Sugar Consumption and Mental Health: The Highs and the Lows

We are all aware of the many ways excess sugar harms our physical health. But could it also affect the mind?

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6 min read
We are all aware of the many ways excess sugar harms our physical health. But could it also affect the mind?
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(FIT is republishing this story in the run-up to World Mental Health Day on 10 October, an international day of raising awareness and spreading information on mental healthcare.)

Is there anything else you would rather have than a steaming cup of hot chocolate at the end of a bad day?

The almost miraculous effect sugar seems to have on our moods and its ‘instant remedial’ properties are well known to us (hence, the hot chocolate). But in any discussion on the health impact of sugar consumption, a sole focus on these 'restorative’ qualities of the former would amount to barely scratching the surface.

In truth, the momentary gratification that we receive as a result of a sugar-binge may actually be damaging our health in the long run. And this damage isn’t restricted to the widely recognised physical outcomes like weight gain or a higher risk of chronic illnesses like diabetes and heart diseases. It is also equally about a relatively lesser-known, yet very real health impact of excessive sugar consumption: the harm it can do to our mental health.

Decoding Sugar Cravings

Delnaaz T. Chanduwadia, chief dietitian and head of department of nutrition and dietetics at Jaslok Hospital, tells FIT, “Added sugar has been seen to have a direct impact on mood by elevating the state of mind - which is described as a ‘sugar rush’ or ‘sugar high’. But because it is so easily digested and absorbed in the system, it slumps also equally fast. This erratic high and low can affect mood.”

“The reason we find ourselves elated is because sugar works at boosting dopamine, which makes us feel good. However, this doesn’t stay for long.”
Delnaaz T. Chanduwadia

In fact, the release of dopamine is what makes sugar almost addictive in the way it activates the brain’s reward circuit.

Kamna Chhibber, Head of Department, Mental Health and Behavioral Sciences at Fortis Gurugram, talks of this, “Many individuals turn to sugar-based products when they feel stressed, experience irritability, anger or low moods. These food items tend to have, for a lack of a better word, an addictive potential which can make people very reliant on them, making it hard to let go.”

Addiction is marked by strong cravings and satiating those cravings in a manner that involves complete dependency on the object. Every interaction with the object of addiction releases dopamine or the ‘feel-good’ hormone. But over time, the same amount of the substance stops producing the same amount of dopamine as before. This ‘tolerance’ leads to the absolute need to increase the dosage in order to reach the state of happiness and euphoria experienced earlier.

With all this at play, many experts have gone so far as to equate sugar addiction with cocaine addiction.

“It’s quite simple. We find it difficult to give up on sugar because it sparks the very wires in the brain that control the reward pathways. This temporary feeling of ‘high’ is something you want to keep coming back to,” Chanduwadia says.

"Over-activating this reward system kickstarts a series of unfortunate events, like loss of control, craving, and increased tolerance to sugar," neuroscientist Nicole Avena explained in a TED-Ed video.

Sugar and Depression: A Plausible Connection

“Sugar can lead to cognitive decline in elderly and ADHD hyperactivity in children,” a neurologist tells us.
“Sugar can lead to cognitive decline in elderly and ADHD hyperactivity in children,” a neurologist tells us.
(Photo: iStock)

While the area is still under rigorous research, preliminary evidence has indicated that a high intake of added sugar may put individuals at an increased risk of getting diagnosed with depression later in life.

One of the most important studies in this regard is an analysis of over 8,000 adults who were followed for 22 years. The findings, published in the peer-reviewed journal Scientific Reports, revealed that men who reported consuming food that contained 67 grams of sugar per day or more were 23% more likely to be diagnosed with clinical depression after five years from the start of the study, regardless of whether they were overweight.

Even though previous researches had also found a link between sugar and depression, there had always been an inverse possibility: that people with low moods tended to consume high amounts of sugar, which may have affected the results. The concerned study stood out because researchers from University College London were able to exclude this potential ‘reverse causation’ as the reason for the observed connection between high sugar intake and low mood.

“Our study findings are consistent with the hypothesis that high sugar intake plays a causal role in the risks of both incident and recurrent depression and common mental disorders.”
Study authors

However, the authors were still cautious in making any definite statements, most importantly because this wasn’t a randomized controlled trial. In a Quartz report, Anika Knuppel, a lead author of the paper, said, “Studies that follow self-reported health data over time are inherently flawed because even when participants have honest intentions, they have poor memories about what they eat. The only thing that could would be a randomized controlled study, which would be unethical to perform knowing the links between sugar and other health consequences.”

Animal research in rats has also shown that diets high in fat and sugar can lead the brain to produce less of a protein called BDNF, which has been associated with anxiety and depression in humans, Knuppel added.

Kamna Chhibber, in conversation with FIT, said,

“Yes, recently, research has come in which talks about the link between increased sugar consumption and mental health-related issues, but these are currently undergoing heavy investigation. It may take some time to be able to say with certainty what the exact link is.”
Kamna Chhibber

But even apart from depression, scientists also find weightage in the role of excessive sugar consumption in cognitive dysfunctioning and in the development of neurodegenerative diseases like Alzheimer’s.

A study, for instance, published in the journal Diabetologia, followed over 5000 individuals for a decade and found that those with high blood sugar had a faster rate of cognitive decline than those with normal blood sugar.

Not just this, there is also sufficient evidence to show that diabetics, both type 1 and type 2, may be more likely to get Alzheimer’s.

Dr Manjari Tripathi, a neurologist from AIIMS, told FIT,

“Yes, sugar is bad for the brain and the body. It can lead to cognitive decline in elderly and ADHD hyperactivity in children.”
Dr Manjari Tripathi

But How Can This Be Explained?

There are many possible explanations for the different ways in which sugar seems to work on the brain.

As discussed above, excess consumption of sugar can influence the BDNF levels and cause inflammation in the brain. Neuroinflammation is known to be associated with depressive symptoms.

For example, a study by researchers from the Department of Neurobiology at Huazhong University of Science and Technology in Wuhan, China, on diabetic rats showed that high blood glucose led to inflammation and neuronal damage.

Insulin resistance and obesity could also explain the linkage. According to a report in The Atlantic, “A high intake of simple sugars can make cells, including those in the brain, insulin resistant, which could cause the brain cells to die. Meanwhile, eating too much in general can cause obesity. The extra fat in obese people releases cytokines, or inflammatory proteins that can also contribute to cognitive deterioration.”

How to Cut Back on Sugar?

“If you are looking to curb sugar intake, set small targets for yourself.
“If you are looking to curb sugar intake, set small targets for yourself.
(Photo: iStock)

While there isn’t conclusive proof for sugar’s role in causing mental health disorders, the ever-growing evidence is convincing enough for doctors to caution against too much sugar in the diet

Nutritionist Delnaaz T. Chanduwadia offers alternatives one can opt for to satisfy sugar cravings, “Fruits, a granola bar, or even dry fruits like dates or figs could help. But in the long run, the most effective solution is eating a wholesome meal which allows you to maintain your sugar levels. This will keep cravings at bay because fluctuating sugar levels cause pangs. Optimise sleep and vitamins in the body. A deficiency of vitamins like magnesium and Vitamin D is known to increase sugar cravings.”

“Overall, mental health is supported by foods that are anti-inflammatory and rich in Omega 3, like nuts, oilseeds, fish and fish oil. Also make sure your plate is colorful with plenty of fruits and vegetables to provide vitamins and antioxidants. Good quality protein is also important.”
Delnaaz T. Chanduwadia

On making the transition, Kamna Chhibber advises, “If you are looking to curb sugar intake, set small targets for yourself. It may be a good idea to start sequentially to eliminate or reduce sugar from your diet, and build it up slowly. You need to be more mindful of what you eat, and most importantly, more aware of what is causing you to consume those foods. That is key to tackling the issue and breaking the chain.”

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