Unhappy Tummy: The Link Between Diet And Mood

There is a growing recognition of the gut-brain connection: experts suggest that our gut may function like a second brain. The gut appears to have a significant influence on thinking, mood and behaviour.

Similarly, a number of studies have shown that processed foods with their toxic cocktail of mind altering ingredients can lead to behavioural problems. Our dietary choices may be behind the increase in violent behaviour among teenagers.

It is widely accepted that a nutritionally deficient diet greatly contributes to ill health. Less accepted is how diet impacts behaviour. Therefore I was pleased to read a very well researched article by Sylvia Onusic, PhD examining the possible relationship between dietary choices and the recent increase in violent behaviour in American teenagers. [1][2]

Sylvia cites many studies showing how processed foods with their toxic cocktail of mind altering excitotoxins (like MSG, HFCS, aspartame, colourings, etc) are clearly linked to behavioural problems.

These same issues are present in most countries; however in the USA the tendency towards a more processed, nutrient-poor diet is especially pronounced.

Nutritional Deficiency and Behaviour Link

Let’s look at some specific examples from studies that I believe are well researched and among the most credible available:


Related Symptoms

Vitamins A, D, K, B1, B3, B6, B12; Folate, Iodine, Potassium, Iron, Magnesium, Zinc, Chromium and Manganese

Lack of these nutrients can contribute to mental instability and violent behaviour[3][4]

Vitamin B12

Vitamin B12 deficiency has a well-known correlation with mental disorders, including irrational anger. A higher incidence of low B12 is found in mental patients than in the general population[5]. Deficiencies can cause poor concentration, depression and severe agitation and even hallucinations.

Pantothenic acid 
(Vitamin B5) 

Diets deficient in pantothenic acid (vitamin B5) are known to promote moody behaviours like being very easily upset, irritable, quarrelsome, sullen and depressed[6].

Vitamin B3

Symptoms of pellagra (Vitamin B3 deficiency) include anxiety, hyperactivity, depression, fatigue, headache, insomnia, and hallucinations.[7]


Zinc deficiency is linked with angry, aggressive and hostile behaviours which can lead to violence[8].


Folate deficiency is linked with a range of mental symptoms, especially depression and cognitive decline in epileptic, neurological, psychiatric, geriatric, and psychogeriatric populations[9].[10] Folate is required for remethylation of homocysteine and hence plays a role in mental health.

Vitamin D3

Low levels of Vitamin D3 (cholecalciferol) are associated with increased risk of depression and panic[11][12]. Natural sun exposure can have a similar effect to the benefits of antidepressants, without the downsides.


Omega-3 deficiency is shown to compromises the function of both serotonin and dopamine which is associated with depression and other mood disorders[13]. Omega-3 deficiency may also impair normal blood flow to the brain possibly leading to depression.

 Additionally, there are also studies shown that: 

  1. Peaceful, harmonious behaviour among well-nourished humans and cats degenerated into disharmonious behaviour patterns with the change to foods devitalized by heat and processing[14].
  2. Unfermented soy[15][16] and refined sugars are associated with antisocial behaviour and learning difficulties[17], hyperactivity, juvenile delinquency and psychiatric-related hypoglycaemia.
  3. Gluten intolerance[18], leaky gut[19], and niacin deficiency[20] have been linked with psychological disorders especially schizophrenia.

Gut-Brain Connection

All of these examples illustrate the growing recognition of the gut-brain connection: experts suggest that our gut may function like a second brain. The gut appears to have a significant influence on our thinking, mood and behaviour. Remember those butterflies in your tummy before a job interview or a first date? That’s your gut-brain working.

Researchers are increasingly finding that depression and a number of behavioural problems appear to stem from nutritional deficiencies and/or an imbalance of bacteria in the gut.

In fact, the greatest concentration of serotonin, which is involved in mood control, depression and aggression, is found in the intestines, not in the brain!

All this evidence is leading Dr. Onusic and other experts to conclude that:  “We can blame violence on the media and on the breakdown of the home, but the fact is that a large number of Americans, living mostly on devitalized processed food, are suffering from malnutrition. In many cases, this means their brains are starving.”

So we are overweight but undernourished, and increasingly stressed, depressed and violent. How depressing!

So what can we do? Vote with your fork!

Or, in the words of Dr Onusic: “Modern commentators are blind to the solution, a solution that is in plain sight: clearly defining good nutrition and putting it back into the mouths of our children, starting before they are even conceived...because food is information and that information directly affects your emotions, nervous system, brain and behaviour.”

Please share what you think.

Caramia Hartley



[3] Eby GA, Eby KL. Rapid recovery from major depression using magnesium treatment. Med Hypotheses. 2006; 67(2):362-70.
[4] Sathyanarayana Rao, T et al. Understanding Nutrition, Depression and Mental Illness. Indian J Psychiatry. 2008 Apr-Jun; 50(2): 77–82.doi: 10.4103/0019-5545.42391. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2738337/
[5] Ssonko, M. Low Serum B12 Levels among Psychiatric Patients admitted to Butabika Mental Hospital in Uganda. BMC Res Notes. 2014; 7: 90. Published online 2014 Feb 17. doi: 10.1186/1756-0500-7-90. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3931663/
[6] Pearson, O. Symptoms of Pantothenic Acid Deficiency. Oct 30, 2017. https://www.livestrong.com/article/342433-vitamin-b-complex-deficiency-symptoms/
[7] Niacin Deficiency. https://www.webmd.com/diet/niacin-deficiency-symptoms-and-treatments#1
[8] Sawada, T. and Yokoi, K. Effect of Zinc Supplementation on Mood States in Young Women. Eur J Clin Nutr. 2010 Mar;64(3):331-3. doi: 10.1038/ejcn.2009.158. Epub 2010 Jan 20. https://www.ncbi.nlm.nih.gov/pubmed/20087376
[9] 3. Bottiglieri T, Crellin R, Reynolds EH. Folate and neuropsychiatry. In: Bailey LB, editor. Folate in health and disease. New York: Marcel Dekker; 1995. pp. 435–462.
[10] Reynolds EH. Benefits and risks of folic acid to the nervous system. J Neurol Neurosurg Psychiatry. 2002;72:567–571. [PMC free article] [PubMed]
[11] Jorde et al. Effects of Vitamin D Supplementation on Symptoms of Depression in Overweight and Obese subjects: Randomized Double Blind Trial. J Intern Med. 2008 Dec;264(6):599-609. doi: 10.1111/j.1365-2796.2008.02008.x. Epub 2008 Sep 10. https://www.ncbi.nlm.nih.gov/pubmed/18793245
[12] Kiaergaard, M et al. Effects of Vitamin D Supplementation on depression scores in people with low levels of serum 25-hydroxy Vitamin D: nestled case-control study and randomised clinical trial. Br J Psychiatry. 2012 Nov;201(5):360-8. doi: 10.1192/bjp.bp.111.104349. Epub 2012 Jul 12 https://www.ncbi.nlm.nih.gov/pubmed/22790678
[13] Patrick, R. and Ames, B. Vitamin D and Omega 3 Fatty Acids control Serotonin Synthesis and Action Part 2: Relevance for ADHD, Bipolar Disorder, Schizophrenia and Impulsive Behaviour. FASEB J. 2015 Jun;29(6):2207-22. doi: 10.1096/fj.14-268342. Epub 2015 Feb 24. https://www.ncbi.nlm.nih.gov/pubmed/25713056
[14] 7. Pottenger FM, Jr. Edited by Pottenger E & Pottenger, RT, Jr. Pottenger’s Cats. A Study in Nutrition, La Mesa: Price-Pottenger Nutrition Foundation. La Mesa, 1983.
[15] Westmark, C. Soy Infant Formulas May be Associated with Autistic Behaviours. Autism Open Access. 2013 Nov 18; 3: 20727.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4229689/
[16] Soy Milk Linked to ADHD. Oct 2002. https://www.nutraingredients.com/Article/2002/10/07/Soy-milk-linked-to-ADHD
[17] Schmidt, E. This is your brain on sugar: UCLA Study shows high-fructose diet sabotages learning, memory. May 2012. http://newsroom.ucla.edu/releases/this-is-your-brain-on-sugar-ucla-233992
[18] 60 Years of Research Links Gluten Intolerance to Schizophrenia. June 22, 2013. https://articles.mercola.com/sites/articles/archive/2013/06/22/gluten-grains-cause-schizophrenia.aspx
[19] Julio-Pieper, M et al. Review Article: Intestinal Barrier Dysfunction and Central Nervous System Disorders: A Controversial Association. Aliment Pharmacol Ther. 2014 Nov;40(10):1187-201. doi: 10.1111/apt.12950. Epub 2014 Sep 28. https://www.ncbi.nlm.nih.gov/pubmed/25262969
[20] Xu XJ1, Jiang GS. Niacin Respondent Sub-set of Schizophrenia – a therapeutic review. Eur Rev Med Pharmacol Sci. 2015;19(6):988-97.https://www.ncbi.nlm.nih.gov/pubmed/25855923

2 Responses

Got my rather large order today, and decided on more of a half dose for most of them,

some every other day, just a booster really at least until I finish the Cardio-K because

I dont like over-do things either since theres really no problem, but some may disagree. :)

But my thoughts brought me back to this blog.

The study deals with deficiency, I wondered if over doing things would have the same effect?. likely I think, the brain is just another organ really.

(omg, that sounds depressing, good thing I got some Neuro-Natural) :)

I know some vitamins shouldnt be taken in excess, A comes to mind.

I guess one of the reasons I chose your product is I like your philosophy of Balance

not too little, not too much and a little bit of everything.

Some stuff I see in the stores, mega doses with a warning, and Health Canada approves it, wow.

Anyways thanks, Canada Customs not so much. (little money grubbing peepers)

ps, thanks for sealed bottles and the plastic wrap too, they didnt touch that.

Dave October 20 2013

Hello Dave

Thank you for your continued loyalty. We appreciate that very much.

Yes balance is key isn’t it? But I think just as, if not more important, is knowing what’s right for you. A little more of X and a little less of Y may be spot on for you, but damaging for someone else.

So I guess my personal philosophy would be ‘Know thyself’ first, then tailor everything around that.

Thanks again and kindly

Xtend-Life Expert October 20 2013

Leave a comment (all fields required)