Can dementia be prevented? Expert explains key risk factors and warning signs

The number of people developing dementia worldwide each year could more than double by 2050. That's according to a new study. Dementia affects memory, thinking, and everyday activities. Alzheimer's is its most common form, accounting for up to 70% of dementia cases. Nearly 11 million people developed dementia in 2023, and by 2050, that figure could rise to nearly 25 million a year. The biggest reason is an aging population. After 65, the risk of developing Alzheimer's roughly doubles every five years. Scientists say that 45% of cases could be prevented or delayed by tackling risk factors like high blood pressure, diabetes, smoking, and hearing loss. Dementia cost the global economy an estimated $1.3 trillion in 2019, according to the World Health Organization. Dr. Ivan Koychev joins us. You're a neuroscientist and a clinical associate professor in neuropsychiatry at Imperial College London. You're joining us from London. Let's start with this. What is the best way to lower one's risk of getting dementia? We now know that about 30 to 40 percent of all cases of dementia are due to preventable risk factors. and these cover things that start from from early age so we know that people who have high levels of education tend to have developed dementia later on in life compared to people who have lower education people in midlife that are taking good care of their heart so things like blood pressure diabetes lipids these people tend to have a lower risk of dementia and then in the older adults the people who stay active so that means socially active intellectually active physically active tend to either not get dementia or get dementia later so all in all these factors add up to about 30 to 40 percent of all cases the rest are due to genetics and to age so the majority then is genetics and age the 60 about 60 to 70 percent is due to genetics and just how old you are yes who is most at risk because the study that we just cited found that women are more at risk than men why would that be that is an interesting question and that's been a very consistent finding in the literature people used to think that this is simply because women are living longer so regardless of where in the world you look at women tend to live six to eight years longer than men so we people used to think that it's just a um a factor of you know uh women women surviving longer but once you correct for the shorter lifespan of men there's still an effect in women and so this could then be due to hormonal changes that happen after the menopause um that is currently thought to be probably the reason why women have a higher risk of dementia the same study also says i'm staying on this topic of who's more at risk that middle income and low income countries there is a higher prevalence of dementia there than in rich countries why is that so this is a projection right um so the study that you are citing effectively found that by 2050 there's going to be much more increase in cases in lower middle lower middle income countries The reason is twofold. One is in these countries, the average life expectancy continues to increase. But then the other one is that in some of these countries, the control of heart condition is somewhat lags behind compared to where this is in the developed countries. And so it's a combination of increasing the life expectancy as well as better cardiovascular care in developed countries. What are the symptoms of this and what should people do if they detect symptoms, either in themselves or, say, with their parents? The earliest symptoms have to do with memory and thinking. People with dementia in the very early stages may struggle to remember things that have happened recently. So they'd be good at remembering things that happened earlier in their lifetime when they were young, for example. But they would struggle to tell you what's happened the previous day. That is a typical symptom of Alzheimer's disease. There are other forms of dementia and they can impact people's ability to pay attention, be changed to their personality and so on. So what people themselves can do, or their family can do if they notice this, is they can seek help from their doctor. What the doctors would do is certainly they will test their memory and thinking, but also they would run some basic tests to see whether there could be something going on with their body that would explain the symptoms. and they may go for a head scan that will look at the structure of the brain. Dr. Ivan Koitchev, thank you so much for joining us on Al Jazeera This Hour.