Lactose Intolerance
Emily Schwichtenberg
1
Lactose Intolerance: The Difference in Lactose Digestion and
Symptoms.
Emily Schwichtenberg
Advanced Nutrition 361
Abstract
Lactose Intolerance
Emily Schwichtenberg
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Lactose Intolerance is the inability to breakdown the disaccharide lactose. It usually
occurs when the enzyme lactase is produced in low amounts or not at all. When milk is
ingested the main disaccharide, lactose, is broken down into glucose and galactose by the
enzyme lactase in the duodenum. If the enzyme is lacking in a persons body lactose
cannot be broken down and this person is considered lactose sensitive. The lactose can
only sit in the intestine and take in water to dilute it enough until it can pass. This causes
much discomfort especially in the abdominal area and can cause diarrhea and gas. Milk is
a vital daily dietary need; it provides most of the calcium and vitamin D used in our
bodies. Most lactose intolerant people can tolerate a small amount of milk and should try
to drink as much as possible before symptoms occur. There are also other conditions in
our body that would cause similar symptoms such as; irritable bowel syndrome, lactose
malabsorption, and milk allergy. When these conditions are experienced one should not
limit milk intake. Calcium deficiencies are very prevalent and should be avoided at all
costs to reduce future problems with health.
Emily Schwichtenberg
Lactose Intolerance
Emily Schwichtenberg
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Advanced Nutrition
Ellen Lutgen Johnson
10 October 2007
Lactose Intolerance: The Difference in Lactose Digestion and Symptoms.
Experiencing stomach cramps, gas and overall discomfort after eating a meal is
not unusual. However, the cause may not be the same with each person. It is easy to
blame one food group or another and then remove it completely from ones diet. However,
doing this may remove essential vitamins or minerals out of ones body, such as, calcium.
When milk is ingested the main disaccharide, lactose, is broken down into glucose and
galactose by the enzyme lactase in the duodenum. If the enzyme is lacking in a persons
body lactose cannot be broken down and this person is considered lactose sensitive. The
lactose can only sit in the intestine and take in water to dilute it enough until it can pass.
Because there is so much water attained it will pass as diarrhea not as solid feces causing
discomfort for the individual experiencing this process. Explained by Dennis A.
Savaiano, a professor in the department of food science and nutrition at the University of
Minnesota and Michael D. Levitt from the Veterans administration medical center in
Minneapolis, Minnesota:
Lactose-deficient persons cannot digest significant quantities of lactose
due to enzyme insufficiency. Because the disaccharide lactose is not
absorbed, the result of this maldigestion is malabsorption, a lack of blood
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glucose elevation, and the transit of lactose to the large intestine where it
is available for fermentation by the microflora (Savaiano p. 397).
Many people suffer from symptoms associated with lactose intolerance such as: gas,
diarrhea, distension, abdominal cramping, and bloating. Although symptoms may be
similar there are differences in bowel disorders most often confused with lactose
intolerance. Discussed will be the difference between Irritable bowel syndrome,
malabsorption of lactose, lactose intolerance and milk allergy. Treatments of these
symptoms can be easy, such as limiting milk intake where as other options involve taking
medication before milk is ingested. Not every person that experiences symptoms may
have any sensitivity to lactose. There are many misdiagnoses when one diagnosis oneself.
This can cause a person to restrict milk and the intake of calcium when it is not necessary
and could cause more dire problems in the future.
Lactose intolerance is a condition that one either has or does not have; it is not a
“sometimes” occurrence. Many people mistake other conditions for Lactose intolerance
such as, Irritable bowel syndrome. Irritable bowel syndrome, or IBS, is an ailment that
anyone can experience after eating a meal. This “syndrome affects 5% to 20% of the
Western population,” (lactose intolerance in IBS patients p. 7). It is comprised of any
combination of common disturbances of the bowel such as diarrhea or constipation, along
with abdominal pain. This can be caused by emotional or physiological stress, and nonspecific food consumption. “While symptoms such as diarrhea, bloating and flatulence
can occur as a result of lactose maldigestion, they are not specific to lactose maldigestion
and may also be experienced after ingestion of other foods” (self-reported LI pg. 52). As
stated by Heather Lovelace and Susan Barr in their research journal based on self-
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Emily Schwichtenberg
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reported lactose intolerance we can safely say that irritable bowel syndrome is not
directly linked to lactose digestion. It would be best to eat foods that are easily digestible
by the stomach such as soups, breads and grains. It is not necessary to reduce the intake
of any food groups while experiencing irritable bowel syndrome.
The most commonly mistaken condition is malabsorption; it is also the most
closely related. Malabsorption is faulty or inadequate absorption of nutrients by the
intestinal tract where as intolerance is the inability to produce the enzyme to help break
down the nutrient lactose. In this case the enzyme is lactase and the disaccharide is
lactose. Malabsorption occurs when “…glucose in blood does not rise at least
20mg/dl…” (Savaiano et al p. 398). “This is tested either by the lack of rise in blood
glucose or the elevation of alveolar hydrogen” (Savaiano et al p.398). This is tested using
a breathing test after lactose ingestion. Those individuals that are classified as lactose
intolerant will not have blood glucose above 20mg/dl and they will experience one or
more of the symptoms previously mentioned. Although this is a slight difference many
people that have self diagnosed lactose intolerance are more than likely just
malabsorbers. In the study done by Carroccio, Montalto, Cavera, Notarbatolo and the
Lactase Deficiency Study Group looking at the difference between lactose intolerance
and malabsorption:
They took 323 volunteers that fit the demographic of the region and
subjected them to the hydrogen breathing test after an overnight fast and
then 25 grams, or less depending on weight, of lactose suspended 250 to
300 milliliters of water. The breaths were taken every thirty minutes for
three hours. Based on the data collected from this procedure the scientists
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concluded that of the 323: 104/323 subjects (32.2%) as lactose
maldigesters but tolerant, 13/323 subjects (4%) as maldigesters and
intolerants, 3/323 subjects (1%) as digesters but intolerants and 203/323
subjects as digesters and tolerant (Carroccio et al. p 632-633).
These two deficiencies lack the ability to utilize the disaccharide lactose in the body.
With intolerance, lactose cannot be broken down and the body cannot use this for an
energy source. Malabsorption is able to break down the disaccharide it is not actively
absorbed into the blood stream to be used as energy.
The most severe symptoms experienced are by those with a milk allergy. An
allergy is a reaction one receives when they are hypersensitive to the allergen. In this case
it is milk, more specifically usually the proteins in milk. Along with the symptoms
discussed earlier milk allergies can also cause the individual to produce hives, experience
wheezing and trouble breathing, vomit or form a rash. This allergic reaction happens
when:
[Milk] proteins are broken down, [and] macromolecules are formed. These
high-molecular weight food proteins are then absorbed via the intestinal
mucosa. This results in the development of antibodies against cow’s milk
protein and is thought to be a normal physiological response.
(Wilson p. 204).
This process is a predisposition to digestion problems of milk throughout ones life. Milk
allergies can usually be identified in infants. This allows doctors to come up with
appropriate treatments to allow the patient adequate intake of calcium to promote future
bone health.
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If one is not lactose intolerant or allergic there are some simple recommendations
to continue milk and calcium intake along with lowering some symptoms. A small
brochure was put out by the National Dairy Council addressing this issue along with
providing general information about lactose intolerance. The first suggestion is not to
eliminate milk completely; start with small doses of milk “try small portions of milk and
milk products. This allows whatever lactase is there to do its job of digesting the lactose
before it starts causing problems.” Work milk and calcium into the diet “Start with a
smaller portion and slowly increase the serving size of the dairy foods you eat. When you
notice symptoms that may signal your limit for the amount of lactose you can handle at
one sitting.” Take dairy products with other foods. This will help slow the emptying of
the duodenum and may decrease symptoms. “Older is wiser” aged cheeses have most of
the lactose removed during processing. “Aged hard cheeses, such as cheddar, Colby,
Swiss and parmesan, are particularly low in lactose… Look for cultured milk products
such as yogurt with live, active cultures, which contain ‘friendly’ bacteria that help digest
lactose.” Reduce the intake of high lactose milk, “look for lactose-free milk in the dairy
case. It has all the nutrients of regular milk.” If necessary, there are pills that one can
take. It is a lactase enzyme pill that when taken with the first bite or drink of a dairy food
will help ones body digest lactose. Taking these small steps may lower the lactose intake
just enough that one will no longer experience symptoms.
A common problem related to lactose intolerance is the decrease in calcium intake
potentially to a level of inadequacy. There are supplements that can help with this such as
calcium chew-ables and other over the counter pills. Other options recommended by the
“2005 dietary guidelines… [are] milk alternatives within the milk food group, such as
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yogurt and lactose-free milk, are the most reliable and easiest way to derive the health
benefits associated with milk and milk products” (National Dairy Council). Other options
would include cheese, ice cream and soy milk. It is important to consume some sort of
dairy products even if one is lactose intolerant to get the essential mineral, calcium, and
vitamin, vitamin D. These are vital to bone health and growth in all ages.
Milk is the most commonly complained about food in our diet and it is the most
common food allergen. Milk is the food that is most blamed for causing discomfort.
However, only 15% of the white population and 53% among Mexican-Americans and
80% in the black population show prevalence of lactose maldigestion in America
(Lactose Intolerance p. 166s). Often time’s lactose intolerance is self diagnosed and is
usually incorrect. Only a physician can test for intolerance and should prescribe a dairy
free diet or any supplements. This misdiagnosis can result in calcium deficiency and
possible bone and health issues in the future.
Lactose intolerance is not as common as many people think. This misconception
causes many people to decrease their milk intake which directly effects calcium and
vitamin D intake. This could affect bone health and bone strength later in life. Milk is a
vital part of our diet. Most discomfort can be avoided with smaller does of milk
throughout the day. This will also help with calcium absorption. Overall, only a physician
can diagnose anyone with intolerance and one should not diagnose oneself.
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Emily Schwichtenberg
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References
A. Carroccio, G. Montalto, G. Cavera, A. Notarbatolo, and the Lactose Deficiency Study
Group. (1998). Lactose intolerance and self-reported milk intolerance: Relationship
with lactose maldigestion and nutrient intake.17 (6), 631-636.
Carlos Felipe Bernarders-Silva, Alexandre C. Perira, Gloria de Fatima Alves da Mota,
Jose Eduardo Krieger, Antonio Atilio Laudanna. (2007). Lactase Persistence/nonpersistence variants, C/T_13910 and G/A_22018, as a diagnostic tool for lactose
intolerance in IBS patients. Science Direct, 7-11.
Dennis A Savaiano, Michael D. Levitt. (1987). Milk intolerance and microbe-containing
dairy foods.70 (2), 397-406.
Heather Y. Lovelace & Susan I. Barr. (2005). Diagnosis, symptoms and calcium intakes
of individuals with self-reported lactose intolerence.24 (1), 51-57.
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Janice Wilson. (2005). Milk intolerance: Lactose intolerance and cow's milk protein
allergy. Newborn and Infant Nursing Reviews, 5(4), 203-207.
National Dairy Council. (2007). The Lowdown on Lactose Intolerance: Making the Most
of Milk.
Tuula H Vesa, Philippe Marteau and Riitta Korpela. (2000). Lactose intolerance.19 (2),
165s-175s.