A new study has found that strawberries could help to prevent later-life dementia – and they’re not the only local fruit we should be eating.
From avocados to acai berries, goji to guavas, plenty of fruits have been dubbed ‘superfoods’ over the years, generally the unusual and exotic ones, often imported from overseas rather than found growing in the UK.
All that could be about to change though, as a new study from the University of Cincinnati has named the humble strawberry as a superfood that may help to prevent dementia. In 2022, the same team published research into the ways that blueberries may lower the chance of developing late-life dementia.
“Both strawberries and blueberries contain antioxidants called anthocyanins, which have been implicated in a variety of berry health benefits, such as metabolic and cognitive enhancements,” explained Professor Robert Krikorian from the university’s Department of Psychiatry and Behavioural Neuroscience. “There is epidemiological data suggesting that people who consume strawberries or blueberries regularly have a slower rate of cognitive decline with ageing.”
The study asked people aged 50-65 to stop eating berries entirely, except for a powder equivalent of one cup of strawberries per day, or a placebo. Those who ate the strawberries for 12 weeks showed improved memory, better executive control, and even a reduction in symptoms of depression.
The researchers believe this might be because, like blueberries, the compounds found in strawberries reduce inflammation, including in the brain. “Executive abilities begin to decline in midlife and excess abdominal fat will tend to increase inflammation, including in the brain,” Prof Krikorian said. “So, one might consider that our middle-aged, overweight, prediabetic sample had higher levels of inflammation that contributed to at least mild impairment of executive abilities. Accordingly, the beneficial effects we observed might be related to moderation of inflammation in the strawberry group.”
In recent years it has become popular among some dieters to criticise fruit for the amount of sugar it contains, but this isn’t really fair, says Jenna Hope, nutritionist and author of How To Stay Healthy.
“The sugar in fruit is fructose and glucose, which can cause blood sugar spikes, but fruit typically contains a lot of fibre, which helps release the sugars into the bloodstream at a much lower rate than if you were to consume the same amount of sugar in sweets or cakes for example,” explains Hope. “Frankly the sugar in fruit doesn’t come close to outweighing the health benefits. The exception is that once you start juicing fruit, you break up the fibre so the sugar becomes more available.”
Unusual and interesting fruits are often dubbed ‘superfoods’ as a marketing technique, and their appeal lies in their exoticism, often meaning they’ve travelled a long way to get into a consumer’s fruit bowl. That sometimes means they’ve lost some nutrients on the way.
“Fruit is generally high in nutrients like vitamin C but those nutrients are sensitive to oxygen, so the longer the time between picking and eating, the more that is lost,” explains Hope.
Practical considerations for growers and transporters are also liable to trump quality and taste too, says Pam Bede, a nutritionist from Abbott’s Lingo, a biosensor and app combo that aims to retrain your metabolism. “Generally growers choose varieties which are best able to be transported versus choosing varieties for flavour and texture,” Bede says. “It’s the bright and brilliant colouring in fruit which is bringing a lot of the nutrients to the table; if that isn’t the priority then the fruit will be less nutritious than those grown for transport.”
So which traditional and nutrient-rich British fruits deserve the ‘superfood’ label?
“The humble apple isn’t championed as much as it should be – they’re affordable, easy to eat and versatile,” says Hope. “An apple a day keeps the doctor away? Not far wrong.”
Studies have shown that people who eat apples daily are 13-22 per cent less likely to develop heart disease and less likely to die of lung cancer. That’s because they’re rich in antioxidants, notably one called quercetin, which lowers inflammation around the body.
“They are also very fibrous, particularly rich in a fibre called pectin, which binds to cholesterol and stops the body from absorbing it, so apples have been shown to help lower cholesterol,” says Hope.
Pears have many of the same benefits as apples. They’re also full of pectin and quercetin, as well as procyanidin antioxidants, which have been linked to decreasing stiffness in heart tissue, potentially reducing the likelihood of cardiovascular illness. Like strawberries and blueberries, pears also have some anthocyanins, which will help with cognition in older age.
“Pears do contain plant chemicals including lutein and zeaxanthin, which are both well known for supporting eyesight, and preventing macular degeneration in later years,” adds Hope. “Lutein is the green colour in the pear so we want to be eating green pears rather than the yellow ones if you want to look after your eyesight.”
While not technically a fruit, rhubarb has numerous health benefits. It’s high in vitamin K, which helps transport calcium around the body and is good for bone development, while also playing an important role in blood clotting.
Also, it is high in potassium, making it a good swap for bananas, which are better known for their potassium content. “Potassium plays a really key role in managing fluid balance, which helps in lowering blood pressure,” says Hope. “While salt constricts blood vessels and increases blood pressure, potassium helps relax them.”
Bede adds, “Rhubarb has a very low glycemic index because it’s so full of fibre, so it won’t spike your blood sugar levels very much. If you add to your rhubarb some cream or yoghurt, you’ll be getting a bit of protein and fat with your fibre and sugar, which will all work together to slow down the pathway of digestion. You’re getting all the nutrients at the table at the same time, which will help control the glucose release in your blood, so it’s a great one to combine with other foods.”
The stone fruits are rich in vitamins A, C, and E. “Vitamin A is important in both eye health and immune health; it plays an important role in supporting the production of immune cells. Likewise, vitamin C is important in their function,” explains Hope. “Vitamin E is important for strong and healthy skin so it can help you avoid wrinkles. Most importantly, they are all antioxidants which will help the body remove free radicals, which are compounds that travel around the body causing damage and death to cells. If we can eliminate some of those free radicals, that supports general health and wellbeing because the body isn’t under attack as much.”
While recent research has linked blueberries and strawberries to preventing cognitive decline, British berries are highly prized for their other health benefits. Gooseberries, for example, are used widely in traditional medicine, where preclinical studies have linked them to fever reduction, pain suppression and lower cholesterol.
“Berries are among the fruits with the highest fibre content and tend to be the lowest in sugar,” says Hope. “They’re also high in polyphenols, antioxidants, and plant chemicals, which can be really beneficial for supporting brain health, heart health, and reducing free radicals, which contribute to inflammation. I’d encourage eating a wide variety of berries.”