Is your daily sugar boost contributing to your depression? Here’s what the research says.

A spoon of sugar cubes as it relates to the link between sugar and depression.Share on Pinterest
Yulia Reznikov/Getty Images

Our hunter-gatherer ancestors got their energy from berries, corn, and other sweet whole foods. These foods were very nutritious, so humans evolved to have a strong taste for sweets.

In an age where technological advances can concentrate, refine, condense, and artificially manufacture more sugar in a single serving than is natural for the body to intake, this preference for sweet things can get us into trouble.

In the United States, adults consume triple the amount of the recommended sugar levels. And depression is predicted to become the leading cause of disability in high-income countries by 2030.

Research suggests there’s a relationship between the two.

Several studies have shown links between sugar and depression.

Sleep disturbances and fatigue are among the symptoms of depression, and inadequate sleep can spur sugar cravings. A 2018 study showed that increasing sleep time led to lower sugar intake the following day.

One study spanning nearly 3 decades examined the dietary habits of more than 10,000 participants, ages 35 to 55. It found that a high-sugar diet played a role in depression and other mental disorders.

A 2009 study found that participants who ate the most whole foods had lower odds of depression than those who ate the least amount of whole foods. In addition, eating more processed foods was linked to a greater chance of depression.

There are several reasons a diet high in added sugars and refined carbohydrates may fuel depression. These include one or more of the following factors:

Chronic inflammation

People who consume a diet high in sugar are more likely to have chronic inflammation, which research has shown is linked to depression.

Chronic inflammation is a form of low-level, long-term inflammation. This is different from acute inflammation — the redness, pain, and swelling that occurs when you burn yourself, for example.

You probably wouldn’t even know you have chronic inflammation. But your body might think it’s under constant attack, so the immune system keeps fighting indefinitely. This can lead to disease, including depression.

Here’s a list of anti-inflammatory recipes.

Nutritional deficiencies

Whole foods include all the nutrients needed to digest them. When folks eat processed foods (stripped of their nutrients), the body must pull these vitamins and minerals from other places.

Low levels of nutrients, such as vitamin D, folate, B12, omega-3 fatty acids, and several minerals, are linked to depression.

Here’s how you can support mood-boosting nutrients.

In addition, research published in 2016 shows that a processed diet leads to low energy and more hunger, which spurs overeating and, in turn, obesity. Also, obesity and depression have strong links of their own.

Unstable blood sugar levels

Whole foods such as fruits and vegetables include fiber, which slows their absorption and keeps blood sugar levels steady.

In contrast, processed foods, like candy, sugary drinks, and refined carbohydrates, have a high glycemic index (GI) — your body absorbs them immediately and spikes your blood sugar levels.

A large study looked at the relationship between depression, dietary GI, and other carbohydrate measures (such as added and total sugars) in about 70,000 postmenopausal women in the United States. Women previously diagnosed with depression were excluded from the study.

The study found that women who consumed a high-glycemic diet, such as refined grains and added sugars (sugars not naturally found in whole foods), had greater rates of depression. In contrast, those who ate more fiber, milk products, fruits, and vegetables had lower odds of depression.

Poor gut health

Healthy gut function is essential to produce hormones and neurotransmitters such as dopamine and serotonin. Diet has a significant effect on gut health, and a diet high in sugar can cause an imbalance in gut bacteria.

Studies show that this microbiome imbalance and gut inflammation may be linked to several mental illnesses, including depression and anxiety.

Here’s foods you might incorporate that support gut health.

Low BDNF

BDNF (brain-derived neurotrophic factor) is a protein that plays a role in the growth and maintenance of brain cells.

Research shows that a high-sugar diet reduces the production of this protein and that low BDNF is often seen in people with depression.

Antidepressants help regulate the expression of BDNF both in the short and long term.

In a quest to avoid sugar, some people opt for alternative sweeteners, such as aspartame — an artificial sweetener commonly used in diet sodas.

Research from 2017 shows that aspartame is linked to behavioral and cognitive problems. Some of these symptoms include:

  • irritability
  • depression
  • insomnia
  • learning problems
  • headaches
  • seizures

Splenda (sucralose) is another commonly used alternative sweetener. Research shows Splenda is linked to poor gut health and inflammation, which are linked to depression.

Stevia, a natural sweetener without calories, is derived from the leaves of a plant in the chrysanthemum family.

Research on Stevia has been mixed. While it may help you lose weight and lower cholesterol, some 2020 research suggests it may disrupt communications between different bacteria in the gut microbiome.

Erythritol, a sugar alcohol, may be a healthier sugar substitute in moderation over alternatives.

The American Heart Association recommends keeping added sugars to 100 calories a day (about 6 teaspoons or 24 grams of sugar) for women, and no more than 150 calories a day (about 9 teaspoons or 36 grams of sugar) for men.

You may opt to stick to fresh or (unsweetened) dried whole fruit for your daily sweets when managing depression, including high-pectin (fiber helpful for the gut) fruits, such as:

  • apples
  • blackcurrants
  • gooseberries
  • oranges
  • plums

Other fiber-rich fruits in their natural form include:

  • bananas
  • kiwi
  • mangoes
  • raspberries
  • strawberries

Outside of steering away from processed sweets, other strategies to curb sugar intake include:

  • eating whole foods
  • consuming more healthy fats, such as olive oil and avocados
  • replacing refined carbs with whole grains
  • getting enough sleep, as a lack of sleep can cause sugar cravings

The dopamine surge from a sugar rush can lift your mood temporarily, so it can be tempting to keep a diet chock-full of simple or artificial sweet ingredients.

But for long-term management of depression, you may want to make minor changes to your routine and diet where possible to increase your energy and support your mood. Favoring whole foods with naturally occurring ingredients, complex carbs, and omega-rich options can be most healthful.