How Do Glucose Levels Impact Depression & Anxiety?

It has been well-documented in research that diabetic individuals – a population that has uncontrolled blood sugars typically illustrated with frequent bouts of hyperglycemia or high blood sugar levels – are twice as likely to have depression as healthy individuals are.  Approximately 25% of diabetics have been diagnosed with depression, and nearly 20% experience anxiety.  

Uncontrolled blood sugars have been shown to increase the risk of mood disorders like anxiety and depression in both diabetic and non-diabetic populations. Utilizing a CGM without diabetes can aid in preventing large variations in blood glucose levels and decrease the risk of undesirable mood changes. 

We also see a correlation between the risk of mood disorder development and frequent high and low blood sugars in a healthy population as well. These relationships are proving to be more important now than ever, as the rate of diabetes, blood sugar dysregulation, insulin resistance and obesity are on the rise .

Relationships between blood sugar levels and overall mood are well-established, especially when looking at continuous highs and lows, otherwise known as poor glycemic regulation. This poor regulation overtime can reflect certain mental health symptoms such as irritability, anxiety, increased worry, and possibly the brain’s desire to run primarily on glucose as its fuel source. 

Comprehensive programs that utilize continuous glucose monitors and nutrition experts can serve as tools to provide real time feedback that will assist in identifying blood sugar trends that may contribute to feelings of anxiety or altered mood. Identifying patterns in glucose dysregulation can lead to lifestyle changes that may prevent the development of depression and anxiety. 

How can glucose levels influence depression?

There are a few reasons for poor glucose control resulting in higher prevalence of depression in both diabetic and healthy populations. Research has shown that diets high in added sugars or foods that ultimately raise your blood sugar are linked to depression and adverse mental health symptoms after several years. This informs us that diets high in added sugar impacts mental health on a long-term basis.

High dietary intake of added sugar has impacts on various metabolic processes that may result in the development of depression

• Excessive sugar intake can lead to inflammation in the body, which is correlated with higher risks of depression, along with varied high and low glucose levels (or dysregulation) that impacts fluctuations in our hormones. Hormone dysregulation can often have a negative effect on our moods and is linked to greater risk for depression over time.
  

Excess sugar intake can have an addictive like effect

• Diets high in added sugar can often impact our pleasure / reward chemical, dopamine, in the brain – resulting in an addictive effect that feeds a cycle of poor mood, depression, and desire for more sugar to improve those feelings.
  

Overall stress related to being diagnosed with and managing diabetes

• This is the most conventional theory related to blood sugar management and depression rates. The overwhelming concern and associated responsibilities (tracking glucose levels, managing medications and/or insulin therapy, lifestyle changes) after a diabetic diagnosis has been associated with increased rates of depression within this population.  Research has shown a positive correlation between increased fasting blood glucose and an increased score on PHQ-9 depression scale—illustrating the added pressure newly diagnosed diabetics feel to manage their glucose levels, with little to no understanding of how to do that at times. 

Studies show a biological relationship related to a mechanism in the brain that predisposes diabetics to depression

• There is MRI data that shows increased blood sugars can decrease the strength of connections in a region of the brain that involves emotions and self-perception which will impact mood and may lead to development of depression. These connections are shown to worsen in diabetics that have poor long term glucose control.
  

Increased blood glucose levels have been associated with increasing the neurotransmitter Glutamate

• Diabetics with continuous elevated glucose levels can have glutamate dysregulation, which is consistently implicated in mood disorders including major depressive disorder and bipolar disorder. This again illustrates how widespread the impact of glucose dysregulation is on other metabolic processes in our body. 

‍How can glucose levels influence anxiety and mood disorders?

A study showed that women with diabetes who had poorly managed or inconsistent blood sugar levels were associated with a decreased quality of life and reported more negative moods. These moods differed depending on glucose levels. For example, high blood sugar levels or hyperglycemia was associated with feelings of anger and sadness, while hypoglycemia or low blood sugar was associated with nervousness .  

That being said, it is not just diabetics that are susceptible to blood sugar fluctuations. Non-diabetic populations that consume high amounts of refined carbohydrates and added sugars are also at risk for this dysregulation. A 2017 prospective study showed a positive association between increased sugar consumption and common mental disorders within an otherwise healthy population. 

Some of the best ways to address these issues are through diet and lifestyle changes such as; managing and decreasing overall stress (for more information on strategies to address this click here), increasing other macro/micro nutrients that help with blood sugar regulation (protein, fat, fiber – click here for more information), and decreasing dietary intake of refined carbohydrates and/or added sugars. Other well documented reasons that glucose levels can influence anxiety and mood are: 

Dips in our blood glucose, or hypoglycemic events, can trigger feelings of anxiety and other mood disruptions. 

• Poor glucose regulation can alter our hormonal responses such as: adrenaline, cortisol, and epinephrine which can cause physical anxiety-inducing symptoms like sweating, shaking, blurred vision, mood swings, and crankiness. 

Contrary to some recommendations – sugar, in fact, does not improve mood and an increased dietary intake can lead to the development of mood disorders overtime, such as anxiety. 

• Research shows that increased added sugar intake over time will impact mental health even in healthy individuals long term.
  

Alterations in gut microbiome or gut health has been associated with increased rates of anxiety and mood disorders.

• Inflammation and poor glucose control may be major factors at play in this correlation. Diets high in added sugar result in inflammation in the body, blood sugar dysregulation, and insulin resistance over time. These can all be contributors to the development of obesity and type 2 diabetes, which can worsen the gut microbiome.
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• Epidemiological studies indicate that more than 2.1 billion people are currently overweight or obese worldwide. If current trends continue, estimations show that 38% of the world's adult population will be overweight and another 20% will be obese by the year 2030 – many publications over the last decade have shown evidence that suggest an association between a dysregulated gut microbiome and obesity, insulin resistance, and type 2 diabetes. These conditions have a higher susceptibility for associated mood issues and anxiety, as well as the possible development of depression over time.