The stress of bereavement may accelerate the ageing process, according to researchers who found evidence that losing a loved one early in life had an impact long before people reach middle age.
Scientists spotted biological markers of faster ageing in people who had lost a parent, partner, sibling or child, but the signs were absent in others who had not experienced the death of someone close to them.
The finding suggests bereavement and grief take their toll on the body’s tissues and potentially increase the risk of future health problems. But it also raises the prospect that counselling and effective social support could help in the aftermath of a death.
Allison Aiello, a professor of epidemiology at Columbia University in New York, said losing someone close was a “significant stressor” and a life experience consistently linked to poorer mental health, cognitive impairment, heart and metabolic problems and an earlier death.
“Our research reveals a significant association between experiencing losses from childhood through adulthood and biological signs of ageing,” Aiello said. The decline in tissue and organ function brought on by accelerated ageing might explain in part why bereavement can have such an impact on health.
The researchers drew on data from the US National Longitudinal Study of Adolescent to Adult Health, which followed participants from their teenage years into adulthood. In particular, they looked at people who were bereaved before the age of 18, and from 19 to 43 years old.
Biological ageing was assessed by analysing people’s DNA for chemical changes that build up over the years. These epigenetic clocks can reveal whether a person’s biological age is older or younger than their chronological age, which has a bearing on disease risk in later life, Aiello said.
Among 3,963 people studied, nearly 40% had lost a loved one by adulthood. Those who experienced more bereavements had significantly older biological ages than those who had not lost people close to them.
Given the results, published in Jama Network Open, Aiello said research should now focus on whether helping the bereaved with counselling and coping strategies reduces the ageing effect. “These insights could inform clinical and public health approaches to improving health outcomes following a loss,” she said.
The study appears alongside separate work on the impacts of a healthy diet and added sugar on biological age. According to the research, women in the US who followed a vitamin- and mineral-rich diet had a younger biological age than those on poorer diets. But even for the women who ate healthily, each gram of added sugar was linked to a rise in biological age.
“It’s the first demonstration of the effect of added sugars on our epigenetic ageing,” said Elissa Epel, an author on the paper and professor in the department of psychiatry at the University of California, San Francisco.
The researchers analysed food records from 342 Black and white women from northern California and compared them with healthy eating habits, such as the Mediterranean diet, which is rich in anti-inflammatory and antioxidant compounds.
Women who ate more healthily had a lower biological age, according to their epigenetic clocks, but the scientists saw faster biological ageing in those who consumed foods with added sugar. The women in the study ate between 2.7g and 316g of added sugar a day.
“It appears … that both having a diet high in nutrients and low in added sugars matters,” said Barbara Laraia, a senior author on the study and professor of community health sciences at the University of California, Berkeley.
Dorothy Chiu, a postdoctoral scholar at the University of California, San Francisco, and first author on the paper, said she would expect similar effects in men.
Under UK guidelines, free sugars – those added to food and drinks, and found naturally in products such as honey and smoothies – should not make up more than 5% of daily calories, with adults having no more than 30g, equivalent to seven sugar cubes daily.
