If we are to judge from the findings of genetic association studies, natural variation in human longevity occurs due to countless distinct factors, each of which provides a small contribution, is highly dependent on environmental circumstances, and is highly linked to other factors. Scientists have struggled to replicate more than a few known associations across different study populations, and those that have been replicated between study groups have small effects.
Blood group is genetically determined, and data on patient blood group is included in many of the data sets that report on disease incidence and mortality. A number of research groups have attempted to find robust associations between blood group and longevity, but on the whole the results seem fairly nebulous to date. Blood group B in particular keeps showing in correlations, but as an association for either longevity or a shorter life expectancy, depending on the study. That suggests that there is no useful underlying association that might be universally applied and, as is the case for the broader study of genetics and longevity, different patient populations have quite different characteristics.
The ABO blood group polymorphism has been associated with different diseases, cancer included. The cancer developments are variegated processes associated with aging. Protection from cancer and atherosclerosis is the main longevity reason. Long-survivors are an important group for the evaluation of genetic markers in cancer pathogenesis. Population studies have demonstrated that the ABO group phenotypes frequencies vary widely from one ethnicity to another.
The ABO genes control the expression of part of the carbohydrates by the epithelial cells in the respiratory, genitourinary, and gastrointestinal systems; the carbohydrate variability acts as a potential receptor for non-pathogenic and pathogenic microorganisms influencing immune responses. The first report on the relation between the ABO blood group and cancer indicated the A blood group to increase the risk of stomach cancer, while the O blood type was protective. Thereafter, the correlation between the ABO blood type and other malignancies, such as gastric and pancreatic, has been continuously reported. A total of 1.6 million healthy blood donors were followed in Denmark and Sweden: the A, B and AB blood groups were associated either with the increased or decreased risk of cancer at 13 anatomical sites as compared with the O blood group. Multiple mechanisms have been indicated to explain the blood type role in cancer progression, including altered immune response, inflammation, and cellular adhesion.
The role of the specific genetic differences contributing to life expectancy is hardly known. Several genome sequencing and GWAS studies compared the total number of disease variants in centenarians and controls, indicating that there are some evidences that centenarians harbor the anti-aging polymorphisms which protect them from diseases, although long-survivors may show numerous disease variants at a rate similar to normal people, but they are protected from their effects. The single nucleotide polymorphism defining the most common allele responsible for the O blood group is related with longevity; the centenarians are more likely than controls to have the O blood group.
The aim of the present study was to assess the ABO blood group polymorphism association with prostate, bladder, and kidney cancer, and longevity. The following data groups were analyzed: Prostate cancer (n=2,200), bladder cancer (n=1,530), renal cell cancer (n=2,650), oldest-old (n=166) and blood donors (n=994) groups. The data on the ABO blood type frequency and odds ratio in prostate cancer patients revealed a significantly higher blood group B frequency. A comparison of the oldest-old and blood donor groups revealed that blood group A was significantly more frequent and blood type B was significantly rarer in the oldest-olds. The results of the present study indicated that blood type B was associated with the risk of prostate and bladder cancer, and could be evaluated as a determinant in the negative assocation with longevity. Blood types O and A may be positive factors for increasing the oldest-old age likelihood.