Lactose intolerance: Causes, effects, diagnosis and symptom control

Lactose intolerance is a very common complaint which leads to a number of distressing gut symptoms in those affected. It can be quite easy to control by reducing milk consumption, and possibly by adding lactase to the diet. However, clinicians should be wary of over-diagnosing this condition, particularly in the indigenous white population, and thereby depriving the individual of a useful, cheap and nutritious food. If lactose intolerance is suspected, it should be carefully investigated and diagnosed, prior to the introduction of dietary management. </jats:p

Lactose Intolerance: Common Misunderstandings

Lactose intolerance primarily refers to a syndrome having different symptoms upon the consumption of foods containing lactose. It is one of the most common form of food intolerance and occurs when lactase activity is reduced in the brush border of the small bowel mucosa. Individuals may be lactose intolerant to varying degrees, depending on the severity of these symptoms. When lactose is not digested, it can be fermented by gut microbiota leading to symptoms of lactose intolerance that include abdominal pain, bloating, flatulence, and diarrhea with a considerable intraindividual and interindividual variability in the severity of clinical manifestations. These gastrointestinal symptoms could be similar to cow's milk allergy and could be wrongly labeled as symptoms of "milk allergy." There are important differences between lactose intolerance and cow's milk allergy; therefore, a better knowledge of these differences could limit misunderstandings in the diagnostic approach and in the management of these conditions

The Relevance of Lactose Intolerance on the Development of Osteoporosis in Middle-Aged Adults via Bone Mass Density (BMD) Scanning

The purpose of this experiment was to determine whether or not lactose intolerance has an effect on the development of osteoporosis. I hypothesized that lactose intolerance would not increase a person\u27s risk of osteoporosis. In order to test this hypothesis, a sample group of 300 people was generated. All of these people were of generally good health and between the ages of 40-50. They were separated into three subgroups based on severity of lactose intolerance by means of a hydrogen breath test: non-lactose intolerant, moderately lactose intolerant, and severely lactose intolerant. Each individual was then administered a BMD (bone mineral density) scan of the vertebral and femoral regions. The results of this experiment showed that the difference in BMD between all individuals tested was too small to be considered significant. Thus, it was determined that lactose intolerance has no noticeable effect on whether or not a person will develop osteoporosis

Severe osteopenia in adolescence: poor bone health for life

Osteoporosis is a systemic skeletal disorder characterized by low bone mass that leads to increased bone fragility and susceptibility to fracture. Lactose intolerance is characterized by abdominal pain and/or diarrhea following the ingestion of lactose in people with lactase deficiency. The most common therapeutic approach to lactose intolerance is to exclude dairy products from the diet, which are the main source of calcium. We studied a group of patients with symptoms attributable to lactose intolerance part of whom was receiving a lactose-free diet and measured their intake of calcium, bone density and body mass index. We found that both groups were introducing a lower amount of calcium than recommended, with no difference between a free-lactose diet and a regular diet. Osteopenia was present in 35% of patients and it was inversely related to body mass index. Proper nutritional education is necessary in children in order to prevent overweight and osteopenia. Also the importance of exercise should be reinforced at school, because the peak of bone mass is obtained during adolescence and it is an essential factor in determining the future risk of osteoporosis and fractures

Standard and Specialized Infant Formulas in Europe: Making, Marketing, and Health Outcomes

Infant formulas are the only suitable substitute for human milk. The most common infant formulas are standard formulas based on cow's milk. In addition, there are formulas for infants showing signs and symptoms of intolerance and for clinical conditions such as allergy, prematurity, and gastrointestinal diseases. A comprehensive review of the literature was made to review the composition of standard and specialized infant formulas and analyze indications for use, real or presumed nutrition differences and properties, and impact on infant growth. A brief consideration on costs is outlined for each formula. Over the past few years, industrial production and advertising of infant formulas have increased. Human milk still remains the most complete source of nutrition for infants and should be continued according to the current recommendations. Few differences exist between infant formulas, both for the nutrition action and the macronutrient/micronutrient composition. Specialized infant formulas have limited indications for use and high costs. The role of the pediatrician is crucial in the management of infant nutrition, promotion of breastfeeding, and prescribing of specialized formulas only in specific clinical conditions

A worldwide correlation of lactase persistence phenotype and genotypes

Background: The ability of adult humans to digest the milk sugar lactose - lactase persistence - is a dominant Mendelian trait that has been a subject of extensive genetic, medical and evolutionary research. Lactase persistence is common in people of European ancestry as well as some African, Middle Eastern and Southern Asian groups, but is rare or absent elsewhere in the world. The recent identification of independent nucleotide changes that are strongly associated with lactase persistence in different populations worldwide has led to the possibility of genetic tests for the trait. However, it is highly unlikely that all lactase persistence-associated variants are known. Using an extensive database of lactase persistence phenotype frequencies, together with information on how those data were collected and data on the frequencies of lactase persistence variants, we present a global summary of the extent to which current genetic knowledge can explain lactase persistence phenotype frequency. Results: We used surface interpolation of Old World lactase persistence genotype and phenotype frequency estimates obtained from all available literature and perform a comparison between predicted and observed trait frequencies in continuous space. By accommodating additional data on sample numbers and known false negative and false positive rates for the various lactase persistence phenotype tests (blood glucose and breath hydrogen), we also apply a Monte Carlo method to estimate the probability that known lactase persistence-associated allele frequencies can explain observed trait frequencies in different regions. Conclusion: Lactase persistence genotype data is currently insufficient to explain lactase persistence phenotype frequency in much of western and southern Africa, southeastern Europe, the Middle East and parts of central and southern Asia. We suggest that further studies of genetic variation in these regions should reveal additional nucleotide variants that are associated with lactase persistence

Phylogenetic analysis of the evolution of lactose digestion in adults

In most of the world's population the ability to digest lactose declines sharply after infancy, High lactose digestion capacity in adults is common only in populations of European and circum-Mediterranean origin and is thought to be an evolutionary adaptation to millennia of drinking milk from domestic livestock, Milk can also be consumed in a processed form, such as cheese or soured milk, which has a reduced lactose content, Two other selective pressures for drinking fresh milk with a high lactose content have been proposed: promotion of calcium uptake in high-latitude populations prone to vitamin-D deficiency and maintainance of water and electrolytes in the body in highly arid environments, These three hypotheses are all supported by the geographic distribution of high lactose digestion capacity in adults. However, the relationships between environmental variables and adult lactose digestion capacity are highly confounded by the shared ancestry of many populations whose lactose digestion capacity has been tested, The three hypotheses for the evolution of high adult lactose digestion capacity are tested here using a comparative method of analysis that takes the problem of phylogenetic confounding into account, This analysis supports the hypothesis that high adult lactose digestion capacity is an adaptation to dairying but does not support the hypotheses that lactose digestion capacity is additionally selected for either at high latitudes or in highly arid environments. Furthermore, methods using maximum likelihood are used to show that the evolution of milking preceded the evolution of high lactose digestion

Acute calcium assimilation from fresh or pasteurized yoghurt depending on the lactose digestibility status

OBJECTIVE: The major aim of this trial was to evaluate the potential interaction of fresh or pasteurized yoghurt intake with lactose intolerance on calcium assimilation by means of the stable isotope 43Ca as a tracer. METHODS: Forty volunteers (age: 32 +/- 7 years) participated in this parallel simple blind study (20 of them with moderate lactose intolerance). The protocol included the intake of a test meal consisting on 43Ca-labelled fresh or pasteurized yoghurt. Volunteers, in whom the calcium status was assessed, collected the 24-h urine before and after the test meal to measure the stable isotope output. The intake-related 43Ca enrichment in urine was measured by isotopic rate mass spectrometry. RESULTS: In lactose tolerant and intolerant volunteers taken together, the fresh yoghurt consumption resulted in a statistically higher circulating calcium levels (p = 0.028) and urinary 43Ca output (p = 0.017) than after the pasteurized yoghurt intake. The lactose maldigestion status resulted in higher urinary 43Ca excretion (p = 0.013) after the fermented milk consumption, regardless of the nature of ingested product (p = 0.887). CONCLUSIONS: This novel and non-aggressive protocol allowed the in vivo comparison of calcium utilization from two different dairy sources, revealing a higher acute calcium assimilation from fresh as compared to the pasteurized yoghurt, in both lactose digesting and maldigesting subjects

Pituitary hyperplasia mimicking macroadenoma associated with primary hypothyroidism in a patient with selective L-thyroxine malabsorption

We present the case of a 29-year-old woman who developed a severe hypothyroidism induced by a thyroxine malabsorption and a secondary pituitary hyperplasia. We performed thyroxine absorption tests to diagnose the malabsorption and to evaluate the best therapeutic intervention. Once assessed a correct therapy lowering TSH, we observed the regression of pituitary mass confirming our diagnosis of secondary pituitary hyperplasia. We suggest to evaluate any possible reason for thyroxine malabsorption and to consider the hypothesis of pituitary hyperplasia in the presence of pituitary mass together with overt hypothyroidism