The Depression and Diabetes Connection

Depression and diabetes. Many people are surprised to learn that these conditions are intimately intertwined. Nutrition emerges as playing a potentially key therapeutic role in preventing and treating depression. But which comes first? Are people unhappy, so they are reaching for exciting, easy, tasty foods? Most people are familiar with being bored or sad and reaching for specific foods to help them feel better. Is it possible though that these conveniently packaged, ultra-processed foods are partly responsible for feeling down and out? It turns out that yes, it is a two-way street. Having very high blood sugar, as is seen in type 2 diabetes, is linked to developing depression while having depression also increases one’s risk of developing type 2 diabetes. One study found that the rate of depression in individuals with prediabetes is three times as high and in diabetes is twice as high as in the general population.

Diabetes and obesity are considered the largest epidemics of our time. But, some could also argue that mental health issues are equally on the precipice. Currently, 1 in 3 adults in the US has pre-diabetes, while depression is estimated at 17% and anxiety at 29%. For this reason, I believe it is imperative to educate on the relationship between the two, and why nutrition is critical for helping with the mental health of our country.

The National Health and Nutrition Examination Survey of US adults between 2011 and 2018 found that dietary sugar intake was positively associated with increased depression rates in US adults. The Women’s Health Initiative Observational Study which looked at more than 87,000 women found that a higher consumption of sweetened beverages, refined flour food such as pastries, and other highly refined carbohydrate foods were a risk factor for depression in post-menopausal women. And a study done on over 3,000 adults in China, found that higher consumption of soft drinks was significantly related to a higher prevalence of depression.

The question you may be asking is, why? What is it about high-sugar foods that affect our mental health? The main theories for this are:

1.        Inflammation

Inflammation is a state of the immune system being on high alert as if it is being attacked, as it so often is in the modern world. Inflammation underlies all chronic disease states, including obesity, diabetes, and even depression. This is called the inflammation hypothesis of depression. It has been observed that those with high levels of certain inflammatory markers for 10 years due to chronic disease are at a higher risk of developing mental health disorders.

2.        Eating processed foods replaces healthy food

When we eat one thing, we are not eating another. Those with mental health issues are seen to eat less vegetables, fruits, whole grains, and fiber. When we choose to eat a doughnut for breakfast, we are therefore not eating an egg omelet, which has a much higher nutrient profile and a much lower impact on blood sugar and inflammation.

3.        Nutrient deficiencies

One of the reasons it is important to eat whole foods is because of their nutrient quantity. Take whole grains for example, when we remove the fiber, which is how refined white flour is made, it removes all the B vitamins. Deficiency and insufficiency of vitamins B1, B6, B9, and B12 have all been linked to depression. One reason is their role in neuron function in the brain. Having low levels of these vitamins has also been associated with poor response to antidepressant drugs. It’s not just B vitamins, but low magnesium, omega 3 fatty acids, amino acids, calcium, chromium, iodine, iron, selenium, and zinc have all been linked to decreases in mental health.

4.        Food additives

Many chemical compounds are added to ultra-processed and high-sugar foods in order to extend shelf life, inhibit mold growth, and increase color, texture, and taste. One study found that artificial sweeteners and artificially sweetened beverage consumption were associated with an increased risk of depression. The discussion about food coloring and children’s mental health is not a new one, and the debate continues.

How we eat affects every part of our health, from our brain to our gut. If we want to feel good in mind and body, we must consider what we consume.

Watch this video from PBS news to dive in further

By Melanie Luther, CHN, MS