What are the most important scientific insights about ageing?
Exercise, a Mediterranean-style diet, stopping smoking and getting enough sleep are the best-supported ways to age more healthily. How you personally view your own ageing turns out to matter more than most people would expect.
At the level of individual cells, ageing involves a combination of DNA damage, changes to how genes are switched on and off, shortening of the protective caps at the ends of chromosomes, and long-term low-level inflammation. These biological processes partly overlap with what happens in cancer: genetic instability, inflammation and a disrupted gut microbiome occur in both. An interesting detail: some ageing processes, such as chromosome-cap shortening and the gradual exhaustion of stem cells, actually appear to suppress cancer. Aged cells that do not die off but do release inflammatory substances are ambiguous: they initially protect against tumours but may, over time, have effects that encourage cancer.
The community of microbes living in the gut changes measurably with age. Bacteria that produce beneficial fatty acids, such as Faecalibacterium, become less abundant. Yet in people aged 90 and older, the variety of gut microbes is actually greater than in younger older adults, and they produce more butyrate, a substance that may benefit the gut lining. Whether this is a cause or a consequence of healthier ageing has not been established: almost all the studies are snapshots taken at a single point in time.
At the lifestyle level the evidence is considerably stronger. Exercise reduces the risk of frailty by around a third and leads to measurable improvements in heart and lung fitness. Physical activity also acts on virtually all the biological ageing processes at once, from DNA damage to how the cells' energy-producing structures work and long-term inflammation. A Mediterranean diet, foods rich in antioxidants and adequate protein reduce the risk of heart disease by around 22% and slow mental decline. Stopping smoking lowers heart disease risk by nearly a third. These are the interventions with the strongest evidence behind them.
Less obvious but equally well supported: how you personally think about your own ageing is linked to how well you age. People with a more positive view of growing older live longer, experience less cognitive decline and are less prone to depression. This has been found repeatedly in long-term studies involving people over 50, though these are associations and other explanations cannot be completely ruled out.
Getting enough sleep (7 to 8 hours) is associated with a 25% lower chance of cognitive decline. Mental exercises are linked to a 25% lower risk of dementia, and strong social connections reduce the likelihood of depression by around 30%. Regular medical check-ups substantially reduce the number of chronic conditions that go undetected. All these associations come from studies involving people over 50, with the strongest claims backed by studies in people where the effect of the intervention was directly tested.
This answer draws on multiple large combined analyses of existing studies, with the strongest findings coming from one such analysis covering 35 studies in people, involving around 25,000 participants, on diet and lifestyle. The biological insights (such as aged cells that linger in the body and their overlap with cancer) come from conceptual overviews without measurable effect sizes; the evidence for cause and effect is thinner there. The gut microbiome data are based on 27 studies in people, but almost all are single-point-in-time snapshots, so cause and effect have not been established. The researchers behind the reviews on these lingering aged cells acknowledge themselves that both processes are not yet fully understood.
How do you train smart for lasting muscle strength in older age?
Research shows that training volume matters in older adults: a low volume is already enough to maintain daily functioning and muscle mass, while you need more volume if you want to increase your maximum leg strength. If you already have muscle loss, the combination of strength training, balance exercises and a protein-rich diet delivers the most measurable gains.
How does your brain construct emotions?
Your brain builds emotions from shared networks that also process your bodily signals and social understanding. That explains why emotion, physical sensation, and empathy are so closely intertwined.
Are smoothies and fresh juice just as healthy as whole fruit?
Whole fruit and fruit juice may look similar, but research shows they do not have the same effect on your blood pressure.