Researchers at the University of East Anglia, Norwich, United Kingdom recently published a review article in the journal frontiers in Neuroscience titled ‘Citrus Polyphenols in Brain Health and Disease: Current Perspectives’.
Polyphenols are compounds created by plants that often serve as a defence function – many, for example, have a bitter or sour taste. In citrus fruits, the main class of polyphenols found are called flavonoids, and among those, flavanones. These are the compounds that give citrus fruits their unique tastes and fragrances.
In short, the paper synthesized existing research that focuses on various aspects of brain health in conjunction with consumption of citrus fruits, and more particularly, polyphenols contained in them.
First, they note that there is a lack of long-term studies and trials, but that may be due to the fact that the study of polyphenols itself is fairly recent.
When brain cells dysfunction, is can lead to cell death, and disorders such as Alzheimer’s disease. The way this happens is complex, which has made drug therapies tricky to develop. This can include a cascade of issues such as inflammation, oxidative stress, and other impairments.
It just so happens that the multiple benefits of citrus polyphenols respond to many of these issues. Among the studies cited, there were some encouraging results.
- One 2020 study showed an inverse relationship between the amount of polyphenols consumed overall and death by heart disease.
- Anti-inflammatory and anti-oxidant properties of citrus polyphenols may also be associated with brain health.
- In a 2016 study, of more than 20,000 participants over 6.5 years, those who ate the most flavanones had the least strokes.
- One small study found that schizophrenic patients who received flavanones along with their antipsychotic medications showed a significant improvement in cognitive tests.
- A 2017 study looked at more than 13,000 participants older than 65 over nearly 6 years. They found the incidence of dementia was lowest among those who consumed the most citrus fruits.
- A Norwegian study with more than 2,000 participants in their 70s found that better cognitive (brain) function was associated with consuming more fruits and vegetables, citing citrus fruits specifically.
More studies are needed, particularly over the long-term, to determine exactly how citrus fruits contribute to preserving good health – including in the brain. However, one of the facts to emerge is that the benefits are associated with eating whole fruits and not extracts.
Making citrus fruits, and a variety of other fruits and vegetables, part of your everyday diet makes good sense, and scientific research is providing a look at just how all the pieces come together.