Readers will be familiar with the specialisation of medicine, which has undoubtedly brought with it enormous progress. However, one of its drawbacks is the tendency for each specialist area to become a silo. For example, a narrow research focus is needed to produce unambiguous results when new treatments are being examined.
But we are not built like an automobile engine, with clearly delineated systems. Our bodily functions are highly interactive, which can sometimes muddy the waters of new treatment effects.
So my attention was grabbed by some multisystem research published recently in the Journal of Neurology, Neurosurgery & Psychiatry. The results showed that making certain lifestyle adjustments could help us cut the risk of developing a stroke, dementia or late-life depression all at the same time. Researchers identified 17 overlapping risk factors for these brain-related conditions.
Dr Aleksandra Pikula, a vascular neurologist with the University Health Network (UHN) in Toronto and one of the authors of the study published earlier this month, told CBC News that while we’ve known for a while about individual risk factors for these three conditions, the overlap hasn’t been closely examined before.
We know that at least 60 per cent of stroke, 40 per cent of dementia and 35 per cent of late-life depression are attributable to modifiable risk factors, with great overlap due to shared pathophysiology. The study aimed to systematically identify overlapping risk factors for these diseases and calculate their relative impact on the overall outcome.
Researchers looked at data from 59 studies published between 2000 and 2023 to create the list of risk factors. They identified four factors that lower the risk of these brain-related conditions:
- Regular cognitive activities (such as reading or doing puzzles);
- Moderate or high levels of physical activity;
- A feeling that your life has purpose;
- Low to moderate alcohol intake (consuming less than one drink a day showed a larger benefit than consuming one to three).
On the other side of the equation, they found 11 factors that were associated with an increased risk of the three conditions:
- High blood pressure;
- Kidney disease;
- Smoking;
- A high blood sugar;
- Poor or disrupted sleep;
- A high body mass index;
- Hearing loss;
- Depressive symptoms;
- Stressful life events;
- Pain;
- High cholesterol.
And two factors were identified that could have protective or detrimental impacts:
- Diet: a diet high in vegetables, fruit, nuts, fish and dairy decreased your risks of developing a brain-related condition, but a diet high in red meat, sugary beverages, candy and excess salt increased the risk;
- Social engagement: a large social network was found to be good for the brain, while loneliness or isolation was bad for it.
The study found that the single most dangerous risk factor for developing any of the three conditions was high blood pressure (hypertension). While the research looked at association rather than “cause and effect”, one of the underlying threads for all three conditions may be damaged blood vessels that compromise blood flow to the brain. And another recent paper, published in Nature Medicine, backed up this theory. The study looked at 34,000 patients in China and found that those who significantly reduced their blood pressure with medication were 15 per cent less likely to develop dementia than those who didn’t.
It’s never too late to make lifestyle changes to improve your health, said Dr Pikula, but the best outcomes are shown when people start minimising their risk factors in midlife, in their 40s and 50s. Addressing even one of these risk factors, which range from high blood pressure to loneliness, can help with some of the others, say researchers. For instance, taking up cycling to increase your physical activity could help with high cholesterol and high blood pressure, which are also risk factors. Or getting more exercise with a friend will also help tackle excess weight and social isolation.
All in all, a nice piece of research with practical benefits.