Functional changes in the brain during ageing can alter learning and memory, gait and balance – in some cases leading to early cognitive decline, disability or injurious falls among older adults. Dietary interventions with strawberry (SB) have been associated with improvements in neuronal, psychomotor and cognitive functions in rodent models of ageing. We hypothesised that dietary supplementation with SB would improve mobility and cognition among older adults. In this study, twenty-two men and fifteen women, between the ages of 60 and 75 years, were recruited into a randomised, double-blind, placebo-controlled trial in which they consumed either freeze-dried SB (24 g/d, equivalent to two cups of fresh SB) or a SB placebo for 90 d. Participants completed a battery of balance, gait and cognitive tests at baseline and again at 45 and 90 d of intervention. Significant supplement group by study visit interactions were observed on tests of learning and memory. Participants in the SB group showed significantly shorter latencies in a virtual spatial navigation task (P = 0·020, ηp2 = 0·106) and increased word recognition in the California Verbal Learning test (P = 0·014, ηp2 = 0·159) across study visits relative to controls. However, no improvement in gait or balance was observed. These findings show that the addition of SB to the diets of healthy, older adults can improve some aspects of cognition, but not gait or balance, although more studies with a larger sample size and longer follow-up are needed to confirm this finding.

We conducted a meta-analysis of randomised controlled trials (RCT) to examine the effects of strawberry interventions on cardiovascular risk factors. We searched multiple databases including PubMed, Web of Science and Scopus to identify eligible studies published before 19 May 2019. The endpoints were blood pressure, total cholesterol (TC), HDL-cholesterol, LDL-cholesterol, TAG, fasting blood glucose, endothelial function and inflammatory factors. Pooled analyses were performed using random- or fixed-effects models according to a heterogeneity test. We also conducted sub-group analyses by baseline endpoint levels. We included eleven RCT in this meta-analysis (six for blood pressure, seven for lipid profile, seven for fasting blood glucose and six for C-reactive protein (CRP)). Overall, the strawberry interventions significantly reduced CRP levels by 0·63 (95 % CI −1·04, −0·22) mg/l but did not affect blood pressure, lipid profile or fasting blood glucose in the main analyses. Our analysis stratified by baseline endpoint levels showed the strawberry interventions significantly reduced TC among people with baseline levels >5 mmol/l (−0·52 (95 % CI −0·88, −0·15) mmol/l) and reduced LDL-cholesterol among people with baseline levels >3 mmol/l (−0·31 (95 % CI −0·60, −0·02) mmol/l). There was little evidence of heterogeneity in the analysis and no evidence of publication bias. In summary, strawberry interventions significantly reduced CRP levels and may improve TC and LDL-cholesterol in individuals with high baseline levels.

In strawberry production, a balanced and accurate irrigation schedule is essential, because of the high sensitivity of strawberry plants to water deficits and waterlogging. The optimal irrigation management strategy can, however, only be obtained by an accurate crop monitoring system. To replace the current visual inspection methods, which are subjective, time consuming and labour-intensive, the performance of the COmpact hyperSpectral Imaging system (COSI) mounted on an RPAS (Remotely Piloted Aircraft System) was evaluated. The study, focusing on different irrigation treatments in strawberry cultivation, unraveled the potential of the COSI system, to monitor field variations, even at small scale. Growth inhibition and differences in plant physiology due to water deficit could be detected. As such, the COSI system has shown potential for steering irrigation management decisions in strawberry cultivation.

Plant-derived foods rich in polyphenols are associated with several cardiometabolic health benefits, such as reduced postprandial hyperglycaemia. However, their impact on whole-body insulin sensitivity using the hyperinsulinaemic-euglycaemic clamp technique remains under-studied. We aimed to determine the effects of strawberry and cranberry polyphenols (SCP) on insulin sensitivity, glucose tolerance, insulin secretion, lipid profile, inflammation and oxidative stress markers in free-living insulin-resistant overweight or obese human subjects (n 41) in a parallel, double-blind, controlled and randomised clinical trial. The experimental group consumed an SCP beverage (333 mg SCP) daily for 6 weeks, whereas the Control group received a flavour-matched Control beverage that contained 0 mg SCP. At the beginning and at the end of the experimental period, insulin sensitivity was assessed by a hyperinsulinaemic-euglycaemic clamp, and glucose tolerance and insulin secretion by a 2-h oral glucose tolerance test (OGTT). Insulin sensitivity increased in the SCP group as compared with the Control group (+0·9 (sem 0·5)×10−3 v. −0·5 (sem 0·5)×10−3 mg/kg per min per pmol, respectively, P=0·03). Compared with the Control group, the SCP group had a lower first-phase insulin secretion response as measured by C-peptide levels during the first 30 min of the OGTT (P=0·002). No differences were detected between the two groups for lipids and markers of inflammation and oxidative stress. A 6-week dietary intervention with 333 mg of polyphenols from strawberries and cranberries improved insulin sensitivity in overweight and obese non-diabetic, insulin-resistant human subjects but was not effective in improving other cardiometabolic risk factors.

Previously, it has been shown that strawberry (SB) or blueberry (BB) supplementations, when fed to rats from 19 to 21 months of age, reverse age-related decrements in motor and cognitive performance. We have postulated that these effects may be the result of a number of positive benefits of the berry polyphenols, including decreased stress signalling, increased neurogenesis, and increased signals involved in learning and memory. Thus, the present study was carried out to examine these mechanisms in aged animals by administering a control, 2 % SB- or 2 % BB-supplemented diet to aged Fischer 344 rats for 8 weeks to ascertain their effectiveness in reversing age-related deficits in behavioural and neuronal function. The results showed that rats consuming the berry diets exhibited enhanced motor performance and improved cognition, specifically working memory. In addition, the rats supplemented with BB and SB diets showed increased hippocampal neurogenesis and expression of insulin-like growth factor 1, although the improvements in working memory performance could not solely be explained by these increases. The diverse polyphenolics in these berry fruits may have additional mechanisms of action that could account for their relative differences in efficacy.

Obesity increases the risk of developing bacterial and viral infections compared with normal weight. In a 7-week double-blind, randomised, cross-over trial, twenty obese volunteers (BMI between 30 and 40 kg/m2) were fed freeze-dried strawberry powder or strawberry-flavoured placebo preparations to determine the effects of dietary strawberries on immune function. Blood was collected at six time points during the study and peripheral blood mononuclear cells (PBMC) were isolated at each time point and activated with CD3 plus CD28 antibodies (T-lymphocyte activation) or lipopolysaccharide (LPS, monocyte activation). Interferon-γ, TNF-α, IL-4 and IL-10 were measured in supernatants from the activated T cells. Supernatants from the activated monocytes were analysed for the production of TNF-α, IL-1β, IL-6 and IL-8. PBMC were pre-stained with PKH (Paul Karl Horan) dye and activated with CD3 plus CD28 antibodies to determine the proliferative responses of CD4+ and CD8+ T-lymphocytes by flow cytometry. To detect global changes in gene expression, microarray analysis was performed on LPS- and vehicle-treated PBMC from two subjects before and after the strawberry intervention. No difference was observed for the production of T-cell cytokines between the intervention groups. The production of TNF-α was increased in the supernatants from LPS-activated PBMC in the group consuming strawberries compared with the placebo. A modest increase in the proliferation of the CD8+ T-lymphocyte population was observed at 24 h post-activation. These data suggest that dietary strawberries may increase the immunological response of T-lymphocytes and monocytes in obese people who are at greater risk for developing infections.

Obesity is a strong risk factor for the development of CVD, hypertension and type 2 diabetes. The overall goal of the present pilot study was to feed strawberries, in the form of freeze-dried powder, to obese subjects to determine whether dietary strawberries beneficially altered lipid profiles and reduced blood markers of inflammation compared with a control intervention. A total of twenty healthy subjects (thirteen females and seven males) aged between 20 and 50 years with a BMI between 30 and 40 kg/m2 completed the present 7-week double-blind, randomised, cross-over trial. Each subject received a prepared diet 7 d/week for 7 weeks consisting of approximately 35 % of energy from fat, 20 % protein, 45 % carbohydrate and 14 g fibre. Blood was collected on days 1 and 8 for baseline information. After the first week, subjects were randomly assigned to the strawberry powder (equivalent to four servings of frozen strawberries) or control (strawberry-flavoured) intervention for 3 weeks. For the remaining 3 weeks, subjects crossed over to the opposite intervention. Blood was collected again at the end of weeks 3, 4, 6 and 7. A comprehensive chemistry panel, lipid profile analyses and measurement of inflammatory mediators were performed for each blood draw. A 3-week dietary intervention with strawberry powder reduced plasma concentrations of cholesterol and small HDL-cholesterol particles, and increased LDL particle size in obese subjects (P < 0·05). Dietary strawberry powder reduced risk factors for CVD, stroke and diabetes in obese volunteers, suggesting a potential role for strawberries as a dietary means to decrease obesity-related disease.

Strawberries contain many antioxidant phytochemicals such as vitamin C, carotenoids and phenolic compounds including anthocyanins (ACN). In the present study, antioxidant composition of fresh strawberries (FS) and stored strawberries (SS) and the bioavailability of the main strawberry bioactive compounds were determined in human subjects. Thirteen healthy volunteers consumed 300 g of FS and SS on two separate occasions. Blood, before and at different time points from meal consumption, as well as 24 h urine, was collected, and parent compounds and metabolites of the different compounds were determined by HPLC or LC/MS/MS. A reduction in α-carotene plasma concentrations v. baseline values was recorded after the consumption of FS, although the amount of this carotenoid was higher in the SS. On the contrary, a significant increase of plasma vitamin C after 2, 3 and 5 h (P < 0·05) of FS and SS consumption was recorded. No quercetin and ACN were found in plasma, while coumaric acid, 4-hydroxybenzoic acid (4HBA, 56 and 54 % of pelargonidin-3-glucoside (Pel-glc) ingested with FS and SS, respectively) and protocatechuic acid (59 and 34 % of cyanidin-3-glucoside ingested with FS and SS, respectively) over 8 h from strawberry consumption were retrieved in the plasma. Pelargonidin glucuronide, pelargonidin glucoside and pelargonidin aglycone peaked in urine within 2 h of strawberry consumption, and the 24 h amount excreted was always approximately 0·9 % of the Pel-glc dose ingested. The data indicated that the content of phytochemicals in strawberries may influence the bioavailability of individual compounds. Furthermore, in the present study, the metabolism of Pel-glc was elucidated, and, for the first time, 4HBA was suggested to be a major human metabolite of Pel-glc.

Anthocyanins are natural dietary pigments with a wide array of biological properties that are possibly involved in the prevention of various diseases. These properties depend on their absorption and metabolism in the body. In the present study we first examined the gastric and intestinal absorption of pelargonidin 3-glucoside (Pg 3-glc) using rat in situ models. A high proportion of Pg 3-glc was rapidly absorbed from both the stomach (23 %) and small intestine (24 %). Its metabolism was further studied by feeding rats during 8 d with a diet enriched in freeze-dried strawberries. Only low amounts of total anthocyanins were recovered in 24 h urine (0·163 (sem 0·013) % of ingested anthocyanins; n 8). Strawberry anthocyanins were analysed in urine by HPLC-electrospray ionisation-tandem MS. Similar proportions of intact glycosides (about 53 %) and glucuronidated metabolites (about 47 %) were found. Pg 3-glc was thus glucuronidated to a larger extent than cyanidin 3-glucoside. These results highlight the influence of the aglycone structure on anthocyanin metabolism.