Plain language summary
The regular intake of foods rich in polyphenols shows many biological activities, such as antioxidant, cardioprotective, anti-inflammation and anti-aging properties. This diversity of compounds found in grapes, especially red grapes, makes it a candidate for testing the role of dietary polyphenols to health. The objective of this single blinded randomised controlled clinical trial was to evaluate the effects of consuming 50g of Málaga muscatel raisins which are dried grapes on cognitive performance, quality of life, and functional activities in healthy adults over 70 years. According to the researchers this is the first study looking at the effect of raisins on cognitive performance. A group of 80 participants were split into two groups with one group adding 50g of raisins a day to their usual diet for six months and a control group of 40 patients receiving no raisins. Cognitive performance was measured by various tests which are summarised in the full text article. The results of this study showed that the supplement of 50 g of raisins slightly improved cognitive performance including spatial orientation, memory and comprehension, reading, writing, and drawing. In addition to a slight improvement in quality of life and functional activities. This shows promising results and that the addition of raisins to the diet along with a variety of foods rich in polyphenols can confer positive health benefits that can prevent age related cognitive decline. More research is needed to know exactly the mechanism of action of polyphenols on cognitive performance.
Abstract
The objective of this study was to evaluate the effects of consuming 50 g of raisins on cognitive performance, quality of life, and functional activities in healthy older adults. This is a parallel randomized controlled clinical trial, in which 80 subjects over 70 years of age participated. For 6 months, the intervention group (IG; n = 40) consumed 50 g of raisins per day added to their usual diet, whereas the control group (CG; n = 40) received no supplement. All variables were measured at baseline and at 6 months. Cognitive performance assessed with the Montreal Cognitive Assessment (MOCA) test shows a difference of 3.27 points (95% CI 1.59 to 4.96), p ≤ 0.001, favorable to the IG, after the intervention. Among the cognitive performances, an improvement is observed in the IG in orientation, assessed both with the MOCA test 0.49 (95% CI 0.10 to 0.87), p = 0.014, and with the Mini-Mental State Examination (MMSE) test, 0.36 (95% CI 0.02 to 0.70), p = 0.038. In visuospatial/executive capacity and in language, improvements were also observed in the IG, 1.36 (95% CI 0.77 to 1.95), p = 0.001, and 0.54 points (95% CI 0.12 to 0.96), p = 0.014, respectively. Immediate and delayed recall, assessed with the Rey Auditory Verbal Learning Test, improved in the IG. In addition, the IG showed a better quality of life and greater autonomy in instrumental activities of daily living after 6 months. No significant changes were observed in the rest of the variables analyzed. Therefore, the consumption of 50 g of raisins produces a slight improvement in cognitive performance, quality of life, and functional activities in the elderly.
Methodological quality
Jadad score
:
2
Allocation concealment
:
No
