Sugar Overconsumption and Mental Health: The Obvious Connection

November 1, 2023 8 mins to read

Sugar is sweet, addicting and a comforting temporary malady for our dopamine fueled brains…we all know too much is bad for us, but it’s often so addicting it’s hard to say no. Did you know you product roughly the same amount of neurotransmitters in your gut, as in your brain? And that 70-80% of your immune system is housed in your gut (digestive tract)? With that in mind, it’s easy to see how overconsumption of all those added sugars is a recipe for poor mental health (and a crippled immune system).

Kates Story

We’ll call her Kate (not real name), a 55-year-old woman who faced a mountain of challenges, from depression and anxiety to PTSD. Life was an emotional roller coaster for her, and binge eating led to obesity. Despite years of struggle, there was no light at the end of the tunnel. I can’t really blame her for having a sweet tooth.

The Turning Point

Everything changed when her psychologist encourages her to gradually transition into a sugar-free life. After just two weeks without sugar: Kate was down four pounds, less irritable, and her sugar cravings vanished. Her energy was steady and without those post-meal crashes. Even her sleep improved allot – no more nightmares. But whenever she went back to sugar, those old, unwanted feelings crept back in, along with bloating and anxiety. A frustrating situation to say the least to say the least! And this may very well be the case for you as well (explained more further down).

Sugar & Depression Tango?

Jessica Russo, a clinical psychologist from Philadelphia, treated Kate. Russo pointed out that sugar was likely a big player in Kate’s depression. This isn’t just one isolated case; there’s a truckload of research backing this up.

Sugar and Mental Health: The Research Speaks

  • Studies have linked excessive added sugar consumption to various mental disorders. High sugar intake is a slippery slope to anxiety, stress & hyperactivity.
  • Clinical psychologist Laurel Basbas has seen too many such cases in her professional practice.
  • A study in 2023 involving over 16,000 American adults, found higher sugar intake significantly increased the chances of depressive symptoms.
  • Sugary drinks are major culprits. A single soda can pack a whopping 40 grams (roughly 8tsp+) of sugar. Research has shown that those who down more sugar-sweetened beverages have a significantly higher risk of depression. So in the short term it might perk you up, but long term it can contribute to or worsen depression!

Why Does Sugar Degrade Mental Health?

1. Sugar Zaps Essential Brain Nutrients

Sugar can mess with your gut microbiom – the delicate flora (bacteria) in your GIT (Gastro-Intesintal Tract), leading to a deficiency of brain and nerve nutrients. Here’s what clinical nutritionist and naturopath Sheridan Genrich had to say:

  • B vitamins, produced by the gut microbiome, are super important for the brain, and neurotransmitter production in the gut and brain.
  • Low levels of essential vitamins like b-vitamins can lead to foggy thinking, even paranoia.
  • These vitamins also help make neurotransmitters, the brain’s messaging service.
  • The gut also produces serotonin (The “feel good” neurotransmitter) and melatonin (we need that for sleep).
  • A high-sugar diet can also drop levels of brain-derived neurotrophic factor (BDNF), which keeps your brain cells happy and healthy – important because most brain cells to not regenerate like other cells in the body – once they die it’s hard to replace them!

2. Sugar Invites Inflammation

Sugar can lead to inflammation, a driving factor behind a wide range of diseases, including mental disorders. Here’s a few ways inflammation negatively impacts mental health:

  • Inflammatory markers in your bloodstream can mess with your emotions, potentially trigger anxiety or depressive symptoms.
  • Added sugar can further disrupt metabolic, inflammatory, and neurobiological (brain) processes, leading to even more inflammation.
  • Sugar can degrade your gut lining, part of your gut’s immune system which is responsible for protecting it from stomach acid and pathogens. Gut permeability aka “leaky gut” can permit unwanted substances to sneak into your bloodstream and cause inflammation, which can contribute to many issues such as autoimmune conditions; where your body attacks it’s own tissue.

3. Sugar and Brain Health

High sugar levels can harm brain blood vessels, through the following ways (not an exhaustive list):

  1. Insulin resistance making it difficult to get energy into brain cells, which is one reason why you’ll hear Dementia or Alzheimer’s referred to as “Type 3 Diabetes”. It can also contribute to memory issues, poor overall cognitive performance, anxiety and depression.
  2. Reducing oxygen-rich blood flow and leading to cell death – aka, brain atrophy.
  3. Messing up dopamine secretion, disrupting the brain’s reward system and leading to emotional dysregulation and issues.
  4. Sugar also produces reactive oxygen species, causing cellular damage and inflammation.
  5. Excessive sugar promotes advanced glycation end products, affecting neuron generation and leading to depression and cognitive decline.


Sugar is moderation is fine and a few teaspoons of natural sugar can be part of a healthy diet. Heck even some candy or ice cream once in a while is unlikely to put your health at risk (assuming you don’t have diabetes or any other pre-existing health issues that may put you more at risk.) But the reality is the American and Canadian diet, often has a whole lot of simple carbs, and added sugars, which long term is a recipe for insulin resistance. And as we’ve seen in this article, can also affect mental health in a variety of ways, contributing to things like anxiety, depression, poor cognitive performance and worse. Let’s not even get into how sugar creates free radicals, mercenary cells, that without adequate antioxidant intake could become dangerous or even cancerous cells! So maybe re-think your sugar, and balance your diet, opting for limited amounts of more natural sugars. You can eat a piece of pie or some cookies once and a while, just don’t make it a regular thing! In all things…Moderation is always key!

With a Nutrition Professional!

Whether you have mental health issues like anxiety, depression or even ADHD. As an integrative nutrition student in college to become a Nutritional Counselor/Consultant and Holistic Nutritionist (in BC, Canada), I have authored several nutritional guides and video courses for conditions like ADHD, and I’m confident I can help you find ways to naturally transform your health and life! Click Book Now on my website menu or Book a Nutritional Consultation (clickable link) to set up an intake session as my patient.


  1. Association Between Sugar and Mental Health Disorders
    • Westover AN, Marangell LB. “A cross-national relationship between sugar consumption and major depression?” Depression and Anxiety. 2002;16(3):118-120.
    • Knüppel A, Shipley MJ, Llewellyn CH, Brunner EJ. “Sugar intake from sweet food and beverages, common mental disorder and depression: prospective findings from the Whitehall II study.” Scientific Reports. 2017;7(1):6287.
  2. Impact of High Sugar Intake on Depression and ADHD
    • Marmorstein NR, Iacono WG, Legrand L. “Obesity and depression in adolescence and beyond: Reciprocal risks.” International Journal of Obesity. 2014;38(7):906-911.
    • Wolraich ML, Wilson DB, White JW. “The effect of sugar on behavior or cognition in children: a meta-analysis.” JAMA. 1995;274(20):1617-1621.
    • Kim Y, Chang H. “Correlation between attention deficit hyperactivity disorder and sugar consumption, quality of diet, and dietary behavior in school children.” Nutrition Research and Practice. 2011;5(3):236-245.
  3. Sugar Intake and Brain Health
    • Beilharz JE, Maniam J, Morris MJ. “Diet-induced cognitive deficits: The role of fat and sugar, potential mechanisms and nutritional interventions.” Nutrients. 2015;7(8):6719-6738.
    • Gomez-Pinilla F. “Brain foods: the effects of nutrients on brain function.” Nature Reviews Neuroscience. 2008;9(7):568-578.
  4. Sugar and Inflammation
    • Della Corte KW, Perrar I, Penczynski KJ, et al. “Effect of dietary sugar intake on biomarkers of subclinical inflammation: a systematic review and meta-analysis of intervention studies.” Nutrients. 2018;10(5):606.
    • Shivappa N, Steck SE, Hurley TG, Hussey JR, Hébert JR. “Designing and developing a literature-derived, population-based dietary inflammatory index.” Public Health Nutrition. 2014;17(8):1689-1696.
  5. Sugar, Insulin Resistance, and Mental Health
    • McIntyre RS, Soczynska JK, Konarski JZ, et al. “Should Depressive Syndromes Be Reclassified as ‘Metabolic Syndrome Type II’?” Annals of Clinical Psychiatry. 2007;19(4):257-264.
    • Kahl KG, Schweiger U, Correll C, Müller C, Busch ML, Bauer M, Schwarz P. “Depression, anxiety disorders, and metabolic syndrome in a population at risk for type 2 diabetes mellitus.” Brain and Behavior. 2015;5(3):e00306.
  6. Sugar and Advanced Glycation End Products (AGEs)
    • Thornalley PJ. “Glycation in diabetic neuropathy: characteristics, consequences, causes, and therapeutic options.” International Review of Neurobiology. 2002;50:37-57.
    • Vlassara H, Uribarri J. “Advanced glycation end products (AGE) and diabetes: cause, effect, or both?” Current Diabetes Reports. 2014;14(1):453.

These studies provide a scientific basis for understanding the relationship between sugar intake and various mental health conditions, as well as the impact of sugar on brain health and systemic inflammation.

Leave a comment

Your email address will not be published. Required fields are marked *