The Science of Celiac

By Aparna Mani, MD, PhD
MGH Medical Walk-In Unit

Aparna Mani, MD, PhD

It seems like many people these days are being diagnosed with celiac disease. While this phenomenon may be the result of increased screening, celiac disease has been recognized in the medical community in both children and adults since the 19th century.

Celiac is an autoimmune illness sparked by a reaction to gluten, a protein found in wheat, affecting  approximately 1 in 105 people in the United States.  Because there is a genetic basis to celiac, it’s thought to have a possible association with other illnesses such as Type 1 Diabetes. In people with celiac disease, exposure to gluten triggers a reaction, causing their own immune system to target and attack an enzyme located in the lining of the intestine. Part and parcel of this attack is inflammation and damage to the intestinal lining.  Since this is where food is absorbed into the bloodstream, people with celiac disease are unable to effectively absorb digested food. Thus, they may develop deficiencies in minerals and nutrients such as calcium, iron and Vitamins A, D, E and K. Without a healthy lining, people with celiac are also unable to absorb carbohydrates and fats; in sum, these deficiencies can cause weight loss, fatigue and slowed growth (particularly in children).

In addition, unabsorbed food in the intestine stimulates diarrhea and gas, both of which may lead to abdominal bloating, cramping, and pain. In some people celiac disease may be a silent or subtle illness showing up only as a borderline anemia due to poor absorption of iron.  In others, celiac may present full force with the entire spectrum of symptoms.

Gastrointestinal symptoms such as recurrent diarrhea and bloating or weight loss should prompt a discussion with a healthcare provider. Because other conditions such as lactose intolerance and irritable bowel disease can present in a similar fashion, it is important to talk to a healthcare provider first rather than making diet modifications or other lifestyle changes based on ‘self diagnosis’. Healthcare providers may themselves suggest testing for celiac disease for someone with unexplained nutritional deficiencies or, given the genetic basis of celiac disease, with Type 1 Diabetes or other autoimmune illnesses. Testing for celiac disease is a multi-step process that often begins with a blood test and may include a biopsy of the small intestine.

Unlike many other diseases, we know the underlying cause of celiac disease: gluten. Treatment then rests in avoidance of this trigger – a task that may be easier said than done. Though ‘gluten-free’ is a quickly growing food category in restaurants and grocery stores alike, adherence to this diet requires care and attention.  If you have been diagnosed with celiac, a nutritionist can help develop an eating plan that works best for you.


What’s the Deal with Gluten-Free Foods?

Question Mark Photo Credit: Steven Goodwin

Perhaps you’ve noticed many items in the grocery store now have the words “gluten-free” on their labels, or “gluten-free” menu options appearing at your favorite restaurant.  Gluten-free foods seem to be everywhere lately, and gluten-free diets have developed a reputation for being an all-around healthier way to eat (helped along by numerous celebrity endorsements).  But what is gluten, and is there really a reason to avoid it?

Gluten is a protein found naturally in wheat, barley and rye.  It helps give breads and other baked goods their chewy texture, and can sometimes be used to thicken sauces and soups.  Most of us can eat products containing gluten with no problems.  For some people, though, eating foods containing gluten can lead to serious health concerns.  People with celiac, an autoimmune disease affecting a small portion of the population, are gluten intolerant.  Eating even a small amount of gluten causes a reaction in the body that damages the small intestine so that it is unable to absorb nutrients in food.  According to the American Diabetes Association, about 10% of people with Type 1 Diabetes also have celiac.

There are also some people who have gluten sensitivity, meaning they experience unpleasant reactions to eating gluten (gas, bloating, diarrhea, etc.) but do not have the damage to the small intestine associated with celiac.  Only a medical professional can diagnose celiac (it requires a blood test and a biopsy of the intestine).  If you have any questions or concerns, it’s best to talk with your health care provider.

So should you start eating gluten-free?  Well if you have celiac, a gluten-free diet is mandatory and a nutritionist can help create an eating plan that works for you.  If you don’t have any type of gluten sensitivity, then there’s really no reason to spend the extra money on gluten-free foods.  Just because an item is gluten-free, it doesn’t mean it’s necessarily healthier – in fact some products can be higher in calories and fat (and lower in some nutrients like fiber) than similar products containing gluten.   A diet emphasizing fresh fruits and veggies, whole grains, lean protein and low-fat dairy while limiting packaged and processed foods will serve you well.  Just make sure you’re watching your portion size!

(Content reviewed by MGH Nutrition Department. Photo credit: Steven Goodwin)


 caduceusWhen we talk about Diabetes, we generally specify between Type 1 and Type 2.  Type 1 Diabetes is an autoimmune disease, meaning at some point the body’s immune system began attacking and destroying the cells in the pancreas that produce insulin.  A person with Type 1 can no longer produce their own insulin and must supply themselves with insulin daily, either through injections or an insulin pump.  Because Type 1 is usually diagnosed at a young age (the peak age for developing Type 1 is 13-15) it was once commonly referred to as Juvenile Diabetes.  

In Type 2 Diabetes, the pancreas still produces some insulin but not enough.  Because Type 2 is often diagnosed in adults, it was once referred to as Adult Onset Diabetes.  As the names imply, it was generally believed that only children developed Juvenile Diabetes and if you were an adult, you had Adult Onset.  We know now, though, that the age division between types of Diabetes isn’t as cut and dry as once thought.  

Diabetes, whether Type 1 or Type 2, can develop at any age.  Although Type 1 is commonly diagnosed in childhood and adolescence young people can also develop Type 2.  Likewise, people in their 30s (or later) can be diagnosed with Type 1.  LADA, or Latent Autoimmune Diabetes in Adults, is essentially Type 1 Diabetes diagnosed in people who are older.  

There is some controversy, however, over whether LADA is just a slowly progressing form of Type 1, or a unique type of Diabetes.  Diagnosing Type 1 is somewhat imprecise.  Relying on the presence of antibodies produced by the immune system attacking the pancreas to diagnose Type 1 is not always 100% certain.  And, as insulin levels vary from person to person over the years, neither is measuring the amount of insulin produced by the pancreas.    

Remember, everyone is different and management plans for Diabetes are developed around an individual’s specific needs.  Talk to your health care provider or Certified Diabetes Educator if you have any questions about your care plan.

(Information reviewed by MGH Diabetes Center)