The incredible new diet that can slash your risk of dementia by a staggering 25 per cent and even slow down ageing – as researchers reveal exactly when you should start following it

If eating healthily protects you against dying young, some diets in particular seem to be better than others in warding off cognitive decline and dementia.

Scientists in the US have just published the results of a large study that found people in their 40s and beyond who followed an eating regimen called the MIND diet were significantly less likely to develop Alzheimer’s disease.

What’s more, they were also far less likely to develop dementia than people adhering to other well-known healthy eating plans, such as the Mediterranean diet.

Even adopting the MIND diet after age 60 helped lower dementia risk.

‘This suggests it’s never too late to adopt a healthy diet to prevent dementia,’ says Dr Song-Yi Park, an associate professor of population sciences at the University of Hawaii at Manoa, who led the research.

The MIND diet stands for Mediterranean-DASH Intervention for Neurodegenerative Delay. It combines the Mediterranean diet (rich in olive oil, fish, wholegrain, fruit and vegetables) with the DASH diet (Dietary Approaches to Stop Hypertension) – which focuses on foods low in salt and rich in potassium, calcium and magnesium to help reduce blood pressure.

The MIND diet also contains lots of berries, particularly strawberries and blueberries – regarded by some as brain ‘superfoods’ – and green, leafy vegetables full of brain-boosting Vitamin K.

It also limits intake of foods such as red meat, processed meats, fried foods and those high in saturated fats and sugar.

As Dr Park tells the Mail: ‘We examined several healthy dietary patterns and found more consistent results with the MIND diet compared to other dietary patterns, such as the Mediterranean diet alone, DASH alone and Healthy Eating Index – which measures adherence to the Dietary Guidelines for Americans.’

The researchers looked at data from nearly 93,000 adults aged between 45 and 75, and found those who improved their adherence to MIND over ten years (including those who didn’t follow the diet closely at first) had a 25 per cent lower risk of dementia compared to those who didn’t stick so closely to the MIND diet as time went on.

However, Dr Park stresses her study does not prove that the MIND diet leads to better brain health – just that there is an association.

The next step, she adds, is to carry out more detailed studies to verify the results.

Nearly one million people in the UK are estimated to be living with dementia and it’s the leading cause of death – more than 74,000 a year.

Recent studies suggest about 45 per cent of cases could be prevented or delayed by addressing 14 risk factors in daily life. These include untreated vision loss, high cholesterol, air pollution, hearing loss, smoking, unmanaged high blood pressure, obesity, excessive alcohol consumption and social isolation.

Experts in the UK have welcomed the new findings. Dr Richard Siow, director of ageing research at King’s College London – who researches the types of foods linked to healthy ageing – says: ‘The benefits of the MIND diet are well-established, but this is the first time we have confirmation that it can reduce the risk of developing dementia in a large study over a long period of time.’

The key, he adds, is that it’s a diet rich in compounds shown to protect brain cells, such as fish oils and polyphenols (potent plant compounds) that can reduce inflammation and oxidative stress – a process where damaging molecules, called free radicals, circulate in the blood and harm healthy cells.

But the diet’s effect on blood pressure is also crucial, he says, as ‘hypertension is known to accelerate cognitive decline’.

Dr Siow adds: ‘This is because small blood vessels in the brain can be damaged by high blood pressure – ultimately reducing blood flow to the brain and leading to damage.

‘Micro-strokes and damage to cells in the small blood vessels in the brain caused by persistent hypertension have a cumulative effect over time, potentially leading to vascular dementia.

‘These processes start in early life, in your 20s and 30s, but may only manifest decades later. The longer you are on the MIND diet, the longer you seem to delay the processes of ageing.’

He suggests the benefits may be down to the way that both diets work in tandem and their effects on the human gut microbiome – the complex community of gut microbes that play a part in our body and brain health.

Dr Siow follows the MIND diet to protect his own brain health: ‘I do try and include more omega-3 fatty acids in my diet by eating two or three portions of fish a week.

‘These are good fats, which are linked to better brain health – partly by reducing levels of ‘bad’ LDL cholesterol and increasing ‘good’ HDL cholesterol.

‘I also eat plenty of berries and coloured fruit and vegetables, which are particularly potent sources of polyphenols.’

He says polyphenols can reduce certain cellular processes that lead to accelerated ageing, including cognitive decline.

Kirsty Robinson, stroke and neuroscience clinical lead dietitian at NHS Tayside, tells the Mail that polyphenols – a type of antioxidant – are essential to ward off brain ageing.

‘Antioxidants are vital chemicals that help neutralise harmful molecules which may contribute to brain ageing and diseases such as Alzheimer’s,’ she says.

‘While the human body naturally produces antioxidants, they are also obtained through diet, with fresh fruits and vegetables serving as rich sources.’

Other key antioxidants needed for this include Vitamin C, Vitamin E and beta-carotene.

Some studies suggest that regular consumption of ‘good’ fat omega-3 may help reduce the risk of dementia, particularly when incorporated into a balanced diet.

Other brain-friendly foods include beans, nuts and seeds as they are packed with vitamins and minerals that can improve the health of blood vessels, boost blood flow to the brain and help control blood sugar levels.

‘This is important as your brain is sensitive to the amount of glucose (or sugar) it receives,’ says Ms Robinson.

‘Both high and low blood sugar levels can damage blood vessels in the brain.’

Caroline Scates, deputy director of Admiral Nurse Development at Dementia UK, adds: ‘There are no guarantees that someone won’t develop dementia, but we can minimise the risk – and the earlier you start, the better.’