Tiny improvements in sleep, nutrition and exercise could significantly extend lifespan, study suggests

Small changes in exercise, sleep and dietary habits could do wonders for people's health and possibly extend their overall lifespan, a large U.K. study suggests.

The research, published Jan. 13 in the journal eClinicalMedicine, sought to find the smallest possible lifestyle improvements that could measurably lengthen people's lifespans. The researchers searched within data collected from almost 60,000 people in the UK Biobank cohort, a repository of medical and lifestyle data from hundreds of thousands of U.K. adults.

The team linked the participants' documented habits to their theoretical overall longevity and health, as calculated using statistical modelling. They found that people who slept as little as five extra minutes daily, engaged in just two extra minutes of moderate-to-vigorous physical activity per day, and added a half serving of vegetables per day tended to live significantly longer than the worst performers — meaning those whose sleep habits, exercise, and nutrition patterns put them in the bottom 5% of the overall cohort.

The former group had an extra year of overall lifespan compared with the latter, according to the statistical model.

That's not to say that adding a few minutes of exercise or sleep and making small changes to diet will guarantee an extra year of life, Stephen Burgess, a statistician at the University of Cambridge who was not involved in the study, told Live Science in an email.

"By itself, this study does not prove that these habits improve health," he cautioned. "They model what might happen to our life span if changing these factors does improve health."

Interestingly, the data suggested that improvements across several aspects of well-being are "greater than the sum of their parts," lead study author Nicholas Koemel, a dietitian and research fellow at The University of Sydney, told Live Science. For instance, to gain one additional year of lifespan through sleep alone, the study suggested a person would have to sleep an extra 25 minutes per night — a luxury many cannot afford. But very small improvements in sleep, exercise and diet may have a significant combined effect.

Koemel said the findings suggest that "healthy habits work better as a package."

"Each one of our behaviors has an interlinking impact on what we do," he said. "If we have a poor night's sleep, we oftentimes eat differently, we move differently. And we see that across all of these different behaviors."

Per the model, the study participants with the most optimal combination of these behaviors — at least 40 minutes of moderate-to-vigorous exercise, seven to eight hours of sleep per day, and an overall healthy diet — were predicted to live an extra nine years, overall, and live nine extra years in good health, compared with the poorest 3% of performers.

By their very design, studies like these, known as cohort studies, need to be taken with a grain of salt. They compare two groups retroactively rather than asking people to change their habits and seeing how that change affects their health. As such, they can never conclusively prove that one particular change caused an associated effect; they can only draw a link between the two.

For instance, sleep and exercise habits were measured for only up to a week in the UK Biobank cohort, and the data assume that people kept up those same habits in the long run. Similarly, diet was assessed only at the beginning of the study, rather than monitored over time. So it's possible that the participants changed their habits after these assessments were taken, which would weaken the possibility that their habits improved their lifespan.

All of this leaves room for the possibility that it was not these lifestyle differences, but rather some other factor that wasn't measured, that caused the improvement in lifespan.

It may be, for instance, that one group is wealthier, and it so happens that this makes it easier for that group to exercise, sleep well and eat well. But ultimately, that difference is partially explained by the wealth, not only the behaviors, Burgess explained. It is also possible wealthy people might live in a less polluted area than poorer people, which could contribute to the difference in lifespan. There's no way of telling from this study alone.

"The overall message that small changes in these factors are likely to be beneficial is probably correct," Burgess said. "But whether the exact numbers are accurate or not is less clear."

Koemel agreed, saying that more research is needed to confirm the findings. Still, the idea that even tiny changes in lifestyle could have large effects could offer an interesting alternative for those looking to improve their overall well-being, he suggested.

"New Year's resolutions oftentimes fail because we're pushing too hard," he argued. "We're trying to go to the gym every day. We're trying to be perfect." This research suggests there may be a "different path to get from A to Z," by making smaller changes across several areas of well-being that can build up to healthier habits while improving overall health.