By John Ely Associate Health Editor for Mailonline
12:42 02 Jul 2024, updated 12:42 02 Jul 2024
Avocado on whole-grain toast isn’t just a trendy brunch staple: It could also be part of a diet aimed at fighting Alzheimer’s and dementia.
Scientists who studied the diet and cognitive abilities of more than 3,000 Britons over 70 years say they have discovered which foods eaten during childhood and early adulthood help brain function later in life.
They found that diets consisting of unprocessed or less processed leafy green vegetables, beans, whole fruits and whole grains were the most protective.
Experts have linked this phenomenon to the high levels of antioxidants and monounsaturated and polyunsaturated fats in these foods, which stimulate circulation and fight harmful substances in the brain.
They found that only 7% of people who followed this type of diet early in life had poor cognitive abilities, which can be a precursor to dementia, during the study.
In contrast, 92% of people who ate diets high in salt, added sugars and refined grains such as white bread suffered a decline in cognitive abilities in old age.
The scientists based their findings on a long-running British study, begun in 1946, which tracked the diet and health of 3,059 Britons aged 4 to 75.
Participants’ diets were examined at five points during the study, and their cognitive abilities were tested seven times.
Cognitive ability is a term that reflects a person’s memory strength and thinking speed.
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Although some cognitive decline occurs naturally with age, it can also be a sign of conditions such as dementia, with a quarter of people with low cognitive abilities in the study also showing signs of the condition.
The authors of the new study, who presented their findings at the annual meeting of the American Society for Nutrition in Chicago, acknowledged that the advice to eat more fruits and vegetables is not new.
However, they added that this research suggested that eating these foods early in life had a longer-lasting protective effect on the brain than previously thought.
Kelly Cara, a researcher and nutrition expert at Tufts University in Boston, said: “These early results broadly support current public health recommendations that it is important to establish healthy eating habits from an early age to support and maintain health throughout life.”
“Our results also provide new evidence suggesting that improving dietary habits through middle age can influence cognitive performance and help mitigate or even reduce cognitive decline in later years.”
She added that while the findings have not yet been peer-reviewed, they suggest a clear pattern in foods that appear to help protect the brain.
“Diets rich in whole or less processed plant food groups, including leafy green vegetables, beans, whole fruits and whole grains, may be most protective,” she said.
“Adjusting our dietary intake at any age to incorporate more of these foods and to adhere more closely to current dietary recommendations is likely to improve our health in several ways, including our cognitive health.”
Additionally, researchers have found that eating habits appear to be established during childhood and then continue later in life, for better or worse.
Fruits and vegetables are generally considered to be rich in antioxidants that fight unstable atoms called “free radicals” that are thought to damage cells.
Foods high in monounsaturated fats help lower bad cholesterol in the blood and include avocados, peanut butter and nuts like almonds.
Polyunsaturated fats have similar benefits and, in addition, provide omega-6 and omega-3 fatty acids, essential fats that your body needs. Foods rich in polyunsaturated fats include fatty fish like salmon, some nuts, and tofu.
The researchers rated the diets of the Britons in the study as high or poor quality, based on the US government’s dietary guidelines.
They recommend that adults generally eat at least two and a half cups (US cooking measure) of vegetables, two cups of fruit, 170 grams of grains, about 155 grams of lean or plant-based protein such as beans, and 27 grams (two tablespoons) of oils each day.
An example of what this would look like is an adult eating 88g of broccoli, two medium carrots, 33.5g of kale, 210g of apples, about four slices of wholemeal bread and a chicken or fish fillet plus 27g of oil for cooking or dressing a salad in one day.
However, the exact amounts vary depending on the specific food and the calorie needs of the adult in question, which vary between men and women.
The NHS guidelines for healthy eating are broadly similar and encourage adults to eat five portions of a variety of fruit and vegetables each day, starchy carbohydrates such as bread or pasta, ideally wholemeal, 30g of fibre per day, low-fat dairy products, for protein beans, pulses, fish, eggs, lean meat (including 2 portions of fish per week, one of which should be fatty) and small amounts of unsaturated oils and spreads.
It is also recommended that adults consume less than 6g of salt and 20g of saturated fat for women or 30g for men each day.
Authors of the new research It was noted that the lengthy nature of the study meant there were gaps and inconsistencies in data collection.
It is estimated that around 944,000 people in the UK are living with dementia, while the figure is estimated at around seven million in the United States.
Alzheimer’s disease is the leading cause of dementia, affecting about six in ten people with the disease.
This is thought to be due to a buildup of amyloid and tau in the brain, which clump together, forming plaques and tangles that make it harder for the brain to function properly.
Eventually, the brain struggles to cope with this damage and symptoms of dementia develop.
The second most common form of dementia is vascular dementia, which occurs when blood flow to the brain is reduced, such as in a stroke.
Memory problems, difficulty thinking and reasoning, and language problems are common early symptoms of the disease, which then worsen over time.
An analysis by Alzheimer’s Research UK found that 74,261 people died from dementia in 2022, up from 69,178 a year earlier, making it the country’s biggest killer.