- Eating a handful of wild blueberries a day can boost cognitive and cardiovascular health, according to a new study.
- Studies have shown that anthocyanins in blueberries are responsible for improving vascular and cerebral blood flow, which are some of the possible mechanisms behind healthy cognitive function.
- Anthocyanins are polyphenols, a family of plant-based compounds associated with a growing number of health benefits.
A cup of wild blueberries is more than just a tasty treat, according to a new study from the United Kingdom’s King’s College London Faculty of Life Sciences and Medicine. It can contribute to brain growth, lower blood pressure and better cardiovascular health.
A randomized, double-blind, placebo-controlled trial found that blueberry eaters demonstrated improved executive function, strengthened short-term memory, and faster reaction times.
Study participants who drank 26 grams (g) of freeze-dried wild blueberry powder a day for 12 weeks had a 3.59 millimeter of mercury (mmHG) drop in systolic blood pressure and improved blood vessel function compared to people who took placebo powder.
Participants who ate blueberries were better at immediate recall of word lists and appeared improved
Research shows American Journal of Clinical Nutrition.
The study included 61 healthy male and female participants from London, aged between 65-80 years. Over 12 weeks, half of them drank a daily drink containing 26 grams of freeze-dried wild blueberry powder, while the other half received a taste-, appearance-, macro-nutrient-, fiber- and vitamin C-matched placebo.
In food studies it is common to use powdered materials to measure fineness.
The 26 grams of blueberry powder that participants consumed per day was equivalent to 178 grams of whole blueberries. This translates to somewhere between 75-80 blueberries, since they vary in size.
Dr. Senior Investigator. Ana Rodriguez-Mateos noted Medical News Today Those blueberries don’t need to be wild, since “there are other studies that have been conducted with other types of blueberries that show cognitive and vascular health benefits.”
Researchers believe that the beneficial effects of blueberries are due to their blue pigment
“Anthocyanins are a class of polyphenols,” explained Michelle Rautenstein, a heart health expert not involved in the study.
“[T]There are about 8,000 different types of polyphenols that provide health benefits,” he added. “Some other foods that contain beneficial polyphenols include green tea, broccoli, pears, and spices like turmeric and cinnamon.”
Strawberries, raspberries, red grapes and purple vegetables also contain anthocyanins.
“There is some evidence for health benefits of other anthocyanin-rich foods, and there is no reason to think that they would not work as well as blueberries, as long as the anthocyanin content of such foods is sufficient and the anthocyanins are bioaccessible and bioavailable.”
– Dr. Ana Rodriguez-Mateos
Dr. Rodriguez-Mateos and co-author Dr. Claire Williams have been separately investigating the cognitive and cardiovascular benefits of blueberries and have seen similar results.
As a result, Dr. Rodriguez-Mateos said, they “decided to investigate the effects on vascular and cognitive function simultaneously in the same clinical study.”
They set out to measure cerebral blood flow because other studies have suggested that this may be a mechanism behind the beneficial effects of polyphenols with increased vascular blood flow.
In addition, recent insights into the gut microbiota and the gut-brain axis have prompted them to explore this relationship as well.
The mechanism behind the beneficial effects of polyphenols is not yet fully understood.
One theory is that polyphenol “metabolites can act as signaling molecules, act through various cell-signaling pathways, modulate nitric oxide bioavailability and various enzymes,” said Dr. Rodriguez-Metos.
Researchers found increased anthocyanin metabolites in participants’ urine after a 12-week study period.
Dr. Rodríguez-Mateos is convinced that “the mechanism of action of blood vessels
Although the study found evidence that blueberries improve cerebral and vascular blood flow, they found no difference in arterial stiffness and blood lipids between people in the fruit and placebo groups.
Nevertheless, “[w]Chicken improves blood flow, benefiting both heart and brain health,” says Ruthenstein.
As far as the role of gut microbiota goes, Dr. Rodríguez-Mateos said, “We proposed a hypothesis in our study that polyphenols may act by increasing the abundance of butyrate-producing beneficial bacteria and therefore producing butyrate.”
He added that this needs to be confirmed in further studies.
According to the American Heart Association, a diet rich in vegetables, fruits, whole grains, healthy proteins, minimally processed foods and moderate oils promotes better cardiovascular and cognitive health.
Recent research has indicated that the Mediterranean diet may be the best diet for heart health.
Routhenstein notes the benefits of “green vegetables, especially spinach, Swiss chard and kale, which are rich in nitrates, which can help dilate arteries.”
“It helps improve blood flow and improve vascular, heart and cognitive function,” he noted.
There are many other foods linked to cognitive health, says Routhenstein. “Omega-3 fats like wild salmon and sardines are linked to better cognition because of their richness
Also, “[s]Some studies show that unsaturated fats, such as omega-3 fats, can help lower levels of beta-amyloid, a factor in the development and progression of Alzheimer’s disease.”