.
The blood pressure benefits of stopping these sodium-containing products are significant.
In a study involving older people taking effervescent paracetamol (3g per day) for osteoarthritis pain, simply switching from fizzy to standard tablets brought their blood pressure down by an average of 13/2.5 mmHg within four weeks.
This is a better effect than is seen with most blood pressure medication, and could allow many people to avoid or stop taking antihypertensive treatments.
Why excess sodium is bad for blood pressure
Some people are more sensitive to salt than others as a result of genetic factors affecting the kidneys. This makes the kidneys less efficient at secreting excess sodium, so that blood pressure rises due to sodium and fluid retention. This effect is most pronounced if potassium intakes are also low.
The adverse effects of sodium can also occur with short-term use, even in healthy people. A study looking at arterial blood flow and dilation found that eating a single high-salt meal produced potentially harmful circulatory effects. These same effects could occur after taking a high sodium effervescent drink, too, especially if the prescribed dose is taken three times a day.
The current average salt intake of 8.1g per day exceeds the recommended maximum of 6g, so most of us would benefit from cutting back on salt, and increasing potassium intakes to flush excess sodium through the kidneys.
Potassium is mainly found in fruit, vegetables and wholegrains. Supplements designed for people with high blood pressure which include sensible amounts of potassium are also available.
Check fizzy supplement labels for sodium
Check the labels of any fizzy, soluble, effervescent or dispersible supplements or painkillers you are taking to see how much sodium they contain.
To convert sodium to salt, simply multiply by 2.5 so, for example, a product containing 0.4g sodium is equivalent to the sodium found in 1g salt (sodium chloride).
The only effervescent vitamin C I am currently aware of that contains no sodium, but instead uses a potassium salt to achieve the fizz is Ruby Breakfast Vitamin C Effervescent Tablets, from healthspan.co.uk. Although this contains a small amount of pink grapefruit juice as flavouring, the level is several hundred times less than is found in a single grapefruit. It is unlikely to cause significant interaction with prescribed medication, but do check the patient information leaflet supplied with any medication you are taking and check with a pharmacist or doctor.
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