Individuals bear at least 80% of the responsibility for their ill health in old age, according to a report aimed at challenging the belief that physical decline is either inevitable or primarily the responsibility of the state.

The report, launched at the Smart Ageing Summit in Oxford last week, argues that individuals have far greater control over their longevity than is commonly understood. The authors call on the government to take legislative action on alcohol comparable to restrictions on smoking.

Living Longer, Better – the Oxford Longevity Project’s first Age-less Report – was co-authored by an interdisciplinary panel of UK-based experts in medicine, physiology, ageing and education policy. It was sponsored by Oxford Healthspan.

The report’s authors, Sir Christopher Ball, Sir Muir Gray, Dr Paul Ch’en, Leslie Kenny and Prof Denis Noble, present the figure of 80% as a conservative estimate.

“Some have gone higher and said it’s approaching 90%,” said Ball, a 91-year-old former Parachute regiment officer who intends to reach 100. “But I think 80% seems about fair.”

The claim, however, has been described as simplistic and said to neglect wider arguments about whether people are genuinely in control of individual choices when it comes to issues including poverty, pollution and healthcare access.

Nancy Krieger, professor of social epidemiology at Harvard TH Chan School of Public Health, said: “The report is to be commended for rejecting genetic determinism but it problematically avoids engaging with the societal determination of health and health inequities; the role of work, economic deprivation and government policies that give corporations free rein to sell unhealthy products.”

Steven Woolf, professor of family medicine and population health and director of the Virginia Commonwealth University Center on Society and Health, agreed, saying the paper “ignores and oversimplifies the actual, multi-layered root causes of the conditions that foster poor health in a population”.

Woolf added: “There are factors affecting health that are beyond personal choice. So while it’s good to give people clear guidance on how their choices affect their health, it’s taking policymakers and others off the hook.”

Devi Sridhar, professor and chair of global public health at the University of Edinburgh, said she would “broadly agree” with the 80% figure, but added that the fact there was a strong link between socioeconomic standing and health was evidence of a correlation between public policy regulation and individual ill-health.

“Otherwise what are we saying?” said Sridhar. “That people who have more expensive houses have more discipline?”

But Ball rebutted those claims. “It’s good news if you’re to blame because that means you’re responsible – and if you’re responsible, you can do something about it,” he said.

“I think I’m bringing hope to the world with this report,” he said. “Whether you’ve got lots of money or little money, whether you’ve got a comfortable home or an extremely uncomfortable hovel, you can still make choices which will enable you to live well longer.

“We live in a culture which is always looking out for some external reason to give the blame to – ‘It’s all the fault of my genes.’ ‘It’s all the fault of my parents.’. No, it isn’t. If you want to play the fault game, it’s all your own fault.”

However, Jay Olshansky, emeritus professor of epidemiology at the University of Illinois Chicago, also questioned the 80% figure.

“These percentage contributions must be translated into something meaningful in order to be useful and understandable,” he said. “If it leads to an average life expectancy at birth of higher than 87 years, it’s likely to be unrealistic.”

Ball, however, pointed to research including the Landmark Twins Study, where researchers concluded at least 75% of human lifespan is determined by environmental and modifiable lifestyle factors.

He also cited large-scale analysis led by Oxford Population Health using data from nearly 500,000 UK Biobank participants which found that environmental exposures and habits carry far greater weight in premature death and biological ageing than inherited genetics.

The report’s recommendations include avoiding processed foods, abstaining entirely from alcohol, prioritising sleep, not eating after 6.30pm, and cultivating what it calls “a not-meat mindset”.

On alcohol, it takes a position more forthright than current government guidance. “Alcohol is toxic, don’t drink it,” said Ball. “The report bravely says so – whereas the government is afraid to tell the public the truth.”