I have felt very guilty for noticing this and for feeling it was an undesirable smell, but I have to tell the truth. It does not affect our friendship or our interactions. It is just one part of the picture. Perhaps I smell strange to them as well. Notice how alcoholics reek of alcohol even when they drank hours earlier.
Indian food uses lots of curry.
When I cook with curry, the smell stays on my fingers for the rest of the day, and the smell is prevalent throughout the house for hours to come. So imagine for a race that eats like that every day. Lastly, in under-developed countries, only very modern folks use deodorant soap and antiperspirant. Coupled with their hot climates, it is not a very pleasant combination. I reckon in years to come, deodorant use will be much more common.