Diet quality and mental health – is this the missing link?

Blog 21st Feb 2016

The Prime Minister has called for the nation to focus on mental health after a review revealed inadequate, underfunded care, leading to “thousands of tragic and unnecessary deaths”.

It was revealed that a staggering 1 in 4 people experience mental health problems each year, and 75% receive no help.

Mental health problems are classified as either neurotic or psychotic, and whilst most people at some point in their lives experience strong emotions such as stress and grief, it is when symptoms persist way beyond the normal reactions to daily events and interfere with a person’s ability to function normally, that they may be considered to have a significant psychological or mental illness.

Panorama was one of several programs aired on national TV last week, as part of a two week focus on mental health.  It referred to the rising demand on mental health resources as a crisis, exacerbated by recent funding cuts reducing the availability of hospital beds. Ward managers regularly face an impossible task involving complex management and juggling priorities: identifying suicidal risk while leaving the less ill in the community, potentially missing out on a level of therapeutic care they may need.

The Not So Secret Life of the Manic Depressive: 10 years on’ was another such program that followed up on a previous one about Stephen Fry’s experience with Bipolar Disorder. Several patients featured, all struggling with their diagnoses and drug treatment side effects. Sadly, diet and the role of nutrient sufficiency were not even discussed.

We know that genetics play a part in conditions like bipolar disorder, (see also Dr Tim Cantopher talking about Bipolar Disorder:  but twin studies have shown that inheriting a genetic predisposition does not guarantee development of this or many other disorders.1  Human genes are malleable, their ‘expression’ is continually subject to environmental influences like diet. Whilst psychological risk factors like a major stress, suffering abuse or bereavement can trigger the development of mental illness, other environmental factors – including diet – can play a part both causatively and as mediator.1

Drugs may manage symptoms, but rarely address root causes. Dietary nutrients on the other hand have been shown not only to ameliorate symptoms, but deficiency of some nutrients – crucially – has been shown to correlate with increased risk of developing mental health disorders.2 The B vitamins are a good example, Folate (B9) deficiency is common among patients with mood disorders and correlates with illness severity. B12 deficiency is observed in a third of depressed patients, and deficiency can cause depression, irritability, agitation, psychosis, and obsessive symptoms. . Alcohol abuse severely depletes B vitamins and common drugs like Omeprazole interfere with B12 absorption. Low B12 levels with elevated homocysteine increase the risk of cognitive decline and Alzheimer’s disease and are linked to a 5-fold increase in the rate of brain atrophy.2

In terms of clinical practice, the difficulty has been in getting funding for the necessary trials to get such dietary risk factors validated and confirmed, so that they can be recognised as the preventative measures they represent.1

Whilst the time lag between the evidence base and clinical practice is frustrating, such trials are at last being published and the evidence they bring prompts me to ask the question: is the existing model for diagnosing mental health disorders based on thoughts, behaviours and feelings, sidestepping an obvious more biological parameter worth measuring, that of nutrient sufficiency?

The western diet may be replete in terms of caloric energy but imbalances or deficiencies in certain key, essential nutrients are quite common.  Omega-3 fatty acids are another example, their deficiency has not only been linked with many chronic diseases, but now case-controlled studies have consistently observed low EPA and/or DHA omega-3 levels in patients with major depressive disorder, bipolar disorder, schizophrenia, and attention deficit hyperactivity disorder.3

So just for starters, why are we not measuring the fatty acid status of any individual presenting with mental health symptoms? The same study showed corrective treatment with fish oil-based products resulted in improvements in psychiatric symptoms – without notable side effects.  A recent study involving 330 depressed patients, (randomised with 660 healthy controls) looked at 2 different dietary patterns and found that those in the 2 ‘unhealthy diet’ quartiles had a significant association with depression.4

Earlier generations certainly ate more oily fish and grass-fed meat, so naturally consumed a healthier ratio of omega-3 to omega-6 fatty acids, but nowhere near our ancestors’ (1:1) on whose shore-based diets abundant with seafood, we evolved.  Today, our protein comes predominantly from grain-fed livestock, and our manufactured foods use seed and grain-based oils, resulting in higher intakes of the more pro-inflammatory omega-6, with today’s average diet showing a ratio of 1:17 (n-3 : n-6).

Dietary nutrients, including omega-3 and omega-6 fatty acids influence gene expression. Omega-3 fatty acids produce anti-inflammatory effects across many physiological parameters, whereas in contrast, a diet with an excess of omega-6 fatty acids leads to increased low-density lipoprotein oxidation, platelet aggregation, alterations in the cell membrane structure and a pro-inflammatory, prothrombotic state with increased risk of mood disorders.5

The rise in mental health disorders correlates perfectly with this change in modern eating habits, and several decades reducing fat consumption has not helped. Coupled with our increased consumption of sugars and refined carbohydrates and the alterations in gut microflora brought about by lower intakes of vegetables and widespread use of antibiotics in the food chain, all of which impact mental health, we have laid the perfect foundation stones for the mental health crisis currently challenging healthcare. Patients with depression, alcohol abuse, eating disorders, obsessive-compulsive disorder or schizophrenia often demonstrate inadequate diets2 but how often is this a point of investigation or factored in to a treatment plan?

So why do we overlook the power of the simple dietary nutrient? The cynic might suggest that the system still generates treatment models that are driven by pharmaceutical profits. Certainly in the world of nutrition, we observe daily the therapeutic effect of dietary nutrients, that may not have the immediacy of drugs but none-the-less can be effective given time, and crucially without generating side-effects.  However, nutrition as therapy still has to fight an uphill battle to be recognised let alone admitted as adjunct therapy to mainstream medicine. And that is where I believe it should be, with nutritional therapists working in tandem in the field of chronic, lifestyle related ill-health, where drugs often perform little better than placebo, and GPs lack the training or the time to educate patients.

It should be noted there are many other dietary nutrients that are also showing good effects with symptoms of mental health, and urine organic acid testing can reveal an individual’s nutrient sufficiency.  Some say we are what we eat, I say, we are what we manage to absorb, and that depends on the health of our gut.

Certain gene dispositions and different lifestyles may equate to higher needs of certain nutrients, but the website MIND for better mental health has an excellent page on ‘Food and Mood’ with a superb 3 minute film ‘How to manage your mood with food – 8 tips’. See the link:-

Please note dietary supplements should only be used under the guidance of a suitably qualified health professional, due to the potential for drug interactions that may reduce the efficacy of certain medications.



1 Schmidt CW (2007) Environmental Connections: A Deeper Look into Mental Illness. Environmental Health Perspectives 115(8): A404 – A410

2 Ramsey D & Muskin PR (2013) Vitamin Deficiencies and mental health: How are they linked? Current Psychiatry 12(1)

3 Messamore E & McNamara RK (2016) Detection and treatment of omega-3 fatty acid deficiency in psychiatric practice: Rationale and implementation. Lipids in Health & Disease 15(1):25

4 Khosravi M et al., (2015) Healthy and Unhealthy Dietary Patterns Are Related to Depression: A Case-Control Study. Psychiatry Investigation 12(4):434-442

5 Simopoulos AP (2006) Evolutionary aspects of diet, the omega-6/omega-3 ratio and genetic variation: nutritional implications for chronic diseases. Biomedicine & Pharmacotherapy 60(9):502-7

6 Chih-chiang Chiu et al., (2008) The Use of Omega-3 Fatty Acids in Treatment of Depression. Online:


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