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High Sugar Intake May Be Linked to Increased Risk of Mental Illness

Are your sweet treats giving you the blues? According to researchers from the UCL (University College London), they very well might be.

A recent study they conducted has found a substantial association between sugar consumption and depression among men. The results of the study point to men with the highest intake of sugar having a 23% increased chance of suffering a common mental affliction after five years.

Perhaps what is most interesting about the study in question is the fact that there were over 7,000 participants, suggesting that this isn’t an isolated incident or any kind of coincidence.

Although previous theories that people with depression are more predisposed to eating sugar have since been debunked, this study confirms that a large percentage of men are likely to develop anxiety and depression as a result of a diet rich in carbohydrates or sweets.

Some of the most common mental disorders include clinical depression, anxiety, PTSD (Post-Traumatic Stress Disorder) and bipolar disorder. So can excessive sugar consumption influence the development of these conditions? The researchers at UCL seem to believe that it can.

The UCL’s Anika Knuppel says, “High sugar diets have a number of influences on our health, but our study shows there might also be a link between sugar and mood disorders, particularly among men.

“There are numerous factors that influence chances for mood disorders, but having a diet high in sugary foods and drinks might be the straw that breaks the camel’s back.”

Where this leaves women is anyone’s guess at this point. Additional studies must be conducted before we’ll know exactly where women stand when it comes to a similar diet.

But one thing’s for sure: Men should be putting down those potato chips and pudding pops if they want to avoid a perpetual case of the Mondays.

This should come as no surprise to people who know anything about sugar’s effects on the human brain. Excess sugar impacts dopamine levels, and several neurobiologists have noted the detrimental effects it can have.

Dr. Mercola has frequently written about these effects. In his words, “Because sugar represents calories, excessive consumption will negatively affect your health.”

He goes on to discuss the obesity epidemic in America and the role sugar plays in this medical scourge, referencing the brain imaging that has confirmed that food addiction is a real thing.

And that’s not where the sugar problem stops. Evidence suggests that excess sugar intake can even contribute to heart attacks, diabetes, brittle bones, pancreatic cancer, prostate cancer, muscle weakness and paralysis.

As Ms. Knuppel says, “There is increasing evidence for the physical damage sugar has on our health. Our work suggests an additional mental health effect.”

But don’t just take Ms. Knuppel at her word. In an article for Psychology Today, Dr. David Sack, MD cited additional research that found “a higher national dietary intake of refined sugar and dairy products predicted a worse 2-year outcome of schizophrenia.”

Dr. Sack writes, “Sugar suppresses activity of a hormone called BDNF that is low in individuals with depression and schizophrenia.”

Of course, not everyone is on board and even some scholars have their doubts. Catherine Collins, a registered dietitian and spokesperson for the British Dietetic Association, responded to the UCL study, saying, “Whilst the food frequency questionnaire used to determine sugar intake was an appropriate tool; ‘translating’ this into daily sugar intake was deeply flawed, and so the findings from this study are interesting, but nothing more.”

Nevertheless, it is an inarguable fact that a poor diet and malnutrition can cause mood disorders.

Katherine Zeratsky, RD, LD, says, “Several studies have found that people who ate a poor quality diet—one that was high in processed meat, chocolates, sweet desserts, fried food, refined cereals and high-fat dairy products—were more likely to report symptoms of depression.”

And she is quick to add, “The good news is that the people who ate a diet rich in fruits, vegetables and fish were less likely to report being depressed.”

In a journal entry from Indian J Psychiatry, the co-authors wrote, “The dietary intake pattern of the general population in many Asian and American countries reflects that they are often deficient in many nutrients, especially essential vitamins, minerals, and omega-3 fatty acids.”

This is interesting for two reasons, the first of which supports the findings of the UCL researchers.

1) Many Americans generally consume a carb-and-sugar-rich diet, thanks to fast food and an on-the-go culture.

2) On the other hand, Asians generally consume a less sugary but more salty diet. This is interesting as it suggests that sugar is just one of the factors that contribute to nutritional deficiency and mental illness.

In light of the emerging body of research, there is a strong case for clean eating as a means to prevent depression and other mental illnesses. But can nutrition also be used to treat trauma?

After fighting two long and costly wars, American military veterans are suffering the consequences. Nearly a million vets have filed PTSD claims in the past year, yet most of them are not getting the benefits they need.

For veterans suffering from PTSD, a proper diet is one of the most fundamental parts of treatment. Nutritional interventions have become a key method for combating the symptoms of Post Traumatic Stress Disorder with Dr. Nina Bailey, PhD urging those with the condition to adopt an anti-inflammatory diet.

The role inflammation plays in PTSD is a big one, and Dr. Bailey suggests that a Mediterranean diet rich in olive oil, unrefined cereals, legumes, vegetables and fruit, oily fish and lean meat can have a profound effect on a patient’s health and wellbeing.

This goes for general depression as well.

Dr. Josh Axe, a perennial favorite on The Dr. Oz Show, has said that there are many ways to cure depression, most notably eating a healthy, well-balanced diet. In his article, he recommends eating salmon, flaxseeds, walnuts, chia seeds, mackeral and egg yolks for their Omega-3 content, fruits and vegetables for their antioxidants, yogurt and raw cheese for its probiotics and lean protein for its energy-boosting, hormone-balancing properties.

Dr. Axe goes on to confirm the obvious—“Avoid Refined Carbohydrates and Sugars.” So if you’re feeling down in the dumps, don’t reach for that Herschey’s bar. Head on over to your neighborhood grocery store and get your hands on some avocados and organic chicken.


In summary, while studies are still inconclusive, it is best to err on the side of caution. If you or a loved one are prone to bouts of depression, anxiety or other mental health conditions, you should strongly consider a sugar-free or light-sugar diet rich in protein and antioxidants.

High Sugar Intake May Be Linked to Increased Risk of Mental Illness

Dan Fries

Dan Fries is an entrepreneur and writer. He is the co-author of three highly-cited papers in the field of translational oncology research. Dan’s diverse background includes positions as a research associate at OSI Pharmaceuticals, an associate scientist at Medtronic Cardiovascular, and research scientist at both the Michigan Center for Translational Pathology and the Meyerson Lab at Dana Farber of Harvard Medical School. He currently writes about the responsible use of nutrition and supplementation as a means for treatment. To learn more about Dan and his current research you can visit his website, Corpina Nootropics.

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APA Reference
Fries, D. (2017). High Sugar Intake May Be Linked to Increased Risk of Mental Illness. Psych Central. Retrieved on March 19, 2019, from


Last updated: 20 Aug 2017
Last reviewed: By John M. Grohol, Psy.D. on 20 Aug 2017
Published on All rights reserved.