Sunday Times, 01 May 2016
The End of Memory: A Natural History of Ageing and Alzheimer’s by Jay Ingram
When she died, Sister Mary of the School Sisters of Notre Dame had her brain removed and examined. It was full of plaques and entanglements, the signs of advanced Alzheimer’s. Perhaps no surprise there, she was 101; except that, right up to her death, Sister Mary had no symptoms of the disease. Quite the reverse, she had remained smart and alert with memories largely intact until the end.
She was one of 678 subjects of the Nun Study, an American experiment begun in 1986. Many findings are still likely to emerge but two already stand out. First, there were other nuns, like Mary, who had all the physical symptoms of Alzheimer’s but none of the mental ones. Second, incipient Alzheimer’s may be detectable in the early twenties. It just so happened that some of these nuns had been asked to write autobiographical sketches when they were young. Close analysis of these revealed a correlation between low “idea density” — a technical term for overtones and meanings — in the prose and the onset of Alzheimer’s decades later.
These are, as we all now know, urgent matters. Alzheimer’s has supplanted cancer and heart disease as the great medical anxiety of the developed world — 10% of people over 60 and 50% over 85 will suffer some form of dementia, usually Alzheimer’s. This is an epidemic, though there are signs that its progress may not be quite as inexorable as we thought. A recent British study suggested there had been a 20% fall over the last two decades. Men in particular seemed to be less at risk, possibly because of the decline in smoking.
Jay Ingram, a celebrated Canadian science writer and broadcaster, is ahead of the curve here; he notes earlier evidence that dementia may be decreasing in Europe. In fact, he notes everything. This is a thorough, lucid report from the dementia front line. Ingram speaks from experience: his mother probably had Alzheimer’s — it was never diagnosed — and he helped look after an aunt who certainly did. He is now 71 and obviously at risk. This is, as a result, a very engaged book.
What emerges most forcibly is how little we know. Aloysius Alzheimer identified a very early onset version of the condition that was to bear his name when, in 1906, he examined the brain of one of his patients who had died in her fifties. He discovered it had been disrupted by “amyloid” plaques and “neurofibrillary” tangles. The assumption thereafter was that these were what caused Alzheimer’s. In fact, we can’t even say that. They may be the result of the condition and, as the Nun Study showed, they may not cause anything. Nevertheless, the theory that the plaques in particular are the culprits is now dominant and the drugs that companies are pursuing — without success so far — are plaque preventing or busting drugs.
There is an even more fundamental problem: is dementia a disease at all? The single strangest medical fact about the modern world is the astounding pace of the increase in life expectancy: since 1840 in some countries it has increased at the rate of one year in every four. Again, we do not know the causes, but we do know that ageing populations are creating a care crisis. Improving the general health of the old is one solution, but it may be that nothing can be done for the ageing brain. Dementia is just what happens to old brains — this is what was believed before it was identified as a medical condition — in which case big life expectancy increases may actually be very bad news indeed.
Ingram somehow manages to provide an entertaining guide to the oddities that Alzheimer’s research has uncovered. One possibly significant fact is that our closest relatives — the other primates — never get Alzheimer’s, however old they are. Perhaps dementia is the price we pay for the explosive growth in our brain power.
Then there is the peanut butter test. Patients were blindfolded and asked to close their mouths and one nostril. Fourteen grams of peanut butter were put before the open nostril and the patients had to identify the smell. If they couldn’t, the stuff was moved closer. The finding was that those with Alzheimer’s needed the peanut butter to be four inches closer than those without. You can, I suppose, try this at home but you can’t use peanut butter because now you’d know.
If you want to protect yourself against dementia, go back to the Sister Mary story. She lived a disciplined life with continuous human interactions. She had, as a result, a high degree of “cognitive reserve”, meaning her brain remained agile and could find new pathways to get round any deterioration. In other words, although she had no symptoms, she may have had Alzheimer’s, but she also had the weaponry to fight it off. Other evidence shows that people with poor education and skills are much more likely to contract dementia. So stay as mentally active as you can and keep learning.
This means, among other things, not watching television. One study found that Alzheimer’s sufferers spent 27% of their leisure hours watching TV against 18% for the non-afflicted.
If giving up smoking is, indeed, the cause of the fall in dementia rates in Britain, then stop it at once and do all the other obvious things — keeping slim, exercising — to preserve your general health. Eating vegetables but not, mysteriously, fruit reduces the risk. In fact the fruit exception may be something to do with the clear link between sugar and dementia. Some have gone so far as to call Alzheimer’s Type 3 diabetes, so close is the correlation.
Eating turmeric, as some say, may help, but don’t bet your brain on it. Avoid nitrosamines, found in cheese, hot dogs, smoked turkey and the like. There’s no direct evidence of the effect on humans, but lab animals did develop diabetes and dementia when fed low levels of the stuff.
I could go on; this is a book rich in strange signs and wonders. Even if you’re terrified of dementia and don’t want to hear any more about it, this is a good read. Ingram has a relaxed, informative style and a way with explanation that makes you feel that at least somebody knows and cares. Remember, above all, the nuns whose cloistered but sociable and hard-working lives may seem more attractive than ever as the years go by.