A new study published in the Archives of Toxicology on September 1 suggests that combinations of pesticides, even at levels deemed safe for human health, may negatively impact the liver and glucose regulation. Researchers from Toxalim, a team at the National Institute for Agricultural Research, Food and Environment, found that four pesticides commonly found in food—when combined—can cause liver dysfunction and impair the body’s ability to regulate blood sugar. The study highlights a phenomenon known as the "cocktail effect," where the combined exposure to multiple substances, even at low levels, can lead to harmful outcomes. This effect is not currently considered in current pesticide regulations, which typically evaluate each chemical individually. To test the effects of these pesticides, the researchers exposed human liver cells to the substances in a laboratory setting and then administered them to mice through food for six months. The study evaluated the impact of the pesticides under two different dietary conditions: a standard diet and a "Western diet," which is high in fats and sugars. The results showed that the harmful effects of the pesticide combination varied depending on the diet. Mice on a normal diet experienced an accumulation of fats in the liver, a sign of liver disease, suggesting that the pesticides had disrupted lipid metabolism. Meanwhile, the Western diet led to changes in glucose metabolism, with the mice showing early signs of diabetes. Interestingly, the study found that the pesticides were present in the livers of mice on the standard diet but not in those on the Western diet. The researchers believe that the way pesticides are distributed in the body depends on diet. In mice fed a high-fat diet, the genes in the liver responsible for detoxification were not activated, meaning the liver could not effectively filter out the toxins. Possible explanations include the idea that fat-soluble pesticides might accumulate in the fatty tissues of the Western diet-fed mice, or that some pesticides might interfere with the enzymes that break down toxins. The four pesticides studied were selected based on data from the Nutrinet Santé cohort, a large-scale research project involving over 170,000 people. This data helped identify pesticides commonly found in food and associated with liver and diabetes-related issues. The study underscores that these substances can still be harmful to health, even at levels considered safe by regulatory agencies. The findings emphasize the need for more research into how pesticides affect the body and highlight the importance of considering diet when assessing pesticide toxicity.