Dementia strikes every three seconds. In the time it takes you to read this sentence, someone will have developed memory loss, confusion and behavioural changes, according to the Alzheimer’s Society’s calculations.
It is a frightening thought, but recent months have finally brought signs of a breakthrough in the global battle against Alzheimer’s disease, the most common form of dementia.
The good news is that a new drug, Donanemab, has been shown to slow the progression of the disease by up to 35 per cent, while another large new study, published in the journal BMC Medicine, points to another potential treatment path.
Sticking to a Mediterranean diet may lower your risk of developing all forms of dementia by a quarter, as data from 60,000 people suggests a plant-rich diet may help, regardless of a person’s genetic risk factors.
Mediterranean or MIND diet?
“A Mediterranean diet, composed of wholegrain cereals, fish rich in omega-3 fatty acids, vegetables and other healthy foods, is excellent for reducing the risk of Alzheimer’s disease,” says Barbara Sahakian, professor of clinical neuropsychology at the University of Cambridge.
Scientists believe it may come down to neurotransmitters, important chemical messengers in the brain. “Acetylcholine, dopamine and serotonin, for example, have roles in cognition, including attention and learning, motivation and mood,” says Sahakian. And they are built from the foods we eat.
Sahakian’s early research showed that taking a drug that boosts acetylcholine had a positive effect on the attention spans of Alzheimer’s sufferers. The NHS in the United Kingdom now uses this same mechanism to treat patients through drugs like donepezil, which raise this crucial brain chemical. But, Sahakian points out, acetylcholine levels also increase when people eat lecithin – a substance that occurs naturally in many foods that take pride of place in the Mediterranean diet, including seafood and vegetables. There may, however, be an even more potent diet for the prevention of Alzheimer’s and other forms of dementia.
The MIND diet (Mediterranean-DASH intervention for neurodegenerative delay) is a hybrid of the Mediterranean and DASH (dietary approaches to stop hypertension) diets. Both are linked with a reduced risk of cardiovascular conditions like high blood pressure, heart attack, and stroke, as well as slower cognitive decline.
“The MIND diet is partially based on the Mediterranean Diet,” explains Sahakian. Alongside whole grains, poultry, fish and olive oil, it also emphasises the regular consumption of leafy green veg and berries, while placing limits on foods like pastries and sweets, red meats, fried foods and butter.
A 2015 study published in the journal Alzheimer’s & Dementia suggested that adhering closely to the diet could reduce your likelihood of developing the disease by as much as 53 per cent.
What more do we know about the foods that protect our little grey cells?
Go full Popeye on the spinach
“It really is best to eatdark-green leafy vegetables,” says Sahakian. Take spinach: “Rich in vitamins and iron, it also has antioxidant activity. While a high-fat diet increases oxidative stress in a variety of tissues, which may contribute to a number of degenerative diseases, foods that are very high in antioxidants prevent oxidative damage to cells,” says Sahakian. A 2018 study found that simply eating a daily serving of spinach or kale was associated with slower cognitive decline among those in later life.
Boost your blueberries
“Recent clinical research has demonstrated that berry fruits can reduce the risk of age-related neurodegenerative diseases and improve motor and cognitive functions,” says James Goodwin, director of Science and Research Impact at the Brain Health Network and author of Supercharge Your Brain. He points to a 2022 study that found blueberry extract improved ability to plan and focus along with working memory and learning.
Eat the rainbow
Don’t squeeze other fruit and vegetables out, however.
“In hunter gatherer times, we ate over 300 types of plants but according to the Food and Agriculture Organisation of the United Nations (FAO), 75 per cent of all prepared food in retail outlets comes from only 12 plants and five animal species,” warns Goodwin. “We have lost all of this diversity, and it’s no wonder we are now susceptible to many life-threatening chronic long-term illness, including dementia.”
A 2021 study showed that consuming just half a serving of colourful plants a day helped to reduce cognitive decline by 20 per cent, because it boosts our consumption of a class of micronutrients called flavonoids. So eat the rainbow.
Fish may have the edge, however. A 2012 study concluded that adding just one extra gram of omega-3 to your diet a day (or half a fillet of salmon per week) was associated with 20 to 30 per cent lower blood levels of beta-amyloid (a protein related to Alzheimer’s disease and memory problems), compared to people who included the average quantity of omega-3 in theirs.
Olive oil is rich in powerful antioxidant polyphenols. Last year, a Yale University study found that the extra-virgin variety enhanced brain connectivity and reduced blood-brain barrier permeability, both of which are markers of mild cognitive impairment and early Alzheimer’s disease.
Meanwhile, research from Harvard suggests that eating olive oil every day reduces your risk of death from neurodegenerative disorders like Alzheimer’s by 29 per cent. Study author Marta Guasch-Ferré recommended consuming three to four tablespoons daily.