QUESTION: I have read that Scots, Irish, Icelanders (despite their predominantly type A Norwegian forefathers) and Basques are the European populations with the highest incidence of type O blood -- can you recommend any reputable or otherwise authoritative source that could explain this and any other question of blood type distribution by geography or nation?

ANSWER: The best book that one can still purchase (most of the early works are long out of print) are the works of A.E. Mourant and a few others. These include:

1. "The distribution of the human blood groups, and other polymorphisms" by A. E. Mourant by Oxford Press

2. "Blood Relations : Blood Groups and Anthropology" by A.E. Mourant by Oxford Press

3. "History and Geography of Human Genes" by LL Cavalli-Sforza by University Press.

4. "Races and Peoples" by Isaac Asimov and William Clouser Boyd by Harcourt

These works are not easy to find, although you can check with your local university library, who may have them in the Reference section. You may also want to try the various electronic and paper Encyclopedias. These sections on blood types and/or anthropology almost always feature population frequency maps of the various ABO groups.

They might take issue with your categorization of the predominantly Celtic Scots and Irish as having 'Norwegian forefathers" however.

STUDY: Association of recurrent vaginal candidiasis and secretory ABO and Lewis phenotype.

JOURNAL: J Infect Dis 1997 Sep;176(3):828-30

AUTHORS: Chaim W, Foxman B, Sobel JD.

ABSTRACT: The relationship between ABO-Le secretor phenotype and susceptibility to recurrent idiopathic vulvovaginal candidiasis (RVVC) was investigated. ABO and Lewis blood typing was done for 38 women with RVVC (case-patients) and for women in 2 control groups, consisting of 58 healthy women, who were friends identified by case-patients, and 38 race-matched, healthy hospital employees. The 3 groups were similar with regard to age and race. There was no difference in the distribution of ABO phenotype between case-patients and controls. Case-patients were more likely than members of either control group to have Le(a+ b-) (nonsecretor) rather than Le(a- b+) (secretor) blood type. With combined nonsecretor Le(a+ b-) phenotype and absence of the Lewis gene Le(a- b-), the relative risk of chronic recurring vulvovaginal candidiasis was 2.41-4.39, depending on the analysis technique and control group. In conclusion, there is an increased frequency of ABO-Le nonsecretor status among women with RVVC.

COMMENTARY: It is known that non-secretors have a higher incidence of fungal and parasitic infections when compared to secretors. This may be the result of several independent factors. First, it has been reported that non-secretors have lover levels of Secretory IgA antibodies (the antibodies which reside in our saliva, vaginal fluid, etc. and which protect our membranes). In addition, some evidence suggests that non-secretors have much more of a difficulty in dealing with simple sugars and carbohydrates, and recurrent vaginal yeast infections have been linked with a high carbohydrate content to the vaginal fluids (which has in turn been linked to a higher sugar/carbohydrate diet in some women).

The best long-term strategy if you suffer from recurrent vaginal yeast infections would be to determine your secretor status, and if necessary, refine your ABO diet by fine-tuning it with the non-secretor information in my book Live Right 4 Your Type.