Quick answer: A meaningful part of dementia risk is modifiable. Treating blood pressure to a target of 120mmHg (rather than 140) can reduce dementia risk by around 20%, and other levers — treating hearing loss, staying socially connected, regular exercise, avoiding excess alcohol, and good sleep and nutrition — each move the odds further in your favour.
Back to the theme of dementia, and we are at week 3. A question I have asked myself many times is can dementia be prevented? Billions are spent looking for treatments, and hopefully success will come, but what if there were ways we could reduce our risk in the first place?
Primary prevention is the term doctors use for interventions designed to reduce the risk of a condition developing before there are any signs of it. I consider myself an ‘at risk’ adult (remember statistically one third of us could be affected to a degree), even though at the time of writing I am 45 years old. Dementia, much like heart disease, is many decades in the making. Lifestyle choices I make consistently at this point in my life are statistically likely to reduce my risk of a number of chronic health issues in my 70s, 80s, and perhaps beyond. An argument in support of this, is that the clear signs of dementia actually occur fairly late. So-called ‘pre-clinical stage’ changes in the brain can occur for decades before the onset of symptoms, but a patient may still have very subtle features of mild cognitive impairment.
Let’s break things down into a few key areas (I will expand on some below):
How can we reduce damage to the brain?
1. How can we reduce neuropathological damage (whether from amyloid / Tau / vascular / inflammatory causes) ?
- Minimise diabetes
- Treat high blood pressure
A blood pressure >140mmHg at age 55 is associated with a 60% increased chance of dementia over an 18 year period! A recent large study has shown that treating blood pressure to a target of 120mmHg instead of 140 REDUCES dementia risk by 20%.
When did you last get your blood pressure checked? Please, if you haven’t done it in the last few months, get it checked. If you don’t have a machine, your GP or pharmacist will. Patients are often surprised when I quote how low I would like their blood pressure to be, but I hope to have convinced you of its importance.
- Prevent head injury
- Stop smoking – increases the risk of dementia by 60%
- Reduce air pollution
- Reduce mid-life obesity
How can we build cognitive reserve?
2. How can we increase and maintain cognitive reserve (brain power)?
A number of studies have looked at this, and the results all point in one direction. Activities such as reading, speaking a second language, playing games, art, playing music…. All of these help.
In people >65, they can reduce the odds of dementia by up to 30% (good news for my mother in law who loves a game of cards with my children!). I would add that I personally think that the idea that people have to retire at a given age is far too simplistic. Why are we marginalising older people who will often have so much to give in the workplace? I do think that their roles may change; for example in my work I can’t see me still operating and putting pacemakers in my 60s, but I absolutely think as an elder medic I would have many supporting roles to play in our hospital. Mentoring roles for older people can absolutely help to keep the grey matter healthy.
- Treat hearing impairment
Hearing loss is surprisingly common, affecting one third of people aged 45-65, yet increases the relative risk of dementia in this age bracket by 90%! It saddens me to say this, but my mum has clearly had hearing impairment for some years, but despite some pressure from myself and others has resolutely refused to address it. I can’t help but wonder if this has contributed to her dementia? Take home message – get your hearing checked (even I have had this done to be on the safe side!)
- Maintain frequent social contact
Loneliness has been identified by the American Surgeon General as a crisis. Covid really didn’t help, but there are many more factors at play here. I am incredibly concerned about the impact of social media on children’s mental health. Although presented by social media companies as a way to connect people, the reality for many, particularly children, is that it can lead to social isolation. Of course it does have many uses, but I for one am glad it did not exist when I was growing up. I also worry about social isolation at the opposite end of the age spectrum, and so have set up a monthly direct debit to a local older person’s charity who do good work in this space.
- Attain high level of education
This is particularly important up to the age of 20 it appears, by which time much of the brain connections are made.
What else affects dementia risk?
There are also factors that have benefit in both of the camps above, both reducing brain damage, and increasing brain power:
- Maintain frequent exercise
I know I am like a stuck record, but exercise really is a wonder-drug. In patients who are used to exercise, and therefore ‘good’ at moving their bodies, the risk and progression of Parkinson’s disease (which predominantly affects movement) is less. It fact, exercise training actually delays the progression of the condition in affected patients!
If you are 30-60, and break into a sweat (by exercise, not reading the news or in the sun!) once a week, on average you reduce your dementia risk by 20% over the next 25 years. Ask yourself, when was the last time you sweated through physical exertion?
- Reduce depression
Alongside hearing loss, this is actually the highest risk factor, with 90% increased risk. Around 1 in 10 people over the age of 65 have a diagnosis of depression, and this is only getting worse over time.
- Avoid excessive alcohol
Regular consumption of >21 units per week increases the risk of dementia by 20%.
- Sleep – I have covered this before!
- Nutrition
There does appear to be benefit from a Mediterranean diet, but whether this is from reducing conventional cardiovascular risk is less clear. I would always promote a whole food diet, rich in vegetables, whole grains, legumes, fruit and nuts, low in saturated fat and meat. It does not appear from the research that supplementation with vitamins makes any difference however.
You will notice that many of these factors are linked: the person who exercises and doesn’t smoke is less likely to have diabetes, high blood pressure and depression for example. The person who attends an art class once a week is less likely to be lonely or have depression. I have tried to highlight what to me felt like important statistics, and hopefully encourage you to reflect and see what you might do in your own lives, or encourage in the lives of your loved ones.