Is it possible to catch Alzheimer’s from Zombie proteins?

A report was published this week by UCL scientists who analysed a decades-old hormonal treatment given to nearly 2000 abnormally short children between 1958 and 1985. Although it sounds like a script from a Mary Shelly novel, these hormones were harvested from dead people's brains.

The treatment was banned when 200 cases of a precocious Alzheimer's like dementia emerged prompting a scary realisation that Alzheimer's, one of the biggest global killers, could be transmitted from one person to another.

This revelation, although alarming, is not actually new. A transmissible cause of dementia, via of a protein called a prion, has been known for years. Historically and most dramatically, a disease termed Kuru by the Fore people in Papua New Guinea. They ritualistically ate the brains of their recently deceased elders, believing they could acquire their knowledge and experiences. Unfortunately, this cannibalistic practice passed on prions which then triggered abnormal plaque of proteins, similar amyloid, in the brain causing damage which started with incoordination, personality change and eventually severe dementia.

I remember first coming across prion related diseases during my neurology training at Queen Square, London in the nineties. The case in question was a man, who developed a trance like gaze, balance and personality problems, characteristic features of Creutzfeldt-Jakob Disease. At this time, information was only emerging that it could have been transmissible from affected animals but with the emergence of bovine spongiform encephalopathy (BSE or "mad cow disease") the situation became clearer. We were fascinated but pretty scared of the potential damage this could cause to mankind but fortunately, although we can't be complacent, it remains very rare.

Prions are tiny proteins that can replicate themselves after they have become embedded in our bodies. They fundamentally differ from infective organisms such as bacteria, viruses, and fungi as they do not contain genetic material (DNA or RNA). The fundamental question arises - are they actually alive. This seems a theoretical issue but it is important because if these "Zombie Proteins" are not alive, they can't be killed. The experiment at UCL, eloquently demonstrated this by finding viable prions in the hormone powder which had been deep frozen for over 40 years. Prion proteins aren't denatured (damaged) by standard disinfectants, radiation or heat so if we eat contaminated meats, even if cooked, we could be affected. What's more they are not killed by the gastric acids in the stomach or recognised as foreign organisms by our immune system.

Fortunately, it seems unlikely that we could get exposed to enough prions via surgical instruments to trigger dementia but the conclusions of this latest research are justified. At least we should be conducting more tests, looking for prions, especially in neurosurgical equipment.

Unless you have a fondness of eating your dead relatives, the more likely source of prions is from contaminated meat. Even though livestock is now rigorously tested and there have not been any significant outbreaks for many years, I personally stick to advice given during the Mad Cow epidemic and avoid meats which could contain brain, spinal cord or nerves such as cheap processed sausages.

Dementia is certainly on the rise, especially the Alzheimer’s variety characterised by inflammatory proteins called amyloid in the brain. Although some of this trend in incidence can be explained by an ageing population adverse dietary and lifestyle factors are major contributory factors. Of particular concern are habits which increase chronic excess inflammation in our bodies (and brains) such as poor gut health, lack of exercise, poor sleep patterns, low fruit and vegetable intake, suboptimal vitamin D levels, lack of omega 3 rich foods and essential minerals in our diets.

The Alzheimer's Society is a really useful resource for lifestyle advice and the latest medical news.