Print This PostDementia has been a real hot topic for news outlets recently. We’ve heard about new treatments, celebrities revealing their diagnosis and now the media are running with the story that dementia cases could be set to double by 2040 due to ‘obesity and other poor life choices’. It all sounds very scary but I think there is a huge silver lining to be seen in this. Before we get to that though, let’s first dive into where this claim comes from.
The link between lifestyle and dementia is not a new one. In the case of Alzheimer’s, the most common cause of dementia, we have known for many years that only 1% of cases are attributed purely to genetic mutations. In the other 99% it is a combination of genetic mutations and environmental factors that all combine together. Age, lack of mental stimulation, social isolation, head injuries, hypertension, diabetes, smoking, alcohol consumption, poor diet, poor sleep patterns… the list literally goes on. Obesity is one that hits home though because we are a population that is exponentially increasing in levels of obesity for many reasons (too many to go into today). So how does obesity contribute to dementia risk?
The short answer is that it’s complicated. The slightly longer answer is that obesity creates a series of scenarios within the body that push an individual into a higher risk category for the development of dementia. It often leads to insulin resistance and type II diabetes. This in turn can lead to dementia with diseases like Alzheimer’s being referred to as type III diabetes by some researchers. Again… the science is complicated but essentially the same mechanisms that impair glucose uptake in diabetes prevent glucose from getting to brain cells (and brain cells REALLY need glucose). This can promote amyloid accumulation, neuroinflammation, blood brain barrier dysfunction… it’s not good news.
On top of that, obesity kickstarts a bucket load of other mechanisms that can lead to dementia. High blood pressure and narrowing blood vessels can limit the blood supply to the brain. Inflammation can rage on in the body and affect the brain, contributing to neurodegeneration. If you’re obese, your gut microbiome is likely to be filled with bugs that secrete neuroinflammatory/neurodegenerative factors as a direct result of the food you are putting into your body. Does our waistline really affect our brain health? Absolutely. Even to the point that you can see brain atrophy (loss of brain tissue) in obese people. We have to take this seriously otherwise it absolutely will contribute to increased cases of dementia in any country that has an obesity problem.
So how is this good news? To let me frame this please allow me to draw upon a personal story that I have talked about a few times within these blogs and on our Food for Thought podcast series (give this a look if you want to hear more about the links between what we eat and our brain health). In 2021 I was diagnosed with a form of inflammatory bowel disease (IBD) called ulcerative colitis. This means my immune system attacks the tissue in my colon and, in my case, it attacks the entire length of the colon. When my disease is active I am incredibly unwell. My body struggles to digest anything I consume and I rapidly lose weight. I have to go to the bathroom 20-30 times a day mostly to get rid of blood. It’s a horrific existence that has landed me in hospital on a steroid drip for a week.
When I was diagnosed I was told it was just bad luck and there was nothing I could do. After reading a lot of studies I realised this was not the case. My IBD was my fault. Yes I probably carry some genetic risk factors but I also lived a lifestyle that promoted inflammation in my digestive tract. No exercise, a diet that was probably 80% ultra processed foods, too much sugar… the only thing I wasn’t doing in excess was drinking alcohol but in many ways what I was consuming was just as bad for my body. I was ‘skinny fat’. A healthy weight on the outside but internally I was causing so much damage with what I was eating. The moment I realised that, I was able to take responsibility for my illness. Recognising that I had contributed to the onset of my disease was weirdly empowering because, for the first time, it gave me hope that I could do something about it. If I got myself into this mess maybe I could drag myself out of it. I u-turned my lifestyle with frequent exercise, stress management exercises and a diet that was rich in fresh, whole foods. Fruits, vegetables, nuts, legumes etc. I got discharged from hospital in February 2022. In May 2022 I had my list signs of colitis. Now I sit here writing this 18 months on knowing all my markers show no inflammation. I haven’t had any symptoms since last May and I fell the healthiest I ever have despite having an ‘invisible disability’.
The reason I am telling this story is because I think it demonstrates the power we have when we recognise and accept predictions like ‘obesity will double dementia rates’. Obesity is not a cystic fibrosis. You aren’t born with a genetic mutation that destines you for obesity. Genetics are thought to contribute to propensity of obesity but we have the power to reverse and prevent it with the right lifestyle choices. For me, the headlines are all pointing at one big bright shiny point.
We have found a big contributor to dementia and it’s a factor that we can actually do something about.
For years we have been fighting against dementia with a broken sword and a shield made out of wet tissue paper. It has ravaged through our loved ones and all we have been able to do is sit back and watch as it tears families apart. Suddenly we have been handed a sharpened blade to fight back with. If obesity rates continue on their current trajectory we could see dementia rates double. 431,845 patients had a recorded diagnosis of dementia on 31 January 2023. This could be pushing 1 million by 2040 and that is just the number of new diagnoses.
HOWEVER, this also means that if we take responsibility for our lifestyles, we could potentially stop or at least impair the growth in rates. How about we start thinking ‘does this mean we could potentially prevent as many as half a million people from getting diagnosed every year by 2040?’ That sounds a lot better doesn’t it?
I don’t know to what extent we can prevent dementia onset by moving ourselves to a healthier lifestyle. I do, however, know that by living better we massively reduce our risk and that will, in turn, reduce the spread of dementia in the wider population. That is enough for me to eat more broccoli!
Dr Sam Moxon
Author
Dr Sam Moxon is a Research Fellow at the University of Birmingham. His expertise falls on the interface between biology and engineering. His PhD focussed on regenerative medicine and he now works on trying to develop 3D bioprinting techniques with human stem cells, so that we better understand and treat degenerative diseases. Outside of the lab he hikes through the Lake District and is an expert on all things Disney.
Adam Smith
Dementia Researcher
Dr Yvonne Couch
Dr Jodi Watt