Fruit and vegetables (F&V) have been a cornerstone of healthy dietary recommendations; the 2015–2020 U.S. Dietary Guidelines for Americans recommend that F&V constitute one-half of the plate at each meal. F&V include a diverse collection of plant foods that vary in their energy, nutrient, and dietary bioactive contents. F&V have potential health-promoting effects beyond providing basic nutrition needs in humans, including their role in reducing inflammation and their potential preventive effects on various chronic disease states leading to decreases in years lost due to premature mortality and years lived with disability/morbidity. Current global intakes of F&V are well below recommendations. Given the importance of F&V for health, public policies that promote dietary interventions to help increase F&V intake are warranted. This externally commissioned expert comprehensive narrative, umbrella review summarizes up-to-date clinical and observational evidence on current intakes of F&V, discusses the available evidence on the potential health benefits of F&V, and offers implementation strategies to help ensure that public health messaging is reflective of current science. This review demonstrates that F&V provide benefits beyond helping to achieve basic nutrient requirements in humans. The scientific evidence for providing public health recommendations to increase F&V consumption for prevention of disease is strong. Current evidence suggests that F&V have the strongest effects in relation to prevention of CVDs, noting a nonlinear threshold effect of 800 g per day (i.e., about 5 servings a day). A growing body of clinical evidence (mostly small RCTs) demonstrates effects of specific F&V on certain chronic disease states; however, more research on the role of individual F&V for specific disease prevention strategies is still needed in many areas. Data from the systematic reviews and mostly observational studies cited in this report also support intake of certain types of F&V, particularly cruciferous vegetables, dark-green leafy vegetables, citrus fruits, and dark-colored berries, which have superior effects on biomarkers, surrogate endpoints, and outcomes of chronic disease.

Apoptosis, programmed cell death type I, is a critical part of neurodegeneration in cerebral ischemia, Parkinson’s, and Alzheimer’s disease. Apoptosis begins with activation of pro-death proteins Bax and Bak, release of cytochrome c and activation of caspases, loss of membrane integrity of intracellular organelles, and ultimately cell death. Approaches that block apoptotic pathways may prevent or delay neurodegenerative processes. Carotenoids are a group of pigments found in fruits, vegetables, and seaweeds that possess antioxidant properties. Over the last several decades, an increasing number of studies have demonstrated a protective role of carotenoids in neurodegenerative disease. In this review, we describe functions of commonly consumed carotenoids including lycopene, β-carotene, lutein, astaxanthin, and fucoxanthin and their roles in neurodegenerative disease models. We also discuss the underlying cellular mechanisms of carotenoid-mediated neuroprotection, including their antioxidant properties, role as signaling molecules, and as gene regulators that alleviate apoptosis-associated brain cell death.

Guideline recommendation for a plant bioactive such as flavan-3-ols is a departure from previous recommendations as it is not based on deficiencies but rather improvement in health outcomes. Nevertheless, there is a rapidly growing body of clinical data reflecting benefits of flavan-3-ol intake that outweigh potential harms. Thus, the objective of the Expert Panel was to develop an intake recommendation for flavan-3-ols and cardiometabolic outcomes to inform multiple stakeholders including clinicians, policymakers, public health entities, and consumers. Guideline development followed the process set forth by the Academy of Nutrition and Dietetics which includes use of Evidence to Decision Framework. Studies informing this guideline (157 randomized controlled trials and 15 cohort studies) were previously reviewed in a recently published systematic review and meta-analysis. Quality and strength-of-evidence along with risk-of-bias in reporting was reviewed. In drafting the guideline, data assessments and opinions by authoritative scientific bodies providing guidance on the safety of flavan-3-ols were considered. Moderate evidence supporting cardiometabolic protection resulting from flavan-3-ol intake in the range of 400-600 mg/d was supported in the literature. Further, increasing consumption of dietary flavan-3-ols may help improve blood pressure, cholesterol levels, and blood sugar. Strength of evidence was strongest for some biomarkers (i.e., systolic blood pressure, total cholesterol, HDL-cholesterol, and insulin/glucose dynamics). It should be noted that this is a food-based guideline and not a recommendation for flavan-3-ol supplements. This guideline was based on beneficial effects observed across a range of disease biomarkers and endpoints. While a comprehensive assessment of available data has been reviewed, evidence gaps identified herein can inform scientists whereby guiding future randomized clinical trials.

Decreases in cognitive function related to increases in oxidative stress and inflammation occur with ageing. Acknowledging the free radical-quenching activity and anti-inflammatory action of the carotenoid lycopene, the aim of the present review was to assess if there is evidence for a protective relationship between lycopene and maintained cognitive function or between lycopene and development or progression of dementia. A systematic literature search identified five cross-sectional and five longitudinal studies examining these outcomes in relation to circulating or dietary lycopene. Among four studies evaluating relationships between lycopene and maintained cognition, three reported significant positive relationships. Neither of the two studies reporting on relationship between lycopene and development of dementia reported significant results. Of four studies investigating circulating lycopene and pre-existing dementia, only one reported significant associations between lower circulating lycopene and higher rates of Alzheimer's disease mortality. Acknowledging heterogeneity among studies, there is insufficient evidence and a paucity of data to draw firm conclusions or tease apart direct effects of lycopene. Nevertheless, as low circulating lycopene is a predictor of all-cause mortality, further investigation into its relationship with cognitive longevity and dementia-related mortality is warranted.

Cardiometabolic risk factors increase the likelihood of cardiovascular disease development by 2-fold. Lycopene, a potent lipophilic antioxidant, may be able to mediate oxidative stress, a mechanism underpinning metabolic syndrome (MetS) and its risk factors. This is, to our knowledge, the first systematic review of the literature with the purpose of investigating the relation between circulating lycopene or dietary intake of lycopene and MetS as well as its risk factors. The review was conducted using PubMed and EBSCOhost databases with the search terms "lycopene" and "metabolic syndrome." Inclusion criteria included human studies published in English in a scholarly, peer-reviewed journal and evaluation of lycopene in relation to ≥3 of the 5 MetS risk factors as defined by the National Cholesterol Education Program's Adult Treatment Panel III (ATP III) report. The process identified 11 studies, including 8 cross-sectional and 3 intervention studies. Cross-sectional studies were grouped into 3 categories, with several studies falling into >1 category, based on results reporting associations of lycopene with the prevalence and outcomes of MetS (5 studies), presence of ATP III risk factors (4 studies), and variables mediating lycopene's influence on MetS risk (3 studies). All studies in each category reported significant protective associations. Of the 3 intervention studies, all reported significant protective effects from a lycopene-rich beverage, despite varying doses and durations of intake. Although a protective relation between lycopene and MetS was generally supported, different MetS components appeared to be influenced by lycopene rather than demonstrating consistent improvement in a single component. Thus, additional research is needed to elucidate the mechanistic effects of lycopene on MetS, as well as to determine evidence-based recommendations concerning dose-durational effects of lycopene and MetS risk reduction. In conclusion, the evidence of lycopene's benefit exists such that lycopene status or lycopene consumption may be associated with favorable alterations to the components of MetS.

Background: Excess adiposity is characterized by alterations in adipokine secretion such that circulating leptin concentrations are increased with reductions in adiponectin. An emerging biomarker for the assessment of this adipose tissue (AT) dysfunction is the adiponectin:leptin (AL) ratio. A low AL ratio may be suggestive of dysfunctional AT and, consequently, a heightened cardiometabolic disease risk. This ancillary study investigated the relationship between the AL ratio and cardiometabolic health among community-dwelling older adults with obesity, as well as the effects of a 12-month exercise and diet intervention on changes in the AL ratio. Methods: Participants (n = 163, 70.2 ± 4.7 years, 38.0% male) were randomized to the exercise only group, exercise + nutrient-dense weight maintenance group (exercise + weight maintenance), or exercise + nutrient-dense caloric restriction of 500 kcal/d group (exercise + intentional weight loss) (clinicaltrials.gov #NCT00955903). Total and regional adiposity as determined by magnetic resonance imaging (MRI) and dual-energy X-ray absorptiometry (DXA), anthropometrics, and cardiometabolic biomarkers were assessed at baseline and 12 months. Results: The AL ratio was significantly (p < 0.05) inversely correlated with body mass index, waist circumference, measures of adiposity, and insulin among all participants at baseline. Among females only, significant positive and inverse correlations were also observed between this ratio and high-density lipoprotein cholesterol and the inflammatory biomarkers high sensitivity C-reactive protein and interleukin-6, respectively. While controlling for biological sex, a significant time by intervention group interaction effect (p < 0.05) was observed such that the AL ratio significantly increased from baseline to study completion among participants in the exercise + weight maintenance group and exercise + intentional weight loss group. Post hoc analysis revealed that the exercise + intentional weight loss group exhibited a significantly greater AL ratio at study completion compared to other groups (p < 0.05 all). Conclusions: Results are in support of the AL ratio as a measure of AT dysfunction among older adults. Furthermore, results suggest that a 12-month exercise and diet intervention with intentional weight loss assists in improving the AL ratio in this population.