The Impact Of Sugar On Mental Health

April 9, 2020

When enjoying your tasty donut, the last thing on your mind your long-term mental health. However, there is plenty of evidence to suggest that you should be thinking of just that. Most of us know the harm of too much sugar on our physical health. It can cause obesity, wide-spread inflammation, and poor dental health and can lead to diabetes. However, few understand the significant impact of a high sugar diet on our mental health. In this article, we will at how a diet filled with too many sweeteners, such as sugar, honey, maple syrup, high-fructose corn syrup, and molasses can have a detrimental impact on mental well-being.

  1. Sugar and mental health: A toxic combination?

We all know how diet affects your physical health, but did you know that it can also have lasting effects on your mental health?  Regular consumption of meals high in sugar can affect your brain increasing your risk of developing mental illnesses and mood disorders like depression.

The science of sugar

Sugars are simple, soluble carbohydrates essential for cell and organ functioning. Our bodies have the ability to break complex carbohydrate molecules into simple sugars and as such, it is not necessary to take sugar in its simple form.

What happens to your neurons when you take too much sugar?

Neurons are very sensitive cells and are not well prepared for sugar level spikes. In fact, individuals with diabetes are at risk of neuronal damage. A study by researchers from the Department of Neurobiology at Huazhong University of Science and Technology in Wuhan, China, performed on diabetic rats showed that high blood glucose, a simple sugar, led to inflammation and neuronal damage and death in the brain.

  1. What is the link between sugar consumption and mental health?
    1. Inflammation

Inflammation is a natural process that helps the body protect itself from damage and also aids in the healing process. Regular consumption of refined carbohydrates and added sugars triggers inflammatory responses that can cause inflammation in the brain and lead to depression.

  1. Stress responses

After consumption of a high sugar meal, one can become hypoglycemic, a condition characterized by very low blood sugar levels. Hypoglycemia occurs when too much insulin is produced following a high sugar meal. Insulin is the hormone that regulates blood sugar. This, in turn, causes the sugar circulating in the body to drop to levels lower than normal. Hypoglycemia can trigger several stress responses including confusion, irritability, insomnia, anxiety, and depression.

High insulin levels can also cause an imbalance of hormone estrogen and progesterone. A balance of these two hormones is important in keeping us happy and calm.

  1. Obesity and depression

High consumption of refined carbohydrates and sugar is associated with excess body weight and obesity. Overweight and obese people are more likely than people with healthy weight to suffer from depression. Obesity can cause poor self-image, low self-esteem and social isolation, all known contributors to depression.

  1. High release of dopamine

Due to the powerful impact sugar has on the mesolimbic dopamine system — the brain’s reward system — sweet foods are highly desirable. Just like drugs, sugar can activate this reward system causing the release of dopamine, a chemical that controls the brain’s reward and pleasure center making you crave more sugar because it makes you feel good. Short term surges in dopamine can be pleasurable, but high concentrations can cause depression and attention deficit disorder.

  1. Increases the risk of mental illnesses

Brain-derived neurotrophic factor is a protein that promotes the survival of nerve cells and cognitive function. Low levels of this factor are associated with psychiatric and neurodegenerative disorders. A diet rich in fats and refined sugar is associated with a low brain-derived neurotrophic factor increasing the risk of psychiatric disorders and depression.

  1. Starving the Brain

When you consume excessive sugar, a lot of insulin is produced to push this sugar into cells for energy production. The resultant dip in blood sugar can alarm the body and the adrenal glands, making them work overtime.  These glands are charged with producing cortisol (which ultimately promotes insulin resistance or the lack of cellular response to insulin) and fight or flight chemicals that can get your heart racing, and rev up anxiety.  This will make you consume more sugar, which will inflict more suffering on your brain and potentially even putting you at risk for Alzheimer’s dementia, down the line.

  1. Disrupting Hormones

When cortisol is in demand for its blood-sugar balancing effects, or because of other psychological or bodily stressors, the body “shunts” the production of progesterone to support further cortisol output. This makes evolutionary sense because if we are under stressful circumstances, preserving progesterone, our “pro-gestational” reproductive hormone, becomes secondary. Insulin can also stimulate the production of DHEA and sex hormones including testosterone, which can drive the pathology we see with the polycystic ovarian syndrome. Sugars have also been demonstrated to reduce liver production of sex hormone-binding globulin, freeing up testosterone and estrogen in ways that may promote symptoms of estrogen dominance including premenstrual moodiness and irritability.

  1. What effects does sugar have on mental conditions?
  • Depression & Schizophrenia: The rapid fluctuation of blood sugar can worsen mood disorders. Research has shown that high sugar can lead to an increased risk of depression and even worse outcomes in patients with schizophrenia. Interestingly, countries with high sugar intake also have correspondingly high rates of depression.
  • Anxiety: Although sugar does not increase your risk of anxiety, it can worsen your symptoms and weaken the body’s ability to respond to stress. By minimizing sugar, you can lessen the severity of anxiety symptoms, improve mood and improve the body’s ability to cope with stress.
  • Addiction: There’s a growing amount of evidence of sugar’s addictive potential. Drugs and sugar both flood the brain with the “feel-good” chemical dopamine. In studies, rats have been shown to prefer sugar-water over cocaine. And they also display classic signs of addiction, including tolerance and withdrawal when the sugary products are removed.
  • Learning & Memory: Sugar can affect how and how much we learn and remember. After 6 weeks of drinking a fructose solution, much like soda, rats “forgot” how to find their way out of a maze. Insulin resistance from a high sugar diet can damage communications between brain cells involved in learning and memory formation.
  1. How do we avoid the pitfalls of sugar?

How easy is it to avoid sugar? We are bombarded with advertisements for convenience foods and tasty treats. But even seemingly healthful foods can have high levels of hidden sugars.

Breakfast cereals, sauces (including ketchup and pasta sauce), flavored milk, wholemeal bread, and many products labeled as low fat, such as fruit yogurts are such culprits.

Smoothies and fruit juices for children were in the spotlight last year in an article published in BMJ Open. It was noted that over 40 percent of products surveyed contained at least 19 grams of sugar – a child’s entire maximum daily amount of free sugars. High sugar levels have also been reported in baby and toddler food products.

Always remember to check the nutritional labels. While the list of ingredients might claim no added sugars, the nutrition facts panel will show the number of carbohydrates and sugars in the product.

What is the evidence that cutting down on sugars will have health benefits? Studies have shown that individuals who experience depression benefit from eating a healthful diet.

The next time a low mood threatens to spoil your day, remember where sugar is hidden in plain sight and look to other tasty treats to lift you out of the doldrums.

  1. Do we need to limit our sugar?

Our bodies and minds were not designed to take in such immense amounts of sugar that have become the norm in American society. Thanks to ongoing research, we are more and more aware of the intricate link between diet and wellness. It has a significant role to play in both physical and mental health. Grappling with mental illness is difficult enough without having additional obstacles in your way. Make sure sugar isn’t making your situation harder than it needs to be.

Additionally, choosing foods that are low in refined ingredients, such as sugar, but high in omega-3 fatty acids, vitamins, and minerals can relieve the symptoms of depression. Scientists think that the power of these foods lies in promoting good brain health.


  1. Everhealth (2012): The Impact of Sugar on Mental Health. Retrieved from
  1. Medical News Today (2017): Sugar and mental health: A toxic combination? Retrieved from
  1. Kelly Brogan:3 Ways Sugar Is Ruining Your Mental Health. Retrieved from
  1. Neuroscience (2017): Sugar is Not So Sweet For Mental Health. Retrieved from
  1. Standard Media (2018): The link between sugar and mental illnesses. Retrieved from
  1. NCBI (2014): Nod-like receptor protein 1 inflammasome mediates neuron injury under high glucose. Retrieved from

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