 Soy
and the Gluten-Free Diet:
A Perfect Match
By Cynthia Kupper,
RD, CD
The number of people following a gluten-free lifestyle is growing
exponentially. Persons with celiac disease follow a medically required
gluten-free diet, while other people choose a gluten-free diet
for various reasons.
Celiac disease is an
immune mediated disorder causing damage to the small intestine,
but with symptoms affecting every body system. Ingestion of the
storage proteins (gluten) found in wheat, rye and barley causes
a t-cell reaction, causing inflammation and various degrees of
villous atrophy with ensuing malabsorption and malnutrition. The
prevalence of celiac disease in the US is about 1:133 persons,
or 3 million people. Worldwide the prevalence is 1:250-300. Higher
risk of celiac disease exists in first and second generation family
members and specific risk groups – persons with anemia, IBS,
type 1 diabetes, thyroid disease, rheumatoid arthritis, some with
bone disease, infertility, failure to thrive, and other types of
autoimmune disorders. Each time a person with celiac disease consumes
gluten damage is done to the intestine. Chronic exposure
and/or non-compliance with the gluten-free diet (GFD) increased
risk of premature bone disease and GI cancers. Dermatitis herpetiformis
(DH) is the skin form of celiac disease. While its skin symptoms
can be treated with Dapsone, without following a GFD, persons with
DH will ultimately also develop GI symptoms.
Some persons following
a GFD do not meet the diagnostic criteria f or celiac disease
(a positive small intestine biopsy consistent with celiac disease);
yet find the removal of gluten to be a positive health benefit.
There is little understanding of exactly what gluten sensitivity
is, if it is not celiac disease. Using the food sensitivity test
, gluten sensitivity may also be called a wheat allergy. Allergies
are reactions to proteins in foods. Wheat is included in the
top eight allergens in the US. Some allergy experts believe that
the allergic response for those with a wheat allergy is to the
same protein that people react to with celiac disease. The difference
is the type of reaction. Common food allergies are IgE antibody–mediated
reactions. They are immediate and can have life-threatening consequences.
Celiac disease, on the other hand is a delayed allergic-type
response caused by a t-cell reaction. These types of reactions
do not have an immediate life threatening response, but rather
a delayed reaction that includes damage to the intestines and
subsequent associated complications from malabsorption of nutrients.
Still other people
may choose a gluten-free lifestyle for other reasons, not related
to an allergic reaction, but rather food sensitivity. It is possible
that, for some, gluten causes a drug-like reaction between the
brain and gut. An example of this may be autism, in which one
theory suggests that gluten (and casein) causes a drug-like effect.
When removed from the diet some persons with autism spectrum
disorders show improvement in their ability to respond positively
to their environment. A metabolic reaction may cause others to
remove gluten. Some people do not digest wheat and other gluten-containing
grains well. They report feeling better when they do not eat
them. Food intolerances such as this are generally to the carbohydrate
or other chemical in the food, rather than to proteins as in
true food allergies. Others remove gluten for various other reasons:
chronic pain and fatigue syndromes, gluten ataxia, migraines,
etc. The role gluten plays in these conditions is not understood.
Whatever the reason,
marketing research tells us that the sale of gluten-free products
has been growing at a rate of 27 percent since 2001 and reached
over $696 million in 2006.
The current accepted
definition of a gluten-free diet in the US avoids all proteins
from wheat, rye, barley and hybrids of these grains, such as
spelt, kamut and triticale. Products that are rendered gluten-free
by removing the proteins, such as vinegar and distilled alcohols,
are allowed in the diet. For persons with celiac disease the
diet is strict and lifelong. A gluten-free diet is currently
the only treatment for celiac disease. While the gluten-free
diet is used for a number of other reasons, it is not clear that
the diet is beneficial in those conditions except on a case-by-case
basis.
Some studies have
shown that persons following a gluten-free diet for several years
may possibly be lacking fiber, B-vitamins, calcium, iron and
magnesium. Persons with celiac disease are also known to have
increased risk for associated health conditions.
Using soy in a
Gluten-free diet may be beneficial in some of these health conditions
reviewed in the chart below. Soy can also play an important role
in improving the overall quality of the gluten-free diet.
| Health/Nutrition Concern |
Role to Celiac Disease |
Role Soy Plays |
|
| Lactose
Intolerance and Calcium Deficiency
|
A
number of persons (up to 20%) with celiac disease experience transient
food intolerances. One of the most common is dairy, generally seen
as lactose intolerance. Without calcium from dairy foods, persons with
celiac disease, already at risk for bone disease, may be at even greater
risk when they are unable to use dairy foods.
Persons with CD may not get adequate calcium from their diet in general
due to dietary choices.
|
Soy
milks can be used as a milk replacement. Many soy foods are a good
source of calcium or are fortified with calcium. Soy protein is
an excellent alternative for persons who have trouble digesting dairy
products.
Soy milk is an excellent milk alternative in GF baking. Soy milk adds additional
protein to GF baked goods, which improves the texture and taste of breads,
cakes, muffins and cookies. Soy milk can be substituted in equal amounts
for cow’s milk in GF recipes. |
|
| Bone Health |
Persons with celiac disease often have
a greater risk of developing early osteopenia and osteoporosis as a result
of the malabsorption of key nutrients. One large study shows that over
60% of women with celiac disease in their 40’s have signs of early
bone disease. This same study showed men in their 40’s also had
significant signs of early bone disease, and over 85% of postmenopausal
women with CD have bone disease. Some early studies suggest that even
children with CD can have signs of bone disease. |
Studies show that people consuming
most of their protein from vegetable sources, such as soy, have less
hip fractures.
Studies in women show that soy protein and isoflavones can have a positive
affect on the bone mineral density of the spine. |
|
| Increased Lipid Levels |
In studies of the general
population, a highly refined and concentrated carbohydrate diet has been
shown to cause an increase in blood lipid levels and cause a potential
increased risk of cardiovascular disease.
GFD can be highly refined and concentrated in carbohydrates, which could
lead to increased cholesterol, lipids and triglycerides, and an increased
risk of heart disease in persons with CD. This is theory and has not been
studied to date in persons with CD. |
Studies have shown that
soy protein can be beneficial to lowering lipids, cholesterol, and risk
of heart disease when combined with a diet lower in saturated fats and
cholesterol.
The isoflavones in soy protein may help to lower
total cholesterol, LDL (bad fats) and triglycerides. Soy protein
may also aid in increased artery elasticity and reduction in plaque
build-up in arteries
Soy is naturally low in saturated fat and is cholesterol-free. |
|
| Obesity |
GFD can be highly refined and concentrated in carbohydrates.
Without realizing it, persons following a GF diet may be consuming more
total calories from the GF products they use. This can lead to an increased
risk of obesity.
|
Soy foods have a low glycemic index. Soy
is a low-fat, high-quality protein and energy source. This combination
along with an overall healthy diet and exercise program can help in weight
control and loss.
Generally it has been recommended that a healthy diet include whole grain
carbohydrate sources. This can in turn control the total carbohydrates eaten,
while providing increased fiber in the diet, both which can aid in calorie
control and weight management. When you cannot have whole grains as part
of your diet, it is recommended by some that use of low glycemic foods is
helpful in weight control. |
|
| Diabetes |
As the celiac population ages and becomes increasingly
overweight and obese, there is not only increased risk of autoimmune (Type
1 diabetes) but also an increased risk of type 2 diabetes. |
|
|
| Glycemic control |
Approximately 4-15% of people with celiac
disease also have type 1 diabetes. For these people it is sometimes difficult
to regulate their blood sugars, in part due to the wide range of carbohydrate
content of GF foods and their impact on blood sugars.
Choosing low glycemic foods may be beneficial to blood sugar control for
type 1 diabetic/celiac persons. Persons with insulin resistance may also
benefit from using low glycemic foods to assist with weight control and ultimately
insulin resistance.
|
In a study of the glycemic
level of soy foods, soy foods tested have had a low glycemic index,
suggesting that soy foods may be an appropriate part of diets intended
to improve control of blood glucose and insulin levels.
Low glycemic foods are digested and absorbed slower, allowing better blood
sugar control.
|
|
| Poor Fiber Intake |
The GF foods are highly refined and generally
lacking in significant sources of fiber.
|
Whole soy beans, tempeh,
soy flour and textured soy protein are high in fiber. 1 cup of
defatted soy flour contains about 17 grams of fiber, while whole fat
soy flour contains 8 grams of fiber.
Most processed soy foods such as tofu and soymilk do not contain much fiber.
|
|
Low Nutritional Quality of the Diet
Adequate
Protein |
The traditional GFD uses flours
and starches that are low in nutritional value.
Persons with classic celiac disease may find themselves with depleted
protein stores due to malabsorption.
Persons who follow a vegetarian/gluten-free lifestyle may not balance
the vegetable sources of proteins in their diet |
Soy is an excellent GF Grain/Starch Alternative.
Soy is one of the original starches identified as an alternative to wheat
in gluten-free foods. The other original GF starch alternatives (white
and brown rice flour, potato flour and starch, and tapioca starch) add
limited nutritional value to GF foods. Soy offers an excellent source
of fiber, nutrients, and is a complete protein source (similar to meats,
eggs, and milk).
Soy is a rich source of B-vitamins (niacin, B6 and folacin), and a source
of other nutrients - zinc, .copper and magnesium, and iron. The iron
in soy is best absorbed by adding a vitamin C food with it, such as oranges
or tomatoes. The best sources of iron in soyfoods are found in fermented
soy products, such as tempeh and miso.
Soy protein makes a great meat-free alternative for people following a
vegetarian diet. It can also be added as a supplement to boost the protein
content of foods. Soy offers more protein than other legumes.
Many soyfoods are gluten-free including soy milks, tofu, and soy frozen desserts.
When soy is used in meat alternatives, it may be blended with gluten-containing
grains. Few vegetarian meat alternatives however are GF. |
|
| Cancer Reduction |
Persons with CD are at a greater risk of developing
cancers of the GI tract, IF they are not compliant with
the GFD. One study suggests the increased risk is five times normal. However
the good news is that, IF a person with celiac disease
adheres to a GFD for 5 years, their risk of cancers of the GI tract is
less than the general population. |
Some studies suggest that
components in soy, such as isoflavones and soy protein, may have beneficial
effects on reducing risks of some types of cancer and tumor growth.
This is an area that requires further study. |
For a healthier gluten-free diet add soyfoods. Soy is an excellent
food to use in the gluten-free diet. There are a number of sources
for gluten-free recipes using soy. A listing of some books can
be found at http://gluten.net/books.htm.
For more information on celiac disease or other forms of gluten
sensitivity, please visit www.gluten.net – health
information.
Cynthia Kupper, RD, CD
Executive Director
Gluten Intolerance Group of North America®
31214 - 124 Ave SE, Auburn WA 98092-3667
|
