Hereï¿½s a listing of the studies of LI demonstrating its largely mythical nature...
This is the big one. It got published in newspapers all the across the nation and was quite a surprise by both the general public and the medical community...Suarez FL. Savaiano DA. Levitt MD.A comparison of symptoms after the consumption of milk or lactose-hydrolyzed milk by people with self-reported severe lactose intolerance. [see comments].New England Journal of Medicine. 333(1):1-4, 1995 Jul 6.BACKGROUND. Ingestion of a large dose of the milk sugar lactose--for example, the 50-g load in 1 liter of milk--causes symptoms such as abdominal pain, diarrhea, bloating, and flatulence in the majority of people with lactose malabsorption. It is uncertain whether the ingestion of more common doses of lactose, such as the amount in 240 ml (8 oz) of milk, causes symptoms. Some people insist that even smaller quantities of milk, such as the amount used with cereal or coffee, cause severe gastrointestinal distress. METHODS. In a randomized, double-blind, crossover trial, we evaluated gastrointestinal symptoms in 30 people (mean age, 29.4 years; range, 18 to 50) who reported severe lactose intolerance and said they consistently had symptoms after ingesting less than 240 ml of milk. The ability to digest lactose was assessed by measuring the subjects' end-alveolar hydrogen concentration after they ingested 15 g of lactose in 250 ml of water. Subjects then received either 240 ml of lactose-hydrolyzed milk containing 2 percent fat or 240 ml of milk containing 2 percent fat and sweetened with aspartame to approximate the taste of lactose-hydrolyzed milk; each type of milk was administered daily with breakfast for a one-week period. Using a standardized scale, subjects rated the occurrence and severity of bloating, abdominal pain, diarrhea, and flatus and recorded each passage of flatus. RESULTS. Twenty-one participants were classified as having lactose malabsorption and nine as being able to absorb lactose. During the study periods, gastrointestinal symptoms were minimal (mean symptom-severity scores for bloating, abdominal pain, diarrhea, and flatus between 0.1 and 1.2 and 2 over black square];.[1 and 2 over black square] indicated trivial symptoms; and 2, mild symptoms]). When the periods were compared, there were no statistically significant differences in the severity of these four gastrointestinal symptoms. For the lactose-malabsorption group, the mean (+/- SEM) difference in episodes of flatus per day was 2.5 +/- 1.1 (95 percent confidence interval, 0.2 to 4.8). Daily dietary records indicated a high degree of compliance, with no additional sources of lactose reported. CONCLUSIONS. People who identify themselves as severely lactose-intolerant may mistakenly attribute a variety of abdominal symptoms to lactose intolerance. When lactose intake is limited to the equivalent of 240 ml of milk or less a day, symptoms are likely to be negligible and the use of lactose-digestive aids unnecessary.
What follows below is what Carper leaves out of his ï¿½up-to-dateï¿½ website...Suarez FL. Savaiano D. Arbisi P. Levitt MD.Tolerance to the daily ingestion of two cups of milk by individuals claiming lactose intolerance.American Journal of Clinical Nutrition. 65(5):1502-6, 1997 May
.We reported previously that consumption of one cup of milk (240 mL) per day produced negligible symptoms in lactase-nonpersistent (LNP) individuals self-described as being severely lactose intolerant. We hypothesized that such LNP individuals could also tolerate two cups of milk per day if taken in two widely divided doses with food, and that psychologic factors play a role in perceptions of lactose intolerance. The Minnesota Multiphasic Personality Inventory 2 (MMPI-2) was administered to 19 LNP subjects self-described as markedly lactose intolerant (S-LNP), 13 LNP subjects who denied lactose intolerance (A-LNP), and 10 lactase-persistent individuals who believed they were lactose intolerant (S-LP). Symptoms were recorded when LNP subjects ingested 240 mL regular or lactose-hydrolyzed milk twice daily for 7 d in a double-blind crossover study. The results showed that neither LNP group had a significant increase in symptoms (P < 0.05) during the regular compared with the lactose-hydrolyzed milk periods. However, S-LNP subjects reported significantly greater gaseous symptoms than did the A-LNP subjects during both treatment periods. The MMPI-2 showed a high score on the "lie" validity scale for S-LNP subjects. We conclude that LNP subjects tolerate two cups of milk per day without appreciable symptoms.
S-LNP subjects have underlying flatulence that is misattributed to lactose intolerance. MMPI-2 results were of questionable validity because of the high rate of dissimulation by LNP subjects.Suarez FL. Adshead J. Furne JK. Levitt MD.Lactose maldigestion is not an impediment to the intake of 1500 mg calcium daily as dairy products. [see American Journal of Clinical Nutrition. 68(5):1118-22, 1998 Nov.
BACKGROUND: A National Institutes of Health consensus conference concluded that a daily calcium intake of 1500 mg reduces the severity of osteoporosis. Because dairy products are the main natural source of dietary calcium, a diet providing 1500 mg Ca must contain large quantities of dairy products. However, it is widely believed that the lactose content of these products will not be tolerated by persons with lactose maldigestion (approximately 30% of the adult US population). OBJECTIVE: We evaluated the symptoms of lactose maldigestion and digestion when the diet was supplemented with dairy products providing 1300 mg Ca/d. DESIGN: Sixty-two women (31 with lactose maldigestion and 31 without) were studied in a double-blind, randomized protocol. Symptoms were compared during 1-wk periods when the diet was supplemented with 480 mL (2 cups) milk, 56 g cheese, and 240 mL yogurt provided as conventional products (34 g lactose/d) or as lactose-hydrolyzed products (2 g lactose/d). RESULTS: Women who digested lactose reported no significant difference in symptoms between the 2 treatment periods. Women with lactose maldigestion reported significantly increased flatus frequency and subjective impression of rectal gas during the period of high lactose intake; however, bloating, abdominal pain, diarrhea, and the global perception of overall symptom severity were not significantly different between the 2 treatment periods. CONCLUSION: The symptoms resulting from lactose maldigestion are not a major impediment to the ingestion of a dairy-rich diet supplying approximately 1500 mg Ca/d.
Hertzler SR. Huynh BC. Savaiano DA.How much lactose is low lactose?.Journal of the American Dietetic Association. 96(3):243-6, 1996 Mar.
OBJECTIVE: To test the hypothesis that complete elimination of lactose is not necessary to ensure tolerance by lactose maldigesters. DESIGN: Double-blind, randomized protocol in which challenge doses of 0, 2, 6, 12, and 20 g lactose in water were fed to subjects after a 12-hour fast. SUBJECTS: 13 healthy, free-living adults who were lactose maldigesters. MAIN OUTCOME MEASURES: Breath hydrogen production (a measure of maldigestion) and symptom response to each challenge dose. STATISTICAL ANALYSIS: Analysis of variance was done to determine overall differences in mean hydrogen gas production (peak and sum of hours 1 through 8). Friedman's test was used to determine overall differences in the mean ranks for each symptom. Fisher's least significant difference test was used for multiple comparisons for hydrogen and symptom and data. RESULTS: Hydrogen production after consumption of the 0- and 2-g lactose doses was not significantly different. Hydrogen production increased with the 6-g dose. Intensity of abdominal pain increased when the dose of lactose was 12 g. Episodes of flatulence did not increase until the dose reached 20 g. No significant differences in the occurrence of diarrhea were observed after the five treatments. CONCLUSIONS: No significant increase in breath hydrogen production or intolerance symptoms occurred after consumption of a 2-g dose of lactose. Up to 6 g was tolerated, even though maldigestion could be measured at the 6-g dose. Thus, lactose maldigesters may be able to tolerate foods containing 6 g lactose or less per serving, such as hard cheeses and small servings (120 mL or less) of milk
The studies above were all done in Minneapolis, but check this out...Vesa TH. Korpela RA. Sahi T.Department of Public Health, University of Helsinki, Finland.Tolerance to small amounts of lactose in lactose maldigesters. [see comments].American Journal of Clinical Nutrition. 64(2):197-201, 1996 Aug.
In this study we examined whether small doses of lactose induced symptoms in 39 lactose maldigesters and 15 lactose digesters in a randomized, crossover, double-blind design. The test doses were 200 mL fat-free, lactose-free milk to which 0, 0.5, 1.5, and 7 g lactose was added. Every third day of a lactose-free diet, after an overnight fast, the subjects drank one of the test milks in random order and registered the occurrence and severity of gastrointestinal symptoms in the next 12 h. During the study, the maldigesters reported significantly more abdominal bloating (P = 0.0003) and abdominal pain (P = 0.006) than the digesters. There was no difference in the mean severity of the reported symptoms between the test milks and the lactose-free milk in the group of lactose maldigesters, of whom one-third did not experience any symptoms from any of the test doses. The same proportion (64%) of the maldigesters experienced symptoms after both the lactose-free milk and the milk with 7 g lactose. However, the symptoms occurred inconsistently with the different test doses in 59% of the maldigesters. Thus, it can be concluded that the gastrointestinal symptoms in most lactose maldigesters are not induced by lactose when small amounts (0.5-7.0 g) of lactose are included in the diet.
Carroccio A. Montalto G. Cavera G. Notarbatolo A.Istituto di Medicina Interna, Universita di Palermo, Italy.Lactose intolerance and self-reported milk intolerance: relationship with lactose maldigestion and nutrient intake. Lactase Deficiency Study Group.Journal of the American College of Nutrition. 17(6):631-6, 1998 Dec.
BACKGROUND: The relationship between lactose-maldigestion, self-reported milk intolerance and gastrointestinal symptoms has not been clearly defined. OBJECTIVES: To evaluate: a) the prevalence of lactose maldigestion and lactose intolerance in a sample of the general population taken from a rural center;
the frequency of self-reported milk-intolerance and its correlation with lactose-maldigestion; c) the influence of lactose maldigestion, lactose intolerance and self-reported milk intolerance on dietary habits and consumption of total calories, protein, and calcium. SUBJECTS: We studied a randomized sample of the general population in a small center in Sicily. 323 subjects (150 males, 173 females), age range 5 to 85 years (median 44) were included and underwent H2-breath test after 25 g lactose load. The preliminary dietary investigation spanned 7 consecutive days using a printed dietary form and was under the daily control of a team of dietitians. METHODS: The dietary investigation was completed in the first part of the study and the results were analyzed for nutrient composition by a computerized database. The subjects were then divided into self-reported milk-intolerants and self-reported milk-tolerants and they underwent H2 breath testing; subjects with H2 concentration >20 ppm over the baseline concentration were considered maldigesters and those with one or more symptoms were classified as intolerants. RESULTS: 104/323 subjects (32.2%) were lactose maldigesters but tolerants, while 13/323 (4%) were lactose maldigesters and intolerants. In each age-class group (pediatric, adult, and elderly subjects) only the lactose maldigester and intolerant subjects showed differences in nutrient intake with a significantly lower daily consumption of milk and a lower calcium intake. 49/323 subjects were self-reported milk-intolerants; of these, 26 (53%) were lactose maldigesters but tolerants, 18 (37%) were lactose digesters and tolerants and only 5 (10%) were lactose maldigesters and intolerants. In the whole group of self-reported milk-intolerants, dietary milk consumption was significantly reduced and calcium intake was lower than in all the other subjects studied (320 mg/day vs. 585 mg/day, p<0.05). CONCLUSIONS: In studies of the general population, the frequency of lactose intolerance is much lower than that of lactose maldigestion. Gastrointestinal symptoms after lactose load in self-reported milk-intolerants are found in only a very low number of these subjects. Furthermore, in these subjects we observed an unnecessary reduction in milk consumption and an insufficient dietary calcium intake.
Parker TJ. Woolner JT. Prevost AT. Tuffnell Q. Shorthouse M. Hunter JO.Irritable bowel syndrome: is the search for lactose intolerance justified?.European Journal of Gastroenterology & Hepatology. 13(3):219-25, 2001 Mar.
OBJECTIVES: To determine if confirmation of hypolactasia offers any benefit to the dietary treatment of patients with irritable bowel syndrome (IBS). METHODS: One hundred and twenty-two consecutive IBS patients (37 male, 85 female) were given lactose hydrogen breath tests (LHBT). Those with positive LHBT followed a low lactose diet for 3 weeks. Those improving on the diet were given double-blind, placebo-controlled challenges (DBPCC) with 5 g, 10 g and 15 g of lactose and a placebo, to confirm lactose intolerance. Those who did not respond to the low lactose diet followed either an exclusion or low fibre diet. Symptoms scores were kept prior to the LHBT, 8 h post-LHBT and daily whilst following any dietary change. Patients with negative LHBT returned to clinic and subsequent dietary interventions were recorded. RESULTS: LHBT was positive in 33/122 (27%) IBS patients. Syrr otom scores prior to LHBT were not significantly different between the two groups, but after LHBT the symptoms in the positive group were significantly worse. Twenty-three patients followed a low-lactose diet of which only nine (39%) improved. Six who did not improve followed an exclusion diet, three improved and all were intolerant of milk. Three tried a low fibre diet with two improving. DBPCC were inconclusive. In the negative LHBT group 35 agreed to try a diet and 24 improved (69%). Eight were intolerant of cow's milk. CONCLUSIONS: Use of a low lactose diet was disappointing in IBS patients with lactose malabsorption.
Food intolerance was demonstrated in IBS patients with positive or negative LHBT and milk was identified as a problem in both groups. DBPCC were inconclusive. There appears to be little advantage in trying to separate patients who malabsorb lactoseSome of these studies were done in Europe, so it does appear that LI is not a problem for people living there either. So they can't use this as an excuse to emigrate to the US
------------------I am not a doctor, nor do I work for profit in the medical/pharmacological field, but I have read scientific and medical texts, and have access to numerous sources of medical information that are not readily available to others. One should always consult a medical professional regarding advice received.[This message has been edited by flux (edited 09-20-2001).][This message has been edited by flux (edited 09-20-2001).]