American scientists say people over 50 who take the painkiller on most days of the week are increasing their chance of getting blood cancer over a 10-year period from about one to two per cent.

Researchers at the Fred Hutchinson Cancer Research Centre in Seattle drew their conclusions after following nearly 65,000 initially healthy older men and women from across Washington State over an average of six years.

Over the study period 577 people, just less than one per cent of the total, developed a form of blood cancer, such as lymphoma or myelodysplastic syndrome (MDS). Emily White, who worked on the research, said: “A person who is age 50 or older has about a one-percent risk in ten years of getting one of these cancers. “Our study suggests that if you use acetaminophen at least four times a week for at least four years, that would increase the risk to about two percent.” However, Dr David Grant, scientific director of the charity Leukaemia & Lymphoma Research, said he was “underwhelmed” by the finding.

He emphasized that a numerical association did not prove a causal link, and could simply be a result of the researchers’ method or a statistical quirk. “There is no known mechanism for paracetamol to cause cancer,” he said. He added: “Asking elderly people to recall their paracetamol usage over many years is not a reliable way to generate data.” An increase from one to two per cent risk over 10 years was also a small increase, he pointed out.

Culled from Telegraph