The role of functional foods in the psychobiology of health and disease

General practitioners roles and experiences with functional foods containing probiotics and plant sterols

AIM

The purpose of this research is to explore whether general practitioners have experiences with functional foods within their clinical practice.

BACKGROUND

Previous research and editorials have suggested that general practitioners should have more involvement and knowledge of functional foods. This is due to the thought that functional foods may be consumed by their patients that could lead to other issues, such as patients not taking their medication. Therefore, research into general practitioners involvement with functional foods needs to be conducted.

METHOD

In all, 10 semi-structured open interviews were used with a topic guide. These interviews where digitally audio recorded and transcribed verbatim. The transcripts where analysed using thematic analysis.

FINDINGS

It was found that general practitioners believed they did not have a direct role with functional foods and should not be involved with discussing them with their patients. They felt that if they where to be involved with functional foods then they would need more training and information about them. They also felt that functional foods could be empowering for their patients.

Food-based strategies for depression management from Iranian traditional medicine resources

Background:

Considering the increasing prevalence of depression in contemporary societies, general tendency for safer treatments with fewer side effects has recently been a subject of interest.

Objectives:

Food-based strategies, which are one of the outstanding medical solutions in Complementary and Alternative Medicine including Iranian Traditional Medicine have been investigated.

Materials and Methods:

In this review study, firstly some important sources of Iranian Traditional Medicine including Kamel al-Sanaat al-Tibbyyah, Al-Qanun fi al-Tibb and Zakhireh Kharazmshahi were reviewed. Next, a literature search was performed on PubMed and Magiran databases with the keywords “depression”, “depressive”, “mood”, “antidepressant”, “antidepressive”, “nutrition”, “nutritional”, “diet”, “meal”, “food”, “functional food”, “healthy food”, “healthy diet”, “medicinal food” and scientific and English terms of all singular foodstuff and some combined foodstuff which are introduced in this paper.

Results:

Food-based strategies for depression management in Iranian Traditional Medicine resources involving both prevention and treatment parts have been classified under three headings singular foodstuffs, combined foodstuffs, and nutrition rules with the separation of prohibition and prescription items. Among the prescribed or the prohibited singular and combined foodstuffs in Iranian Traditional Medicine manuscripts, only the effectiveness of fish, garlic, milk, oregano, mint, and spinach on depression has been examined by modern medicine methods.

Conclusions:

The presented food-based strategies in this study introduce a precise management for depression benefiting from Iranian Traditional Medicine Resources.

Food can lift mood by affecting mood-regulating neurocircuits via a serotonergic mechanism

It is commonly assumed that food can affect mood. One prevalent notion is that food containing tryptophan increases serotonin levels in the brain and alters neural processing in mood-regulating neurocircuits. However, tryptophan competes with other long-neutral-amino-acids (LNAA) for transport across the blood-brain-barrier, a limitation that can be mitigated by increasing the tryptophan/LNAA ratio. We therefore tested in a double-blind, placebo-controlled crossover study (N=32) whether a drink with a favourable tryptophan/LNAA ratio improves mood and modulates specific brain processes as assessed by functional magnetic resonance imaging (fMRI). We show that one serving of this drink increases the tryptophan/LNAA ratio in blood plasma, lifts mood in healthy young women and alters task-specific and resting-state processing in brain regions implicated in mood regulation. Specifically, Test-drink consumption reduced neural responses of the dorsal caudate nucleus during reward anticipation, increased neural responses in the dorsal cingulate cortex during fear processing, and increased ventromedial prefrontal-lateral prefrontal connectivity under resting-state conditions. Our results suggest that increasing tryptophan/LNAA ratios can lift mood by affecting mood-regulating neurocircuits.

Influence of specific nutrients on progression of atherosclerosis, vascular function, haemostasis and inflammation in coronary heart disease patients: a systematic review

Epidemiological evidence suggests that the diet influences CHD risk, although the protective effects of dietary intervention for patients in diseased states has gained less attention. Secondary care prevention strategies for patients often involves drug therapy that is expensive and can result in undesirable side effects. Therefore, it is potentially beneficial to utilise other strategies, such as diet, in the management of CHD. A systematic review was conducted to examine the effects of specific nutrients on progression of atherosclerosis, vascular function, haemostasis and inflammation in CHD patients. Results show substantial evidence for the efficacy ofn–3 oils in reducing cardiovascular mortality and one mechanism may be related to the stabilisation of vulnerable atherosclerotic plaques, although the effects on progression of atherosclerosis, haemostatic activity and vascular inflammation remain equivocal. Promising data also exist for the efficacy of flavonoid-rich foods for improving endothelial function, although strong clinical endpoint evidence is lacking. The variation in the efficacy of certain nutrients in CHD patients may be explained by genetics, existing risk factors, psychosocial factors and methodological issues, although these are often not adequately taken into consideration. We conclude that there is a need to undertake more appropriately designed trials in specific clinical populations, controlling for additional lifestyle and risk factors, examining potential interactions with medications, and also establishing methods to increase compliance to dietary recommendations before specific nutrients can be widely prescribed for secondary prevention. Future research should also utilise techniques that provide a direct measure of atherosclerosis.

The effects of tea on psychophysiological stress responsivity and post-stress recovery: a randomised double-blind trial

RATIONALE

Tea has anecdotally been associated with stress relief, but this has seldom been tested scientifically.

OBJECTIVES

To investigate the effects of 6 weeks of black tea consumption, compared with matched placebo, on subjective, cardiovascular, cortisol and platelet responses to acute stress, in a parallel group double-blind randomised design.

MATERIALS AND METHODS

Seventy-five healthy nonsmoking men were withdrawn from tea, coffee and caffeinated beverages for a 4-week wash-out phase during which they drank four cups per day of a caffeinated placebo. A pretreatment laboratory test session was carried out, followed by either placebo (n = 38) or active tea treatment (n = 37) for 6 weeks, then, a final test session. Cardiovascular measures were obtained before, during and after two challenging behavioural tasks, while cortisol, platelet and subjective measures were assessed before and after tasks.

RESULTS

The tasks induced substantial increases in blood pressure, heart rate and subjective stress ratings, but responses did not differ between tea and placebo treatments. Platelet activation (assessed using flow cytometry) was lower following tea than placebo treatment in both baseline and post-stress samples (P < 0.005). The active tea group also showed lower post-task cortisol levels compared with placebo (P = 0.032), and a relative increase in subjective relaxation during the post-task recovery period (P = 0.036).

CONCLUSIONS

Compared with placebo, 6 weeks of tea consumption leads to lower post-stress cortisol and greater subjective relaxation, together with reduced platelet activation. Black tea may have health benefits in part by aiding stress recovery.