For a number of years, experts have talked about cholesterol in terms of “good” and “bad”.
The former – known as HDL – is said to clear away cholesterol so that it is processed by the liver and removed from the body.
In contrast, the latter – called LDL – is understood to contribute to the build-up of inflamed fatty deposits.
Studies have suggested high levels of HDL lower the likelihood of heart attacks – and people have been encouraged to consume lots of “healthy” fats like olive oil, oily fish and nuts in order to raise it.
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However, according to the Daily Mail, new research suggests that after a certain point it can actually become a risk factor.
Speaking to the paper, Dr Laura Corr, a consultant cardiologist, said: “It’s true that very low HDL isn’t a good thing, and the risk of a heart attack lowers as HDL rises.
“But we now know unusually high HDL in some people isn’t protective and is associated with an increased risk of heart attacks. It was a surprise when the research started to show this.”
In 2018, scientists at Emory University School of Medicine in Atlanta looked at the link between HDL and risk of heart attack and death in 6,000 patients.
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They discovered that there were more heart attacks among those with low HDL – which wasn’t a surprise – but there was also a spike among those with high HDL too.
This trend persisted even taking into account “bad” LDL cholesterol levels, and factors like smoking or diabetes.
Dr Marc Allard-Ratick, the cardiologist who led the study, said: “Traditionally, doctors have told their patients that the higher your ‘good’ cholesterol, the better.
“However, the results from this study and others suggest this may no longer be the case.”
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Women are also more likely to have higher HDL levels, although researchers are still unclear why.
Last month, a study found that eating oily fish can reduce the risk of heart attacks and strokes by balancing the concentration of fats and cholesterol in the blood.
Scientists from the Universitat Rovira i Virgili (URV) and Harvard Medical School, discovered that consuming omega-3 – the fatty acids present in fish – can regulate the body’s lipoproteins.
These are the particles that transport lipids, or fat, through the blood – and this in turn can lower the risk of a person suffering cardiovascular problems.