Evidence against nutritional adaption of tolerance to lactose

@article{Flatz2004EvidenceAN,
  title={Evidence against nutritional adaption of tolerance to lactose},
  author={Gebhard Flatz and Hans Werner Rotthauwe},
  journal={Humangenetik},
  year={2004},
  volume={13},
  pages={118-125}
}
SummaryControversy exists over the etiology of primary lactose intolerance with intestinal lactase deficiency. The low activity of lactase may be either due to a genetically controled reduction of enzyme activity or to an adaptive response to a lack of dietary lactose. Lactose tolerance tests in 24 subjects (9 persons who are offspring of marriages between Asians and Europeans, 6 lactose tolerant individuals from populations with a high incidence of lactose intolerance, and 9 lactose intolerant… 

Lactose digestion in humans: intestinal lactase appears to be constitutive whereas the colonic microbiome is adaptable

  • R. Forsgård
  • Medicine
    The American journal of clinical nutrition
  • 2019
TLDR
Current knowledge regarding the acclimatization of lactose processing in humans concludes that in susceptible individuals, dietary lactose might improve intolerance symptoms via colonic adaptation, which might lower the threshold for intolerance symptoms if lactose is reintroduced into the diet.

Primary adult lactose intolerance in the Kivu Lake area: Rwanda and the bushi

  • J. CoxF. Elliott
  • Biology, Medicine
    The American Journal of Digestive Diseases
  • 2005
TLDR
In order to investigate the ethnic differences of lactose intolerance in the Bantu and Hamitic races, lactose loading tests were performed on the populations living around Kivu Lake in central Africa and the results are in favor of a genetic origin of dairy intolerance.

Genetics of Lactase Persistence and Lactose Intolerance

TLDR
A putative causal nucleotide change has been identified and occurs on the background of a very extended haplotype that is frequent in Northern Europeans, where lactase persistence is frequent and does not explain all the variation in lactase expression.

Genetics of lactase persistence and lactose intolerance.

TLDR
A putative causal nucleotide change has been identified and occurs on the background of a very extended haplotype that is frequent in Northern Europeans, where lactase persistence is frequent.

Persistence of high intestinal lactase activity (lactose tolerance) in Afghanistan

TLDR
In the Afghan sample there were no significant differences of the frequency of PHILA in different ethnic groups, and subjects classified as persistence of high intestinal lactase activity (PHILA) were classified.

On the Evolution of Lactase Persistence in Humans.

Lactase persistence-the ability of adults to digest the lactose in milk-varies widely in frequency across human populations. This trait represents an adaptation to the domestication of dairying

Lactose intolerance in Arabs

SummaryA high incidence (minimum 20/26, maximum 24/26) of lactose intolerance was found in a group of adult Arab subjects. A selective reduction of intestinallactase activity was present in 4

Lactase deficiency in Singapore-born and Canadian-born Chinese

TLDR
The similar prevalence of lactase deficiency in the Singapore- and the Canadian-born Chinese despite a larger estimated amount of daily milk ingestion supports the concept that lact enzyme deficiency, which is transmitted genetically, does not have an adaptable component related to the quantity of lactose ingested.

Dairying, Milk Use, and Lactose Malabsorption in Eurasia: A Problem in Culture History

1. Origins and Spread of Dairying in the Old World 2. Hypotheses Advanced for the Early Failure of Dairying in Eastern Asia 3. Primary Adult Lactose Malabsorption (LM): Definition, Biology, and

References

SHOWING 1-10 OF 30 REFERENCES

Lactose Tolerance in Asians: a Family Study

TLDR
This survey in northern Thailand found that the only adult Thai with lactose tolerance came from Ayuthaya Province, approximately 70 km north of Bangkok, and no lactase induction has been found in individuals with lactase intolerance after either prolonged daily intake of fresh milk3 or daily intake for a month.

Studies of Lactose Intolerance in Families

TLDR
Data support a genetic factor in the etiology of an isolated lactase deficiency with late onset of symptoms that is more common in the older individuals with the defect.

Lactose intolerance in Singapore.

Primary lactase deficiency: Genetic or acquired?

TLDR
It would seem that in the Chinese, at least, and presumably in other ethnic groups, the major factor influencing lactase activity is the dietary content of lactose, provided milk intake continues at the high level found in most Western European populations, beyond the normal age of weaning.

A racial difference in incidence of lactase deficiency. A survey of milk intolerance and lactase deficiency in healthy adult males.

TLDR
The data strongly favor a genetic etiology for the isolated lactase deficiencies seen so commonly in adults, particularly in Negroes, in contrast to only one of 20 whites.

Lactose malabsorption in Greenland Eskimos.

TLDR
Clinical signs of lactose malabsorption were rare, but so was milk consumption in general, and clinical reactions to lactose ingestion during a lactose tolerance test were less pronounced than in lactasedeficient white patients.

Adult lactose tolerance.

TLDR
Evidence seems to indicate that Westerners, despite the trappings of civilization, are not free from such biases, and racial-cultural groups differ greatly in their ability to benefit nutritionally from certain foods, in particular milk and many milk products.

Acquired lactose malabsorption in Thai children.

TLDR
Environmental factors may be important in the pathogenesis of lactase deficiency in Thai children, although genetic influences cannot be excluded.