A study on flavanols and cognition suggests that consuming black tea, apples, berries, and a small amount of dark chocolate may help maintain cognitive function, The Times reported.
According to the study, flavanols, which are compounds found in various foods like fruits, vegetables, cocoa, and tea, have shown potential for enhancing memory in older individuals, although there is a lack of systematic trials in this area.
The research involved approximately 3,500 older participants who were randomly assigned to receive flavanol supplements over a three-year period, with cognitive tests administered during the study.
Published in the Proceedings of the National Academy of Sciences, the study found that the supplements had minimal impact on cognition for most participants.
However, a notable group emerged—those with initially poor diets or low flavanol levels.
Remarkably, the report stated that this specific group experienced a roughly 10 per cent improvement in memory test performance after receiving flavanol supplements compared to those given a placebo.
While some researchers expressed skepticism about the strength of this finding, the study's scientists proposed that flavanols could be considered a necessary "nutrient for the ageing brain" when consumed at a certain level, crucial for normal functioning.
Professor Scott Small from Columbia University highlighted the importance, emphasising the adverse effect on memory when insufficient amounts of flavanols are consumed.
The study benefitted from a urine test developed at Reading University, utilised by slightly over one-third of the participants.
This test allowed for more effective assessment of flavanol levels in the specific group before the trial, enabling the researchers to examine the effectiveness of flavanols compared to this baseline after a year.
Professor Small further emphasised that it is those who do not consume enough flavanols that benefit the most, considering it a hallmark of a nutrient necessary for promoting positive aging.
The significance of the findings drew varying opinions among scientists.
Dr Davide Bruno from Liverpool John Moores University regarded it as a convincing piece of work, although he acknowledged the “modest” effects on memory.
On the other hand, Professor David Curtis from UCL expressed skepticism, remaining unconvinced that the findings could not be attributed to chance, suggesting no need for dietary changes.
In contrast, Professor Aedin Cassidy, a nutrition and preventive medicine expert from Queen's University Belfast, viewed the study as highly important and aligned with a growing body of evidence.
Cassidy noted that while animal experiments and short-term human studies have shown cognitive improvements from flavanols, this study represents the first long-term intervention trial demonstrating that dietary flavanols can restore memory in older adults with poor diets.
She emphasised that achievable doses for these brain health benefits include options like a mug of tea, a few squares of dark chocolate, or a couple of servings of berries or apples.