Around 50 million people have dementia worldwide, with 10 million new cases emerging each year (World Health Organization: 2019). Most prominent in people over 60, its causes are widely debated and clinical trials for drugs to stop or slow its progression are often disappointing. This in mind, researchers are now looking into how lifestyle changes may be able to slow down, or even prevent the onset of dementia.
Dementia is an umbrella term for a variety of diseases known to cause memory loss. Alzheimer’s disease (AD) is the most common variety of dementia, happening when plaques of tangled proteins form in the brain. Another type is vascular dementia, thought to happen by damaged blood vessels in the brain. Whatever the variety however, experts believe that both genetic and lifestyle factors, including exercise, diet and habits such as smoking, contribute to the likelihood of dementia.
Although CRISPR techniques to combat dementia are under development to edit dementia-causing genes, as of yet, the genes behind this condition are still considered unmodifiable (Fernandez: 2019). As lifestyle changes are more flexible, focus is now being put on how these can be managed to prevent progression of the disease.
For example, a recent study published in JAMA analyzing medical records of 196, 383 people aged 60 and older found that healthy lifestyles were associated with a lower risk of dementia in participants with both high and low genetic risk factor (Lourida: 2019). In fact, they found that those with both an unhealthy lifestyle and a high genetic risk score were more than twice as likely than those with low genetic risk scores and healthy lifestyles to develop dementia.
Despite this however, they found that lifestyle and genetic factors were not synergistic in predicting dementia risk. Instead, they act independently of each other. This means that although people with a high genetic risk for dementia and unhealthy lifestyles may be more at risk, their overall risk is still calculated from a direct sum of both their lifestyle and genetic factors, as opposed to the two leading to an exponential increase in risk (Patel: 2019).
Although interesting findings, due to the few lifestyle factors analyzed as well as the lack of clinical trials to verify them, it is worthwhile regarding them with caution. Researchers from Harvard Medical said, “choosing a candidate list doesn’t capture our complex lifestyles and may lead to false findings. For example, what exactly constitutes a “healthy” diet (ibid.)?” They further pointed out the issue of compounding factors. For example, if weight is associated with diet and dementia, then it may be difficult to separate it from being associated with diet.
To conclude, although certain correlations have been found between a subjective “healthy” lifestyle and the risk of developing dementia, they are inconclusive due to the complexity of lifestyle choices that were otherwise not investigated. Despite this however, as regular exercise and abstaining from habits such as smoking and alcohol consumption have positive health effects regardless, physicians recommend these lifestyle habits regardless.
Fernandez, Tara: Massive Science
Lourida, Ilianna: JAMA Network
Patel, Chirag: Harvard Health Publishing