The World Health Organization released a 96 page document to help address the global problem of dementia and cognitive difficulties, said to affect 50 million right now (the combined populations of NY and TX, more than Spain), with 10 million new cases a year (the population of Michigan, more than Switzerland).  It focuses on health conditions that may increase the risk of a person having cognitive problems.

On first take, I was mad at the vague summary recommendations; the authors themselves admit that several have low evidence scores! On second take, I was sad at the “opportunity cost,” in other words, could the intellectual and financial resources used in producing this document have been better spent toward something more directly therapeutic??

Dozens of experts distilled recommendations after scouring the world medical literature (the methodology is described).  The Summary of Recommendations lists twelve issues: 1. physical activity, 2. tobacco cessation, 3. nutrition, 4. alcohol use, 5. “cognitive interventions,” 6. social activity, 7. weight management, 8. high blood pressure, 9. diabetes, 10. cholesterol, 11. depression, 12. hearing loss.  The authors grade the recommendations, ONLY five are “strong”, the rest are “conditional” or are not listed.  They also grade the evidence: out of 17 listings, 11 were LOW or INSUFFICIENT.

The text does provide some details: over age 65, do 150 minutes of moderate activity a week. They don’t provide menus, but mention fish, nuts, olive oil and coffee (a Seattle diet more than Mediterranean, but I’m biased).

There are no specific recommendations for therapy, but that was not a goal for this work group.  Several of the reference citations were of previous reviews.  There were suggestions for further studies.

My lay summary: “be healthy and stay healthy, and you may avoid cognitive decline.”  By how much?  Over how long? And what of those with early onset disease who have none of the risk factors mentioned, but are demonstrating text-book progressive deterioration?

OK, I’m no expert, but I’ve actually read several prevention and risk assessment studies over the last several years, and I consider it a difficult field to study (compared to cancer clinical studies).  Diagnostic definitions, a variable natural history, variable assessments of cognitive skills, co-morbid conditions, cultural factors, and longitudinal factors all confound this literature.  Still, the authors come up with things not to do, like don’t take vitamins B and E, etc.

Interestingly, the document doesn’t mention avoiding certain medications (opioids, anesthetics, marijuana, anti-cholinergics) that seem to have at least short-term effects on cognition.  They do say this document is about primary, rather than secondary dementias, so maybe the evidence was too low in their evaluation.

There is also an idea that just recently, some developed countries are showing less of an incidence of dementia.  Some have speculated that it might be due to improvements in cardiovascular or life style changes.  Although there may be a secular trend  in these countries showing a decreasing incidence of dementia, this has not been demonstrated in the Netherlands.

I’m naive about how one measures the impact of recommendations like these.  In a hypothetical clinical trial, a “six recommendation program,”  how many subjects would be required (number needed to treat, NNT) to demonstrate the prevention of cognitive decline?  Would it be really be prevention, or would it be some measurable delay to decline?  There are terrific efforts at recruiting cohorts now, but my understanding is that they are observational at this point.

Prevention is a laudable concept, despite the paucity of much strong evidence in dementia. So, while I do think the WHO document may be helpful in perhaps extending life, and maybe even impacting the elusive improvements in “quality of life,”  I’m not sure how we will know if it’s been worth the effort.  If one takes a step back, since there is really no disease-modifying therapy, isn’t all of this basically part of palliative care?

“Crucially, while age is the strongest known risk factor for cognitive decline, dementia is not a natural or inevitable consequence of ageing [sic, British spelling].”  This striking statement is part of the Executive Summary.  Maybe all these recommendations will help us with aging well.  Numerous therapy clinical trials attacking the Amyloid Cascade Hypothesis (in Alzheimer’s dementia) seem to have failed, so perhaps resources need to be shifted to find the Fountain of Youth, and fight off that strongest known risk factor.

(image CCO Pixabay)