Cognition: the new frontier for nuts and berries

Pistachio (Pistacia vera L.) consumption improves cognitive performance and mood in overweight young adults: A pilot study

This pilot study evaluated the impact of pistachio consumption on cognitive performance and mood in overweight young adults. Pistachios were characterized (chemical and nutraceutical), and a baseline-final, uncontrolled nutritional intervention was performed (28 g of pistachio/28 days). Psychometric tests were applied to estimate cognitive performance and mood; anthropometric evaluation, biochemical analysis, and plasma antioxidant activity were included. The main component of nuts was lipids (48.1%). Pistachios consumption significantly (p ≤ 0.05) reduced waist circumference (-1.47 cm), total cholesterol (-10.21 mg/dL), LDL (-6.57 mg/dL), and triglycerides (-21.07 mg/dL), and increased plasma antioxidant activity. Pistachio supplementation improved risk tolerance (p ≤ 0.006) and decision-making strategy (p ≤ 0.002; BART-task), executive functions (BCST-task; p ≤ 0.006), and selective and sustained attention (Go/No-Go-test; p ≤ 0.016). The mood state was positively modulated (p ≤ 0.05) for anxiety, anger-hostility, and sadness-depression. These results show for the first time the benefits of pistachio consumption on cognitive performance and mood in overweight young adults.

Consumption of Berries and Flavonoids in Relation to Mortality in NHANES, 1999-2014

BACKGROUND

Berries are foods that are abundant in nutrients, especially flavonoids, that promote good health; however, the effects of total berries on mortality are not well characterized.

OBJECTIVES

We evaluated whether intakes of total berries and specific berry types including blueberries, strawberries, cranberries, flavonoids, and subclasses of flavonoids (anthocyanidins, flavonols, flavones, flavanones, flavan-3-ols, and isoflavones) in relation to mortality risk in United States adults.

METHODS

A nationally representative sample of the United States adult population was obtained using data from the 1994-2014 NHANES (n = 37,232). Intake of berries was estimated using 24-h food recalls (1999-2014), and flavonoids intake was calculated using the matched USDA's expanded flavonoid database. Mortality outcomes based on 8 y of follow-up were obtained using linked death certificates.

RESULTS

Compared with nonconsumers, the multivariable-adjusted hazard ratio for all-cause mortality was 0.79 [95% confidence intervals (CI): 0.7, 0.89] for any berry consumption, 0.86 (0.75, 0.99) for strawberry consumption 0.79 (0.66, 0.95) for blueberries, and 0.69 (0.51, 0.93) for cranberries. Compared with the lower median of intake, risk of all-cause mortality for greater intake was 0.85 (0.74, 0.97) for total flavonoids, 0.85 (0.76, 0.95) for anthocyanidins, 0.9 (0.82, 0.99) for flavan-3-ols, 0.89 (0.79, 0.9) for flavanols, and 0.89 (0.8, 0.99) for flavones. There was a dose-response relationship between intakes of total flavonoids, anthocyanidins, and flavones and lower all-cause mortality risks (Ptrend < 0.05). Risk for cardiometabolic mortality was 0.75 (0.58, 0.98) for berry consumers and 0.49 (0.25, 0.98) for cranberry consumers. For respiratory disease mortality, risk was 0.41 (0.2, 0.86), compared with blueberry nonconsumers.

CONCLUSION

Higher intakes of berries and flavonoids were associated with a lower overall mortality risk in adult Americans. Few adults regularly consume berries, indicating that increased intake of berries and flavonoid-rich foods may be beneficial to health.

Perspective: Council for Responsible Nutrition Science in Session. Optimizing Health with Nutrition-Opportunities, Gaps, and the Future

Achieving optimal health is an aspirational goal for the population, yet the definition of health remains unclear. The role of nutrition in health has evolved beyond correcting malnutrition and specific deficiencies and has begun to focus more on achieving and maintaining 'optimal' health through nutrition. As such, the Council for Responsible Nutrition held its October 2022 Science in Session conference to advance this concept. Here, we summarize and discuss the findings of their Optimizing Health through Nutrition - Opportunities and Challenges workshop, including several gaps that need to be addressed to advance progress in the field. Defining and evaluating various indices of optimal health will require overcoming these key gaps. For example, there is a strong need to develop better biomarkers of nutrient status, including more accurate markers of food intake, as well as biomarkers of optimal health that account for maintaining resilience-the ability to recover from or respond to stressors without loss to physical and cognitive performance. In addition, there is a need to identify factors that drive individualized responses to nutrition, including genotype, metabotypes, and the gut microbiome, and to realize the opportunity of precision nutrition for optimal health. This review outlines hallmarks of resilience, provides current examples of nutritional factors to optimize cognitive and performance resilience, and gives an overview of various genetic, metabolic, and microbiome determinants of individualized responses.

Perspective: Challenges and Future Directions in Clinical Research with Nuts and Berries

Consumption of nuts and berries are considered part of a healthy eating pattern. Nuts and berries contain a complex nutrient profile consisting of essential vitamins and minerals, fiber, polyunsaturated fatty acids, and phenolics in quantities that improve physiological outcomes. The spectrum of health outcomes that may be impacted by the consumptions of nuts and berries includes cardiovascular, gut microbiome, and cognitive, among others. Recently, new insights regarding the bioactive compounds found in both nuts and berries have reinforced their role for use in precision nutrition efforts. However, challenges exist that can affect the generalizability of outcomes from clinical studies, including inconsistency in study designs, homogeneity of test populations, variability in test products and control foods, and assessing realistic portion sizes. Future research centered on precision nutrition and multi-omics technologies will yield new insights. These and other topics such as funding streams and perceived risk-of-bias were explored at an international nutrition conference focused on the role of nuts and berries in clinical nutrition. Successes, challenges, and future directions with these foods are presented here.

Nut consumption and academic performance among adolescents: the EHDLA study

PURPOSE

The aim of this study was to examine the relationship between nut consumption and academic performance in Spanish adolescents and to explore the role of sociodemographic, anthropometric, and lifestyle covariates on this association.

METHODS

A cross-sectional study was carried out using a food frequency questionnaire for estimating nut consumption in the number of 20-30 g servings per week, and academic performance data were obtained from school records. Analyses of covariance were adjusted for sociodemographic, anthropometric and lifestyle covariates, including total energy intake.

RESULTS

Among the 846 adolescents included in the analyses (55.3% girls, age range from 12 to 17 years), the mean ± standard deviation consumption of nuts was 2.7 ± 2.8 servings per week, while the mean of all school grades recorded was 6.5 ± 2.0. Furthermore, compared to no consumption, the consumption of ≥ 3 nut servings per week was consistently associated with higher grades in language (p for trend = 0.005), combination of language and math (p for trend = 0.026), grade point average (p for trend = 0.039), and combination of all school records (p for trend = 0.046). These associations were observed regardless of all covariates considered, although sex and socioeconomic level played a significant role in the completely adjusted models.

CONCLUSION

Nut consumption is associated with higher academic performance in a representative sample of Spanish adolescents. These cross-sectional results should be confirmed in longitudinal and intervention studies.

Multicultural Healthy Diet to Reduce Cognitive Decline & Alzheimer's Disease Risk: Study protocol for a pilot randomized controlled trial

BACKGROUND

Emerging evidence indicates that healthy dietary patterns are associated with higher cognitive status; however, few clinical trials have explored this association in diverse middle-aged adults before the onset of cognitive decline. We use novel ambulatory methods to assess cognition in natural settings in tandem with diet recording.

AIMS

We investigate whether the Multicultural Healthy Diet Study to Reduce Cognitive Decline & Alzheimer's Disease Risk, a pilot randomized controlled trial of an anti-inflammatory dietary pattern compared to usual diet, can mitigate cognitive decline and Alzheimer's Disease risk in a diverse population of 40-65 year old adults in Bronx, New York.

METHODS

Primary cognitive outcomes assessed at nine months are collected in an ecological momentary assessment "measurement burst" design, over the course of participants' daily lives. These ultra-brief, ambulatory cognitive assessments examine processing speed, visuospatial working memory, short-term associative memory binding, long-term associative memory, and working memory capacity. Key secondary outcomes relate to comparing dietary intake between study arms with respect to cognitive outcomes. We assess diet with food records using the National Cancer Institute's Automated Self-Administered 24-h record and serum biomarkers. We further investigate the association of self-reported diet and dietary biomarkers with inflammatory-based biomarkers.

CONCLUSION

This randomized controlled trial of diet and cognition for the first time combines novel measures of ambulatory cognitive assessment with web-based assessment of dietary intake recording. This new approach enabled the study to continue in the midst of the COVID-19 pandemic in remote format.

Systematic Review on the Potential Effect of Berry Intake in the Cognitive Functions of Healthy People

The increase in life expectancy poses health challenges, such as increasing the impairment of cognitive functions. Berries show a neuroprotective effect thanks to flavonoids, able to reduce neuroinflammatory and to increase neuronal connections. The aim of this systematic review is to explore the impact of berries supplementation on cognitive function in healthy adults and the elderly. Twelve studies were included for a total of 399 participants, aged 18–81 years (mean age: 41.8 ± 4.7 years). Six studies involved young adults (23.9 ± 3.7 years), and four studies involved the elderly (60.6 ± 6.4 years). Most studies investigated effects of a single berry product, but one used a mixture of 4 berries. Non-significant differences were detected across cognition domains and methodologies, but significant and positive effects were found for all cognitive domains (attention and concentration, executive functioning, memory, motor skills and construction, and processing speed), and in most cases they were present in more than one study and detected using different methodologies. Although some limitations should be taken into account to explain these results, the positive findings across studies and methodologies elicit further studies on this topic, to endorse the consumption of berries in healthy populations to prevent cognitive decline.

Association Between Adherence to the MIND Diet and Cognitive Performance is Affected by Income: The ELSA-Brasil Study

BACKGROUND

The relationship between the Mediterranean-DASH Diet Intervention for Neurodegenerative Delay (MIND) diet and cognition has not been widely investigated in low- to middle-income countries. We investigated the relationship between MIND diet and cognition in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) baseline data.

METHODS

We included 11,788 participants. MIND diet adherence was based on the intake of 15 components according to a food frequency questionnaire. We analyzed the association between MIND diet adherence and global cognition, memory, and executive function using adjusted linear regression. We examined the interaction between income and MIND diet adherence on cognition and presented income stratified analyses.

RESULTS

MIND diet adherence was not associated with cognition in the whole sample. Income was an effect modifier of MIND adherence on global cognition (P=0.03) and executive function (P<0.001). For participants with high income, greater adherence was associated with better executive function [β=0.015, 95% confidence interval (CI)=0.002; 0.028, P=0.025]; while for participants with low income, greater adherence was associated with lower global cognition (β=-0.020, 95% CI=-0.036; -0.005, P=0.010) and executive function (β=-0.023, 95% CI=-0.039; -0.007, P=0.004). Adherence to the MIND diet was higher among participants with high income (P<0.001).

CONCLUSION

For high-income participants, greater adherence was associated with better cognitive performance; for low-income participants, greater adherence was associated with lower cognitive performance.

The Association of High-Frequency Nut Intake With a Low Risk of Psychological Problems in Female Methamphetamine Users

BACKGROUND

Recent years have witnessed a gradual increase in the number of female methamphetamine users. Meanwhile, female methamphetamine users are more likely to have psychological problems than male methamphetamine users. The association between diet and psychological problems have been found among non-methamphetamine user. The present study aims to investigate the relationship between dietary intake frequency and psychological problems in female methamphetamine users.

MATERIALS AND METHODS

A total of 109 female methamphetamine users, collected from a Compulsory Isolated Drug Rehabilitation Centre in northern China, participated in the study. All participants completed the Symptom Checklist 90 (SCL-90) questionnaire to assess psychological status. The relation of dietary intake frequency with the SCL-90 score was tested in partial correlation analysis. Multivariable regression models were used to calculate odds ratios to evaluate the association of dietary intake frequency with psychological problems.

RESULTS

Of the current female methamphetamine population, 33 participants were diagnosed with psychological problems using SCL-90. In the terms of dietary intake frequency, the frequency of nut intake in the psychiatric symptom group was significantly lower than that in the asymptomatic group. However, there was no difference in the frequency of other food intakes between the two groups. The frequency of nut intake was negatively correlated with the total score of SCL-90 and 8 different symptom clusters of psychopathologies on SCL-90. Logistic regression analysis indicated that the increased frequency of nut intake was associated with a lower risk of psychological problems.

CONCLUSION

In the female methamphetamine population, increasing the frequency of nut intake may reduce the risk of psychological problems for female methamphetamine users.

Underutilized Northern plant sources and technological aspects for recovering their polyphenols

Consumers worldwide are increasingly interested in the authenticity and naturalness of products. At the same time, the food, agricultural and forest industries generate large quantities of sidestreams that are not effectively utilized. However, these raw materials are rich and inexpensive sources of bioactive compounds such as polyphenols. The exploitation of these raw materials increases income for producers and processors, while reducing transportation and waste management costs. Many Northern sidestreams and other underutilized raw materials are good sources of polyphenols. These include berry, apple, vegetable, softwood, and rapeseed sidestreams, as well as underutilized algae species. Berry sidestreams are especially good sources of various phenolic compounds. This chapter presents the properties of these raw materials, providing an overview of the techniques for refining these materials into functional polyphenol-rich ingredients. The focus is on economically and environmentally sound technologies suitable for the pre-treatment of the raw materials, the modification and recovery of the polyphenols, as well as the formulation and stabilization of the ingredients. For example, sprouting, fermentation, and enzyme technologies, as well as various traditional and novel extraction methods are discussed. Regarding the extraction technologies, this chapter focuses on safe and green technologies that do not use organic solvents. In addition, formulation and stabilization that aim to protect isolated polyphenols during storage and extend shelflife are reviewed. The formulated polyphenol-rich ingredients produced from underutilized renewable resources could be used as sustainable, active ingredients--for example, in food and nutraceutical industries.

Health Benefits Related to Tree Nut Consumption and Their Bioactive Compounds

Long-term studies with regular tree nut consumption have indicated positive outcomes for multiple health benefits. Here, we review the beneficial effects of tree nuts, highlighting the impact on glucose modulation, body weight management, cardiovascular risk, inflammation, oxidative stress, cognitive performance, and gut microbiota. Nuts are important sources of nutrients and phytochemicals, which, together with a healthy lipid profile, could help prevent certain chronic diseases, protect against oxidative stress and inflammation, and improve cognitive performance, thus reducing the impact of aging and neurodegeneration.

Almond oil: A comprehensive review of chemical composition, extraction methods, preservation conditions, potential health benefits, and safety

Almond oil, a rich source of macronutrients and micronutrients, is extracted for food flavorings and the cosmetics industry. In recent years, the need for high-quality and high-quantity production of almond oil for human consumption has been increased. The present review examines the chemical composition of almond oil, storage conditions, and clinical evidence supporting the health benefits of almond oil. From the reviewed studies, it appears that almond oil contains a significant proportion of poly and monounsaturated fatty acids, with oleic acid as the main compound, and an important amount of tocopherol and phytosterol content. Some variations in almond oil composition can be found depending on the kernel's origin and the extraction system used. Some new technologies such as ultrasonic-assisted extraction, supercritical fluid extraction, subcritical fluid extraction, and salt-assisted aqueous extraction have emerged as the most promising extraction techniques that allow eco-friendly and effective recovery of almond oil. This safe oil was reported by several clinical studies to have potential roles in cardiovascular risk management, glucose homeostasis, oxidative stress reduction, neuroprotection, and many dermatologic and cosmetic applications. However, the anticarcinogenic and fertility benefits of almond oil have yet to be experimentally verified.

Associations between nut intake, cognitive function and non-alcoholic fatty liver disease (NAFLD) in older adults in the United States: NHANES 2011-14

BACKGROUND

Nuts are nutrient-rich and reported to provide some cognitive and cardiometabolic health benefits, but limited studies have focused on older adults. This study investigated the cross-sectional relationship between habitual nut intake, dietary pattern and quality, cognition and non-alcoholic fatty liver disease (NAFLD) in older adults.

METHODS

Older adults (≥ 60 years) from the NHANES 2011-12 and 2013-14 cohorts, who had complete data on cognitive function (as CERAD total, delayed recall, animal fluency and digit-symbol substitution test) and variables to calculate the Fatty Liver Index (FLI), an indicator of NAFLD, were included (n = 1848). Nut intake and diet quality (Healthy Eating Index 2015) were determined using two 24-hour diet recalls. Participants were categorised into one of four groups based on their habitual nut intake: non-consumers (0 g/d), low intake (0.1-15.0 g/d), moderate intake (15.1-30.0 g/d) or met recommendation (> 30 g/d), with all outcomes compared between these nut intake groups.

RESULTS

Cognitive scores of older adults were the lowest in non-consumers and significantly highest in the moderate intake group, with no further increase in those who consumed nuts more than 30 g/d (p < 0.007). FLI was the lowest among older adults with moderate nut intake but the associations disappeared after adjusting for covariates (p = 0.329). Moderate nut intake was also associated with better immediate and delayed memory in older adults with high risk of NAFLD (FLI ≥ 60) (B = 1.84 and 1.11, p < 0.05 respectively). Higher nutrient intake and better diet quality (p < 0.001) were seen with higher nut intake but did not influence energy from saturated fat intake. Factor analysis revealed 'Nuts and oils' as one of the four major dietary patterns associated with better cognition and lower FLI scores.

CONCLUSIONS

Moderate nut intake (15.1-30.0 g/d) may be sufficient for better cognitive performance, but not NAFLD risk of older adults in the US.

Walnut-Associated Fatty Acids Inhibit LPS-Induced Activation of BV-2 Microglia

Walnuts have high levels of the omega-3 fatty acid alpha-linolenic acid (C18:3n-3, ALA) and the omega-6 fatty acid linoleic acid (C18:2n-6, LA). Previous research has demonstrated that pre-treatment of BV-2 microglia with walnut extract inhibited lipopolysaccharide (LPS)-induced activation of microglia. As an extension of that study, the effects of walnut-associated fatty acids on BV-2 microglia were assessed. BV-2 murine microglia cells were treated with LA, ALA, or a combination of LA+ALA prior to or after exposure to LPS. Nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) were measured in cell-conditioned media. Cyclooxeganse-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression were assessed in BV-2 microglia. Both LA and ALA protected against LPS-induced increases in NO, iNOS, COX-2, and TNF-alpha when used before LPS exposure. When BV-2 microglia were treated with fatty acids after LPS, only COX-2 and TNF-alpha were significantly attenuated by the fatty acids. There was no synergism of LA+ALA, as the LA+ALA combination was no more effective than LA or ALA alone. Fatty acids, like those found in walnuts, may protect against production of cytotoxic intermediates and cell-signaling molecules from microglia and may prove beneficial for preventing age- or disease-related neurodegeneration.

An Almond-Based Low Carbohydrate Diet Improves Depression and Glycometabolism in Patients with Type 2 Diabetes through Modulating Gut Microbiota and GLP-1: A Randomized Controlled Trial

Background: Alow carbohydrate diet (LCD) is more beneficial for the glycometabolism in type 2 diabetes (T2DM) and may be effective in reducing depression. Almond, which is a common nut, has been shown to effectively improve hyperglycemia and depression symptoms. This study aimed to determine the effect of an almond-based LCD (a-LCD) on depression and glycometabolism, as well as gut microbiota and fasting glucagon-like peptide 1 (GLP-1) in patients with T2DM. Methods: This was a randomized controlled trial which compared an a-LCD with a low-fat diet (LFD). Forty-five participants with T2DM at a diabetes club and the Endocrine Division of the First and Second Affiliated Hospital of Soochow University between December 2018 to December 2019 completed each dietary intervention for 3 months, including 22 in the a-LCD group and 23 in the LFD group. The indicators for depression and biochemical indicators including glycosylated hemoglobin (HbA1c), gut microbiota, and GLP-1 concentration were assessed at the baseline and third month and compared between the two groups. Results: A-LCD significantly improved depression and HbA1c (p < 0.01). Meanwhile, a-LCD significantly increased the short chain fatty acid (SCFAs)-producing bacteria Roseburia, Ruminococcus and Eubacterium. The GLP-1 concentration in the a-LCD group was higher than that in the LFD group (p < 0.05). Conclusions: A-LCD could exert a beneficial effect on depression and glycometabolism in patients with T2DM. We speculate that the role of a-LCD in improving depression in patients with T2DM may be associated with it stimulating the growth of SCFAs-producing bacteria, increasing SCFAs production and GPR43 activation, and further maintaining GLP-1 secretion. In future studies, the SCFAs and GPR43 activation should be further examined.

Amelioration of motor and non-motor deficits and increased striatal APoE levels highlight the beneficial role of pistachio supplementation in rotenone-induced rat model of PD

Pistachio contains polyphenolic compounds including flavonoids and anthocyanins which have antioxidant and antiinflammatory activity. Present study was aimed to evaluate the protective effects of pistachio on neurobehavioral and neurochemical changes in rats with Parkinson's disease (PD). Animal model of PD was induced by the injection of rotenone (1.5 mg/kg/day, s.c.) for 8 days. Pistachio (800 mg/kg/day, p.o.) was given for two weeks in both pre- and post-treatment. At the end of treatment brain was dissected out and striatum was isolated for biochemical and neurochemical analysis. Memory was assessed by Morris water maze (MWM) and novel object recognition (NOR) test while open field test (OFT), Kondziela inverted screen test (KIST), pole test (PT), beam walking test (BWT), inclined plane test (IPT) and footprint (FP) test were used to observe motor behavior. Rotenone administration significantly (p < 0.01) impaired the memory but pistachio in both pre- and post-treatment groups significantly (p < 0.01) improved memory performance. Rotenone-induced motor deficits were significantly attenuated in both pre- and post-pistachio treatment. Increased oxidative stress and decreased DA and 5-HT levels induced by rotenone were also significantly attenuated by pistachio supplementation. Furthermore, raised apolipoprotein E (APoE) levels in rotenone injected rats were also normalized following treatment with pistachio. Present findings show that pistachio possesses neuroprotective effects and improves memory and motor deficits via increasing DA levels and improving oxidative status in brain.

Edible Nuts for Memory

Nuts hold prime significance throughout the world as they offer multiple health benefits owing to their highly nutritious profile. A number of scientific studies have demonstrated their actions against inflammation, oxidative damage, the aging process, as well as dementia or memory loss. However, only walnuts, followed by almonds, hazelnuts and pistachios, have shown promising results in empirical studies for memory improvements. So, the current review focuses on presenting hypotheses regarding anti-dementia property of nine different nuts: almond, walnut, pistachio, Brazil nut, peanut, pecans, cashew, hazelnut, and chestnut. The nutritious profile of nuts contains essential fats (mostly mono- and poly-unsaturated fatty acids), proteins (source for arginine, lysine and tryptophan), vitamins (riboflavin, folate, and various tocopherols), fibers, minerals (calcium, sodium, magnesium, phosphorus and potassium) and trace elements (copper, zinc, and selenium). Interestingly, the constituents of natural products, nuts being an excellent example, work synergistically and/or in a side-effect neutralizing manner. These latter properties can make nuts an alternate therapy for humankind to fight against memory loss.

Effect of a 12-Week Almond-Enriched Diet on Biomarkers of Cognitive Performance, Mood, and Cardiometabolic Health in Older Overweight Adults

Long term nut consumption is associated with reduced risk of coronary heart disease and better cognitive function. This study examined supplementing habitual diets with almonds or carbohydrate-rich snack foods (providing 15% energy) on biomarkers of cardiovascular and metabolic health, mood and cognitive performance. Participants (overweight/obese, 50-80 years) were randomised to an almond-enriched diet (AED) or isocaloric nut-free diet (NFD) for 12 weeks. Body weight, blood lipids, glucose, insulin, blood pressure (BP), arterial stiffness, cell adhesions molecules, C reactive protein (CRP), mood, and cognitive performance (working memory primary outcome), dietary profiles and energy intake/expenditure were measured at baseline and Week 12 in 128 participants (n = 63 AED, n = 65 NFD). Compared with NFD, AED was associated with altered macro and micronutrient profiles, but no differences in energy intake or expenditure. The AED significantly reduced triglycerides and SBP but there were no other changes in cardiometabolic biomarkers, mood, or cognitive performance. The inclusion of almonds in the diet improves aspects of cardiometabolic health without affecting cognitive performance or mood in overweight/obese adults.

Systematic Review of the Effects of Blueberry on Cognitive Performance as We Age

The effect of flavonoid-rich food, such as blueberries, on cognitive function has been subject to a growing amount of research interest in recent years. Epidemiological, prospective, preclinical, and clinical trials have revealed positive cognitive benefits from flavonoid interventions, particularly in relation to the amelioration of cognitive decline in older adults. This review will specifically consider the existing clinical research from both acute and chronic blueberry interventions on cognition in human subjects. The results of 11 studies are reported with 4 studies considering blueberry intervention with children aged 7-10 years, 4 considering adults aged 60 years and older, and 3 considering adults suffering from mild cognitive impairment (MCI). Findings from these studies indicate that cognitive benefits may be found for delayed memory and executive function in children and for delayed memory, executive function, and psychomotor function in older healthy and MCI adults. There is less evidence to suggest positive benefits of blueberry intervention on working memory. Recommendations for future research, including dose used, cognitive tasks, and age groups considered, are proposed.

[Nut consumption and cognitive function: a systematic review]

Introduction

Antioxidant-rich diet patterns could contribute to the prevention and treatment of early stages of dementia. Nuts have an appreciable antioxidant load and there is evidence of their positive effects on several chronic diseases incidence and death rates. Moreover, they are rich in polyunsaturated fatty acids, which might also play a positive role in neurogenesis. The aim of this systematic review was to summarize the evidence from studies related to the effects of nut consumption on cognitive function among adults. We conducted a systematic search of articles published in PubMed, Scopus and Web of Science. A total of 19 articles met the inclusion criteria (seven cross-sectional, four prospective cohorts and eight experimental); these were independently extracted and reviewed by two reviewers. The evidence from the cross-sectional and cohort studies was uncertain, due to the disparity of results and risk of bias. However, in most experimental studies a protective effect of nut consumption on some dimension of cognitive function was observed and the methodological quality of these studies was acceptable. In addition, the effects appear to be independent of nut type, amount of intake, age and baseline status of subjects. In summary, these results suggest that the inclusion of daily nut consumption in the healthy diet pattern of adults could have positive effects on their cognitive function. Nevertheless, more well-designed longitudinal and experimental studies are needed to provide strength to this suggestive evidence.

Blueberries Improve Neuroinflammation and Cognition differentially Depending on Individual Cognitive baseline Status

Daily supplementation of blueberries (BBs) reverses age-related deficits in behavior in aged rats. However, it is unknown whether BB is more beneficial to one subset of the population dependent on baseline cognitive performance and inflammatory status. To examine the effect of individual differences on the efficacy of BB, aged rats (17 months old) were assessed for cognition in the radial arm water maze (RAWM) and divided into good, average, and poor performers based on navigation errors. Half of the rats in each cognitive group were then fed a control or a 2% BB diet for 8 weeks before retesting. Serum samples were collected, pre-diet and post-diet, to assess inflammation. Latency in the radial arm water maze was significantly reduced in the BB-fed poor performers (p < .05) and preserved in the BB-fed good performers. The control-fed good performers committed more working and reference memory errors in the post-test than pretest (p < .05), whereas the BB-fed good performers showed no change. An in vitro study using the serum showed that BB supplementation attenuated lipopolysaccharide (LPS)-induced nitrite and tumor necrosis factor-alpha, and cognitive performance was associated with innate anti-inflammatory capability. Therefore, consumption of BB may reverse some age-related deficits in cognition, as well as preserve function among those with intact cognitive ability.

Walnut diets up-regulate the decreased hippocampal neurogenesis and age-related cognitive dysfunction in d-galactose induced aged rats

Recently, dietary intervention has been considered as a prospective strategy in delaying age-related cognitive dysfunction and brain plasticity degeneration. This study explored the effect of walnut diets (6% and 9%, 8 weeks) on cognitive behavior, hippocampal neurogenesis and the neurotrophic signaling pathway in d-galactose (d-gal) model rats. Behavioral tests showed that walnut diets significantly reversed spatial memory loss in the Morris water test, locomotor activity deficiency in an open field test, and a recognition behavior reduction in a novel object recognition task. Immunohistochemistry analysis demonstrated walnut diets significantly increased the hippocampal neurogenesis in d-gal model rats. Moreover, western blot results indicated that walnut diets reserved a d-gal induced decrease of hippocampal pCREB (Ser133) and BDNF expression, two crucial intracellular molecules involved in hippocampal neurogenesis. These findings confirmed that chronic walnut-rich diets could ameliorate cognitive dysfunction in d-gal model rats, and the up-regulation of neurogenesis, as well as the expression of pCREB and BDNF in hippocampus, may be one of the molecular and cellular mechanisms underlying these effects.

Dietary Patterns Associated with Cognitive Function among the Older People in Underdeveloped Regions: Finding from the NCDFaC Study

Although dietary patterns are crucial to cognitive function, associations of dietary patterns with cognitive function have not yet been fully understood. This cross-sectional study explored dietary patterns associated with cognitive function among the older adults in underdeveloped regions, using 1504 community-dwelling older adults aged 60 and over. Diet was assessed using a food frequency questionnaire and 24-h dietary recall. Factor analysis was used to extract dietary patterns. Global cognitive function was assessed using the Mini-Mental State Examination (MMSE). Two dietary patterns, a “mushroom, vegetable, and fruits” (MVF) pattern and a “meat and soybean products” (MS) pattern, were identified. The MVF pattern, characterized by high consumption of mushrooms, vegetables, and fruits was significantly positively associated with cognitive function (p < 0.05), with an odds ratio of (95% CIs) 0.60 (0.38, 0.94) for cognitive impairment and β (95% CIs) 0.15 (0.02, 0.29) for –log (31-MMSE score). The MS pattern, characterized by high consumption of soybean products and meat, was also associated with better cognitive function, with an odds ratio of 0.47 (95% CIs 0.30, 0.74) for cognitive impairment and β (95% CIs) 0.34 (0.21, 0.47) for –log (31-MMSE score). Our results suggested that both the MVF and MS patterns were positively associated with better cognitive function among older adults in underdeveloped regions.

Stool Immune Profiles Evince Gastrointestinal Inflammation in Parkinson's Disease

BACKGROUND

Gastrointestinal symptoms are common in Parkinson's disease and frequently precede the development of motor impairments. Intestinal inflammation has been proposed as a driver of disease pathology, and evaluation of inflammatory mediators in stool could possibly identify valuable early-stage biomarkers. We measured immune- and angiogenesis-related proteins in human stool to examine inflammatory profiles associated with Parkinson's disease.

METHODS

Stool samples and subjects' self-reported metadata were obtained from 156 individuals with Parkinson's disease and 110 without, including spouse and nonhousehold controls. Metadata were probed for disease-associated differences, and levels of 37 immune and angiogenesis factors in stool homogenates were measured by multiplexed immunoassay and compared across experimental groups.

RESULTS

Parkinson's disease patients reported greater incidence of intestinal disease and digestive problems than controls. Direct comparison of levels of stool analytes in patients and controls revealed elevated vascular endothelial growth factor receptor 1, interleukin-1α, and CXCL8 in patients' stool. Paired comparison of patients and spouses suggested higher levels of multiple factors in patients, but this was complicated by sex differences. Sex, body mass index, a history of smoking, and use of probiotics were found to strongly influence levels of stool analytes. Multivariate analysis accounting for these and other potential confounders confirmed elevated levels of interleukin-1α and CXCL8 and also revealed increased interleukin-1β and C-reactive protein in stool in Parkinson's disease. These differences were not dependent on subject age or disease duration.

CONCLUSIONS

Levels of stool immune factors indicate that intestinal inflammation is present in patients with Parkinson's disease. © 2018 International Parkinson and Movement Disorder Society.

Evaluation of Polyphenol Anthocyanin-Enriched Extracts of Blackberry, Black Raspberry, Blueberry, Cranberry, Red Raspberry, and Strawberry for Free Radical Scavenging, Reactive Carbonyl Species Trapping, Anti-Glycation, Anti-β-Amyloid Aggregation, and Microglial Neuroprotective Effects

Glycation is associated with several neurodegenerative disorders, including Alzheimer’s disease (AD), where it potentiates the aggregation and toxicity of proteins such as β-amyloid (Aβ). Published studies support the anti-glycation and neuroprotective effects of several polyphenol-rich fruits, including berries, which are rich in anthocyanins. Herein, blackberry, black raspberry, blueberry, cranberry, red raspberry, and strawberry extracts were evaluated for: (1) total phenolic and anthocyanins contents, (2) free radical (DPPH) scavenging and reactive carbonyl species (methylglyoxal; MGO) trapping, (3) anti-glycation (using BSA-fructose and BSA-MGO models), (4) anti-Aβ aggregation (using thermal- and MGO-induced fibrillation models), and, (5) murine microglia (BV-2) neuroprotective properties. Berry crude extracts (CE) were fractionated to yield anthocyanins-free (ACF) and anthocyanins-enriched (ACE) extracts. The berry ACEs (at 100 μg/mL) showed superior free radical scavenging, reactive carbonyl species trapping, and anti-glycation effects compared to their respective ACFs. The berry ACEs (at 100 μg/mL) inhibited both thermal- and MGO-induced Aβ fibrillation. In addition, the berry ACEs (at 20 μg/mL) reduced H₂O₂-induced reactive oxygen species production, and lipopolysaccharide-induced nitric oxide species in BV-2 microglia as well as decreased H₂O₂-induced cytotoxicity and caspase-3/7 activity in BV-2 microglia. The free radical scavenging, reactive carbonyl trapping, anti-glycation, anti-Aβ fibrillation, and microglial neuroprotective effects of these berry extracts warrant further in vivo studies to evaluate their potential neuroprotective effects against AD.

Walnut supplementation reverses the scopolamine-induced memory impairment by restoration of cholinergic function via mitigating oxidative stress in rats: a potential therapeutic intervention for age related neurodegenerative disorders

The brain is highly susceptible to the damaging effects of oxidative reactive species. The free radicals which are produced as a consequence of aerobic respiration can cause cumulative oxygen damage which may lead to age-related neurodegeneration. Scopolamine, the anti-muscarinic agent, induces amnesia and oxidative stress similar to that observed in the older age. Studies suggest that antioxidants derived from plant products may provide protection against oxidative stress. Therefore, the present study was designed to investigate the attenuation of scopolamine-induced memory impairment and oxidative stress by walnut supplementation in rats. Rats in test group were administrated with walnut suspension (400 mg/kg/day) for four weeks. Both control and walnut-treated rats were then divided into saline and scopolamine-treated groups. Rats in the scopolamine group were injected with scopolamine (0.5 mg/kg dissolved in saline) five minutes before the start of each memory test. Memory was assessed by elevated plus maze (EPM), Morris water maze (MWM), and novel object recognition task (NOR) followed by estimation of regional acetylcholine levels and acetylcholinesterase activity. In the next phase, brain oxidative status was determined by assaying lipid peroxidation, and measuring superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) activities. Results showed that scopolamine-treatment impaired memory function, caused cholinergic dysfunction, and induced oxidative stress in rats compared to that saline-treated controls. These impairments were significantly restored by pre-administration of walnut. This study demonstrates that antioxidant properties of walnut may provide augmented effects on cholinergic function by reducing oxidative stress and thus improving memory performance.

Dietary Intake is Positively Associated with Cognitive Function of a Chinese Older Adults Sample

OBJECTIVE

The relationship between cognitive function and dietary intake in older adults was under-studied in China. This study examined this relationship in a Chinese sample while controlling for the effects of sleep quality and socio demographic confounders.

METHODS

The sample consisted of 340 Chinese older adults (age > 60) who were randomly selected from Wuhan city in central China. Cognitive function was assessed by the Mini-mental State Examination [MMSE], sleep quality by the Pittsburgh Sleep Quality Index [PSQI], and dietary intake by frequencies of intake of meat products, fruits, fish/seafood/aquatic products, nuts and mushroom/algae over the past year. First, confirmatory factor analysis (CFA) was conducted to evaluate the measurement properties of cognitive function, dietary intake, and sleep quality. Second, structural equation modeling (SEM) was conducted to examine the relations of cognitive function, dietary intake, and sleep quality.

RESULTS

Dietary intake was found to be positively related to cognitive function. Older age, lower education status, monthly income, and living alone or without a spouse were significantly associated with poorer cognitive function. SES status had an indirect effect on cognitive function via dietary intake.

CONCLUSION

Dietary intake may be critical to maintain normal cognitive function of older adults in China.

Dairy-Based and Energy-Enriched Berry-Based Snacks Improve or Maintain Nutritional and Functional Status in Older People in Home Care

OBJECTIVE

Consumption of energy- and nutrient-dense snacks are recommended for older people to maintain adequate nutrition. We evaluated the effects of dairy-based and energy-enriched berry products consumed as snacks on nutritional and functional status among vulnerable older people receiving home care services.

DESIGN

Randomised controlled study.

SETTING AND PARTICIPANTS

The study sample consisted of 85 home care clients, with mean age of 81.9 (SD 7.1) years in the intervention group (n=50) and 83.7 (SD 8.1) years in the control group (n=35), and 72% women in both groups.

INTERVENTION

In the intervention group, the participants consumed both high-protein dairy-based products and energy-enriched berry purées for three months. The snack products provided nearly 300 kcal and 14 g protein per day.

MEASUREMENTS

The Mini Nutritional Assessment (MNA), body mass index (BMI), mid-arm muscular area (MAMA) and concentrations of plasma albumin and prealbumin and blood haemoglobin were used to determine nutritional status, and handgrip strength was used to determine functional status at baseline and after the intervention.

RESULTS

After adjustment for age and gender, the intervention showed a significant effect on MNA scores (2.1, 95% [CI]: 1.0 to 3.3) (p=0.003), albumin concentration (2.0 g/L, 95% [CI]: 1.1 to 3.2) (p=0.006) and handgrip strength of the right hand in women (2.4 kg, 95% [CI]: 1.2 to 3.3) (p=0.007). The MNA scores improved in the intervention group, while albumin concentration and handgrip strength decreased in the control group.

CONCLUSIONS

Regular use of dairy- and energy-enriched berry-based snacks may improve or maintain nutritional and functional status among older people in home care.

Daily supplementation with GrandFusion® improves memory and learning in aged rats

Studies have shown that supplementation with extracts from various sources, including fruits and vegetables reverse the age-related changes in movement and cognition. We hypothesized that these beneficial effects result from the presence of anti-oxidants and anti-inflammatory compounds in the fruits and vegetables that contribute to reduced oxidative stress, inflammation and cell death while potentially enhancing neurogenesis. The present study was performed to determine the impact of supplementation with GrandFusion^®(GF) to aged Fisher 344 rats for 4 months to determine the impact on attenuation or reversal of the age-related deficits. When the aged rats consumed a diet enriched with the extracts the results showed an improved motor performance, and enhanced cognitive functions. In addition, the rats showed reduced oxidative stress and inflammation, and enhanced neurogenesis, Nrf2 and anti-oxidant expression. The effect of GF extracts on the augmentation of memory and learning is significant and may function through the modulation of antioxidant enzymes, signaling pathways and additional mechanisms to improve the aging process. These studies further support the recommendation of USDA for the consumption of fruits and vegetables to improve healthy aging.

Perspective: Neuroregenerative Nutrition

Good health while aging depends upon optimal cellular and organ functioning that contribute to the regenerative ability of the body during the lifespan, especially when injuries and diseases occur. Although diet may help in the maintenance of cellular fitness during periods of stability or modest decline in the regenerative function of an organ, this approach is inadequate in an aged system, in which the ability to maintain homeostasis is further challenged by aging and the ensuing suboptimal functioning of the regenerative unit, tissue-specific stem cells. Focused nutritional approaches can be used as an intervention to reduce decline in the body's regenerative capacity. This article brings together nutrition-associated therapeutic approaches with the fields of aging, immunology, neurodegenerative disease, and cancer to propose ways in which diet and nutrition can work with standard-of-care and integrated medicine to help improve the brain's function as it ages. The field of regenerative medicine has exploded during the past 2 decades as a result of the discovery of stem cells in nearly every organ system of the body, including the brain, where neural stem cells persist in discrete areas throughout life. This fact, and the uncovering of the genetic basis of plasticity in somatic cells and cancer stem cells, open a door to a world where maintenance and regeneration of organ systems maintain health and extend life expectancy beyond its present limits. An area that has received little attention in regenerative medicine is the influence on regulatory mechanisms and therapeutic potential of nutrition. We propose that a strong relation exists between brain regenerative medicine and nutrition and that nutritional intervention at key times of life could be used to not only maintain optimal functioning of regenerative units as humans age but also play a primary role in therapeutic treatments to combat injury and diseases (in particular, those that occur in the latter one-third of the lifespan).

Postprandial glycaemic response to berry nectars containing inverted sucrose

Sucrose is commonly used for sweetening berry products. During processing and storage of berry products containing added sucrose, sucrose is inverted to glucose and fructose. We have previously shown that postprandial glycaemic response induced by intact sucrose is attenuated when sucrose is consumed with berries rich in polyphenols. It is not known how inversion of sucrose affects glycaemic response. We investigated postprandial glycaemic and insulinaemic responses to blackcurrant (Ribes nigrum) and lingonberry (Vaccinium vitis-idaea) nectars and a reference drink (water) sweetened with glucose and fructose, representing completely inverted sucrose. The nectars and reference drink (300 ml) contained 17·5 g glucose and 17·5 g fructose. Polyphenol composition of the nectars was analysed. A total of eighteen healthy volunteers participated in a randomised, controlled, cross-over study. Blood samples were collected at fasting and six times postprandially during 120 min. Inverted sucrose in the reference drink induced glycaemic and insulinaemic responses similar to those previously observed for intact sucrose. In comparison with the reference, the blackcurrant nectar attenuated the early glycaemic response and improved glycaemic profile, and the lingonberry nectar reduced the insulinaemic response. The responses induced by inverted sucrose in the berry nectars are similar to those previously observed for berry nectars containing intact sucrose, suggesting that inversion has no major impact on glycaemic response to sucrose-sweetened berry products. The attenuated glycaemic response after the blackcurrant nectar may be explained by inhibition of intestinal absorption of glucose by blackcurrant anthocyanins.

Mitigating the effects of high fat diet on the brain and behavior with berry supplementation

Berries are rich in bioactive compounds like anthocyanins and show promise for mitigating the effects of high fat diet on the brain and behavior.

Role of fruits, nuts, and vegetables in maintaining cognitive health

Population aging is leading to an increase in the incidence of age-related cognitive dysfunction and, with it, the health care burden of caring for older adults. Epidemiological studies have shown that consumption of fruits, nuts, and vegetables is positively associated with cognitive ability; however, these foods, which contain a variety of neuroprotective phytochemicals, are widely under-consumed. Surprisingly few studies have investigated the effects of individual plant foods on cognitive health but recent clinical trials have shown that dietary supplementation with individual foods, or switching to a diet rich in several of these foods, can improve cognitive ability. While additional research is needed, increasing fruit, nut, and vegetable intake may be an effective strategy to prevent or delay the onset of cognitive dysfunction during aging.

NUT CONSUMPTION IS ASSOCIATED WITH DEPRESSIVE SYMPTOMS AMONG CHINESE ADULTS

BACKGROUND

Affective disorders, especially depressive symptoms, bring such a burden to mortality and morbidity that they are associated with physical and psychological health and quality of life. Nuts, a foodstuff rich in multiple micronutrients, macronutrients, and other useful components, were considered to be a protector against depressive symptoms. Here, we conducted an analysis to examine the relationship between nut consumption and depressive symptoms.

METHODS

The study performed a cross-sectional study to examine whether nut consumption is related to depressive symptoms among 13,626 inhabitants in Tianjin. Nut consumption was assessed using a validated food frequency questionnaire and depressive symptoms was assessed using the Chinese version of 20-item Self-rating Depression Scale (SDS) with four cutoffs (40, 45, 48, and 50) to indicate elevated depressive symptoms.

RESULTS

The prevalence of depressive symptoms was 38.7, 19.1, 11.4, and 7.3% for SDS ≥40, 45, 48, and 50, respectively. After adjustments for potential confounding factors, the odds ratios (95% confidence interval) of having elevated depressive symptoms with SDS ≥40 by increasing frequency of nut consumption were 1.00 for <once per week (reference), 0.82 (0.75, 0.90) for 1-3 times per week, and 0.82 (0.73, 0.92) for ≥4 times per week. Similar relations were observed with the use of other cutoffs as a definition of depressive symptoms.

CONCLUSION

The present study is the first to find that nut consumption is independently associated with depressive symptoms. It is suggested that nut consumption may be beneficial to the prevention of depressive symptoms.

Effects of Walnut Consumption on Mood in Young Adults-A Randomized Controlled Trial

Walnuts contain a number of potentially neuroprotective compounds like vitamin E, folate, melatonin, several antioxidative polyphenols and significant amounts of ω-3 fatty acids. The present study sought to determine the effect of walnuts on mood in healthy volunteers. Sixty-four college students were randomly assigned to two treatment sequences in a crossover fashion: walnut-placebo or placebo-walnut. At baseline mood was assessed using Profiles of Mood States (POMS). Data was collected again after eight weeks of intervention. After six-weeks of washout, the intervention groups followed the diets in reverse order. Data was collected once more at the end of the eight-week intervention period. No significant changes in mood were observed in the analyses with both genders combined and in females. However, we have observed a significant medium effect size improvement in the Total Mood Disturbance score (-27.49%, p = 0.043, Cohen's d = 0.708) in males. In non-depressed healthy young males, walnuts seem to have the ability to improve mood.

Is it always Alzheimer's? Let's talk to our patients about "cardiocerebrovascular" prevention

Unlike Alzheimer's, vascular dementia can, in part, be prevented. The preventive approach foresees treatment for high blood pressure, atrial fibrillation, diabetes, high cholesterol, low HDL cholesterol, sedentary lifestyle, smoking, alcohol abuse, obesity, and sleep apnea. Moreover, also a well-balanced diet and physical activity are cornerstones of prevention, with beneficial effects on the brain and cognition.

Promoting brain health through exercise and diet in older adults: a physiological perspective

The rise in incidence of age-related cognitive impairment is a global health concern. Ageing is associated with a number of changes in the brain that, collectively, contribute to the declines in cognitive function observed in older adults. Structurally, the ageing brain atrophies as white and grey matter volumes decrease. Oxidative stress and inflammation promote endothelial dysfunction thereby hampering cerebral perfusion and thus delivery of energy substrates and nutrients. Further, the development of amyloid plaques and neurofibrillary tangles contributes to neuronal loss. Of interest, there are substantial inter-individual differences in the degree to which these physical and functional changes impact upon cognitive function as we grow older. This review describes how engaging in physical activity and cognitive activities and adhering to a Mediterranean style diet promote 'brain health'. From a physiological perspective, we discuss the effects of these modifiable lifestyle behaviours on the brain, and how some recent human trials are beginning to show some promise as to the effectiveness of lifestyle behaviours in combating cognitive impairment. Moreover, we propose that these lifestyle behaviours, through numerous mechanisms, serve to increase brain, cerebrovascular and cognitive reserve, thereby preserving and enhancing cognitive function for longer.

Impact of Nutrition on Cerebral Circulation and Cognition in the Metabolic Syndrome

The increasing prevalence of Metabolic Syndrome (MetS), defined as the clustering of abdominal obesity, dyslipidemia, hypertension, and hyperglycemia, appears to be driving the global epidemics cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). Nutrition has a major impact on MetS and plays an important role in the prevention, development, and treatment of its features. Structural and functional alterations in the vasculature, associated with MetS, might form the link between MetS and the increased risk of developing CVD and T2DM. Not only does the peripheral vasculature seem to be affected, but the syndrome has a profound impact on the cerebral circulation and thence brain structure as well. Furthermore, strong associations are shown with stroke, cognitive impairment, and dementia. In this review the impact of nutrition on the individual components of MetS, the effects of MetS on peripheral and cerebral vasculature, and its consequences for brain structure and function will be discussed.

Dietary intakes of fats, fish and nuts and olfactory impairment in older adults

It is unclear whether lifestyle modifications, such as dietary changes, should be advocated to prevent olfactory dysfunction. We investigated the association between dietary intakes of fats (saturated, mono-unsaturated and polyunsaturated fats, and cholesterol) and related food groups (nuts, fish, butter, margarine) with olfactory impairment. There were 1331 and 667 participants (older than 60 years) at baseline and 5-year follow-up, respectively, with complete olfaction and dietary data. Dietary data were collected using a validated semi-quantitative FFQ. Olfaction was measured using the San Diego Odor Identification Test. In a cross-sectional analysis of baseline data, those in the highest v. lowest quartile of n-6 PUFA intake had reduced odds of having any olfactory impairment, multivariable-adjusted OR 0.66 (95% CI 0.44, 0.97), P for trend = 0.06. Participants in the highest v. lowest quartile of margarine consumption had a 65% reduced odds of having moderate/severe olfactory impairment (P for trend = 0.02). Participants in the highest quartile compared to the lowest quartile (reference) of nut consumption had a 46% (P for trend = 0.01) and 58% (P for trend = 0.001) reduced odds of having any or mild olfactory impairment, respectively. Older adults in the highest v. lowest quartile of fish consumption had 35% (P for trend = 0.03) and 50% (P for trend = 0.01) reduced likelihood of having any or mild olfactory impairment, respectively. In longitudinal analyses, a marginally significant association was observed between nut consumption and incidence of any olfactory impairment, highest v. lowest quartile of nut consumption: OR 0.61 (95% CI 0.37, 1.00). Older adults with the highest consumption of nuts and fish had reduced odds of olfactory impairment, independent of potential confounding variables.