Why eating your greens could reduce your risk of dementia

Yet another reason to fill your plate

• In this article:

• What we know about dementia and its causes

• Why eating fruits and vegetable is linked to a lower risk

• The recommended dietary guidelines to follow

According to new research, incorporating fruits and vegetables into our diet as early as possible may significantly reduce our risk of developing dementia, as well as other chronic health conditions. 

Dementia is a condition that affects more than 400,000 people in Australia. It’s much more common after the age of 65 and is also the leading cause of death for women. Anyone who has seen a loved one struggle with dementia understands just how debilitating the condition can be. 

Now, new research out of Japan shows that the dietary choices we make now can impact our risk of developing dementia later in life.

What is dementia?

Dementia describes a collection of symptoms caused by disorders affecting the brain. It’s a broad term that covers the effects on people of a number of different medical conditions, including Alzheimer’s disease, vascular dementia, the Lewy body dementias and more. 

The effects of dementia vary from person to person, but it commonly features changes to mood, memory, thinking and behaviour. There is no single cause of dementia, and in many cases it occurs when there is no family history of the condition. 

The Australian Institute of Health and Welfare (AIHW) has identified seven key risk factors for developing dementia. These are: diabetes, hypertension (high blood pressure) in midlife, obesity in midlife, physical inactivity, depression, smoking, and low educational attainment. The risk of developing type 2 diabetes, hypertension and obesity can be reduced by following a healthy diet, but what does that actually look like?

The Australian Dietary Guidelines are still the gold standard for a healthy diet that reduces the risk of chronic health problems such as heart disease, type 2 diabetes, some cancers and obesity. However, the 2024 study published in the Journal of Nutrition highlights the particular importance of fruit and vegetable intake when it comes to reducing the risk of developing dementia.

Incorporating fruits and vegetables into our diet as early as possible may significantly reduce our risk of developing dementia. Image: Pexels

What did the study show?

The study assessed the dietary habits of more than 40,000 participants in Japan over ten years. Participants were aged 50-79 years, and researchers used surveys to assess their diets at baseline and then again ten years later. Researchers identified how many participants had been diagnosed with disabling dementia by the end of the study and controlled for confounding factors such as smoking, alcohol consumption, physical activity, and energy intake.

The researchers compared the participants’ fruit and vegetable intake against the World Health Organisation (WHO) target of 400g of fruit and vegetables per day. Women who met or exceeded this target had an 11% lower risk of disabling dementia than those who did not meet the target. 

The WHO target is modest compared with Australia’s current recommendations of a combined 675g fruit and vegetables per day. However, the latest available AIHW data shows that only 5 per cent of adults in Australia are achieving the 675g target. This study suggests that even if Australians continue to fall short of the 675g target, achieving a more modest 400g of fruit and vegetables per day could have a significant impact on our risk of disabling dementia. Every little bit helps!

This study gives us even more motivation to eat our greens to promote a healthy body and mind. Image: iStock

Which vegetables are the best to ward off dementia?

Cruciferous vegetables, such as cabbage and broccoli, seemed to be particularly powerful in reducing dementia risk amongst males in this population, while green vegetables and alliums, such as onions and garlic, stood out for females. While these foods are all nutritional powerhouses, it’s worth keeping in mind that this study was conducted in Japan where dietary patterns and quite different to those seen in Australia.

It is possible that associations with these specific types of vegetables were observed because they are the vegetables most commonly consumed in the Japanese diet. This doesn’t mean that they are the only vegetables that are associated with a reduced risk of dementia.

While we’ve always known that fruit and vegetables are important for our health and wellbeing, this study gives us even more motivation to eat our greens to promote a healthy body and mind now and into the future. Even if you’re not currently getting your 2 and 5 each day, just adding a little bit more could have a big impact! 

Ashleigh Jones is an Accredited Practising Dietitian and leads a team of dietitians at Lite n’ Easy. She is known for her practical, no-BS approach to healthy eating and her experience in helping patients with IBS. You can follow her on Instagram here.

Originally published as Why eating your greens could reduce your risk of dementia