You’ve probably heard of the “sugar high,” a concept that goes back as far as the 1920s when W. Ray Shannon, MD linked a child’s bad behavior to sugar consumption. However, the term didn’t hit the mainstream until the 1970s when Dr. Ben Feingold told the anecdote of a boy who went wild after consuming sugar-rich foods. While subsequent studies have provided some support for the existence of sugar highs, whether high blood sugar levels are actually linked to changes in behavior and mental health remains controversial. In this article, we will talk about what anxiety is, the research regarding blood sugar and anxiety, and ways (including dietary choices) to maintain your mental well-being.

One principal conclusion: sugar consumption may be correlated with the onset of anxiety, but other lifestyle and environmental factors play a much bigger role than diet alone.

What is anxiety?

Anxiety disorder is a highly prevalent condition worldwide, impacting an estimated 33.7% of all adults within their lifetime. This condition covers a range of mental health problems that encompasses excess feelings of fear. The many categories within anxiety disorders cover both chronic conditions (such as generalized anxiety disorder) and acute situations such as panic disorder. Regardless, people experiencing anxiety disorder are likely to experience at least one of the following symptoms:

• Feelings of restlessness, irritability, or impending doom
• Bodily pain (whether from your head, chest, or your muscles)
• A pounding or racing heart
• Impaired cognitive and higher-function abilities

With each of these symptoms, it’s important to distinguish between clinical anxiety and a stress response. The two can easily be confused because they are so intricately linked. Feeling stressed is commonly tied to a specific situation, whereas anxiety doesn’t have a specific sensor tied to it.

Blood sugar and anxiety: what does the research say?

Although the initial research into sugars and the nervous system focused on cognitive functions in children, a growing body of research is focusing on the relationship between blood sugar (glucose) levels and anxiety. The research literature demonstrates that there is some correlation between high sugar consumption and anxiety onset:

• A 2016 study demonstrated that rats exposed to a high-fat/high sugar diet were more likely to experience anxiety symptoms and sustain them. Modifications to brain function that help with anxiety reduction were detected among these rats.
  

• A 2017 study of adults aged 35 to 55 showed that people who consumed the most sugar had the highest odds of common mental disorders such as anxiety and depression.
  

• A 2019 study of Greek older adults showed that those who followed a diet high in sugar and unsaturated fats were the most likely to have anxiety.
  

• Diets high in sugar can also impair cognitive functions. People with type 2 diabetes (T2D) may experience cognitive dysfunctions, such as difficulties in thinking clearly, poor attention, and memory lapses.

While scientific research provides support for this relationship, the mechanisms that explain the processes are varied, numerous and still being clarified:

• Cravings after eating sugar: Eating foods rich in sugar can activate a series of opioid receptors — those that affect your reward center. When one suddenly stops eating sugar, withdrawal symptoms can arise. Studies done on rat models have demonstrated that hormones associated with stress responses are altered when the animals are withdrawn from a high sugar diet, leading to elevated anxiety. A case study done on a 15-year old female with generalized anxiety showed that eating foods rich in refined sugars resulted in worsened anxiety symptoms tied to low blood sugar levels. These symptoms were improved after she ate a fiber-, protein-, and vegetable-rich diet. The results suggest that the low blood sugar levels (hypoglycemia) present after a sugar high may contribute more to anxiety than the actual rise in blood sugar levels after eating sugar-rich foods.
  

• Imbalances in blood sugar levels: People who experience dysglycemia, recurrent episodes of too high or too low blood sugar levels, may also experience mood disorders. Individuals with T2D are more likely to have worsened depressive symptoms and experience common mental disorders. People who eat a diet high in ultra-processed foods also have a higher risk of T2D, due in part to the high sugar content of such food products.
  

• The gut-brain axis: The gut microbiome may contribute to the relationship between obesity, T2D, and mental health disorders. Your gut microbes produce chemicals called neurotransmitters that impact how your nervous system functions. Changes to the gut microbiome reduce insulin signaling in the brain and cause inflammation in the sections of your brain that control emotional and cognitive responses.
  

• Oxidative stress takes place when excess levels of reactive oxygen species (ROSs) are formed in your body. Diets high in fats, refined carbohydrates, and sugars are potent triggers of oxidative stress. The constant need to break down the glucose entering the body results in the production of more ROSs, further driving cardiovascular disease (CVD) and T2D.

Although the research does provide a link between sugar consumption and anxiety onset, none of these studies have considered other lifestyle choices and environmental variables that may have stronger impacts on mental health. A lack of exercise, consumption of foods high in unhealthy fats and added salts (e.g., saturated fatty acids), cigarette and alcohol consumption, and other environmental/lifestyle variables may all play a significant role in triggering or worsening anxiety and other mental health problems.

How can you use your diet to combat anxiety?

While many other factors play a role in anxiety onset, a healthy diet can still go a long way in helping you manage your anxiety. Many of the foods linked with improved mental health are key components of the Mediterranean diet and also plant-based diets.

• Seafood is an excellent choice if you plan to harness your diet to combat anxiety. Low zinc levels have been observed among individuals diagnosed with anxiety, and fish and other seafood contain very high zinc levels. Many kinds of fish are also rich in omega-3 fatty acids. A 2018 systematic review of 19 studies showed that taking omega-3 supplements may reduce clinical anxiety symptoms. Consider integrating oysters and mackerel into your seafood consumption since they provide the richest source of zinc and omega-3s, respectively.
  

• Leafy-green vegetables are foods rich in magnesium. A 2017 systematic review of 18 studies determined that magnesium consumption had a beneficial effect among people vulnerable to anxiety. Leafy-green vegetables are also rich in antioxidants such as vitamin K and vitamin B9 that help maintain cognitive function as people age. Foods rich in antioxidants also reduce oxidative stress in your body, potentially helping to mitigate adverse responses to stress and anxiety. Spinaches, collard greens, and kale are excellent leafy-green vegetables to integrate into your diet for your mental health.
  

• Probiotic foods are rich in microbes that provide benefits to your body, especially the gut. A 2016 systematic review of 10 studies determined that probiotic supplementation can improve anxiety and depressive symptoms. These benefits may stem from the gut-brain axis, a two-way relationship (through an intricate network of nerves) between the gut and nervous system. Consider adding fermented foods such as pickles, sauerkraut, and kefir to provide a leg up for your mental health.
  

• Beans and legumes are great alternative sources of protein to red meat. With the potential links between blood sugar levels and anxiety, having protein in your diet may help lower blood glucose levels for individuals with T2D. On top of that, these foods provide a rich source of vitamin B, dietary fiber, and other minerals.

You should also think about eating less of or avoiding these foods and drinks altogether: 

• Soft drinks often contain high concentrations of added sugar that enhance taste but contain a high amount of calories and scant nutrients. The high-fructose corn syrup in many soft drinks greatly increases the risks of both obesity and CVD, and obesity is strongly linked to the onset of diabetes.
  

• Sugary desserts: Although foods like cookies, sweet rolls, and ice cream provide an immediate boost to your mood, they can also make you feel worse in the long run — especially if you indulge your sweet tooth too often. Sugary desserts are high in processed sugars which can increase the risk of worsening anxiety.

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Key takeaways

Concerns about the impact of a high sugar diet have grown alongside the growth of soft drinks and other carbohydrate-rich foods in the Western diet. Factors such as gut inflammation, altered insulin signaling, and the gut-brain axis all play a role in a high-sugar diet — potentially making anxiety worse. However, many confounding variables exist —  including a high-fat diet, a sedentary lifestyle, and other unhealthy behaviors — that complicate this sugar-anxiety relationship. Thus, minimizing the risk of anxiety requires a holistic approach. To better control the dietary influencers, it’s best to up your intake of the many healthy foods that improve your body’s functioning, and in turn your mental health, such as most plant-based foods and seafood.