go to content

What We Know About These 9 Potential Risk Factors For Dementia

Spoiler: You should be eating well and getting exercise, but you don't need to take Ginkgo biloba supplements or worry that you're watching too much TV.

Posted on

Let's get this out of the way: There are some things that increase your risk of dementia that you won't be able to do anything about.

Sanyasm / Getty Images

Dementia is a set of symptoms that can include problems with thinking, language, spatial skills, orientation, and memory loss. It's caused by diseases that damage your brain, like Alzheimer's disease.

Aging is the most significant risk factor for dementia, and there's nothing we can do about it. (For the sake of this post, let's assume that in our lifetimes there's not going to be any miracle anti-aging technology.)

It looks like women are slightly more likely to get dementia than men, even when accounting for the fact that women tend to live longer. Genes can also play a part, but nobody fully understands how.

And then there are risk factors from your environment and lifestyle that you could do something about.

That's what we're going to focus on here, because those are the factors that are reported (and misreported) the most.

With help from the Alzheimer's Society, we've looked at how strong the evidence is for each risk factor. Here's what you need to do to lower your risk, and what you don't need to worry about.

1. DO: Get some exercise.

well.blogs.nytimes.com

"Of all the lifestyle interventions studied so far, taking regular physical exercise appears to be the best thing you can do to reduce your risk of Alzheimer’s disease and dementia," according to the Alzheimer's Society.

One study, published in PLOS One in December 2013, followed 2,235 men aged 45–59 years in Caerphilly, Wales, over 30 years. It found that adopting four of five factors for a healthy lifestyle — consisting of not smoking, eating well, being physically active, drinking in moderation, having a body mass index (BMI) of between 18 and 25 — reduced the risk of cognitive decline by up to 60%.

"I think it's pretty clear that what you need to do in life is exercise and eat well," Dr. Claudia Cooper from the Division of Psychiatry at University College London told BuzzFeed Science.

Verdict: Strong evidence for exercise reducing risk of dementia.

2. DO: Quit smoking.

A systematic review of studies relating smoking and dementia found that when you remove those studies funded by the tobacco industry, smokers have a significantly greater risk of dementia.

This is probably because smoking is related to cardiovascular disease and high blood pressure, which could cause damage to blood vessels in your brain.

If you're a smoker right now, I have good news: There's some evidence that if you quit smoking your dementia risk will go back to that of a nonsmoker.

Verdict: Strong evidence that smokers are more likely to get dementia.

3. DO: Protect your head.

Mike Watson Images / Getty Images

There've been a variety of observational studies on this, on everyone from professional boxers to NFL players and war veterans. There's even a phrase for it: chronic traumatic encephalopathy has been used to describe long-term neurological side effects of repeated head injuries since the 1960s.

Verdict: Strong evidence that repeated concussion and traumatic head injuries increase your risk of dementia.

4. DO: Eat a healthy diet.

Image Source White / Getty Images

There's some evidence that a Mediterranean diet — rich in fish, fresh fruit and veg, whole grains, nuts and seeds — might reduce risk of cognitive decline and dementia. But it's not clear what aspect of this diet might be helping, and NHS Choices warns that some of the media coverage of this diet overstates its benefits.

There's not yet been a big randomised control trial (where a drug or treatment is compared to a "control" treatment and participants are assigned to each group randomly) that looks at the affect of a Mediterranean diet on dementia, so we can't say for sure that the diet is what's causing the reduced risk.

But one of the biggest risk factors for dementia is diabetes, and a surefire way to reduce your risk of that is to eat well and exercise. "Strong evidence is coming out about diabetes [as a dementia risk factor], but all the people in these studies have got Type 2 diabetes, not Type 1," says Cooper. "And I think that what's behind that whole diabetes story is probably diet."

Verdict: Some evidence that a healthy diet can reduce your risk of dementia, but we can't say for sure if a Mediterranean diet is best.

5. DO: Try to get enough sleep.

ostrichpillow.com

Some studies have found that people who say they regularly get less than six or more than nine hours sleep per night are at a higher risk of dementia.

Verdict: Some evidence that sleep disorders or disrupted sleep can increase your risk of dementia.

6. MAYBE: Do a crossword.

Thinkstock / express.co.uk / dailymail.co.uk

A systematic review that looked at how "cognitive leisure activities" — like reading, doing a crossword, or doing a sudoku puzzle — concluded that while they may be beneficial in preventing dementia, "the evidence is currently not strong enough to infer a direct causal relationship." We also can't say which sorts of activities would be best.

Verdict: If you enjoy doing puzzles, keep doing them, but don't feel like you have to.

7. DON'T WORRY ABOUT: Eating specific foods or taking supplements.

Thinkstock / express.co.uk /foxnews.com

Turmeric, coconut oil, and cinnamon have all been touted as potential ways to protect against dementia, but the only evidence comes from experiments in animals. (Findings from research conducted in animals can't necessarily be extrapolated to humans.)

When it comes to supplements, Ginkgo biloba is often marketed as improving memory. But a recent meta-analysis of the supplement in healthy older people found no evidence that it can reduce the rates of dementia.

"Nobody's suddenly going to find a magical herb to cure it, because it's more complicated than that," says Cooper. "It's a complicated disease and it's got a complicated solution."

Verdict: Little evidence that that specific foods can decrease your risk of dementia. Strong evidence that Ginkgo biloba does not reduce risk.

8. DON'T WORRY ABOUT: Watching too much TV.

washingtonpost.com

Data presented at an international conference on Alzheimer's this week tracked more than 3,000 people over 25 years, starting when they were young adults, and found that those who watched more than four hours of TV per day performed more poorly on a cognitive test in middle age.

This resulted in headlines like the one above. But while we already know that people who exercise are less likely to get dementia than people who have a sedentary lifestyle, there's not currently enough evidence to say that TV itself is a risk factor.

"We cannot draw any conclusions about whether a sedentary lifestyle or excessive TV watching in young adults affects the risk of cognitive decline or dementia later on," said Dr. Doug Brown, director of research at the Alzheimer's Society.

Verdict: Low evidence for increased risk of dementia due to watching TV. Although there is evidence that a sedentary lifestyle can increase risk.

9. DON'T WORRY ABOUT: Playing video games.

You might have seen media reports of video gaming being linked to Alzheimer's. This was based on a paper published in the journal Proceedings of the Royal Society B that found people who play a lot of video games make increased use of a certain part of the brain that has previously been linked to a decrease in the volume of the hippocampus. Other studies have suggested that a reduced hippocampus volume can mean an increased risk of Alzheimer's... Still with us?

The original paper did not look at hippocampus volume, and did not mention Alzheimer's once (though, unsurprisingly, the press release for the study did).

As Professor Chris Chambers and Dr. Peter Etchells wrote in The Guardian, this series of logical leaps can't be equated to evidence that video games increase your risk of Alzheimer's.

There have been other studies looking at whether playing certain kinds of video games might actually improve cognition in older people. One randomised control trial published in the journal Frontiers in Aging Neuroscience suggests that non-action video games might help improve some aspects of cognition, but there is no evidence that this translates to reduced rates of dementia.

Verdict: No evidence that video games increase your risk of dementia.

Kelly Oakes is science editor for BuzzFeed and is based in London.

Contact Kelly Oakes at kelly.oakes@buzzfeed.com.

Got a confidential tip? Submit it here.