Black tea improves attention and self-reported alertness

A review of psychological and neuroscientific research on musical groove

When listening to music, we naturally move our bodies rhythmically to the beat, which can be pleasurable and difficult to resist. This pleasurable sensation of wanting to move the body to music has been called "groove." Following pioneering humanities research, psychological and neuroscientific studies have provided insights on associated musical features, behavioral responses, phenomenological aspects, and brain structural and functional correlates of the groove experience. Groove research has advanced the field of music science and more generally informed our understanding of bidirectional links between perception and action, and the role of the motor system in prediction. Activity in motor and reward-related brain networks during music listening is associated with the groove experience, and this neural activity is linked to temporal prediction and learning. This article reviews research on groove as a psychological phenomenon with neurophysiological correlates that link musical rhythm perception, sensorimotor prediction, and reward processing. Promising future research directions range from elucidating specific neural mechanisms to exploring clinical applications and socio-cultural implications of groove.

Effect of single or combined caffeine and L-Theanine supplementation on shooting and cognitive performance in elite curling athletes: a double-blind, placebo-controlled study

PURPOSE

Previous studies have investigated the effect of single or combined caffeine (CAF) and L-theanine (THE) intake on attention performance. However, its effect on shooting performance and cognitive performance in a sport is unknown. The aim of this study was to investigate the hypothesis "Does single or combined CAF and THE supplementation have an effect on shooting and cognitive performance in elite curling athletes?." It is predicted that over the next decade, studies based on nutritional ergogenic supplements in the developing sport of curling will continue to increase, leading to a significant increase in studies examining the effects of CAF and THE supplementation, alone or in combination, on throwing and cognitive performance in elite curling athletes.

METHODS

In this double-blind, randomized controlled crossover study, twenty-two elite national curling athletes (age 20.20 ± 1.61 and sports age 6.20 ± 0.51 years, height 174.10 ± 7.21 cm, BMI 21.80 ± 3.47 kg/m2) were randomly assigned to CAF (6 mg/kg single dose CAF), THE (6 mg/kg single dose THE), CAF*THE (6 mg/kg CAF and 6 mg/kg THE combined) and PLA (400 mg maltodextrin) groups at each of four sessions. 60 minutes after taking the supplement, the athletes were first given the Stroop test and then asked to shoot.

RESULTS

Our main findings have shown that the performance of athletes in guard (F=3.452, P < .001, ηp2 = .842), draw (F=1.647, P < .001, ηp2 = .485), and take-out (F=3.121, P < .001, ηp2 = .743) shot styles significantly improved when comparing the combined intake of CAF and THE to the PLA. Regarding cognitive performance evaluation through the Stroop test, during the NR task (F=4.743, P = .001, ηp2 = .653), the combined intake of CAF and THE significantly improved reaction times compared to the intake of single CAF, THE, or PLA. The best reaction times during the CR and ICR (respectively; F=2.742, P = .004, ηp2 = .328; F = 1.632, P < .001, ηp2 = .625) tasks were achieved with the combined CAF and THE intake, showing a significant improvement compared to PLA. During the NER (F=2.961, P < .001, ηp2 = .741), task, the combined intake of CAF and THE significantly improved error rates compared to the intake of CAF, THE, or PLA single. The best accuracy rates during the CER and ICER (respectively; F=4.127, P < .001, ηp2 = .396; F=3.899, P < .001, ηp2 = .710) tasks were achieved with the combined CAF and THE intake, leading to a significant reduction in error rates compared to PLA. Based on these findings, it has been demonstrated in this study that the best shooting scores and cognitive performance were achieved, particularly with the combined intake of CAF and THE.

CONCLUSIONS

Based on these findings, it has been demonstrated in this study that the best shooting scores and cognitive performance were achieved, particularly with the combined intake of CAF and THE. The combined use of these supplements has been found to be more effective on shooting and cognitive performance than their single use.

Groove Rhythm Enhances Exercise Impact on Prefrontal Cortex Function in Groove Enjoyers

A positive affective response modulates the effects of aerobic exercise on prefrontal executive function (EF). Groove rhythm (GR), eliciting the feeling of wanting to move to music, is useful for inducing positive affective response during exercise. Three minutes of listening to GR activated the left dorsolateral prefrontal cortex (l-DLPFC) and enhanced EF in participants who had higher psychological responses to GR. This finding prompted us to test the hypothesis that the combination of GR and exercise (GREX) induces positive psychological responses that enhance PFC function through entrainment of body movements and musical beats. 41 participants were administered two experimental conditions: three min of very light-intensity (30% V̇ O2peak) exercise combined with GR and combined with a white-noise metronome (WMEX). Before and after exercise, participants performed a Stroop task and were monitored for l-DLPFC activity with functional near-infrared spectroscopy. GREX enhanced EF and l-DLPFC activity in participants who experienced greater subjective feelings of audiomotor entrainment and increased excitement with GREX. These psychological responses were predictive of the impact of GREX on l-DLPFC activity and EF. These findings, together with previous results, support the hypothesis that GR allows us to boost the cognitive benefits of exercise via l-DLPFC activity only in those who enjoy groove, and suggest that subjective audiomotor entrainment is a key mechanism of this boosting effect.

The effects of tea polyphenols on emotional homeostasis: Understanding dementia risk through stress, mood, attention & sleep

Decades of research provide evidence that certain phytochemicals in tea (Camellia sinensis) and other herbal beverages are protective against the development of sporadic types of dementia in later life. Since tea drinking is an economical and widely adopted social-cultural practice across all age groups, it is an ideal product to target in designing low-cost dietary interventions for Alzheimer's Disease (AD), the most prevalent form of dementia. In this review, we focus on the protective roles of tea-derived polyphenols and other phytochemicals on mood, the stress response, attention, and sleep, in keeping with the perspective that many early neuropathological events in AD may stem, in part, from allostatic overload. This approach aligns with the perspective that many forms of dementia, including AD, begin to take root in the brain decades prior to symptom onset, underscoring the need for early uptake of accessible and viable lifestyle interventions. The findings reviewed here suggest that consuming green and oolong tea can improve mood and reduce overall stress. However, given the caffeine content in tea and its association with stress reactivity, the effects of daily whole tea consumption on the emotional state are likely dose-dependent with an inverted-U relationship to wellbeing. Plant-based beverages that are to be consumed in high daily quantities for health purposes and which are naturally free of caffeine, such as Rooibos, may be more appropriate as a dietary supplement for managing emotional regulation over the lifetime.

Groove rhythm stimulates prefrontal cortex function in groove enjoyers

Hearing a groove rhythm (GR), which creates the sensation of wanting to move to the music, can also create feelings of pleasure and arousal in people, and it may enhance cognitive performance, as does exercise, by stimulating the prefrontal cortex. Here, we examined the hypothesis that GR enhances executive function (EF) by acting on the left dorsolateral prefrontal cortex (l-DLPFC) while also considering individual differences in psychological responses. Fifty-one participants underwent two conditions: 3 min of listening to GR or a white-noise metronome. Before and after listening, participants performed the Stroop task and were monitored for l-DLPFC activity with functional near-infrared spectroscopy. Our results show that GR enhanced EF and l-DLPFC activity in participants who felt a greater groove sensation and a more feeling clear-headed after listening to GR. Further, these psychological responses predict the impact of GR on l-DLPFC activity and EF, suggesting that GR enhances EF via l-DLPFC activity when the psychological response to GR is enhanced.

Habitual Tea Consumption and Risk of Fracture in 0.5 Million Chinese Adults: A Prospective Cohort Study

Background: Tea consumption may have favorable effects on risk of fracture. However, little is known about such association in Chinese adults. The aim of this study was to examine the association between tea consumption and risk of hospitalized fracture in Chinese adults. Methods: The present study included 453,625 participants from the China Kadoorie Biobank (CKB). Tea consumption was self-reported at baseline. Hospitalized fractures were ascertained through linkage with local health insurance claim databases. The results: During a median of 10.1 years of follow-up, we documented 12,130 cases of first-time any fracture hospitalizations, including 1376 cases of hip fracture. Compared with never tea consumers, daily tea consumption was associated with lower risk of any fracture (hazard ratio (HR): 0.88; 95% confidence interval (CI): 0.83, 0.93). Statistically significant reduced risk of hip fracture was shown among daily consumers who most commonly drank green tea (HR: 0.80; 95% CI: 0.65, 0.97) and those who had drunk tea for more than 30 years (HR: 0.68; 95% CI: 0.52, 0.87). Our conclusions: Habitual tea consumption was associated with moderately decreased risk of any fracture hospitalizations. Participants with decades of tea consumption and those who preferred green tea were also associated with lower risk of hip fracture.

Black tea differs from green tea: it suppresses long-term memory formation in Lymnaea

Foods, such as Green tea (GT), containing the flavonol, (-)-Epicatechin (Epi), enhance the formation of long-term memory (LTM) when snails are operantly conditioned in that substance. That is, a single 0.5 h training session results in LTM; whereas similar training in pond water does not result in LTM. It was of interest to determine if Black tea (BT), which is a more popular beverage than GT and which is derived from the same tea leaves, also enhances LTM formation. We found that BT, unlike GT, depressed homeostatic aerial respiratory behaviour and obstructed LTM formation. We used two different methods to determine if BT altered LTM formation and both procedures showed us that BT obstructed LTM formation. We conclude that BT obstructs LTM formation and depresses homeostatic aerial respiration

Effect of Green Tea Phytochemicals on Mood and Cognition

BACKGROUND

Green tea is traditionally known to induce mental clarity, cognitive function, physical activation and relaxation. Recently, a special green tea, matcha tea, is rapidly gaining popularity throughout the world and is frequently referred to as a mood- and brain food. Matcha tea consumption leads to much higher intake of green tea phytochemicals compared to regular green tea. Previous research on tea constituents caffeine, L-theanine, and epigallocatechin gallate (EGCG) repeatedly demonstrated benefits on mood and cognitive performance. These effects were observed when these phytochemicals were consumed separately and in combination.

METHODS

A review was conducted on 49 human intervention studies to summarize the research on acute psychoactive effects of caffeine, L-theanine, and EGCG on different dimensions of mood and cognitive performance.

CONCLUSION

Caffeine was found to mainly improve performance on demanding long-duration cognitive tasks and self-reported alertness, arousal, and vigor. Significant effects already occurred at low doses of 40 mg. L-theanine alone improved self-reported relaxation, tension, and calmness starting at 200 mg. L-theanine and caffeine combined were found to particularly improve performance in attention-switching tasks and alertness, but to a lesser extent than caffeine alone. No conclusive evidence relating to effects induced by EGCG could be given since the amount of intervention studies was limited. These studies provided reliable evidence showing that L-theanine and caffeine have clear beneficial effects on sustained attention, memory, and suppression of distraction. Moreover, L-theanine was found to lead to relaxation by reducing caffeine induced arousal.

Black tea and improvement of attention: evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006

Following an application from Unilever NV, submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of Ireland, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to black tea and improvement of attention. The scope of the application was proposed to fall under a health claim based on newly developed scientific evidence. The food proposed by the applicant as the subject of the health claim is black tea. The Panel considers that black tea characterised by its content of tea solids, caffeine and l‐theanine, which is the subject of the health claim, is sufficiently characterised in relation to the claimed effect. The claimed effect proposed by the applicant is ‘improves attention’. The Panel considers that improvement of attention is a beneficial physiological effect. Three human intervention studies provided by the applicant show an effect of black tea on attention under the conditions of used proposed by the applicant. The applicant proposed that the claimed effect depends on the concerted action of two substances, caffeine and l‐theanine, both of which are present in black tea. The Panel considers that the effect of black tea on attention observed in the three human intervention studies provided by the applicant can be explained by its caffeine content. The Panel concludes that a cause and effect relationship has been established between the consumption of black tea and improvement of attention. The Panel considers that the effect of black tea on attention can be explained by its caffeine content. The following wording reflects the scientific evidence: ‘Owing to its caffeine content, black tea improves attention’. In order to obtain the claimed effect, 2–3 servings of black tea providing at least 75 mg of caffeine in total should be consumed within 90 min.

Diabetes and Alzheimer's Disease: Can Tea Phytochemicals Play a Role in Prevention?

Dementia and diabetes mellitus are prevalent disorders in the elderly population. While recognized as two distinct diseases, diabetes has more recently recognized as a significant contributor to risk for developing dementia, and some studies make reference to type 3 diabetes, a condition resulting from insulin resistance in the brain. Alzheimer's disease, the most common form of dementia, and diabetes, interestingly, share underlying pathological processes, commonality in risk factors, and, importantly, pathways for intervention. Tea has been suggested to possess potent antioxidant properties. It is rich in phytochemicals including, flavonoids, tannins, caffeine, polyphenols, boheic acid, theophylline, theobromine, anthocyanins, gallic acid, and finally epigallocatechin-3-gallate, which is considered to be the most potent active ingredient. Flavonoid phytochemicals, known as catechins, within tea offer potential benefits for reducing the risk of diabetes and Alzheimer's disease by targeting common risk factors, including obesity, hyperlipidemia, hypertension, cardiovascular disease, and stroke. Studies also show that catechins may prevent the formation of amyloid-β plaques and enhance cognitive functions, and thus may be useful in treating patients who have Alzheimer's disease or dementia. Furthermore, other phytochemicals found within tea offer important antioxidant properties along with innate properties capable of modulating intracellular neuronal signal transduction pathways and mitochondrial function.

Pharmacological values and therapeutic properties of black tea (Camellia sinensis): A comprehensive overview

Medicinal plants are essential parts of traditional medicine due to their phytochemical constituents having pharmacological values and therapeutic applications. Black tea have thousands of various biological compounds such as flavonoids (Thearubigins (TRs) and theaflavins (TFs) and catechins), amino acids (L.theanine), vitamins (A, C, K), phenolic acids (caffeic acid (CA), gallic acid (GA), chlorogenic acids (CGA) and cauramic acid), lipids, proteins, volatile compounds carbohydrates, β-carotene and fluoride that illustrated many promising pharmacological effects regarded as growth promoter, cardioprotector, potent cholesterol-lowering effect, antioxidant and antimicrobial, etc inhuman. Although there is an exponential growth in molecular evidence of cholesterol-lowering and antioxidant effect in human, there is still a lack of information of the pharmacological effects of black tea. To fill this information gap, therefore, this review article underscores broadening the new insight pertaining to black tea that could be used as safe food additive. This article also illuminates the interesting role of black tea as an herbal medicine that is the future demand to get rid of synthetic health promoters in the human health practice. Moreover, this information would be useful in terms of the low-cost practice of natural medicines with no residual effects, and a natural protection of the human being. In addition, further studies at a molecular level are needed to reveal its mechanism of action particularly for the hypocholesterolemic effect of black tea to overcome the heart-related diseases, fewer side effects and being a natural safeguard of human health.

Black tea aroma inhibited increase of salivary chromogranin-A after arithmetic tasks

Background

Growing attention has been paid to the effects of food flavor components on alleviating negative brain functions caused by stressful lifestyles. In this study, we investigated the alleviating effect of two kinds of black tea aromas on physical and psychological stress induced by the Uchida-Kraepelin test, based on salivary chromogranin-A (CgA) levels as a stress marker and subjective evaluations (Profile of Mood States).

Results

Compared with the water exposure control, inhaling black tea aroma (Darjeeling and Assam in this study) induced lower salivary CgA concentration levels after 30 min of mental stress load tasks. This anti-stress effect of black tea aroma did not differ between the two tea types even though the concentration of the anti-stress components in the Darjeeling tea aroma was higher than that in the Assam aroma. However, Darjeeling tea aroma tended to decrease the tension and/or anxiety score immediately after the first exposure.

Conclusions

Inhaling black tea aroma may diminish stress levels caused by arithmetic mental stress tasks, and Darjeeling tea aroma tended to improve mood before mental stress load.

Tea, cocoa, coffee, and affective disorders: vicious or virtuous cycle?

BACKGROUND

The prevalence of psychiatric disorders is increasing worldwide, which underscores the importance of increasing research in this field, in terms of better detection, prevention based on improvement of lifestyle and diet, and effectiveness of treatment. Increasing evidence suggest that diet and exercise can affect proper neuronal development and physiology and protect the brain from neurological illnesses or injuries. Of note, cocoa, tea, and coffee are being actively investigated because they are rich in (poly)phenolic compounds that can modulate mental health, namely brain plasticity, behavior, mood, depression, and cognition.

METHODS

We here systematically review human studies conducted on tea, cocoa, and coffee as related to affective disorders such as depression and anxiety. We carried out a systematic literature search in April 2016, using MEDLINE, on data from the last 10 years. After screening 955 articles, we selected 17 articles that met the criteria of being human studies and that used whole foods or their components.

RESULTS

The results of our systematic review indicate that consumption of tea, cocoa, or coffee might have protective effects against depression.

CONCLUSIONS

Even though this is encouraging, it should be underscored that the near totality of the current evidence comes from observational studies. Ad-hoc human trials and mechanistic, basic science studies are needed before we can provide sound advice to the public.

An intervention study on the effect of matcha tea, in drink and snack bar formats, on mood and cognitive performance

Matcha tea is gaining popularity throughout the world in recent years and is frequently referred to as a mood-and-brain food. Previous research has demonstrated that three constituents present in matcha tea, l-theanine, epigallocatechin gallate (EGCG), and caffeine, affect mood and cognitive performance. However, to date there are no studies assessing the effect of matcha tea itself. The present study investigates these effects by means of a human intervention study administering matcha tea and a matcha containing product. Using a randomized, placebo-controlled, single-blind study, 23 consumers participated in four test sessions. In each session, participants consumed one of the four test products: matcha tea, matcha tea bar (each containing 4g matcha tea powder), placebo tea, or placebo bar. The assessment was performed at baseline and 60min post-treatment. The participants performed a set of cognitive tests assessing attention, information processing, working memory, and episodic memory. The mood state was measured by means of a Profile of Mood States (POMS). After consuming the matcha products compared to placebo versions, there were mainly significant improvements in tasks measuring basic attention abilities and psychomotor speed in response to stimuli over a defined period of time. In contrast to expectations, the effect was barely present in the other cognitive tasks. The POMS results revealed no significant changes in mood. The influence of the food matrix was demonstrated by the fact that on most cognitive performance measures the drink format outperformed the bar format, particularly in tasks measuring speed of spatial working memory and delayed picture recognition. This study suggests that matcha tea consumed in a realistic dose can induce slight effects on speed of attention and episodic secondary memory to a low degree. Further studies are required to elucidate the influences of the food matrix.

Caffeine and theanine exert opposite effects on attention under emotional arousal

Tea is perceived as more relaxing than coffee, even though both contain caffeine. L-theanine in tea may account for the difference. Consumed together, caffeine and theanine exert similar cognitive effects to that of caffeine alone, but exert opposite effects on arousal, in that caffeine accentuates and theanine mitigates physiological and felt stress responses. We evaluated whether caffeine and theanine influenced cognition under emotional arousal. Using a double-blind, repeated-measures design, 36 participants received 4 treatments (200 mg caffeine + 0 mg theanine, 0 mg caffeine + 200 mg theanine, 200 mg caffeine + 200 mg theanine, 0 mg caffeine + 0 mg theanine) on separate days. Emotional arousal was induced by highly arousing negative film clips and pictures. Mood, salivary cortisol, and visual attention were evaluated. Caffeine accentuated global processing of visual attention on the hierarchical shape task (p < 0.05), theanine accentuated local processing (p < 0.05), and the combination did not differ from placebo. Caffeine reduced flanker conflict difference scores on the Attention Network Test (p < 0.05), theanine increased difference scores (p < 0.05), and the combination did not differ from placebo. Thus, under emotional arousal, caffeine and theanine exert opposite effects on certain attentional processes, but when consumed together, they counteract the effects of each other.

Infusing pleasure: Mood effects of the consumption of a single cup of tea

Tea has historically been associated with mood benefits. Nevertheless, few studies have empirically investigated mood changes after tea consumption. We explored immediate effects of a single cup of tea up to an hour post-consumption on self-reported valence, arousal, discrete emotions, and implicit measures of mood. In a parallel group design, 153 participants received a cup of tea or placebo tea, or a glass of water. Immediately (i.e. 5 min) after consumption, tea increased valence but reduced arousal, as compared to the placebo. There were no differences at later time points. Discrete emotions did not differ significantly between conditions, immediately or over time. Water consumption increased implicit positivity as compared to placebo. Finally, consumption of tea and water resulted in higher interest in activities overall and in specific activity types compared to placebo. The present study shows that effects of a single cup of tea may be limited to an immediate increase in pleasure and decrease in arousal, which can increase interest in activities. Differences between tea and water were not significant, while differences between water and placebo on implicit measures were unexpected. More servings over a longer time may be required to evoke tea's arousing effects and appropriate tea consumption settings may evoke more enduring valence effects.

Tea Consumption Reduces the Incidence of Neurocognitive Disorders: Findings from the Singapore Longitudinal Aging Study

OBJECTIVES

To examine the relationships between tea consumption habits and incident neurocognitive disorders (NCD) and explore potential effect modification by gender and the apolipoprotein E (APOE) genotype.

DESIGN

Population-based longitudinal study.

SETTING

The Singapore Longitudinal Aging Study (SLAS).

PARTICIPANTS

957 community-living Chinese elderly who were cognitively intact at baseline.

MEASUREMENTS

We collected tea consumption information at baseline from 2003 to 2005 and ascertained incident cases of neurocognitive disorders (NCD) from 2006 to 2010. Odds ratio (OR) of association were calculated in logistic regression models that adjusted for potential confounders.

RESULTS

A total of 72 incident NCD cases were identified from the cohort. Tea intake was associated with lower risk of incident NCD, independent of other risk factors. Reduced NCD risk was observed for both green tea (OR=0.43) and black/oolong tea (OR=0.53) and appeared to be influenced by the changing of tea consumption habit at follow-up. Using consistent non-tea consumers as the reference, only consistent tea consumers had reduced risk of NCD (OR=0.39). Stratified analyses indicated that tea consumption was associated with reduced risk of NCD among females (OR=0.32) and APOE ε4 carriers (OR=0.14) but not males and non APOE ε4 carriers.

CONCLUSION

Regular tea consumption was associated with lower risk of neurocognitive disorders among Chinese elderly. Gender and genetic factors could possibly modulate this association.

Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis

A systematic review and meta-analysis was conducted on 11 randomized placebo-controlled human studies of acute effects of tea constituents L-theanine and epigallocatechin gallate, administered alone or in combination with caffeine, on cognitive function and mood. The outcome measures of mood were alertness, calmness, and contentedness, derived from the Bond-Lader scales, and state anxiety, from the State-Trait Anxiety Inventory. Cognitive measures assessed were attentional switch, intersensory attention, and rapid visual information processing. Standardized mean differences between placebo and treatment groups are presented for each study and outcome measure. Meta-analysis using a random-effects model was conducted when data were available for three or more studies. Evidence of moderate effect sizes in favor of combined caffeine and L-theanine in the first 2 hours postdose were found for outcome measures Bond-Lader alertness, attentional switching accuracy, and, to a lesser extent, some unisensory and multisensory attentional outcomes. Moderator analysis of caffeine and L-theanine doses revealed trends toward greater change in effect size for caffeine dose than for L-theanine dose, particularly during the first hour postdose.

Acute effects of tea consumption on attention and mood

Tea has historically been associated with mood and performance benefits, such as relaxation and concentration. This review summarizes the research on the acute effects of tea, and its ingredients theanine and caffeine, on attention and mood. Consistent with abundant research on the benefits of caffeine, the performance benefits of tea were identified in a number of studies, with particularly consistent evidence for improved attention. Tea consumption also consistently improved self-reported alertness and arousal, whereas effects on pleasure or relaxation were less consistent. In addition to the research on caffeine in real-life performance, 2 recent studies have provided a broader perspective on tea's effects on psychological function in that they showed beneficial effects in related areas such as work performance and creativity. These studies showed the validity of laboratory findings by supporting the idea that tea consumption has acute benefits on both mood and performance in real-life situations.

Nutrition and the risk of Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that accounts for the major cause of dementia, and the increasing worldwide prevalence of AD is a major public health concern. Increasing epidemiological studies suggest that diet and nutrition might be important modifiable risk factors for AD. Dietary supplementation of antioxidants, B vitamins, polyphenols, and polyunsaturated fatty acids are beneficial to AD, and consumptions of fish, fruits, vegetables, coffee, and light-to-moderate alcohol reduce the risk of AD. However, many of the results from randomized controlled trials are contradictory to that of epidemiological studies. Dietary patterns summarizing an overall diet are gaining momentum in recent years. Adherence to a healthy diet, the Japanese diet, and the Mediterranean diet is associated with a lower risk of AD. This paper will focus on the evidence linking many nutrients, foods, and dietary patterns to AD.

Behavioural effects of compounds co-consumed in dietary forms of caffeinated plants

Research into the cognitive and mood effects of caffeine in human subjects has highlighted some fairly robust and well-accepted effects. However, the majority of these studies have focused on caffeine in isolation; whilst caffeine is normally consumed in the form of plant-derived products and extracts that invariably contain other potentially bioactive phytochemicals. The aim of the present review is to consider the possible mechanisms of action of co-occurring phytochemicals, and any epidemiological evidence suggesting that they contribute to potential health benefits ascribed to caffeine. Intervention studies to date that have been conducted to explore the effects on brain function of the non-caffeine components in caffeine-bearing plants (coffee, tea, cocoa, guaraná), either alone or in combination with caffeine, will also be summarised. Research is beginning to accumulate showing independent effects for several of the phytochemicals that co-occur with caffeine, and/or a modulation of the effects of caffeine when it is co-consumed with these naturally concomitant phytochemicals. The present review highlights that more research aimed at understanding the effects of these compounds is needed and, more importantly, the synergistic relationship that they may have with caffeine.

Gazing into the crystal ball: future considerations for ensuring sustained growth of the functional food and nutraceutical marketplace

Over the last decade the concept of functional foods and nutraceuticals (FFN) has gained support from various stakeholders including the food industry, scientific and academic community, government institutions or regulators, producers and consumers. However, as one begins to evaluate the global FFN industry, several issues emerge including (i) a lack of consensus across jurisdictions for acknowledging safe and efficacious FFN, (ii) challenges regarding the classification of novel food-derived bioactives as FFN or drugs, and (iii) a disconnect between nutrient requirements and dosages of FFN required to facilitate health benefits. The objectives of the present review are to discuss the role of existing stakeholders within the FFN marketplace and identify performance indicators for growth within the FFN sector. In addition, the following report provides feasible resolutions to present and future challenges facing the global FFN industry to ensure sustained long-term growth.

Gender differences in tea, coffee, and cognitive decline in the elderly: the Cardiovascular Health Study

Although caffeine can enhance cognitive function acutely, long-term effects of consumption of caffeine-containing beverages such as tea and coffee are uncertain. Data on 4,809 participants aged 65 and older from the Cardiovascular Health Study (CHS) were used to examine the relationship of consumption of tea and coffee, assessed by food frequency questionnaire, on change in cognitive function by gender. Cognitive performance was assessed using serial Modified Mini-Mental State (3MS) examinations, which were administered annually up to 9 times. Linear mixed models were used to estimate rates of change in standard 3MS scores and scores modeled using item response theory (IRT). Models were adjusted for age, education, smoking status, clinic site, diabetes, hypertension, stroke, coronary heart disease, depression score, and APOE genotype. Over the median 7.9 years of follow-up, participants who did not consume tea or coffee declined annually an average of 1.30 points (women) and 1.11 points (men) on standard 3MS scores. In fully adjusted models using either standard or IRT 3MS scores, we found modestly reduced rates of cognitive decline for some, but not all, levels of coffee and tea consumption for women, with no consistent effect for men. Caffeine consumption was also associated with attenuation in cognitive decline in women. Dose-response relationships were not linear. These longitudinal analyses suggest a somewhat attenuated rate of cognitive decline among tea and coffee consumers compared to non-consumers in women but not in men. Whether this association is causal or due to unmeasured confounding requires further study.