Survey questions «Questionnaire on lactose intolérance© » available : http://www.medisport.be.
Many links concerning lactose intolerance are available on line.
Lactose intolerance affects more than 50 million Americans. It is one of the most common gastrointestinal disorders seen by primary care physicians. Lactose intolerance is commonly misdiagnosed because of its overlapping symptoms of diarrhea and abdominal bloating. When this disorder is properly diagnosed, the patient is easily treated with education and dietary.
Our study of the symptoms of lactose intolerance highlights a high percentage of diarrheas among diagnosed as lactose intolerant people. The symptoms are often felt by them either as a «discomfort»or as a «great discomfort»" in their everyday life.
The «classic» treatment often choosen by lactose intolerant people is a complete elimination of lactose in their diet. But this is not the best solution because it geopardizes the necessary daily intake of calcium. Moreover it is rather rare that someone has to totally eliminate milk or dairy products from his diet.
· Improvement of dietetic awareness of lactose intolerant people. Indeed, our study as shown that they absorb insufficient quantities of dairy products and of substitutive dairy products (lactose free dairy products).
The degree of lactose tolerance varies from one person to another. Thanks to individual tolerance test, on one hand, and to appropriate dietetic guidelines, on the other hand, a pertinent solution to the problem can be found and should allow lactose intolerant people to live comfortably without symptoms nor deficiencies.
Lactose intolerance is due to the impossibility to digest significant quantities of lactose, the most important sugar of milk. This deficiency is the consequence of a shortage of the enzyme called lactase (lactase phlorizin hydrolase), which is normally produced by the cells that line the small intestine. Lactase deficiency leads to the maldigestion of lactose : the intestine is unable to hydrolize the totality of lactose into glucose and galactose. This leads to a malabsorption of lactose. The not digested lactose in the small intestine can cause the symptoms felt by the lactose intolerant people : cramps, distensions, gases or diarrhea. These symptoms generally appear from 30 minutes till 2 hours after lactose intake. The importance of the symptoms depends on the quantity of residual intestinal lactase, the quantity of lactose intake and the conditions of ingestion (for example: the lactose has been intake with or without other food). This explain why the symptoms can varie significantly from one person to another.
· secondary deficiency is generally a temporary state due to a deterioration of the mucous membrane of the small intestine. It lasts approximately one week after recovery. Young babies (infants) and children suffering from gastro-intestinal infection or malnutrition are particularly vulnerable to this type of secondary deficiency of lactase enzyme. It can also be caused by a coeliac disease, by an allergy to cow's milk, by certain drugs and by gastro-intestinal surgery (1).
· to define the symptoms described by people claiming they suffer from lactose intolerance and to try to establish if such symptoms were attenuated by the adoption of a specific diet.
· to explore dietetic knowledge of people claiming they are lactose intolerant and to determine if there are differences in the food habits between the people " believing to be lactose intolerant " and the " diagnosed as lactose intolerant people ".
This study aimed adult people (18 years old & older) and covered, in addition to potentially lactose intolerant people, health professionals such as : physicians, dieticians and nurses who could fill out the questionnaire for one of their patients.
The survey took place between December 15, 2000 and March 31, 2001 by means of a questionnaire published on an Internet site.
· 20 questions concerning life style and food habits.
For some questions a CHI-SQUARE statistical test(X2) has been applied. When the result is statistically significant, it is taken again accompanied by the threshold of significance.
All participants answered themselves to the questionnaire. The characteristics of the participants are described in table 1.
Group 3: 16 people not belonging to the 2 above mentioned sub-groups.
The most frequent complaints are diarrheas (75 %) in the " diagnosed as intolerant " sub-group and pains - cramps and flatulences (69,2 %) in the " believing to be intolerant ".
Did you take synthetic lactase ?
Synthetic lactase seems to decrease significantly the symptoms of lactose intolerance "quite as much" in the " believing to be intolerant " sub-group (85,7 %) as in the " diagnosed as intolerant " sub-group (90 %).
In your opinion : can you find any lactose in following food ?
We have noticed a VERY BAD KNOWLEDGE in the 2 sub-groups (16 % of good answers) for pork-butcheries.
For other foods or industrial food products, there is a real lack of information : croissants, biscuits (cookies) (57 %), eggs (58,2 %) and commercial mayonnaise, dressings (59,5 %).
Do you consume following dairy products ?
· Persons in the " diagnosed as intolerant " sub-group consume AS MUCH AS cream than persons in the " believing to be intolerant "
Do you consume lactose free products (substitute of the dairy products ) ?
The most consumed lactose free products are the soya milk, sorbets, soya desserts, milk lactose reduce and the soya yoghourt. Those products are consumed mainly by the diagnosed lactose intolerant persons. However it is important to notice that from 57 % to 76 % of the participants don't consume any lactose free products.
Do you consume following cheeses ?
Let us notice that FEW participants consume cheese (from 20 to 30 %).
Persons in the "diagnosed as intolerant " sub-group consume DEFINITELY LESS Gouda, goat's cheese, fromage frais (soft white cheese) and cheese spread than persons in the " believing to be intolerant " sub-group. Persons in the " diagnosed as intolerant " sub-group consume MORE Gruyere, Camembert cheese and Brie cheese than persons in the " believing to be intolerant " sub-group.
Do you tolerate following cheeses ?
Note: by Swiss cheese it is necessary to understand hard cheese : Gruyère or Emmenthal cheese.
As well as a clinical point of view as a dietetic point of view, this study tried to show relevant differences between persons in " diagnosed as intolerant " and persons " believing to be intolerant ".
Those two aspects are synthesized with through on the one hand symptoms and on the other hand dietetic knowledge and diet habits.
· the strong percentage (75 %) of diarrheas found in the " diagnosed as intolerant " sub-group shows that for main persons in the " diagnosed as intolerant " sub-group the problem is serious and not under control. Moreover for 60 % of the persons concerned, symptoms are felt like " discomfort " or " great discomfort " in their everyday life. The obtained results are in adequacy with the literature (1) (2) (3) (4) : diarrheas, pains - cramps and flatulences.
· synthetic lactase seems to have a very good efficiency considering the reduction of lactose intolerance symptoms. These high percentages of symptoms reduction is very similar in the 2 sub-groups (85,7 % and 90 %), whatever the sub-groups of participants. These results have to be confirmed in a future survey. Despite, from now it seems interesting to sensitize persons "diagnosed as intolerant " and moreover persons " believing to be intolerant " to test the benefit of the synthetic lactase. Moreover since the use of this product seems not very widespread.
· In the " diagnosed as intolerant " sub-group : the LACTOSE FREE DIET seems to have the MOST SIGNIFICANT IMPACT on symptoms disappearance. This observation is still reinforced by the fact that in this sub-group the symptoms are not attenuated by a diet with a LOW lactose intake.
· The " believing to be intolerant " sub-group did not test such diets definitely more often than the " diagnosed as intolerant " sub-group. In the same way, the " believing to be intolerant " did not test lactose free diets because they were not aware of such diets more often than "diagnosed as intolerant " sub-group. This considerable proportion (1/5) which does not know these adapted diets (and which probably would have tested them if they had known them) illustrates the work which it remains to make, as well sensitizing as of popularization of these lactose free diets or low lactose intake diet.
· Synthetic lactase is mainly consume by " diagnosed as intolerant " sub-group. A promotion (as well in the " diagnosed as intolerant " sub-group as in the " believing to be intolerant " sub-group ) for an improvement of the use of this product should be necessary, according to the great efficiency of this product.
· the 2 sub-groups have a VERY GOOD knowledge of the lactose content for milk. For prepared dishes : the knowledge is VERY GOOD in the " diagnosed as intolerant " sub-group and GOOD in the " believing to be intolerant " sub-group. On the other hand for pork-butcheries : the knowledge is VERY BAD in the 2 sub-groups. Within the framework of a nutritional education it should be necessary to insist on this food products or preparated food products. These figures are the witnesses of the ignorance of the participants. This lead us to insist on the importance of an adapted nutritional information.
· It would be advisable to sensitize " diagnosed as intolerant " as " believing to be intolerant " those persons witch kind of dairy products, substitute for dairy products and cheeses they are able to digest. The objective is : to try to reach a sufficient daily calcium intake, without or with the appearance of few symptoms.
· Mention that " diagnosed as intolerant " tolerate tofu AS MUCH AS lactose free cheese.
· the case of each lactose intolerant person is different. There is probably as much lactose intolerance as lactose intolerant individuals. The only way of knowing the lactose tolerance degree of an individual is to carry out tests. It is rather rare that someone has to totally eliminate milk or dairy product from his diet (5).
· It is necessary always to keep in mind that the dairy products are our principal source of calcium (6) (7).
· In addition, it was proven that the gradual increase consumption of lactose containing foods, increases the lactose tolerance among intolerant persons (1) (3) (4).
· Use of synthetic lactase should be promote, according to the great efficiency of this product (as well in " diagnosed as intolerant " sub-group as in the " believing to be intolerant " sub-group).
· Improvement of dietetic awareness of lactose intolerant people. Indeed, our study as shown that they absorb insufficient quantities of dairy products and of substitutive dairy products. Appropriate dietetic guidelines, is a pertinent solution to the problem and should allow lactose intolerant people to live without symptoms nor deficiencies.
We would conclude by mention the great interest of lactose intolerant people to find useful information. In the field of lactose intolerance it seems possible to share informations and resources with the " peers " and contribute to improve the knowledge and the management of the symptoms. A future survey especially devoted to precise the use and the impact of the synthetic lactase could be interesting and should be very useful. Also, we would be very happy if this article could suggest interest in this direction to the scientific community.
NIDDK- National Digestive Diseases Information Clearringhouse.
New York, pages 190-204, ISBN 0-8160-3127-4.
New York, pages 55-64, ISBN 0-8160-3127-4.
New York, page 56, ISBN 0-8160-3127-4.
New York, page 55, ISBN 0-8160-3127-4.
New York, page 57-62, ISBN 0-8160-3127-4.
New York, pages 81-99, ISBN 0-8160-3127-4.