The Impact Of Sugar On Mental Health

Too much sugar harms mental health. It triggers inflammation in the brain. It crashes blood sugar into stress responses such as anxiety and irritability. And it overdrives the dopamine reward system. A diet high in refined sugar is linked to depression and a higher risk of psychiatric disorders.

When you are enjoying a tasty donut, the last thing on your mind is your long-term mental health. Yet there is plenty of evidence to suggest you should be thinking of just that. Most of us know the harm too much sugar does to the body. It can cause obesity, widespread inflammation and poor dental health, and it can lead to diabetes. Few people understand the significant impact of a high-sugar diet on mental health. In this article, we look at how too many sweeteners can harm mental well-being. Those sweeteners include sugar, honey, maple syrup, high-fructose corn syrup and molasses.

1. Sugar and mental health: A toxic combination?

We all know how diet affects physical health. But did you know it can also have lasting effects on your mental health? Eating meals high in sugar on a regular basis can affect your brain. That raises your risk of mental illnesses and mood disorders like depression.

The science of sugar

Sugars are simple, soluble carbohydrates. Cells and organs need them to work. But our bodies can break complex carbohydrate molecules down into simple sugars. So it is not necessary to eat 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 spikes. In fact, people with diabetes are at risk of neuronal damage. Researchers from the Department of Neurobiology at Huazhong University of Science and Technology in Wuhan, China, ran a study on diabetic rats. It showed that high blood glucose, a simple sugar, led to inflammation and to neuronal damage and death in the brain.

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

Inflammation is a natural process. It helps the body protect itself from damage, and it aids healing. But eating refined carbohydrates and added sugars on a regular basis triggers inflammatory responses. These can cause inflammation in the brain and lead to depression.

2. Stress responses

After a high-sugar meal, one can become hypoglycemic. That means blood sugar levels are very low. Hypoglycemia occurs when the body makes too much insulin after a high-sugar meal. Insulin is the hormone that controls blood sugar. Too much of it causes the sugar in the blood to drop below normal. Hypoglycemia can trigger several stress responses, including confusion, irritability, insomnia, anxiety and depression.

High insulin levels can also throw off the balance of the hormones estrogen and progesterone. A balance of these two hormones is important in keeping us happy and calm.

3. Obesity and depression

Eating large amounts of refined carbohydrates and sugar is associated with extra body weight and obesity. People who are overweight or obese are more likely to suffer from depression than people at a healthy weight. Obesity can cause poor self-image, low self-esteem and social isolation. All are known contributors to depression.

4. High release of dopamine

Sugar has a powerful impact on the mesolimbic dopamine system, the brain’s reward system. Due to that impact, sweet foods are highly desirable. Just like drugs, sugar can switch on this reward system and release dopamine. Dopamine is a chemical that controls the brain’s reward and pleasure center. It makes you crave more sugar because it makes you feel good. Short bursts of dopamine can be pleasant. But high levels can cause depression and attention deficit disorder.

5. Increases the risk of mental illnesses

Brain-derived neurotrophic factor is a protein. It helps nerve cells survive and supports cognitive function (thinking). Low levels of it are associated with psychiatric and neurodegenerative disorders. A diet rich in fats and refined sugar is associated with low levels of this protein. That raises the risk of psychiatric disorders and depression.

6. Starving the Brain

When you eat too much sugar, the body makes a lot of insulin to push that sugar into cells for energy. The dip in blood sugar that follows can alarm the body and the adrenal glands, making them work overtime. These glands make cortisol. Cortisol ultimately promotes insulin resistance, or the lack of cellular response to insulin. The glands also make fight-or-flight chemicals that can get your heart racing and rev up anxiety.  This will make you eat more sugar. More sugar inflicts more suffering on your brain. It could potentially even put you at risk for Alzheimer’s dementia down the line.

7. Disrupting Hormones

Sometimes the body needs cortisol to balance blood sugar, or because of other psychological or bodily stress. At those times, the body “shunts” the production of progesterone to make more cortisol. This makes evolutionary sense. That is because under stress, saving progesterone, our “pro-gestational” reproductive hormone, comes second. Insulin can also boost the production of DHEA and sex hormones, including testosterone. That can drive the pathology we see with the polycystic ovarian syndrome. Sugars have also been shown to lower the amount of sex hormone-binding globulin the liver makes. This protein normally holds on to sex hormones. With less of it, more testosterone and estrogen are set free. That may promote symptoms of estrogen dominance, such as premenstrual moodiness and irritability.

3. What effects does sugar have on mental conditions?

• Depression & Schizophrenia: Fast swings in blood sugar can worsen mood disorders. Research has shown that high sugar can lead to a higher risk of depression. It can also lead to even worse outcomes in patients with schizophrenia. Interestingly, countries with high sugar intake also have high rates of depression.
• Anxiety: Sugar does not increase your risk of anxiety. But it can worsen your symptoms and weaken the body’s ability to respond to stress. Cutting back on sugar can lessen the severity of anxiety symptoms, improve mood and improve the body’s ability to cope with stress.
• Addiction: There is 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. They also show 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. Rats drank a fructose solution, much like soda, for 6 weeks. After that, they “forgot” how to find their way out of a maze. Insulin resistance from a high-sugar diet can damage communication between the brain cells involved in learning and memory formation.

4. How do we avoid the pitfalls of sugar?

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

Breakfast cereals, sauces (including ketchup and pasta sauce), flavored milk, whole wheat bread, and many products labeled 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 noted that over 40 percent of the products surveyed had at least 19 grams of sugar. That is a child’s entire maximum daily amount of free sugars. High sugar levels have also been reported in baby and toddler food products.

Always check the nutrition labels. The list of ingredients might claim no added sugars. But the nutrition facts panel will show the amount of carbohydrates and sugars in the product.

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

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

5. Do we need to limit our sugar?

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

Also, some foods can relieve the symptoms of depression. These foods are low in refined ingredients, such as sugar. And they are high in omega-3 fatty acids, vitamins and minerals. Scientists think the power of these foods lies in promoting good brain health.

Frequently asked questions

Can quitting sugar cure depression?

Cutting sugar takes away a driver of depression. A high-sugar diet inflames the brain. It crashes blood sugar into stress responses. And it overdrives the dopamine reward system. Each of those is tied to low mood. People who experience depression benefit from a healthful diet. Foods low in refined ingredients such as sugar, but high in omega-3 fatty acids, vitamins and minerals, can relieve its symptoms.

What are the 5 signs you’re eating too much sugar?

Watch what happens after a sugary meal. Too much insulin can drop blood sugar below normal. That crash triggers confusion, irritability, insomnia, anxiety and depression. Constant cravings are another sign. That is because sugar releases dopamine in the brain’s reward system and makes you want more. A racing heart and revved-up anxiety come from the adrenal glands working overtime to answer each dip.

What happens when you cut out sugar?

Anxiety symptoms get less severe, mood improves and your body copes with stress better. You also step off a cycle. In that cycle, each sugar load brings an insulin surge, a blood-sugar dip and a cortisol response that sends you back for more. Read labels while you do it. Breakfast cereals, sauces, flavored milk and low-fat fruit yogurts hide sugar in plain sight.

Can your body survive without eating sugar?

Yes. Your cells run on simple sugars. But your body breaks complex carbohydrates down into simple sugars on its own. So you do not need to eat sugar in its simple form. Our bodies and minds were never designed for the immense amounts of sugar that have become normal in American society. The brain pays for that surplus.

Related reading

• Fast Food and Your Immune System
• Essential Oils and Heart Health
• Rats, Food, Prisons: Reversing the Diabetes Pandemic
• Anxiety and Depression: The Insulin Resistance Link

References:

1. Everhealth (2012): The Impact of Sugar on Mental Health. Retrieved from http://everhealth.net/patient-education/the-impact-of-sugar-on-mental-health

2. Medical News Today (2017): Sugar and mental health: A toxic combination? Retrieved from https://www.medicalnewstoday.com/articles/318818.php

3. Kelly Brogan: 3 Ways Sugar Is Ruining Your Mental Health. Retrieved from https://kellybroganmd.com/3-ways-sugar-ruining-mental-health/

4. Neuroscience (2017): Sugar is Not So Sweet For Mental Health. Retrieved from https://neurosciencenews.com/sugar-mental-health-7194/

5. Standard Media (2018): The link between sugar and mental illnesses. Retrieved from https://www.standardmedia.co.ke/article/2001282656/link-between-sugar-and-mental-illnesses

6. NCBI (2014): Nod-like receptor protein 1 inflammasome mediates neuron injury under high glucose. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/24014157

Medically reviewed by Dr. Gurpreet Singh Padda, MD, MBA, MHP
Interventional pain physician, addiction medicine specialist and obesity medicine diplomate.
Licensed in Missouri and Illinois.
Last reviewed June 18, 2026