Type I Diabetes: Different, but no Less Important

The recent and projected rise in rates of Type 2 diabetes in the United States and the world has led to important improvements in general understanding of this complex disease, however another consequence seems to be a reduction in the amount of education and general information that is made available to people with Type 1 diabetes. The reason for this discrepancy is the dramatic distribution of diabetes in the US, with over 80% of people with diabetes having Type 2 diabetes. Arguably from a public health perspective, this choice is the correct one, i.e. spending more time and resources on educating about the more common form. However, if you are an individual with Type 1 diabetes, it is reasonable to want more attention and resources directed to further understanding of Type 1. I am guilty of this same phenomenon in my writing for Diabetes Action, my articles, with few exceptions, have been directed more to those suffering from Type 2 than from Type 1. I do not expect this article to fully make up for this disparity, but I hope it does help answer some questions and, more importantly, debunk some misconceptions.

What Causes Type 1?

Type 1 diabetes is fundamentally an autoimmune condition of insulin deficiency- however how this deficiency occurs originally is not fully known for all people. “Autoimmune” means your body produces antibodies to your own tissues, in this case the pancreatic beta cells that produce and secrete insulin; essentially your body thinks certain tissues are foreign and unwanted and therefore attacks them.

Briefly, some of the existing theories about factors that cause type 1 diabetes include diabetes as a viral disease, lack of breastfeeding, dietary exposures, and deficiencies of certain vitamins, including vitamin D. The food exposures that have been linked to increased rates of diabetes include dairy products and some cereal grains. However this data is not very consistent and generally not robust enough in size or design to make definitive claims regarding exposure. Some studies have shown elevated antibodies to dairy proteins and cereal grains in individuals with Type 1 diabetes. Fortunately, food exposures are still being studied. A large study is underway to determine if dairy exposure early in childhood increases risk for developing Type 1 diabetes. Also, at the University of Washington, a group of researchers will be conducting a clinical trial evaluating using supplemental vitamin D to see if extra vitamin D reduces risk of Type 1 diabetes. Fortunately, we are going to learn more about risk factors for developing Type 1 diabetes, but unfortunately this research isn’t going to do much for those who already have the disease.


Should I Avoid Milk and Cereal Grains if I have Type 1 Diabetes?

I wish I knew the answer to this question absolutely, but as with most questions, the answer is very individualized. In my observations in practice, almost everyone has food sensitivities to a few foods- and some people have sensitivities to many foods- and as a general rule I think it is important to general health and quality of life to avoid these foods. However, a “sensitivity” is a very general word that could mean anything from a food causing a little extra gas, to making your joints hurt or producing frank pain and discomfort. So having a food “sensitivity” and having antibodies to foods can be separate issues. Antibodies for foods can be tested. Further confusing matters, there are other autoimmune diseases that have clear relationships with foods. The prime example of this type of “allergy” or “intolerance” is celiac disease, a condition in which the body produces antibodies against gluten, a protein found in wheat and other grains. In celiac disease, the structure of the protein is similar to some markers on cells in the intestines, and thus a cross reactivity occurs.

I generally think avoiding food sensitivities- and allergies- is important, but I don’t think we know enough about how these allergies affect health to make any special recommendations for those people with Type 1 diabetes. The lame, but accurate, answer is there just isn’t any data that suggests avoiding foods that you have antibodies against does any good for long term health in diabetes- unless a frank “allergy” (e.g. peanut allergy, seafood allergy, etc) or a separate autoimmune process related to foods (e.g. like celiac disease) exists.


If I have Type 1 Diabetes am I at Risk for Other Autoimmune Disorders?

Yes. It is generally accepted that individuals with Type 1 diabetes do have increased risk for developing several other autoimmune disorders; the most common concurrent autoimmune diseases include Celiac disease and Hashimotos thyroiditis[1].

Celiac disease is a digestive disease where the body cross-reacts with gluten (a protein in wheat, rye, oats, spelt and barley) and certain markers on cells in the intestines. The result can be serious abdominal pain and malabsorption of protein and vitamins. In certain cases, a rash is also present. There is a wide range of symptom severity in celiac disease. Blood tests for celiac disease are available from your doctor; the best tests include anti-endomysial antibody and anti-tissue transglutaminase. Older tests, including anti-gliaden antibodies, are still tested but are less sensitive than newer tests.

Hashimoto’s Thyroiditis is a disease of the thyroid gland, a small organ at the base of the throat. Hashimoto’s ultimately leads to destruction of the thyroid gland, requiring thyroid replacement therapy. Hashimoto’s can present as a disease of increased thyroid function (while the gland is being destroyed extra hormone can enter the circulation), but more commonly it presents as a slow, progressive reduction of thyroid function. Some doctors only test global blood markers of thyroid status (i.e. thyroid stimulating hormone or TSH) when testing the function of the thyroid gland and may not believe in testing antibodies. However, the combination of antibodies called anti-TPO antibodies along with an elevated TSH makes the diagnosis.

Some controversy exists regarding the best reference range for thyroid studies like TSH; my opinion is that clinical signs and symptoms should direct the decision regarding whether or not to replace thyroid hormone, and I think individuals with Type 1 diabetes deserve special consideration when making this decision.

The presence of either of these conditions can have a significant impact on controlling Type 1 diabetes. For example, thyroid abnormalities affect how long insulin stays active in circulation but also regulates metabolic activity, which impacts insulin sensitivity.


“I Can Eat Whatever I Want as Long as I Take Enough Insulin.”

The statement above is one the misconceptions about Type 1 diabetes that I spend considerable time trying to debunk in practice. In my opinion, the worst mistake an individual with Type 1 diabetes can make is to think that they are immune or somehow protected from the dangers of poor diet choices or lack of exercise because they can just use more insulin. In fact, I would propose that because people with Type 1 are more likely to have periodic increases in their blood glucose do to inadequate insulin coverage, it is much more important for people with Type 1 to follow a healthy diet and exercise regularly.

It becomes very difficult clinically when patients with Type1 also develop the features of Type 2 diabetes, i.e. insulin resistance. This “double diabetes” is difficult to manage even with the newest insulin formulations and the best drugs.

So what should someone with Type 1 diabetes eat? Whole, healthy foods low in saturated fat, high in mono and polyunsaturated fats (like olive oil, flax oil, walnut oil, avocado oil, and fish oils) high in fiber with lots of colorful vegetables and fruits and free of refined carbohydrates, fried foods or too much animal-based protein. Sound familiar? It should, because I have written about it a few times in past articles on Type 2 diabetes! (see Are You What You Eat? and Got Fiber). The rules for a healthy diet don’t change for people with Type 1 diabetes. The dietary risk factors for developing insulin resistance and heart disease still apply, despite using extra insulin.


Do Differences in Insulin Therapy and Timing Matter?

There are reasons to think that tissue damage occurs during periods of hyperglycemia, and the degree of damage is proportional to the degree of hyperglycemia. For example, in the United Kingdom Prospective Diabetes Study (UKPDS), if post-meal blood sugar was well-controlled there were fewer complications than others with the same hemoglobin A1c measurement (a measure of blood sugar over about 3 months- rather than just day to day) but without their post-meal glucose well controlled[2]. Although this study was performed on individuals with Type 2 diabetes, there is reason to believe the same degree of damage occurs during hyperglycemia in people with Type 1. Test tube models suggest high blood glucose after meals increased susceptibility of LDL cholesterol to oxidative stress (see Cholesterol: The Good, the Bad and the Ugly for more information on oxidized LDLs) [3]. A study in humans, performed by Monnier et al., found that a measure of oxidative stress, called isoprostanes, was closely correlated to the degree of high blood glucose, suggesting not only average blood sugar is important, but also the variability of blood glucose [2,4].

For these reasons, the timing and type of insulin can matter significantly. For example, many pepople with Type 1 diabetes chose to use pre-mixed insulin in which the long-acting and short-acting insulin are combined. This type of insulin preparation can be used safely and effectively for a long time, but in my opinion, it can be very difficult to finely tune glucose variability because the rapid acting insulin doesn’t often last long enough to cover some part of the day and the long-acting insulin isn’t as stable as some administered separately. The end result are periods of time, sometime hours, during the day when there isn’t enough insulin in circulation to be effective- resulting in high blood glucose and impacting glucose variability. Although separate short- and long-acting insulin requires more injections, the results are frequently better as more precision is possible.

Similarly, checking your blood glucose to see if you need insulin supplements is a good habit. Insulin “supplements” are small doses of short- or rapid-acting insulin, usually only a few units, given to compensate for too low of an insulin dose for a given meal, or to compensate for say a workout that wasn’t quite long enough to bring down glucose to target levels. The best time to use insulin supplements are before meals (if your blood sugar is too high going into a meal, your insulin supplement gets added to the dose you anticipate needed to cover the meal you are about to eat), about 1 hour after an exercise workout and about 3 hours after a meal. You should always check your blood sugar first to see if you need a little extra insulin to get you to target. Although every person responds differently, a good rule of thumb for an insulin supplement is to use one extra unit per 50-point (mg/dL) elevation in blood sugar relative to your goal.


Are There Nutritional Supplements I Should Take if I have Type 1 Diabetes?

Of course, this is a very individualized question depending on the duration of diabetes, whether any complications are present and the status of other health conditions and risk factors, especially risk factors for heart disease. For the generally healthy person with Type 1 diabetes, I do not recommend more than a good quality multivitamin, a healthy diet and regular exercise. However, if complications are present then other supplements can be helpful. Rather than attempt to provide an exhaustive list here, I encourage you to read over the article archives and decide if any of the risk factors or complications I discuss in past articles are relevant to your situation. Since the primary concern with both Type 1 and Type 2 diabetes is the damage caused by high blood sugar, many of the same supplements are very useful.



Type 1 diabetes is no less important to manage than Type 2 diabetes, although in some ways the management is easier due to the obligate need for insulin. Although using insulin does allow one to tightly control blood sugar despite dietary choices, I caution against using insulin to compensate for a poor, highly inflammatory diet; instead I strongly recommend following a healthy, whole foods diet with lots of vegetables and plant-based proteins. Tight blood glucose control- both a low average and a low degree of variability- is important for reducing the risk of developing diabetic complications. Therefore insulin supplements- or small, extra doses taken to correct elevations- are important to incorporate into your daily routine (as needed of course). Finally, nutritional supplements really aren’t necessary in people with well-controlled Type 1 diabetes who remain free of insulin resistance, elevations in other heart disease risk factors, or complications from their diabetes.

Ryan Bradley, ND, MPH     May, 2008


1. Ch'ng, C.L., M.K. Jones, and J.G. Kingham, Celiac disease and autoimmune thyroid disease. Clin Med Res, 2007. 5(3): p. 184-92.

2. Brownlee, M. and I.B. Hirsch, Glycemic variability: a hemoglobin A1c-independent risk factor for diabetic complications. Jama, 2006. 295(14): p. 1707-8.

3. de Castro, S.H., H.C. Castro-Faria-Neto, and M.B. Gomes, Association of postprandial hyperglycemia with in vitro LDL oxidation in non-smoking patients with type 1 diabetes--a cross-sectional study. Rev Diabet Stud, 2005. 2(3): p. 157-64.

4. Monnier, L., et al., Activation of oxidative stress by acute glucose fluctuations compared with sustained chronic hyperglycemia in patients with type 2 diabetes. Jama, 2006. 295(14): p. 1681-7.