Sir Donald Acheson was a British physician and epidemiologist who served as Chief Medical Officer of the United Kingdom from 1983–91. He was born in Belfast, Northern Ireland.

His father Captain Malcolm King Acheson, MC, MD was a doctor who specialised in public health, and his mother Dorothy Josephine nee Rennoldson was the daughter of a Tyneside ship builder. He was educated at Merchiston Castle School, Brasenose College, Oxford.

In the hot seat of the Government’s Chief Medical Officer he found himself in an environment at some remove from that of university and MRC research. His post was one without executive powers or a budget, though it did carry the power to influence ministers and to reassure, or alarm, the public. This was especially so in an era when health issues were becoming ever more at the forefront of public concern, and when health problems that might have been the subject of dispassionate, exhaustive analysis in a MRC atmosphere could suddenly be translated into white-hot crises under media scrutiny.

In such circumstances the chief medical officer’s task could be an extremely difficult and delicate one, given the weight that was likely to be ascribed by ordinary people to whatever he said. A considered and temperate opinion might well be oversimplified in transmission through the press, radio or television and could easily return to vex its originator.

Among the burgeoning health problems which Acheson was required to address himself with frequent public statements during his tenure were screening for breast cancer (about which he occasionally got himself into hot water with women’s groups), meningitis among children, and the spread (and control) of Aids (for which he promoted a bold and explicit advertising campaign). But none more starkly exemplified the difficulties of his position than an outbreak in 1988 of bovine spongiform encephalopathy (BSE), commonly known as mad cow disease. 

Although he faced some criticism from doctors who felt he had acted too slowly in protecting haemophiliacs from contaminated blood products, he introduced tests to screen the blood of donors within six months. He also persuaded the government to double spending on Aids, and produced precise guidelines for those at particular risk, not just haemophiliacs but also nurses, homosexuals and drug users.

Even under the most fortunate circumstances, the role of the CMO is a delicate one. In 1985 Acheson remarked: "I feel I'm putting my reputation on the line in public quite frequently in this job. If my scientific credibility goes, nobody will believe me. So I must personally satisfy myself of the evidence on every issue."

In November 1998 Acheson conceded at an inquiry that he might have misled the public over the safety of beef at the height of the "mad cow" epidemic in 1990, which was linked to the deaths of 29 people from a new form of Creutzfeldt-Jakob Disease.

At the time of the outbreak he had said in a television interview: "There is no risk associated with eating British beef, and everyone – children, adults, patients in hospital – can be quite confident with the safety of beef."

Looking back, Acheson said, he should have stuck to the more cautious line, previously agreed with his scientific advisers, that there was "no scientific justification for not eating British beef". The advice of his experts had been that "there was a remote risk, not no risk".