People genetically predisposed to a shorter life could live around five years longer if they followed a healthy lifestyle, scientists have discovered.

In the first study of its kind, experts explored how the odds of survival can be improved through exercise, a healthy diet, getting enough sleep and not smoking, despite the huge influence of genetics.

The study involved 353,742 people from the UK Biobank and showed that those with a high genetic risk of a shorter life have a 21% increased risk of early death compared with those with a low genetic risk, regardless of their lifestyle.

Meanwhile, people with unhealthy lifestyles have a 78% increased chance of early death, regardless of their genetic risk.

The study also found that having both an unhealthy lifestyle and shorter lifespan genes more than doubled the risk of early death compared with people with luckier genes and healthy lifestyles.

However, researchers found that people did appear to have a degree of control over what happened.

Their findings showed that the genetic risk of a shorter lifespan or premature death might be offset by a favourable lifestyle by around 62%.

They said: “Participants with high genetic risk could prolong approximately 5.22 years of life expectancy at age 40 with a favourable lifestyle.”

The “optimal lifestyle combination” for a longer life was found to be “never smoking, regular physical activity, adequate sleep duration, and healthy diet.”

Plant-based diet
Eating a healthy diet has an impact on lifespan (David Davies/PA)

Published in the journal BMJ Evidence Based Medicine, the study followed people for 13 years on average, during which time 24,239 deaths occurred.

People were grouped into three genetically determined lifespan categories including long (20.1%), intermediate (60.1%), and short (19.8%), and into three lifestyle score categories including favourable (23.1%), intermediate (55.6%), and unfavourable (21.3%).

Researchers used polygenic risk scores to look at multiple genetic variants to arrive at a person’s overall genetic predisposition to a longer or shorter life.

Other scores looked at whether people smoked, drank alcohol, took exercise, their body shape, healthy diet and sleep.

The researchers included staff from Zhejiang University School of Medicine in China and the University of Edinburgh.

Matt Lambert, senior health information officer at the World Cancer Research Fund, said: “This new research shows that, despite genetic factors, living a healthy lifestyle, including eating a balanced nutritious diet and keeping active, can help us live longer. We also know it can reduce the risk of cancer.”

He acknowledge that “making healthy changes can be daunting” but suggested people look at the fund’s online healthy living programme, Activ8.