In a blog for non-medical people, James Garrard, Specialist Registrar in Geriatric Medicine, looks at the evidence on various drug and non-drug approaches to try and prevent dementia.
Take-home points
From both personal and professional experience, I have witnessed the awful effects of a dementia diagnosis on both the person with dementia and their loved ones. Initially, dementia causes a decline in memory and thinking, but as it progresses it can affect almost any bodily function such as mobility, swallowing, speech, bowel, and bladder control. The financial impacts are also huge. Dementia costs the UK economy £34 billion annually, most of which is paid by the people affected with dementia for support and care.
Dementia currently affects around 1 million people in the UK, but the number of people living with dementia is expected to double by 2050. There are many types of dementia, the commonest being Alzheimer’s Dementia and Vascular Dementia which account for over three-quarters of dementia diagnoses.
What do we know about ways to reduce the risk of dementia?
The diagnosis of dementia often comes when symptoms are at a relatively early stage, triggering fear and anxiety about what the future holds. I have been asked many times by relatives of people with dementia ‘what can I do to prevent me getting dementia in the future?’. Below, I look at the Cochrane evidence on taking blood pressure medications, vitamin and mineral supplements, aspirin, brain training, intensive management of Type 2 Diabetes, and interventions to target more than one known dementia risk factor.
Taking medication for high blood pressure is common – does this help to prevent dementia?
Blood pressure lowering drugs have other benefits though: they reduce the risk of other vascular events (such as heart attacks) and probably reduce the risk of recurrent stroke, although they probably have little or no effect on the risk of dying.
Some big claims are made about vitamin and mineral supplements, but can they really help prevent dementia?
Vitamin E supplements probably do not change the risk of people with mild cognitive impairment developing dementia over three years.
Vitamins and mineral supplements are not routinely prescribed by a doctor (other than for deficiency), so a decision to buy vitamins could be expensive and add to the burden of taking extra tablets. Supplements can cause side effects, they can interact with prescribed medication and some supplements can cause harm if too many are taken. If you take supplements, do tell your doctor what you are taking.
The review also found that other anti-inflammatory medications probably do not reduce the risk of dementia. Both aspirin and non-steroidal anti-inflammatory medications were associated with higher rates of bleeding from the gut, and the studies were all stopped early because of a lack of benefit and risk of harm.
Brain training tools and apps are becoming more widely available, but do they work to prevent dementia?
Brain training interventions rely on access to technology, computer literacy and internet connection, which may limit who can take part in them. These practical barriers to taking part will typically affect older people and people from lower socio-economic backgrounds more, where the risk of dementia is higher.
There are lots of other potential reasons for people to be prescribed statins. The Cochrane Review Statins for the prevention of dementia (January 2016) looked at the use of statins in 26,000 patients aged 65 and over, or patients with a history of cardiovascular disease. Statins probably make little or no difference to the rate of dementia diagnosis, nor do they lead to differences in the results of memory testing. In 3 years of follow up, the risk of side effects was low, and few people stopped taking their statin.
Does a more intensive approach to managing type 2 diabetes affect the risk of developing dementia?
For patients with type 2 diabetes, a more intensive treatment regime probably makes little to no difference to the rate of dementia diagnosis or to performance on memory tests, in up to 5 years of follow up. The intensive treatment regime probably increases the risk of low blood sugar (hypoglycaemia), which can be a major problem for patients with diabetes. This is according to the Cochrane Review Effect of the treatment of Type 2 diabetes mellitus on the development of cognitive impairment and dementia (June 2017).
Could an intervention to target two or more dementia risk factors prevent the onset of dementia?
Current evidence indicates that interventions targeting multiple different risk factors (for example, increasing physical activity plus taking medication to reduce blood pressure or cholesterol) make little to no difference to the rate of dementia diagnosis, finds the Cochrane Review Multi‐domain interventions for the prevention of dementia and cognitive decline (November 2021).
It is unclear whether people managed to stick to the interventions, but there were no reported harmful effects.
People showed a small improvement in detailed tests of cognitive function, but this could have been explained by them receiving brain training as part of the intervention. In people with an increased genetic risk of dementia (ApoE4 gene), the improvement in memory testing scores was greater.
So, what can you do to reduce your risk of dementia and where can you look for help?
Overall, there appears to be a lack of evidence to support any one intervention or medication to prevent dementia. Currently, it is unknown whether starting any of the tablets or interventions mentioned in this blog in mid-life reduces dementia risk in the long-term, as there is a lack of research for long enough.
We know that the risk of dementia increases with age, as well as with many medical, sociological, and psychological factors. In a previous blog Behind the headlines: can one in three dementia cases be prevented? Kirsty Marais from Alzheimer’s research UK discussed the 12 risk factors which can be changed, accounting for up to a third of dementia cases.
The 12 risk factors are:
hearing loss
low education
smoking
depression
lack of physical activity
social isolation
high blood pressure
obesity
diabetes
excessive alcohol consumption
head injury
air pollution.
The NHS website talks through some ways to try and address some of the changeable risks of dementia. Alzheimer’s Research UK discusses three simple rules to try and protect our brains:
Love your heart – trying to maintain a healthy diet, good blood pressure control and regular activity or exercise
Stay sharp – keeping your mind active can help improve your brain reserve, it is important to consider doing something you enjoy
Keep connected – keeping connected to the people around us is another good way to give back to our brains, and can make us feel happier and healthier in general.
Join in the conversation on Twitter with @jamie_garr@CochraneUK or leave a comment on the blog.
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