By Ruby Kell
As our population ages, it is thought that one in three people will have developed Alzheimer’s disease by the age of 85. This means we will all experience, either for ourselves or through friends and family, the devastating loss of memory, change in personality and inability to communicate brought on by this form of dementia.
But despite its growing prevalence, it seems there is little we can do about Alzheimer’ disease. There are currently just four FDA-approved drugs, the most recent of which was developed over a decade ago in 2002. All of these aim to increase levels of the neurotransmitter acetylcholine, which is known to be involved in memory and thought processing. However these at best will only slow symptoms for 6-12 months.
This is because they combat an effect (brain cell death and overall brain shrinkage) rather than the cause of Alzheimer’s disease: abnormal clumps, or plaques, of a protein called amyloid beta, and ‘tangles’ of a protein called tau in neurons. These abnormal protein deposits reduce the ability of neurons to send signals within the brain, and eventually lead to their death. Scores of candidate drugs aiming to interfere with the formation of plaques and tangles have been put to the test in clinical trials, yet none have shown significant benefit to patients. Among these, some have even worsened the course of the disease, or triggered severe side effects.
So what keeps going wrong for Alzheimer’s research? In the view of some experts, the pitfalls for various failed candidate drugs can be explained as ‘too little, too late’. In other words, by the time plaques and tangles have emerged in the brain, and Alzheimer’s symptoms have been noticed, it may already be too late to act.
This seems like a bleak reality. But as our understanding of the disease increases with research, we are discovering more and more ways to take matters into our own hands. Of course, some factors are out of our control, like the increased risk that comes with age and the personal deck of cards dealt to you by your genetics and family history. But in recent years, more and more connections between lifestyle and reducing the chance of developing Alzheimer’s disease have come to light, providing a glimmer of hope in the dark confusion.
For example, one of the most promising lifestyle changes associated with Alzheimer’s protection could be as simple as a cup or two of green tea a day. In 2010, a long term study of almost 1000 participants over the age of 55 found that regular tea drinkers (i.e. consuming several cups a day of green, black or oolong tea) had a lower risk of developing a cognitive disorder, had improved memory, language abilities and attention than non-tea drinkers. This effect may be explained by a second study, which found that when a concentrated green tea was applied to rat neurons, it protected them from dying in the presence of the Alzheimer’s-causing amyloid beta protein.
It is thought that one component of green tea in particular, called epigallocatechin gallate (EGCG), may be responsible for this ‘anti-Alzheimer’s’ effect. Research has found that EGCG can coat amyloid beta proteins reducing the protein’s stickiness and preventing it from forming the amyloid beta clumps found in the brains of Alzheimer’s patients. Excitingly, EGCG may even be able to bind amyloid beta that has already begun the plaque-forming process, and reverse it back to a non-toxic state.
Something else we have surely all heard before is the benefit of a healthy, Mediterranean diet on reducing our risk of cardiovascular disease But perhaps less well known is the link this diet has with protecting our brains from cognitive decline later in life. For example, one found that elderly people with diets high in green leafy veg, fish and nuts, and low in red meat, had a 50% lower chance of developing Alzheimer’s than those with less healthy food habits. Luckily for those of us that struggle with maintaining ideal food habits, even participants who stuck to the diet less closely were less likely to develop Alzheimer’s during the course of the study.
Finally, if you are among the 39% of us in the UK able to speak more than one language, you may have a brain that will age slower than those that don’t. Researchers at the University of Edinburgh re-tested participants in their 70s on an intelligence test they took at the age of eleven, and found that those who had learnt a second language did significantly better than predicted from their baseline intelligence. In general, bilingual participants also had better memory, reasoning and processing speed, all of which normally decline with the onset of Alzheimer’s.
So maybe it is time to try swapping your morning milky English breakfast for a cup of green tea, adding some more leafy greens to your diet and finally picking up that second language you have always wanted to; at least while we let the researchers find a cure for Alzheimer’s.
About the Author
Ruby is a Molecular Biology Masters student at the University of Sheffield. Her research focuses on the effect of antibiotics and how we may be able to overcome the growing issue of antimicrobial resistance. Ruby has a particular interest in science communication and outreach, and has been volunteering with the BSA since November. You can follow her on Twitter @Ruby_Kell