Mitigating Multimorbidity

Aging is an unavoidable double-edged sword. Whilst it remains, as numerous wags have suggested, far better than the alternative, alongside the upsides of wisdom and experience, we often acquire long-term conditions (LTCs). Once these arrive in late-life, they usually hang around to plague us as unwelcome, life-long travelling companions. There are many diseases in this category, including diabetes, hypertension, heart or kidney disease, and neurodegenerative conditions like Parkinsons.

Worse, we often don’t escape with only one condition, but instead must shoulder the burden of multimorbidity, the presence of two or more conditions, something that afflicts the majority of the elderly population. 

Multimorbidity is bad news from a longevity perspective. A UK study from 2019 of half-million Biobank participants showed a bit less than doubling of mortality for those with two long-term conditions. This is an aggregate effect, however, diluting down the seriousness of certain highly impactful combinations. For example, a 15-year longitudinal study from Denmark analysed data for nearly four-million people and found a six-fold increase in mortality rate for those suffering two conditions combined across the Cancer and Neurological categories. Seventeen combinations of two disease categories resulted in a greater than four-fold impact on mortality rate, while twenty combinations create a multiplier between two- and four-fold. Such substantial risk multipliers create a pressing need to adjust the resulting mortality risks in a more favourable direction.

Given how many of us face multimorbidity, even assuming adherence to best available medical treatments, what strategies or choices should we adopt to improve our outcomes? Some research from August 2025 analysed this question using data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). The dataset was relatively small compared to those previously discussed: just 21,418 participants, but all were 60-plus, and consequently many participants suffered from multimorbidity. However, even while the smaller dataset encourages us to interpret the results cautiously, they are consistent with what we would intuitively expect. The research tested the effects on mortality of a healthy lifestyle score computed from five modifiable lifestyle factors (BMI, smoking status, alcohol consumption, physical activity and dietary intake). The researchers found that, within their dataset, physical activity had the single strongest association with reduced mortality. Further, the effect of healthy versus unhealthy lifestyle was most pronounced for participants with multimorbidity, providing a hazard ratio of 0.58. That is a big downward shift, simply by attending to the sensible, most obvious things.

In short, multiple long-term conditions are a frequent consequence of aging, but the attendant increase in mortality risk is not something we are powerless against. On life's journey, nobody can push the brakes on the passage of time, but sensible lifestyle choices, especially in maintaining our levels of physical activity, allow us to remain in the mortality-risk driving seat.