Can Gluten Cause Diabetes?
Research has definitely made several links between gluten and diabetes, but before we dive into the connection, let’s define diabetes. Diabetes is a chronic health condition that affects how the body turns food into energy.
In simplified terms, carbohydrate-containing food that we eat gets broken down into sugar (or glucose) by the body and released into your bloodstream. When your blood sugar rises, it signals your pancreas to release insulin. Insulin helps to get the sugar from the blood into your body’s cells to be used as energy.
In a healthy person with properly-functioning insulin, this process works efficiently. However, if a person has diabetes, the body either doesn’t make enough insulin or can’t use the insulin it makes as well as it should. When there isn’t enough insulin, or if our cells stop responding to insulin, the amount of sugar rises in your bloodstream.
So how might gluten influence this process of food intake, blood sugar, and insulin function? We’ll discuss that below.
Types and Incidence of Diabetes
First, some background on diabetes. There are three main types of diabetes. For this article, we focus on type 1 and type 2 diabetes.
- Type 1 diabetes: Type 1 diabetes is an autoimmune condition that prevents the body from making insulin. Symptoms generally develop quickly and include increased thirst, frequent urination, extreme hunger, unintended weight loss, irritability and other mood changes, fatigue and weakness, blurred vision, and bed-wetting in children who previously didn’t wet the bed during the night. Type 1 diabetes is less common than type 2 diabetes, with only 5-10% of all diabetes cases being type 1.
- Type 2 diabetes: In type 2 diabetes, the body is unable to use insulin well and can’t keep blood sugar at normal levels. It typically develops over several years and may or may not involve obvious symptoms. Type 2 diabetes is far more common than type 1 diabetes, with 90-95% of diabetes cases being type 2.
- Gestational diabetes: Gestational diabetes is somewhat of a temporary condition that can develop in pregnant women who have never had diabetes. It does cause increased pregnancy risks, but can often be managed through a conscious diet and carefully monitoring blood sugar. While gestational diabetes goes away after the baby is born, it does increase a woman and her child’s risk for type 2 diabetes later in life.
The 2020 National Diabetes Statistics Report shared that 26.9 million people of all ages, or 8.2% of the US population, had diagnosed diabetes. In addition, the report shared that 1.5 million new cases of diabetes—or 6.9 per 1,000 persons—were diagnosed in 2018.
How is Gluten Related to Type 1 and Type 2 Diabetes?
Diabetes might seem far removed from gluten, but research has demonstrated a link between the two, beginning over 50 years ago in the late 1960s. We know that at least 10% of patients with type 1 diabetes develop celiac disease at some point in their lives (although some research has estimated this number as high as 19.7%). The comorbidity of type 1 diabetes with celiac (the presence of both diseases) has been attributed to an overlap in the genetic susceptibility to both diseases caused by the existence of the gene sequence HLA-DR3-DQ2. This particular set of genes is present in over 90% of individuals with celiac disease and 55% of those with type 1 diabetes. Interestingly, type 1 diabetes rarely develops after diagnosed celiac disease. This may indicate a protective role of a gluten free diet for diabetes.
Other studies have linked intake of a gluten-free diet to reduced incidence of obesity and type 2 diabetes, suggesting that a gluten free diet may have a role in reducing leptin- and insulin-resistance and increasing beta-cell volume, all factors in reducing diabetes risk. In addition, research has pointed to the beneficial effects of gluten-free diets in reducing adiposity (fat) gain and inflammation.
A study looked at the effects of a gluten free diet on components of metabolic syndrome, including serum triglyceride levels. It found “favorable changes” in serum triglycerides in the group following a gluten free diet as compared with the control group. Lower serum triglycerides can lead to reduction of cardiovascular and other disease risks. The study suspects that elimination of gluten-containing flour and cereals, processed foods, and refined wheat products such as white bread by those who followed a gluten free diet may have contributed to these results.
While some previous studies have suggested that those who follow a gluten free diet consume more carbohydrates and sugars, other studies have suggested that changes in the lipid profiles of those who adhere to a gluten free diet may be related to non-gluten-related dietary modifications such as higher fat consumption (due to replacement of gluten-containing flour and grains with fats). However, participants in this study reported similar consumption of macronutrients in both groups. This is interesting, as it shows that the results are not affected by other dietary components.
This protective effect may extend beyond just individuals. Animal and human studies have demonstrated that a gluten-free diet during pregnancy reduces the risk of type 1 diabetes in the developing child.
Some research even suggests that a gluten free diet seems to be most effective when applied in utero. This research has demonstrated that maternal ingestion of low amounts of gluten during pregnancy has been shown to reduce the risk of type 1 diabetes in their offspring by two-fold.
The Leaky Gut Connection
One of the suggested mechanisms behind the link between diabetes and gluten sensitivity is increased intestinal permeability and changes in intestinal microbiota. While more research is needed, we know that intake of gluten affects the microbiota and increases intestinal permeability. This can lead to the leaking of antigens into the bloodstream, which can prompt an immune response and inflammation elsewhere in the body. This reaction can then trigger further autoimmunity, like that found in type 1 diabetes.
Is a Gluten-Free Diet Always Preventative?
It’s important to note that not all gluten free diets are created equal. One of the most common myths about gluten free diets is that gluten free foods are always healthier than their gluten containing counterparts.
This is simply not true. A processed food labeled gluten free is generally still junk food, full of refined carbohydrates and unhealthy additives. Researchers are starting to look at how the rise of gluten free products available are contributing to other health concerns. The reality is that these processed foods, gluten free or not, can contribute to diabetes by raising blood sugar and contributing to insulin resistance.
Rather than seeking out foods with gluten-free labels, seek out healthy whole foods that don’t come with a laundry list of ingredients that you can’t pronounce or understand. Filling your plate with foods like fresh produce and pastured meat and eggs will help mitigate risk of diabetes by providing protein, fat, and fiber to balance blood sugar and nourish the body. Most foods that are naturally gluten-free don’t come with a label and they are far better options than products intended to mimic a gluten-containing counterpart.
Diabetes-Related Gluten-Induced Nutritional Deficiencies
We know that nutrient deficiencies are common in newly diagnosed celiac patients. And in fact, research suggests that deficiencies and imbalances can exist even after a gluten free diet is implemented, and even if symptoms are not present.
There are a number of these gluten-induced nutritional deficiencies that impact blood sugar or that may contribute to diabetic complications:
- Vitamin D: Vitamin D deficiency is common in those with celiac disease and research has shown that high dose vitamin D improves insulin sensitivity and decreases risk of progression toward diabetes in patients with pre-diabetes and hypovitaminosis D.
- Chromium: Chromium deficiency is common in celiac disease patients and research has suggested that supplementation to animals that were rendered insulin resistant improves resistance and markers of glucose metabolism. The research concludes that the beneficial effects of chromium may justify its use as an adjunct therapy in the management of insulin resistance and type-2 diabetes.
- Magnesium: Magnesium deficiency is common in those with celiac disease and research has shown that oral magnesium supplementation reduces insulin resistance and improves the glycemic control indicators among type 2 diabetes patients.
- Zinc: Zinc deficiency is common in those with celiac disease and research has shown that several key glycemic indicators are significantly reduced by zinc supplementation, suggesting that zinc supplementation may have clinical potential as an adjunct therapy for preventing or managing diabetes.
- B Vitamins: Deficiency of several B vitamins is common in those with celiac disease as well as type 2 diabetes and research has shown that supplementation has shown improvement of the metabolic control in diabetic patients. In addition, it is important to note that the absorption of folic acid and vitamin B12 is decreased by the prolonged use of metformin, which is the first choice drug in uncomplicated diabetes cases.
- CoQ10: Research shows that those with gluten sensitivity and celiac disease have lower antioxidant status. CoQ10, or ubiquinone, is an antioxidant which is found in every cell in the body, and is necessary for use in cellular energy production. CoQ10 has been studied with respect to its role in blood sugar management for decades and research has shown that CoQ10 treatment can improve glycemic control, total and LDL cholesterol.
- Multi-Vitamin/Mineral: We know that a number of nutrient deficiencies are common in those with celiac disease. While targeted supplementation is helpful, so is broad supplementation with a multivitamin. In fact, research showed that a multivitamin and mineral supplement reduced the incidence of participant-reported infection and related absenteeism in a sample of participants with type 2 diabetes mellitus and a high prevalence of subclinical micronutrient deficiency. Incredibly, 93% of participants who did not receive a supplement reported an infection compared with 17% of those receiving supplements.
It is clear that there is a link between celiac disease and diabetes. While mechanisms are not fully understood and there is great need for a more efficient, targeted diagnostic approach, we can safely say that it is important for patients of both conditions to be screened to further explore and understand how we may prevent and manage both conditions simultaneously with something as simple as dietary changes and supplementation to address deficiencies.