Effects of Mixed-Berry Beverage on Mental and Heart Health in Healthy Older Adults

by | Apr 30, 2018 | 2017, Brain Health, Cardiovascular Health, Cognitive Health, Fruits and Vegetables

Written by Joyce Smith, BS. A five-week daily diet intervention rich in polyphenols and carotenoids significantly improved cardiovascular risk factors and cognitive function in participating healthy subjects.

fruits and vegetables - berriesLifestyle habits, particularly diet, play a pivotal role in the development of obesity, type 2 diabetes and cardiovascular disease and the associated risk of cognitive decline 1-3. Various studies have shown that berries can improve biomarkers for metabolic syndrome, type 2 diabetes, and cognitive decline 4 ; however, few have shown the impact of berries on cardiovascular risk factors and cognitive decline. Therefore, Nilsson et al, building on previous studies extolling the virtues of berries in promoting physical and mental health, 5 chose the following randomized, cross-over study design 6 to evaluate the effects of berries on cognitive function and cardiometabolic risk markers in healthy humans.

Forty healthy subjects, between 50–70 years of age, consumed daily for 5 weeks a combination berry beverage consisting of 150g blueberries, 50g blackcurrant, 50g elderberry, 50g lingonberries, 50g strawberry, and 100g tomatoes or a water-based control beverage. Before and after the study, subjects provided blood samples for cardiometabolic risk markers including blood pressure, fasting blood glucose, insulin, blood lipids and markers of inflammation and oxidative stress. Cognitive tests including working memory, and selective attention and psychomotor reaction time were done as well.

Following the 5-week intervention, analyses revealed a significantly reduced total- and LDL cholesterol in the berry group compared to baseline and the control beverage (P<0.005 and P<0.01, respectively). The control beverage had increased glucose concentrations (P<0.01) and tended to increase insulin concentrations (P = 0.064) from baseline, and increased insulin concentrations in comparison to the berry beverage (P<0.05).

Subjects who drank the berry beverage had a modest but significant 5% improvement in working memory compared to those who drank the control beverage (P<0.05); however significant improvements were seen in both selective attention (P<0.001) and reaction times (P<0.001), the results of which indicated a pronounced learning effect for those in the berry beverage group.

Researchers suggest the protective effect of berries on cardiometabolic risk factors and cognition was due to their antioxidant properties. Berries are rich in polyphenolic compounds, namely anthocyanins, flavonols, ellagitannins, proanthocyanidins, and phenolic acids. Anthocyanins (the pigments that give berries their red, blue, or purple colors) are powerful antioxidants that have the potential to improve cholesterol profile, blood pressure, fasting glucose, BMI, HbAlc, and inflammatory markers 3 . Other studies have shown that berries are able to reduce postprandial insulin concentrations in overweight and normal adults 7,8 and lower the postprandial blood glucose response to a sucrose challenge 9 . In addition, anthocyanins and flavonols, and their metabolites are capable of crossing the blood brain barrier to support learning and memory. Moreover, they have been shown to alter the gut microbiota to promote a more favorable gut flora and/or release bacterial metabolites such as short chain fatty acids10 . These metabolites stimulate the release of gut hormones such as GLP-l, a neuropeptide that also benefits cognitive functions such as learning and memory.

Potential study limitations include a preponderance of participating female participants (75%), no product blinding, and no control of participant compliance. These study results support the data that a diet rich in polyphenols and carotenoids can benefit both cardiovascular risk markers and cognitive function; however, additional studies are warranted to clarify the underlying mechanisms involved.

Source: Nilsson, Anne, Ilkka Salo, Merichel Plaza, and Inger Björck. “Effects of a mixed berry beverage on cognitive functions and cardiometabolic risk markers; A randomized cross-over study in healthy older adults.” PloS one 12, no. 11 (2017): e0188173.

© 2017 Nilsson et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Click here to read the full text study.

Posted April 30, 2018.

Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from  the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.

References:

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