The Brain Health Paradox – dementia rates have fallen, even as drugs have failed

The Brain Health Paradox – Dementia rates have fallen, even as drugs have failed.

Billions of dollars have been spent looking for a pharmaceutical cure for Alzheimer’s and other forms of dementia. Their fail rate through the 21^st century is stuck at 100%. Yet the rates of dementia have been falling for the past three decades. Professors Daniel R George, and neurologist Peter J Whitehouse ask if it isn’t drugs, what is stopping the dementia tsunami? In their new book, ‘American Dementia: Brain Health in an Unhealthy Society’, published in September (John Hopkins University Press) they look through a population health lens for the answer, and find signs that show it may not continue as countries’ values and commercial systems change.

Dementia rates have fallen for three decades in the United States, Canada, United Kingdom, France, Sweden, Denmark and the Netherlands over the past decade. A 2020 study compiling data from those countries from 1988 to 2015 calculated that, while the overall number of people affected by dementia is incrementally rising, as would be expected in a growing population of ageing individuals, the incidence rate of dementia has consistently declined by 15% per decade and by 16% for Alzheimer’s, the most common form of dementia.

The scientists attribute this to better prevention and treatment of cardiovascular disease, and increased access to long-term education. Healthier societies mean healthier hearts and heads. The risk for cardiovascular disease has been reduced by marked improvements in health care systems, benefiting millions of ageing brains.

The human brain contains an intricate network of blood vessels, so its health is deeply intertwined with that of the heart and circulatory system. Nearly 20% of the heart’s output delivers oxygen and glucose to the brain.

After two world wars and the intervening Great Depression, the countries in which dementia rates are falling made a legal commitment to extend healthcare coverage to all citizens. Older people in these countries have had access to clinical care all their lives and have benefited from programmes which have been helped prevent vascular illnesses. These same countries also showed a consistent rise in total years of education among older adults. In the US those with college degrees increased from 8% in 1960 to 37% in 2020. More education in life equates to increased ‘cognitive reserve’, a condition that makes the brain more resilient to neuronal damage.

Anti-smoking campaigns have also made a huge difference. In the 1960s, 42% of adults smoked: in 2019 it was only 14%. And reducing lead levels in our air and water has also been good for the brain as lead is a known neurotoxin and risk factor for dementia. It also lowers IQ, creates emotional disturbances, reduces academic achievement, and is a major risk-factor for cardiovascular disease.

Is globalisation beginning to reverse these gains?

Intentionally improving the health of their populations has lowered rates of dementia. But now, with the surge in globalisation, the authors believe that these healthy brain trends may be reversing. Instead of seeing national governments influencing capital control, redistribution, and public investments, as was the situation during the post-depression post-World War II period in the mid-20^th century, now there’s a shift to global capital mobility, market expansion and deregulation, decreased taxation of the wealthy, and cutting and privatising public goods and services. And the soaring tuition costs in higher education mean that longer years of education are expected to reduce.

Alzheimer’s is not likely to be curable via single-drug approaches. The scientists warn that unless there is a continuing commitment to social ‘goods’ and processes, dementia rates will begin to rise again in these countries.

How can we, as individuals, reduce our dementia risk?

The main guidance hasn’t changed:

1. Don’t allow loneliness to creep into your life – stay connected to friends and family.
2. Be socially involved – try volunteering. If you live near one of our housing or care homes, ask about sharing a skill you have with our residents.
3. Check your blood pressure and blood sugar levels. If necessary, control with medication.
4. Exercise regularly – some experts describe exercise as ‘the silver bullet’.
5. Keep your brain active – acquiring a new language is a recommendation.
6. Eat a healthy diet – the most recommended is the Mediterranean diet.
7. Laugh a lot! Laughter is shown to have very beneficial effects on the brain.
8. Get enough sleep – enough sleep for you, that is. The old rule of 7 or 8 hours has gone out of the window, it’s what suits you. Don’t worry if you wake up during the night, as long as you go back to sleep afterwards. We need three 90-minute sleep cycles, say experts.