Can brisk walking reduce your biological age?

A lifetime of walking at a brisk pace could reduce your biological age by 16 years by the time you reach midlife, according to news headlines based on a recent study from the University of Leicester.

Walking speed is widely considered to be a good indicator of overall health. The researchers say this is likely to be because walking is a fairly complex activity that relies on and builds the health of your muscles and bones, your heart and lungs, as well as thinking skills and mental health. Walking speed also tends to be linked to doing regular exercise.

The researchers wanted to find out if there was a relationship between walking pace and the length of telomeres in your DNA. Telomeres are like protective caps for your DNA (a bit like the plastic tips at the end of your shoelaces) – they sit at both ends of your chromosomes, helping to protect your chromosomes from getting damaged. They get gradually shorter as we get older. Some scientists believe they can act as markers of your “biological age” and help indicate people’s risk of age-related diseases. Shorter telomeres have been linked with a shorter life expectancy.

Previous research has suggested that higher levels of physical activity and cardiovascular fitness could be linked to longer telomeres, and potentially slower biological ageing.

This new research studied 405,981 middle-aged participants from the UK Biobank – a biomedical database used for long-term study and research. They were asked to self-report their walking speeds, with 4mph or faster considered ‘brisk’, 3-4mph ‘steady/average’, and less then 3mph ‘slow’.

The length of participants’ telomeres was also measured, and researchers found that people with a faster self-reported walking pace were more likely to have longer telomeres.

The findings suggested that brisk walking led to a lower biological age, rather than the other way round.Overall, they suggest that a faster walking pace could be ‘potentially important’ in determining overall health.

How good was the research?

Leicester’s researchers used a large sample size from a reliable source – the main strength of this study.

They also adjusted for many different dietary and health-related factors, including health conditions, smoking, drinking alcohol, salt intake, and fruit and vegetable consumption.

They actually used two different methods of studying the effect of walking speed and separating it from other factors that could affect the results. They used different methods of analysing this. When they looked at the findings and adjusted for other factors that could affect the results (for example, the faster walkers tended to be less overweight, and were less likely to smoke), they found that faster walking was linked to a biological age two years younger.

The researchers also used a different method that involved comparing people in the different groups who had similar gene variations.

This method is used to help researchers account for other factors, including unknown factors, that could affect the results. It’s also useful for showing which way round any effect happens (whether walking pace affects telomere length, or whether telomere length affects walking pace).

Using this method led to a finding that faster walkers had a biological age equivalent to 16 years younger that their actual age.

The researchers warn that in this case, “the size of the effect should be interpreted with caution and is likely to be greater than the magnitude of change that can be anticipated from any future intervention” – in other words, starting to walk faster probably won’t lower your biological age by 16 years.

One weakness of the study is that it relied upon self-reported information. This could mean there are some inaccuracies - although, data recorded by activity monitoring devices was also used in part of the study, and led to similar findings.

The research only looked at middle-aged participants, with an average age of 56.5.

The BHF verdict

This research can’t tell you that increasing your walking speed will lower your biological age. It does suggest, however, that those who have had a faster walking pace across their lifetime may have longer telomeres, and that this could be an indicator of better overall health.

What we do know is that regular exercise is good for your heart and wider health. Most of us are recommended to do at least 150 minutes of moderate-intensity activity each week, whether that’s brisk walking, dancing, swimming, water aerobics or moderate cycling. If you have a health condition, check with your GP before starting a new exercise regime.

How good was the media coverage?

The media coverage of this study included the Mail Online, The Telegraph and on ITV’s ‘This Morning’ show.

ITV’s coverage included an interview with the study’s author, Professor Tom Yates. The presenters asked the researcher about important details such as sample size and allowed him to explain useful information, such as which speeds were defined as ‘brisk’ and ‘slow’.

The Mail Online led with the headline ‘Forget Botox…regular brisk walks make you look AND feel 16 years younger by middle age, experts say’. This is inaccurate. The study did not look at whether participants looked or felt younger. Some previous research has suggested that there may be an association between longer telomeres and looking younger, but the evidence around this is limited, and there is even less evidence around whether telomere length is directly linked to how you feel.

This headline also ignores that changes to DNA take place over the course of a lifetime – a sudden change in walking pace will not make you look 16 years younger – although this is addressed later in the piece.

None of the news coverage explained that the 16 years figure needs to be treated with caution, as the researchers themselves said. The article does acknowledge that researchers were unable to prove that walking pace is linked with biological age and that more research is needed.

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