Denmark has the best environmental, social and political conditions you need to age more slowly and lead a healthier life as you grow older, according to new research.
Published in Nature Medicine, the study identified the factors that shape the biological processes behind how healthily you age. The international team of researchers analysed the data of over 160,000 people from 40 countries to compare how these factors affect ageing across the world.
First, they had to determine average rates of ageing. They did this by using a measure called the ‘biobehavioural age gap’ clock, an artificial intelligence (AI) model that calculates the difference between someone’s chronological age and their predicted age, based on the risk factors around them. For example, if you are 50 years old but based on your risk factors, the model predicted that you were 55 years old, your biobehavioural age gap would be five years.
The result? Across the four continents studied – Africa, Asia, Europe and South America – they found that European people have the highest levels of healthy ageing. Meanwhile, older biobehavioural ages were more common in lower-income countries.
“This study is important because it redefines ageing as a product not only of biology and lifestyle but also of broader environmental and sociopolitical forces – highlighting that where and how people live can significantly accelerate or delay ageing,” Dr Morten Scheibye-Knudsen, who was not involved in the study, told BBC Science Focus. Scheibye-Knudsen is an associate professor of ageing at the University of Copenhagen in Denmark.
The fastest agers were in Egypt, where individuals’ biobehavioural ages were an average of 4.75 years higher than their chronological age. Egypt was followed by South Africa and then countries in South America. Within Europe, the eastern and southern regions experienced faster ageing.
On the other end of the scale, the slowest agers were found in Denmark, who were an average of 2.35 years younger than their chronological age. Next came the Netherlands and Finland.
The conditions needed for healthy ageing
So what makes Denmark – and the rest of northern and western Europe – such a good place to age? The researchers found that the key factors were physical ones, like air quality, and social ones, including gender equality and socioeconomic status.
But interestingly, the other big influence was sociopolitical factors. Healthy ageing, it turns out, is strongly tied to whether politicians act in your interest, having freedom for political parties, whether there are democratic elections and if you have the right to vote.
“Why politics appear to accelerate ageing is a considerable and intriguing mystery in this study,” said Scheibye-Knudsen. “Mechanisms such as chronic elevated stress responses due to insecurity and healthcare disparities could perhaps be involved in this response.”
The study found that those with accelerated ageing were eight times more likely to find it difficult to complete day-to-day tasks, and four times more likely to experience cognitive decline.
While the research spanned four continents, there was limited representation of certain regions, especially Africa, where only Egypt and South Africa were included.
The researchers also emphasise that their findings reveal associations rather than causal relationships. Nevertheless, they say that the study underscores the urgent need to address health disparities across the world.
“Surprisingly, risk factors had a stronger impact than protective ones, and individuals in lower-income countries showed significantly accelerated ageing regardless of individual socioeconomic status,” said Scheibye-Knudsen.
“I think this is another strong argument for investing in universal solutions such as universal education and healthcare to maintain population health.”
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About our expert
Dr Morten Scheibye-Knudsen is an associate professor of ageing at the University of Copenhagen, in Denmark, and group leader of the Scheibye-Knudsen research group. He is also the president of the Nordic Aging Society.