Millions of people could be forced to permanently cut a specific food from their diets to avoid serious heart complications, according to medical experts. Failing to do so could result in a potentially "toxic" reaction developing inside the body. Statins, a widely prescribed drug commonly given to those with high cholesterol levels, are taken by around seven to eight million people across the UK, according to the British Heart Foundation. These once-daily tablets work by reducing cholesterol production and removing LDL, commonly known as 'the bad cholesterol', from the bloodstream. Keeping this 'silent killer' in check is crucial, as high cholesterol typically shows no warning signs until it reaches a considerably advanced stage. If your blood vessels become blocked, this dramatically increases the risk of suffering heart attacks and strokes. Statins work by restricting the amount of cholesterol produced by the liver while helping it to remove existing cholesterol from the blood. They also help to stabilise plaque, a waxy substance that can accumulate within artery walls, and can reduce inflammation throughout the arterial walls. The NHS states that the vast majority of people taking statins will likely need to continue taking them for life. If the treatment is stopped for any reason, cholesterol levels may gradually begin to rise once more. As a result, patients need to be aware that certain foods and drinks are not appropriate to consume while undergoing statin therapy. One surprising item that is frequently overlooked is the need to avoid grapefruit, reports Bristol Live . Experts at Harvard Health Medical School have explained why this particular citrus fruit, along with its juice, should be eliminated from your diet when taking specific medications. The chemical reaction between certain drugs and the fruit can cause problems, sometimes leading to "toxic" outcomes. Statins are broken down in the intestines through an enzyme known as CYP3A before entering the bloodstream, a process that is disrupted after eating grapefruit. Grapefruit juice contains furanocoumarins, substances that inhibit CYP3A, leading to higher drug absorption and potentially making it "toxic in some cases". However, grapefruit does not significantly affect all statin treatments, meaning a blanket ban is not always necessary. A doctor may suggest switching from those medications most severely affected, including atorvastatin, lovastatin and simvastatin. Medical guidance may range from complete abstinence from grapefruit to limited intake. It is vital not to carry out personal experiments or modify treatment without the advice of a qualified medical professional. The precise quantity of grapefruit needed to trigger an adverse reaction remains uncertain. For some people, just one glass of grapefruit juice could cause complications, while others may need to consume larger amounts of the fruit or its juice before encountering any problems. Those taking statins can generally enjoy oranges and other citrus fruits without worry, however.