i’m giving blood as i have many times over the years ( and you should too! ) and it occured to me that i don’t think i’ve ever asked about my blood type. as it turns out, i have “b positive” blood. and for the life of me i couldn’t remember what that meant. i drew a total blank as i imagined my high school biology teacher scowling.
so, here’s the refresher course. the gene that determines blood type has multiple alleles which we call “A” “B” and “O” ( “O” is actually defined as the absense of “A” and “B” antigens ). the positive or negative after the letter indicates whether or not the Rh antigen is present. simple enough.
while the B+ blood type isn’t a “rare” blood type ( and i’d have no trouble finding a suitable donar should i need blood ), it is interesting to note that the B is the rarest blood allele worldwide with only about 16% of humanity carrying it ( wikipedia says it’s a bit higher, but still the “rarest” ). the highest distribution of the B allele is in central asia and lowest native Americas and australia ( every population has all four blood types in varying frequencies – being type B doesn’t mean that’s where my ancestors came from ).
and i suppose i shouldn’t be surprised that there’s a blood type diet. proponents argue blood type is an important factor in determining a healthy diet. The Establishment, unsurprising, claims the theory is lacking in scientific support.