WHO Disappoints: The Missed Opportunity of the World Health Organization Guidelines for Preventing Dementia
It is safe to say that prevention is one of the few areas of dementia research that have seen significant recent scientific advancement. The opportunity to provide evidence-based guidance on steps we can take to potentially lower risk for significant memory disorders has meaningfully increased, even as progress in other areas such as early detection and pharmacological treatments has been set back.
Moreover, the interventions shown to reduce dementia risk jive with findings in other areas of health promotion, such as cardiac fitness, overall well-being and successful aging. These include regular physical activity, managing chronic medical conditions and staying socially connected, among others. The suggested lifestyle changes carry little risk and much potential benefit to the average adult, with many being readily actionable through population-based campaigns or low-cost prevention programs.
After decades of growing evidence for the use of lifestyle interventions to reduce dementia risk, it is only right that major health policy influencers such as the World Health Organization, the National Academies of Science and the Lancet provide policy guidance on their use. Several have considered the utility of such interventions from a public health perspective, from the 2010 U.S. National Institutes on Health report to the more recent Lancet Commission on Dementia Prevention, Intervention and Care (2017) recommendations
Yet the recently released World Health Organization (WHO) Guidelines for Risk Reduction of Cognitive Decline and Dementia (World Health Organization, 2019) stands apart as especially disappointing. Out last month, the guidelines are the first response to the seven priority areas set at the 70thWorld Health Assembly in 2017, as part of a global action plan to dementia. Tasked with providing global policy makers with evidence-based recommendations for lifestyle interventions to reduce dementia risk, the WHO panel of experts instead has produced a report of limited value with muddied recommendations.
Like other expert panels, the WHO group considered the evidence regarding a range of lifestyle interventions that have been shown to impact dementia risk. They then rated the quality of that evidence and made recommendations about the potential benefit of an intervention from a public health perspective. This well-reasoned approach should have resulted in a straightforward report with a clear pathway linking the available evidence to the strength of recommendation for a lifestyle intervention. (The resulting recommendations are summarized in the table below.)
This, however, is not the case. The WHO Guidelines fail in two major respects. First, the panel decided to base the strength of their recommendations not only on the available evidence, but also on their own opinion regarding the overall benefit of an intervention. As the authors state, “(I)n some instances, even when the quality of evidence was low or very low, it was agreed that if the recommendation would be of general benefit, and this was seen to outweigh the harms, it may still be rated as strong.” This is problematic. Once the panel decided to make strong recommendations to include interventions such as smoking cessation, where the evidence of benefit to dementia risk reduction is low, why not then offer a strong recommendation for other factors with low evidence? Or the inverse? Divorcing the evidence from the recommended action opens the guidelines to subjective bias.
Second, many experts agree that the guidelines err in being overly cautious. Many of the lifestyle interventions evaluated are known to be of significant benefit to overall well-being. The Lancet Commission found that addressing hearing loss could eradicate 9% of incidental dementia globally. Many public health institutions have recognized the scourge of social isolation, with the U.K. going as far as appointing a minister to set policy to improve social engagement. Objectively many of the non-medical lifestyle interventions included in the WHO report offer little risk but much potential benefit. So why not strongly recommend their inclusion, especially in light of their more subjective approach?
Given these greater issues, it seems trivial to quibble about other details, such as the lumping together of all aspects of cognitive engagement under “cognitive training,” despite the fact that ongoing intellectual engagement has been shown in many studies to greatly impact dementia risk, while targeted skills training does not. Or the absence of other lifestyle factors strongly endorsed by the WHO elsewhere, such as the value of self-efficacy to promoting healthy aging.
The WHO panel had a tremendous opportunity to provide global leadership in the fight for dementia prevention. What results instead is a missed opportunity to provide stronger guidance for meaningful changes in public health to reduce risk.
Dementia is one of the fastest growing global health challenges. Estimates suggest that by 2030 over 85 million individuals will be diagnosed with dementia worldwide, with the greatest burden of disease affecting low to middle income countries. As the editors of the Lancet so aptly state in their evaluation of these guidelines, “WHO needs to step up towards a global leadership role, be bolder, and demonstrate true leadership to effect the desperately needed change in the trajectory of dementia.”
WHO GUIDELINES FOR RISK REDUCTION OF COGNITIVE DECLINE AND DEMENTIA: SUMMARY
Livingston G, Sommerlad A, Orgeta V et al.Dementia prevention, intervention, and care. Lancet. 2017 Dec 16;390(10113):2673-2734. doi: 10.1016/S0140-6736(17)31363-6. Epub 2017 Jul 20. Review. PubMed PMID: 28735855.
National Institutes on Health. NIH Consensus Development Conference Statement on Preventing Alzheimer’s Disease and Cognitive Decline. 2010. https://consensus.nih.gov/2010/docs/alz/ALZ_Final_Statement.pdf
World Health Organization. Risk reduction of cognitive decline and dementia: WHO Guidelines. 2019. ISBN: 978-92-4-155054-3. https://www.who.int/mental_health/neurology/dementia/guidelines_risk_reduction/en/