Falafel Faves and Favism
★ I flagged the Palestinian taxi driver with some relief: the streets were deserted, the restaurants in the old city of Jerusalem were shuttered for Shabbat and I was growing increasingly peckish. After I convinced him, with some effort and considerable diplomacy, that I did not want a tour of Bethlehem, he admitted defeat with good humor and took me to a little Palestinian restaurant where I had the most delicious falafels– golden nuggets of chickpea goodness drizzled with tangy tahini atop mounds of fluffy pita bread, still warm from the oven.
★ Did you know that falafels were originally made from fava beans by the Egyptian Copts, who become vegans during Lent? But fava beans can trigger life-threatening anemia in a fraction of people of Mediterranean descent, including Jews, so chickpeas have been used as a safer replacement. Known as favism, the disorder is due to inherited variants in the enzyme G6PD, which stands for glucose-6-phosphate dehydrogenase, a somewhat less tasty mouthful than falafel.
★ In red blood cells, G6PD replenishes an important anti-oxidant, glutathione that guards against damaging free radicals generated from certain compounds (like vicine and divicine) found in broad beans. People with G6PD deficiency, nearly all males since the gene is located on the X-chromosome, lack this protective mechanism and their damaged red cells gives them anemia, jaundice and occasional hemolysis. For extra credit: why did these harmful mutations persist in some populations instead of being weeded out by natural selection? It turns out that G6PD mutations protect against malaria, likely by hastening clearance of red blood cells infected with the malarial parasite Plasmodium.
★ To make falafel, start with dry chickpeas. Fresh bought works best (save those fossilized pellets from the back of your pantry for ammunition in case of squirrel invasion). Soak the chickpeas overnight in generous excess of water and they will reward you by becoming pleasingly plump and doubling in quantity. One cup dry chickpeas should be plenty, two will feed a crowd. As any responsible scientist would do, I repeated my falafel experiment for n = 3 before publishing. Many thanks to my enthusiastic students for confirming the protocol and consuming the product! For the recipe see: https://madamescientist.wordpress.com/2015/09/15/falafel-faves-and-favism/