Which lifestyle factors influence your biological age the most?
Sitting for prolonged periods, a disrupted circadian rhythm and muscle loss are the best-supported negative factors for your biological age; exercising regularly and maintaining a consistent sleep-wake rhythm are the most concrete steps you can take right now.
Prolonged sitting accelerates multiple biological ageing processes simultaneously. This holds true regardless of how much you exercise: even people who work out regularly but spend most of the rest of their day seated face an elevated risk. Sedentary behaviour is therefore an independent risk factor, not merely an absence of physical activity.
Your circadian rhythm is more disrupted than you might think. Artificial light in the evening, night shifts, long-haul flights across time zones and the constant availability of calorie-dense food all disturb metabolism and the epigenome (the layer above your DNA that determines which genes are active). This can indirectly accelerate the ageing process. A regular sleep-wake rhythm is therefore not simply a luxury, but biologically relevant. When you eat also matters: aligning food intake with your circadian rhythm appears to be beneficial for your gut microbiome and epigenome, although the evidence for this is still largely observational.
The loss of muscle mass over the years, known as sarcopenia, makes a measurable contribution to disease and early death at older ages. The level of fitness and muscle strength is associated with the molecular composition of muscle tissue at the cellular and epigenetic level. Lifestyle, and in particular physical activity, can slow that decline.
Lifestyle also influences brain health. Inflammation in the brain is a key mechanism in Alzheimer's disease, and lifestyle factors such as diet and exercise play a role in this. How large that contribution is relative to genetic predisposition has not yet been precisely established.
An important caveat: which lifestyle factors are most decisive for your biological age has not yet been definitively determined. In addition, not everyone responds in the same way: genetic variants in circadian rhythm genes influence how your body responds to diet and lifestyle, meaning that an approach that works well for one person may have less effect for another.
All claims are based on associational or probably causal studies; no large controlled randomised trials. The evidence for circadian rhythm and chrono-nutrition is largely observational. Evidence is moderate across all sub-areas.
How can I measure my biological age?
DNA clocks, and GrimAge in particular, give the most reliable picture of your biological age. These measurement methods are currently used mainly in research.
What does alcohol do to your biological age?
Alcohol accelerates multiple biological ageing processes, including gut damage, inflammation, and brain deterioration. The older you are, the more vulnerable your body is to that damage, so drinking less is worthwhile at every stage of life.
What does smoking do to your biological age?
Smoking measurably accelerates the biological ageing of lung cells, the immune system, and the reproductive system. Stopping smoking reverses some of that damage, in some cases even completely after ten years.
Does the country you live in affect your biological age?
Where you live and grow up is linked to how quickly you age biologically. Higher education, cleaner air, a nutritious diet, and greater socioeconomic security are all associated with slower biological ageing.
Can you really lower your biological age, and does research support this?
There are promising hints that biological age is measurable and perhaps steerable, but this has not been proven. Wait for larger studies in people before basing major decisions on this.
Can you see your biological age in your blood pressure?
A rising systolic blood pressure and a widening gap between the upper and lower numbers are recognisable signs of vascular ageing, but a truly reliable picture of your biological vascular age requires additional measurements that a general practitioner does not routinely perform.