The Relationship Between Dietary Inflammation Index® and Depressive Symptoms

Inflammation is the body’s response to illness or injury; the swelling around a cut or a bruise is part of this process. The inflammatory model of depression suggests that, for some people, depression may be caused or exacerbated by inflammation.

Supporting this theory is the finding that people with depression tend to have higher levels of markers of inflammation in their blood. In addition, inducing an inflammatory immune response (by injecting participants with particles of bacteria) promotes the development of depressive symptoms in placebo-controlled trials.

Though inflammation is most obviously the response to a pathogen, it also occurs in response to other non-injury factors such as prolonged stress, an imbalance of bacteria in the gut, or poor diet.

The Dietary Inflammatory Index® (DII®) is a scale that measures the inflammatory potential of dietary patterns. On this scale diets high in saturated fatty acids, trans fats and cholesterol are ranked as pro-inflammatory. In contrast, diets higher in vegetables, fruits, fibre/wholegrains, herbs and spices such as ginger, garlic and turmeric, green and black tea, and dietary patterns such as the Mediterranean diet are associated with lower biomarkers of inflammation. It should be noted that the DII® scores overall dietary intake rather than highlighting specific nutrients.

Landmark studies such as the ‘SMILES Trial’ and ‘HELFIMED’ have demonstrated that dietary modification may be a useful depression intervention for many patients. A new study, using the DII®, seems to add to these results, indicating a role for nutrition in depressive illness. This study followed people for eight years, tracking their diet and their risk of developing depressive symptoms.

3,648 participants (1,577 males, 2,071 females; mean age: 60.6 years) with/at risk of knee osteoarthritis took part. Participants filled out a food frequency questionnaire, indicating how often they ate certain foods from ‘never’ to ‘every day’. This data was used to give each participant a ranking on the DII®. They were also assessed for depression.

At the start of the study (baseline), those with the most pro-inflammatory (higher scores on the DII®) diets also had higher depression scores. Over the course of the eight-year follow-up period 837 people developed depressive symptoms, and the incidence of depression was significantly higher in people with the most pro-inflammatory diets at baseline, potentially indication a cumulative effect of inflammation on depression. In further analysis, being female and having a higher BMI were also associated with increased incidence of depressive symptoms during follow-up. The authors report that participants with the highest DII score had a 24% increased risk of developing depressive symptoms over the course of the study.

More research is required to clarify and confirm these results and, since depression is one of the leading global causes of disability, I look forward to more research in this important area of mental health.



Shivappa, N., Hébert, J. R., Veronese, N., Caruso, M. G., Notarnicola, M., Maggi, S., ... Solmi, M. (2018). The Relationship Between the Dietary Inflammatory Index (DII®) and Incident Depressive Symptoms: A Longitudinal Cohort Study. Journal of Affective Disorders. DOI: 10.1016/j.jad.2018.04.014

Shivappa, N., Steck, S. E., Hurley, T. G., Hussey, J. R., & Hébert, J. R. (2014). Designing and developing a literature-derived, population-based dietary inflammatory index. Public Health Nutrition, 17(8), 1689–1696.

A Mediterranean-style Dietary Intervention Improves Mental Health in People with Depression: A Randomized Controlled Trial

The year in Nutritional Psychiatry started with the publication of the first RCT into the positive effect of a healthy diet on depression (the SMILES Trial). A new study bookended the year with similar promising results. 

In this study people with self-reported depression were randomly assigned to one of two groups. The first group received nutritional education, a fortnightly food box containing ingredients that adhered to the Mediterranean diet for three months, and six months of fish oil supplements. The control group were assigned to receive regular social support for the same amount of time. 

At the end of the trial the MedDiet group saw a significant reduction in their depression scores and overall Quality of Life with 60% fewer persons experiencing extremely severe levels of depression, 72% of anxiety and 69% of stress in the MedDiet group compared to the social support group. 

This was a small trial and replications of the SMILES are already underway which will give use a deeper understanding of the role of diet on mental health and clarify the most effective interventions for different treatment groups. 



Parletta, N., Zarnowiecki, D., Cho, J., Wilson, A., Bogomolova, S., Villani, A. Itsiopoulos, C., Niyongsenga, T., Blunden, S., Meyer, B., Segal, L., Baune, B. T. & O’Dea, K. (2017). A Mediterranean-style dietary intervention supplemented with fish oil improves diet quality and mental health in people with depression: A randomized controlled trial (HELFIMED).Nutritional Neuroscience, 1-14.

Vitamin D and Sleep

Vitamin D modulates hundreds of genes and plays an essential role in many biological systems, including those linked to brain function and sleep.

Consistently poor sleep is a serious health concern and is linked to increased risk of weight-gain, type 2 diabetes, heart disease and increased susceptibility to illness. Psychologically, poor sleep and sleep disorders are a common feature of many mental health concerns such as anxiety, bipolar disorder, post-traumatic stress disorder, Alzheimer’s Disease and other forms of dementia. So an accessible intervention that improves sleep is valuable. A recent clinical trial tested the effect of vitamin D supplementation on sleep quality.

The researchers took a group of 89 people all of whom had sleep disorders characterised by long sleep latency (taking a long time to fall asleep), low sleep quality, duration and/or efficiency (spending a lot of time in bed but not much of it asleep). The participants were randomly assigned to two groups, one received a very high dose vitamin D supplement every fortnight for a total of eight weeks, the other received an identical looking placebo. :
At the start all the participants had insufficient vitamin D. As expected, at the end, the supplement group had sufficient levels and the placebo group had not changed. In addition, supplement group reported better overall sleep quality, with longer duration and reduced latency, suggesting that adequate vitamin D levels can help support healthy sleep.

It is important to note that the supplement in this trial was a very high, clinical dose. For example, the NHS recommends UK adults supplement with 10mcg of vitamin per day (equivalent to 140mcg per fortnight). The dose in this trial is equivalent to 1250mcg per fortnight. Very high dose supplements may be available on prescription and a blood test would need to be taken first to establish that there was definitely a deficiency.

Majid, M. S. et al (2017). The effect of vitamin D supplement on the score and quality of sleep in 20–50 year-old people with sleep disorders compared with control group. Nutr Neuro. DOI: 10.1080/1028415X.2017.1317395

B Vitamins Reduce Symptom Severity in Schizophrenia

Schizophrenia is a serious, long-term mental health disorder characterised by experiences of distorted reality (such as visual and auditory hallucinations) and cognitive impairments such as false beliefs, paranoia, and language deficits. Though many people are able to live full lives following a diagnosis of schizophrenia, for a large proportion of patients the illness destroys their quality of life and is associated with increased mortality.

Medication saves lives but the side-effects can be distressing and debilitating, so it is essential that research continues to look for safe and effective treatments for patients. A systematic review and meta-analysis published this year by an international team of researchers found that high-dose B vitamin supplementation alongside prescribed medication reduced the severity of symptoms, particularly in those with low baseline levels, high homocysteine, and when given earlier on in the illness progression. The authors conclude that further research is warranted to understand the underlying biological mechanisms and work out which combination and dosages of nutrients would have the most benefit. -

The effects of vitamin and mineral supplementation on symptoms of schizophrenia: a systematic review and meta-analysis. 10.1017/S0033291717000022

One Hour of Exercise Per Week Reduces Depression Risk by 44%

A new study published yesterday suggests that even modest amounts of exercise could prevent some cases of depression. The prospective study monitored over 22,000 healthy people, seeing how many of them went on to develop depression over 11 years.

At follow-up and accounting for factors such as smoking, alcohol consumption, BMI, other illness and social support, people who, at the start of the study, said they didn't do any exercise had a 44% increased risk of developing depression compared to people doing just 1-2 hours of exercise per week. This outcome was the same for males and females, and younger and older people. On top of this it didn't seem to matter whether it was intense exercise. People didn't need to break a sweat to get the protection. Just moving was enough to reduce the likelihood of developing depression.

Why is this so important? Rates of depression and treatment-resistant depression (that don't respond to medication) are on the rise. If there is a causal relationship between exercise and depression (and no other confounding factors) this research suggests that 1 in 8 cases of depression could be *prevented* with just one hour a week of exercise (or that severity could be reduced). This research also helps shift the thinking from treatment to *prevention*. While many of the causes of depression such as genetics and traumatic life events are out of our control, physical activity is a 'modifiable risk factor' i.e. we can do something about it. And if we can save some people the distress of depression that is something everyone should get behind.


Exercise and the Prevention of Depression: Results of the HUNT Cohort Study.American Journal of Psychiatry Online. DOI: 10.1176/appi.ajp.2017.16111223

Probiotic Supplementation in Pregnancy Reduces the Risk of Anxiety and Depression

Though the evidence of the role of diet and the gut in the development of psychological disorders is established and growing, the majority of the research has either been epidemiological (observations of large groups of people – these do not show causality) or animals trials (show the mechanisms but might not completely translate to humans). At the end of all of these papers the authors remark that more high-quality human trials are required to draw firmer conclusions. Earlier in the year we had the publication of the SMILES Trial, a study that showed a cause and effect relationship between poor diet and depression and now a new paper provides more good evidence of the role of probiotics and the gut microbiome on mental health. Even more interesting is that this was not even the main aim of the research.

Researchers in New Zealand set up a trial to see whether giving pregnant women probiotics would affect their children’s risk of developing eczema. Eczema is an inflammatory skin condition and the gut microbiome plays an essential role in regulating inflammation. A baby’s gut microbiome is seeded at birth during its transit through the birth canal, or from skin contact after delivery by caesarean section. In the study 423 pregnant women were randomly assigned to two groups. One group received a daily supplement of a strain of bacteria called Lactobacillus rhamnosus (HN001). The other group received an identical looking/tasting placebo. The women took the supplement/placebo from the moment they enrolled until their child was born, and from birth until 6 months if the mother was breastfeeding. Information about the women’s mental state was taken at baseline (14-16 weeks pregnant), when the child was 6 months and 12 months old. They found a strong effect of the probiotic. The women who had taken the supplement (and none of the women knew whether they were taking the active supplement or the placebo) were much less likely to experience depression and anxiety after the birth of their children.  

The researchers report that between 10%-15% of women experience post-partum (post-natal) depression, which can impair the development of a strong bond between mother and infant, creating psychological and physical health risks for both. Medication options for breastfeeding women are limited because of the risk that the medication would be ingested by the baby in breast milk. In addition, it is practically difficult for women to access psychological or psychosocial interventions on top of the demands of a new baby. Further, some women feel reluctant to ask for help because they feel ashamed or guilty that they should feel so unhappy following the birth of their baby. Clearly then, the development of accessible and effective treatments is essential. There are many questions still to be answered about what a probiotic treatment might look like. This trial looked at only one strain and it might be that others of a combination are important too. We also need to know how long treatment should last and what the dose should be. But this well-designed study adds to the evidence of the role and importance of gut health in mental health and of taking the health of the whole body in to consideration when looking to treat mental health problems.



Effect of Lactobacillus rhamnosus HN001 in Pregnancy on Postpartum Symptoms of Depression and Anxiety: A Randomised Double-blind Placebo-controlled Trial. DOI: 10.1016/j.ebiom.2017.09.013


Vitamin D Supplementation Improves Sleep Quality in Sleep Disorders

Vitamin D is a corticosteroid hormone that modulates the activity of hundreds of genes and plays an essential role in many other biological functions, including those linked to brain function and sleep regulation. I have previously reported research showing that serum levels of vitamin D predicted cognitive performance in adults

Consistently poor sleep should be considered a serious health concern. Inadequate sleep is linked to an increased risk of weight-gain, type 2 diabetes, heart disease and increased susceptibility to illness. Psychologically, poor sleep and sleep disorders are a common feature of many mental health concerns such as anxiety, bipolar disorder, post-traumatic stress disorder, Alzheimer’s Disease and other forms of dementia. Sleep problems such as insomnia or excessive sleep are diagnostic criteria for depression, the major cause of global disease burden. Rather than being just a symptom, impaired sleep can precede the onset of other symptoms and, conversely, improving sleep quality can help to alleviate symptom severity. So an accessible intervention that improves sleep is a valuable weapon in the mental health armoury. A recent clinical trial tested the effect of vitamin D supplementation on sleep quality.

Published in the journal Nutritional Neuroscience researchers at the Ahvaz Jundishapur University of medical science in Iran took a group of 89 people all of whom had sleep disorders characterised by long sleep latency (taking a long time to fall asleep) low sleep quality, duration and/or efficiency (spending a lot of time in bed but not much of it asleep). The participants were randomly assigned to two groups, one received a very high dose vitamin D supplement every fortnight for a total of eight weeks, the other received an identical looking placebo of edible paraffin.  

What was helpful about this study was that the researchers assessed the participants baseline vitamin D levels at the start of the trial and then again after it. This is important because it help to determine more accurately what blood levels might be most beneficial and helps to identify any individual differences between the participants that might influence the outcomes. At the start all the participants had insufficient levels of vitamin D (less than 29ng/mol of 25 (OH) D). At the end, as you might expect, the supplement group had sufficient levels and the placebo group had not changed significantly. In addition, at the end of the trial, the supplement group reported better overall sleep quality, with longer duration and reduced latency, suggesting that adequate vitamin D levels can help support healthy sleep.

It is important to note that the supplement administered in this trial was a very high, clinical dose. For example, the NHS recommends that adults in the UK consider supplementing with 10mcg of vitamin per day (equivalent to 140mcg per fortnight). The dose in this trial is equivalent to 1250mcg per fortnight. Very high dose supplements may be available on prescription and a blood test would need to be taken first to establish that there was definitely a nutritional deficiency.


Majid, M. S., Ahmad, H. S., Bizhan, H., Hosein, H. Z. M. & Mohammad, A. (2017). The effect of vitamin D supplement on the score and quality of sleep in 20–50 year-old people with sleep disorders compared with control group. Nutritional Neuroscience. Epub ahead of print. DOI: 10.1080/1028415X.2017.1317395


Disclaimer: This information is provided for information purposes only and should not be taken as advice or instruction. This information does not replace the advice of your doctor. Please consult an appropriate health professional if you believe you are experiencing a mental or physical health concern.

Emotional Awareness and Expression Training Reduces Symptom Severity in Irritable Bowel Syndrome

IBS is a functional gut disorder that disturbs the normal functions of the bowel but with no obvious, single cause. The main signs and symptoms of IBS are abdominal pain or discomfort, that is associated with either diarrhoea or constipation or a combination of both. IBS is suspected to be a disorder that involves the dysfunction of the brain-gut-microbiome axis; for some reason the signalling and feedback to and from the brain and the gut is impaired leading to changes in motility, increased nerve sensitivity and comorbid symptoms of depression and anxiety. For a fuller overview of the disorder tune in to the podcast episode all about understanding the illness. Listen here.

It is well documented that people with a diagnosis of IBS tend to experience high levels of psychological stress and/or have experienced traumatic experiences in the past. They are also more likely to have difficulty in intimate relationships and in expressing their feelings. Building on previous research that psychological therapies are an effective treatment for IBS, a new randomised controlled trial investigated the utility of a type of therapy specifically designed to address emotional awareness and expression in people with IBS.

In this study IBS patients were recruited and were then randomly assigned to one of three groups:

1.      Emotional Awareness and Expression Training (EAET)

2.      Relaxation training, which has been shown to be helpful for IBS patients

3.      Waiting list – this was the control group, to compare whether any changes seen in the other two groups would have happened anyway without any intervention.

Both the EAET and relaxation groups received three 50-minute training session delivered over three consecutive weeks i.e. one session a week. They were then assessed two weeks after the end of the last session and then again 10 weeks after that. Participants in groups one and two received a similar explanation about the link between stress and IBS but the EAET group were provided with specific skills to improve emotional expressions such thinking of someone they have a difficult relationship with and being encouraged to describe those feelings out loud as if the person was present. They were later encouraged to express their emotions directly with that person. The relaxation group were coached in muscle relaxation, deep breathing and mindfulness meditation.

Most of the 106 participants in this study were women (IBS is more common in women than men) and had had IBS for more than 20 years. At the end of the 10-week follow-up period 63% of the people in the EAET group reported significant improvements in their IBS symptoms. People in the relaxation and waiting list groups did not report any significant change in the severity of their IBS. Both relaxation and EAET improved the participants’ quality of life. What is striking about this result is that the intervention was very brief, less than three hours in total, and the participants had been ill for many years. The therapists administering the treatment were clinical psychology graduate students. This could mean that, in practical terms, provision of this kind of treatment might be highly cost-effective.

This was a small study with a short follow-up period. It will be important to replicate and extend the research by looking at larger groups and whether the results are sustained over many months. Nonetheless, this paper supports the theory that psychological stress and emotional suppression lead to overstimulation of the stress response and that this dysregulates the nervous communication between the brain and the gut. On an everyday level we recognise this as, for example, feeling so nervous about something that we feel nauseous or have butterflies in our stomachs. In IBS there is  understood to be a continuous over-activation of this system, and the body struggles to return to equilibrium.

Separately, this study also reinforces the importance of acknowledging and expressing emotions rather than ignoring, avoiding or denying them. Unexpressed emotional states don’t just go away, they exert a physiological effect that can lead to somatic symptoms.

As a side note, the researchers’ description of EAET sounds akin to the Distress Tolerance protocols inherent in a type of therapy called Dialectical Behaviour Therapy (DBT), originally designed to help people with a diagnosis of Borderline Personality Disorder to improve how they manage their emotions and their interpersonal effectiveness. There are many Clinical and Counselling Psychologists trained in DBT so this may prove a more accessible route for clients than trying to find an EAET trained therapist.



Thakur, E. R, Holmes, H. J, Lockhart, N. A., Carty, J. N., Ziadni, M. S., Doherty, H. K., Lackner, J. M., Schubiner, H. & Lumley MA. (2017). Emotional awareness and expression training improves irritable bowel syndrome: A randomized controlled trial. Neurogastroenterology, Epub ahead of print. doi: 10.1111/nmo.13143


Psychotherapy Improves Mental Health and Daily Functioning in Irritable Bowel Syndrome: Meta-Analysis.

Last year I reported on a study that showed that psychotherapy was effective at reducing the physical pain of Irritable Bowel Syndrome (IBS) and that, at the same time, it was superior to medication at reducing healthcare costs associated with the illness. A new meta-analysis extends the work on psychological treatments for IBS and shows that talking therapies are also effective for improving the mental health and quality of life sufferers. Quality of Life is a psychological measure that looks at the wellbeing of an individual or group and can assess how much satisfaction they derive from their lives or from an aspect of it, such as work or relationships. IBS can reduce quality of life by getting in the way of normal daily activities like work or socialising and can create mental distress but, for example, increasing anxiety around eating and meal times, depression and, in severe cases, suicidal thoughts.

This new meta-analysis looked not only at the efficacy of psychotherapy on improving mental health in IBS sufferers but also at which type of therapy was most effective. The researchers collated 31 randomised controlled trials that provided data on overall mental health and daily functioning of nearly 2000 individuals from different countries. The researchers found that all kinds of psychotherapy were effective at improving psychological wellbeing, people felt better. When it came to daily function cognitive behaviour therapy (CBT) appeared to be the most effective, compared to psychodynamic, hypnosis or relaxation therapy.

Whilst this research is encouraging in relation to the value of therapy in treatment of IBS it does present with a number of problems. First, the researchers have been unable to distinguish between what types of CBT were being provided. For example, some ‘brands’ of CBT focus more on mindfulness, whilst others focus on acceptance and behaviour change. It may be that there is further variability within these groups. In addition, CBT was by far the most studied therapy. Looking at mental health, for example, there were 19 CBT trails compared to 3 psychodynamic. More research on other types of psychotherapy will be useful to add strength to the conclusions. Also, another paper published this year suggested that though CBT did lead to improvements in quality of life for IBS sufferers the results did not last long after the therapy ended.

What we can be surer of is that psychological therapy does improve the mental wellbeing of IBS patients and can be an important tool in helping improve their quality of life. Though there is further research required this meta-analysis adds to the body of research highlighting the powerful role that psychological therapies play in IBS treatment.



Laird, K. T., Tanner-Smith, E. E., Russell, A. C., Hollon, S. D. & Walker, L. S. (2017). Comparative efficacy of psychological therapies for improving mental health and daily functioning in irritable bowel syndrome: A systematic review and meta-analysis. Clinical Psychology Review, 51, 142-152.

Dehkordi AH, Solati K. The effects of cognitive behavioral therapy and drug therapy on quality of life and symptoms of patients with irritable bowel syndrome. Journal of Advanced Pharmaceutical Technology & Research. 2017;8(2):67-72. doi:10.4103/japtr.JAPTR_170_16.

Exercise (Walking) Increases Effectiveness of CBT in Reducing Depression and Suicidal Thoughts

Depression is now the leading cause of global disease burden. This means that depression is a greater cause of loss of quality of life and days without illness than other illnesses such as heart disease and type 2 diabetes. This week the Mental Health Foundation published a report indicating that only 13% of people in the UK report living with good mental health. More than ever we need to find ways to support mental wellness and increase the efficacy of standard treatment.

I have reported elsewhere research indicating the beneficial effects of physical exercise on mental health. Exercise improves brain function in a number of ways including increasing blood flow to the brain, promoting the growth of new brain cells and increasing levels of serotonin and dopamine, neurotransmitters associated with good mood and satisfaction. A new study compared the effectiveness of Cognitive Behavioural Therapy (CBT), a recognised effective treatment for depression, against a combined treatment package of exercise and CBT for treating depression. In this Iranian study 54 (70 started, 16 dropped out) sedentary people with mild to moderate depression were assigned to either a combined CBT and exercise group or a CBT only group. The CBT was delivered in groups of 4-6 people, one 90-minutes session per week for 12 weeks. Interestingly, and importantly, the exercise was not strenuous or high-impact. It involved:

  • 5 minutes of warm up flexibility exercises
  • 5 minutes of clapping and light movements
  • 20 minutes walking at moderate intensity
  • 5 minutes cool down and deep breathing.

This was repeated three times per week for 12 weeks in the evening.

The authors conclude that both groups saw improvements in their depression and reduced suicidal thoughts. However, the combined CBT and exercise group also improved their daily functioning and the combined treatment was superior than CBT alone at reducing depression and suicidal thoughts.

Using exercise as an adjunct to traditional therapy provides a low-cost, safe, easily accessible way to improve the effectiveness of standard treatment that has the added benefit of improving physical health too. This work adds further support to the importance approaching mental health from a whole-body perspective.



Abdollahi, A., LeBouthillier, D. M., Najafi, M., Asmundson, G. J. G., Hosseinian, S., Shahidi, S., Carlbring, P., Kalhori, A., Sadeghi, H. & Jalili, M. (2017). Effect of exercise augmentation of cognitive behavioural therapy for the treatment of suicidal ideation and depression. Journal of Affective Disorders,

Dietary Intervention for Depression – The SMILES Trial

I have reported on epidemiological studies that show a relationship between a consistently healthy diet and depression in the general population and in women. This research has been correlational; it shows that there is a relationship but cannot say that what causes what. It could be that depressed people are more likely to eat a poor diet. All that changed recently with the publication of a randomised controlled trial of the use of diet as a treatment of depression; The ‘SMILES’ Trial.

The 67 participants in this 12-week Australian study were depressed adults who had a clinically defined poor diet. A poor diet was one that was low in fibre, fruit and vegetables and lean protein, and high in sweets, salty snack foods and processed meats. Some participants were receiving treatment in the form of medication, talking therapy or both.

Participants were randomly assigned to either a nutritional intervention group or a befriending control group. In the intervention group the participants had seven one-hour sessions with a registered nutritionist who provided them with personalised nutritional advice, meal plans, and coached them around goal setting and motivation to help them to stick to the nutritional recommendations. They were encouraged to eat (servings in brackets):

  • Whole grains (5–8 servings per day)
  • Vegetables (6 per day);
  •  Fruit (3 per day),
  • Legumes/beans (3–4 per week);
  • Low-fat and unsweetened dairy foods (2–3 per day);
  • Raw and unsalted nuts (1 per day);
  • Fish (at least 2 per week);
  • Lean red meats (3–4 per week);
  • Chicken (2–3 per week);
  • Eggs (up to 6 per week); and
  • Olive oil (3 tablespoons per day).

In addition, participants were encouraged to reduce their intake of “‘extras’ foods, such as sweets, refined cereals, fried food, fast-food, processed meats and sugary drinks (no more than 3 per week). Red or white wine consumption beyond 2 standard drinks per day and all other alcohol (e.g. spirits, beer) were included within the ‘extras’ food group. Individuals were advised to select red wine preferably and only drink with meals.” Those in the social support/befriending group had seven one-hour meetings with a trained professional who talked to them about neutral. Anxiety, depression and general mood were assessed at the beginning and end of the study, along with biometric and anthropometric data such as weight, waist circumference, fasting blood glucose and cholesterol.

People in the dietary intervention group were four times more likely to be in remission at the end of 12 weeks than those in the befriending group. They also had reduced severity of anxiety symptoms. There was no change in BMI, blood glucose, cholesterol or physical activity within or between the groups.

The NNT in the SMILES Trial was four. This compares favourably to common antidepressant medication which can vary from 5-16, which is still considered effective particularly in relation to the high global rates of depression. The authors also make the point that that this nutritional intervention would also have positive outcomes for other problems that are commonly associated with depression such as heart disease, type 2 diabetes and obesity. Crucially, the researchers also looked at the affordability of the diet and found that, on average, people adhering to the diet spent $26 less per week on food and drink than they were at the start of the study.

Of course, this was a small study and it will both interesting and exciting to see the trial replicated with more participants from different ethnic backgrounds. However, it is also, I think, hugely important. It is the first study that demonstrates a direct influence of diet on depression. Depressed people who improved their diet felt better. The upshot is that improving diet in line with general guidelines had a significantly positive effect on depression. The benefit of this kind of intervention is that there are no waiting lists or side-effects, and it doesn’t have to be expensive. We eat several times a day and this research shows us that each meal provides us with a valuable opportunity to make a difference to how we feel.


Jacka, F. N., O’Neil, A., Opie, R., Itsiopoulos, C., Cotton, S., Mohebbi, M., Castle, D., Dash, S., Mihalopoulos, C., Chatterton, M. L., Brazionis, M., Dean, O.M. Hodge, A. M. & Berk, M. (2017). A randomised controlled trial of dietary improvement for adults with major depression (the “SMILES” trial). BMC Medicine15, 23.


Tea Protects Cognitive Function in the Elderly

A new paper has  highlighted the role of tea drinking on protecting brain function. Researchers tracked 957 people aged over 55 who all had normal cognitive function at the start and then assessed them a few years later as part of the Singapore Longitudinal Aging Study. They found that non-tea drinkers had almost twice the risk of developing neurocognitive disorder as consistent tea drinkers (11.1% vs 5.9%), and protection could start with just a few cups per week.

Interestingly, this study also looked at people who were carriers of the APOE ε4 gene, which is a gene variation that is linked with an increased risk of developing Alzheimer’s Disease. The researchers found that women and APOE ε4 carriers benefitted most from the protective effects of tea consumption.

As an important side note, in this paper cognitive decline was associated with higher rates of heart disease, depression and lower levels of social and productive activities, which previous research indicates might all share stress as an influencing factor.

Though the participants in this research were older Chinese adults the results are consistent with results with people from different backgrounds. As yet there is no cure for Alzheimer’s Disease and much of the focus of research in this area is on understanding its causes and finding preventative strategies. Encouraging people to drink a daily cup or two of green, black or oolong tea could be an effective and affordable way to help protect brain function in aging.



L. Feng, M-S. Chong, W-S. Lim, Q. Gao, M. S. Z. Nyunt, T-S. Lee, S. L. Collinson, T. Tsoi, E-H. Kua, & T. -P. Ng. Tea consumption reduces the incidence of neurocognitive disorders: Findings from the Singapore longitudinal aging study. The Journal of Nutrition, Health & Aging, 2016; 20 (10): 1002 DOI: 10.1007/s12603-016-0687-0


Effect of Probiotics on Central Nervous System Functions in Animals and Humans: A Systematic Review

Many by now will be familiar with the term ‘friendly bacteria’, referring to the vast population of bacteria in the digestive tract. This population of microbes (the microbiome) play an important role in maintaining our digestive health and many people consume yogurt and other fermented milk drinks to promote gut health. Increasingly research is showing us that the gut microbiome has a significant effect on our mental as well as physical health.

To gain a better overview of the current status of research in this area a systemic review of random controlled trials was conducted and published in the Journal of Neurogastroenterology & Motility. The researchers reviewed 25 animal and 15 human trials. Of the studies involving human participants just over half described significant effects of probiotics on central nervous system function and an intake of probiotics for four weeks appeared to be the threshold for noticeable effects. In the human trials the most common bacterial strains tested were Bifidobacterium longum, B. breve, B. infantis, Lactobacillus helveticus, L. rhamnosus, L. plantarum, and L. casei, all of which are present in fermented foods such as yogurt, kefir and traditional (unpasteurised) sauerkraut.

Looking at both the animal models and human trials the results of this review indicated that probiotics were an effective intervention for a range of mental health disorders including anxiety, depression, Obsessive Compulsive Disorder (OCD) and memory function. A number of potential mechanisms were identified:

  • Reduced cortisol (stress hormone) levels

  • Reduced inflammation.

  • Improved immune function

It is also feasible that some of the known metabolites of the microbiome such as GABA, an inhibitory neurotransmitter, might play a role either via the vagus nerve or more directly by crossing the blood-brain barrier. Whilst the review is generally positive the researchers called for further studies to be conducted with human participants in order to be able to draw firmer conclusions on the promising role of probiotics on mental diseases.



Wang, H., Lee, I., Braun, C. & Enck, P. (2016). Effect of Probiotics on Central Nervous System Functions in Animals and Humans: A Systematic Review. Journal of Neurogastroenterology & Motility, 22, 589-605.

Poor Diet Associated with Increased Risk of Depression in Women

The Whitehall II Study is a large, longitudinal study following the health and wellness of over 10,000 British civil servants between the ages of 35 and 80. Recruitment started in 1985 and follow-up is ongoing. Whilst the study primarily releases data on the relationship between physical health and socioeconomic status the enormous amount of data collected is often shared with and analysed by international researchers interested in other aspects of health and lifestyle. A paper published in Clinical Psychological Science reviewed the Whitehall data looking at the relationship between diet and depression. They were curious as to whether the inflammatory potential of a person’s diet had any bearing on their risk of developing the illness.

Inflammation is they way that the body responds to physical illness and injury and is also associated with lifestyle factors such as chronic stress and poor diet. The Dietary Inflammatory Index (DII) is a reliable assessment of how likely certain foods are to promote inflammation in the body. Broadly, processed foods increase inflammation while whole foods, fruits, vegetables, nuts and oily fish reduce it. A higher score on the DII is linked to higher markers of inflammation in the body.

In this analysis the researchers looked at the available dietary information and depression status of 4246 people over a period of five years. They were interested in what they have called ‘recurrent depression’ - people who had depression at the start and again at the end of this five-year period. (They did not look at whether the depression was ongoing during this period or whether it had gone in to remission at any point.) Alongside diet they looked at other health-related factors such as level of exercise, smoking status, alcohol consumption, obesity, heart disease, diabetes and stroke. 

The researchers found that women with high scores on the Dietary Inflammatory Index were significantly much more likely to develop recurrent depression, and this effect was independent of other health factors. This is similar to the results of the large Spanish 'SUN Project' that showed that healthy (anti-inflammatory) diets were linked to a reduced risk of depression in men and women. The authors comment that these results support the growing body of research in to the relationship between diet, inflammation and depression. 



Akbaraly, T. N., Kerlau, C., Wyart, M., Chevallier, N., Ndiaye, L., Schivappa, N., Hébert, J. R., Kivimäki, M. (2016). Dietary Inflammatory Index and Recurrence of Depressive Symptoms: Results From the Whitehall II Study. Clinical Psychological Science, first published on August 8, 2016 doi:10.1177/2167702616645777


The Role of Emotion Suppression in Chronic Fatigue Syndrome

Last month a report on the possible biological mechanisms underlying Chronic Fatigue Syndrome (CFS) generated a lot of interest on social media so I thought I would follow that up with a new study that discusses the psychological and emotional processes of the disorder.

This study from researchers at King’s College London looked at the relationship between emotional suppression and fatigue in CFS. Patients recruited from two specialist CFS services (and healthy controls) were required to watch a distressing film clip. Half of the group were told that they could deal with the emotions from watching the film in any way that they liked and the other half were told that they had to suppress their emotional responses. All were monitored for signs of distress by video-tape and skin conductivity.

Before watching the video participants completed a questionnaire about their beliefs about emotions. This scale is designed to uncover whether people hold unhelpful beliefs, for example that showing emotions is a sign of weakness, that it is important to keep up a brave face or that others will think less of you for expressing your true feelings. Participants also completed a measure of depression and anxiety. After watching the clip participants were asked how fatigued the felt.

The results showed that participants with CFS experienced higher rates of distress but were less likely to express them, even when they were allowed to. This study indicates that this is partly due to self-held beliefs by the CFS group that expression of emotion is unacceptable. Interestingly, all participants in the suppression condition experienced higher levels of anxiety at the end of watching the film.

The researchers also showed an important relationship between emotional suppression and fatigue. When emotions were suppressed the distress didn’t go away but showed up in the body, and this increased physiological distress was associated with higher rates of fatigue. In short: the more suppression the more fatigue.

In addition, people in the CFS group were so efficient at hiding their feelings that observers found it difficult to tell if they were suffering. In the real world this makes it harder for individuals to access support and increases the likelihood of being overwhelmed and isolated.

This paper is important for individuals and professionals dealing with CFS. It highlights the importance of addressing the beliefs about emotions as a way of relieving the symptoms of the syndrome. Psychotherapy and mindfulness-based treatments are an effective way of helping people to stop supressing their emotions and learn how to accept, process and manage them providing hope for the 250,000 people with CFS in the UK.


Rimes, K. A., Ashcroft, J., Bryan, L., & Chalder, T. (2016). Emotional Suppression in Chronic Fatigue Syndrome: Experimental Study. Health Psychology. Advance online publication.

Chronic Fatigue in Your Gut Not Your Head

In April I reported a study demonstrating that probiotic supplementation had a beneficial effect on one of the psychological symptoms of Chronic Fatigue Syndrome (CFS). In that 2009 paper patients on the treatment for eight weeks were significantly less anxious than those taking the placebo product. Published in June this year a new study builds on that observation. The researchers at Cornell University first noted the frequent comorbidity of gastro-intestinal disorders with CFS, as well as evidence of abnormal immune response in individuals with CFS as indicated by markers of inflammation in the blood. They hypothesised that, taken together, gut microbiome diversity and levels of inflammation could predict who had a diagnosis of CFS.

This study compared the samples of 39 healthy people and 49 individuals with CFS. By looking at differences in the samples the researchers were able to identify disease cases with 83% accuracy. They found that those with CFS were significantly more likely to show signs of microbial translocation, where bacteria that reside in the gut break through the gut wall and enter the blood stream. Since they should not be present in this part of the body the immune system recognises these roving bacteria as intruders and launches an immune (inflammatory) response. This inflammation is associated with many of the symptoms of illness in CFS and other infections.

Compared to the samples of healthy individuals ME patients had reduced numbers and diversity of a type of bacteria called Firmicutes¸ typically the most abundant phyla in the human gut microbiome, as well as significantly lower amounts of types associated with an anti-inflammatory affect.

In the long-running debate about what causes Chronic Fatigue Syndrome the arguments tend to fall dichotomously: it’s either psychological OR biological in nature. Some research has shown a positive effect of psychotherapy in alleviating symptoms whilst others have found improvement with microbiome modification. The likelihood is, therefore, that a combined treatment approach will yield the best results for patients, helping them to manage both the physical and psychological symptoms of this debilitating disease. 

Giloteaux, L., Goodrich, J. K., Walters, W. A., Levine, S. M., Ley, R. E. & Hanson, M. R. (2016). Reduces diversity and altered composition of the gut microbiome in individuals with myalgic encephalomeylitis/chronic fatigue syndrome. Microbiome, 4:30.

Jason, L. A., Torres-Harding, S. Friedberg, F., Corradi, K., Njoku, M. G., Donalek., J., Reynolds, N., Brown, M., Weitner, B. B., Rademaker, A. & Papernik, M. (2007). Non-pharmalogical interventions for CFS: A randomized trial. Journal of Clinical Psychology in Medical Settings, 14, 275-296.

Borody, T. J., Nowak, A & Finlayson, S. (2012). The GI mircobiome and its role in Chronic Fatigue Syndrome: A summary of bacteriotherapy. Journal of the Australasian College of Nutritional and Environmental Medicine, 31, 3-8.

Mental Health Awareness Week – Special Focus on Depression (Probiotics)

Just last week the NHS reported a study stating that there was insufficient evidence that probiotics were beneficial for healthy people. The trials analysed so far had not been well enough designed to be sure.

“Given the limitations of the studies – including the variety of probiotics examined – it is not possible to conclude with certainty that all probiotics are ineffective.

Absence of good-quality evidence is not evidence of there being no effect. Better-designed studies may yet find some benefit from taking probiotics.”

However, there is certainly some good evidence that particular probiotics do have a beneficial effect on depression, particularly where that depression is associated with cellular inflammation. Inflammation is the body’s immune response to illness or injury; the swelling around a cut or a bruise is part of this process. But inflammation also happens within and around the cell in response to other non-injury factors such as poor diet, prolonged stress or an imbalance of bacteria in the gut. Inflammatory diseases such as rheumatoid arthritis and inflammatory bowel disease are commonly associated with psychological and behavioural changes such as lack of energy or interest, loss of appetite, loss of appetite; and depression. This consistent relationship between inflammation and depression has led to the inflammation theory of depression; that is to say that for some sufferers inflammation may be contributing to the severity of their depressive symptoms.

A well-designed study of petrochemical workers published in 2015 showed that probiotic yogurt and supplements significantly improved scores of depression and anxiety. I have reported elsewhere that probiotics have been shown to alleviate the negative thoughts associated with low mood. A more recent controlled study showed that eight weeks of probiotic supplementation was associated with a significant reduction on depression scores in patients with a diagnosis of Major Depressive Disorder. It is thought that part of the mechanism underlying this effect are the by-products of the bacteria’s metabolism. When breaking down food in the gut (particularly fibre) gut bacteria produce a number of metabolites, many of them beneficial to the human body such as vitamin K and some B vitamins. They also produce short-chain fatty acids. One of these, butyric acid, in a potent anti-inflammatory. It also forms part of a neurotransmitter called GABA, which has a calming, tranquilizing effect on the brain.

There are a lot of probiotic products on the market and it can be difficult to know which is likely to be the most effective. There is very good research data supporting the anti-inflammatory properties of a highly concentrated probiotic supplement called VSL#3 in a number of different diseases. Whilst not necessarily a recommendation, this is the product that I use as well as ensuring regular consumption of fermented and high fibre foods.

Mohammadi, A. A., Jazayeri, S., Khosravi-Darani, K., Mohammadpour, N., Asemi, Z., Adab, Z., Djalali, M., Tehrai-Doost, M., Hosseini, M. & Eghtesadi, S. (2015). The effects of probiotics on mental health and hypothalamic–pituitary–adrenal axis: A randomized, double-blind, placebo-controlled trial in petrochemical workers. Nutritional Neuroscience. Published online April 16th.

Laura Steenbergen, Roberta Sellaro, Saskia van Hemert, Jos A. Bosch, and Lorenza S. Colzato. 2015. A randomized controlled trial to test the effect of multispecies probiotics on cognitive reactivity to sad mood. Brain, Behavior, and Immunity, 48, 258-264.

Akkasheh, G., Kashani-Poor, Z., Tajabadi-Ebrahimi, M., Jafari, P., Akbari, H., Taghizadeh, M., Memarzadeh, M. R., Asemi, Z., & Esmaillzadeh, A. (2016). Clinical and metabolic response to probiotic administration in patients with major depressive disorder: A randomized, double-blind, placebo-controlled trial. Nutrition, 32, 315-20.

D'Mello, C.Ronaghan, N.Zaheer, R.Dicay, M.Le, T.MacNaughton, W. K.Surrette, M. G.Swain, M. G. (2015) Probiotics Improve Inflammation-Associated Sickness Behavior by Altering Communication between the Peripheral Immune System and the Brain. Journal of Neuroscience, 35, 10821-18030.

Mariman, R.Tielen, F.Koning, F. & Nagelkerken, L. (2014). The probiotic mixture VSL#3 dampens LPS-induced chemokine expression in human dendritic cells by inhibition of STAT-1 phosphorylation. PLoS One, 9: e11567.



This information is provided for information purposes only and should not be taken as advice or instruction. This information does not replace the advice of your doctor. Please consult an appropriate health professional if you believe you are experiencing a mental or physical health concern. Speak to your GP or a trainer before making any significant changes to your exercise routine.

Mental Health Awareness Week – Special Focus on Depression (Mindfulness)

Yoga, Meditation & Mindfulness

Mindfulness meditation - the skill of paying attention without judgement – has been a feature of some religious and cultural traditions for centuries. Over the last 30 years psychology has been interested in how this ancient practice might have beneficial effects on our modern lives. Mindfulness mediation really came to public attention in 2011 when a study at Harvard University showed that eight weeks of mindfulness practice was able to reshape the brain’s structure, improving function in the areas associated with memory, empathy and stress. More recently, a study published in the journal Neural Plasticity used functional MRI to demonstrate the nature of meditation-induced brain changes and showed that meditation was able to significantly reduce the participants’ depression scores; participants who at the start of the study were identified as depressed had scores below the cut-off for diagnosis by the end of the intervention, a near 50% reduction in symptoms in eight weeks. Earlier, researchers at the University of Bologna compared the efficacy of mindfulness-based therapy to a matched psychoeducation programme. The mindfulness-based intervention yielded significantly greater improvement in depression scores.

The practice of yoga has a strong mindfulness component, requiring practitioners to focus on the position of their bodies, their breathing as well as any thoughts or emotions they become aware of during the practice. The case for yoga and meditation as a useful tool in tackling depression is strong and growing. A randomised control trial comparing yoga to walking found that yoga was more effective at improving mood (and decreasing anxiety). A recent study published in Depression and Anxiety found that yoga had a significantly beneficial effect on depression scores compared to standard treatment alone, and that it also improved overall wellbeing. In another recent trial a consistent yoga practice was associated with better outcomes and recovery from Post-Traumatic Stress Disorder and depression.

Both yoga and mindfulness/meditation have health benefits beyond a sense of calm. As well as reducing the severity of depressive symptoms they can increase levels of brain chemicals that promote the growth of new brain cells, reduce levels of stress hormones, increase concentration and reduce anxiety. Yoga also comes with the added physical advantages of increased strength, balance and flexibility, all of which are important in slowing the process of aging. Both yoga and mindfulness are practices whose benefits are accumulative, requiring regular application for the best results. As with physical exercise, it is best to start with shorter, manageable efforts and build up to a longer regular practice. When introducing my own clients to mindfulness I recommend starting with just one minute a day first thing in the morning, before they can get distracted. Mindfulness practice is also helpful before bed as it can help to ease you into a restful sleep. There are free apps, such as Headspace, and online tutorials and guided meditations that can be useful to get you started as well a number of taught courses and books. Those interested in giving it a try might find this video from Martin Boroson an easy introduction.


Hölzel, B. K., Carmody, J., Vangel, M., Congleton, C., Yerramsetti, S. M., Gard, T., & Lazar, S. W. (2011). Mindfulness practice leads to increases in regional brain gray matter density. Psychiatry Research191(1), 36–43.

Yang, C.-C., Barrós-Loscertales, A., Pinazo, D., Ventura-Campos, N., Borchardt, V., Bustamante, J.-C., … Walter, M. (2016). State and Training Effects of Mindfulness Meditation on Brain Networks Reflect Neuronal Mechanisms of Its Antidepressant Effect. Neural Plasticity2016, 9504642.    

Streeter, C. C., Whitfield, T. H., Owen, L., Rein, T., Karri, S. K., Yakhkind, A., … Jensen, J. E. (2010). Effects of Yoga Versus Walking on Mood, Anxiety, and Brain GABA Levels: A Randomized Controlled MRS Study. Journal of Alternative and Complementary Medicine16(11), 1145–1152.

de Manincor, M., Bensoussan, A., Smith, C. A., Barr, K., Schweickle, M., Donoghoe, L.-L., Bourchier, S. and Fahey, P. (2016). Individualized yoga for reducing depression and anxiey, and improving well-being: A randomized controlled trial. Depression and Anxiety. doi: 10.1002/da.22502

Rhodes, A., Spinazzola, J. & van der Kolk, B. (2016). Yoga for adult women with chronic PTSD: A long-term follow—up study. The Journal of Alternative and Complementary Medicine, 22, 189-196. doi:10.1089/acm.2014.0407.

Chiesa, A., Castagner, V., Andrisano, C., Serretti, A., Mandelli, L., Porcelli, S. & Giommi, F. (2015). Mindfulness-based cognitive therapy vs. psycho-education for patients with major depression who did not achieve remission following antidepressant treatment. Psychiatry Research, 226, 474 – 483.



This information is provided for information purposes only and should not be taken as advice or instruction. This information does not replace the advice of your doctor. Please consult an appropriate health professional if you believe you are experiencing a mental or physical health concern. Speak to your GP or a trainer before making any significant changes to your exercise routine