Common Nutrient Keeps Flies Sharp into Old Age: Scientific American

Here is another clue to a diet change that could improve memory and longevity.  Polyamines -- which include putrescine, cadaverine, and spermidine (doesn't that sound gross) are chemicals found in wheatgerm and fermented soya beans.

Common Nutrient Keeps Flies Sharp into Old Age: Scientific American:

Apparently natto, a Japanese product increases the amount of polyamines in human blood.  Natto, according to Wikipedia:

 Nattō is a traditional Japanese food made from soybeans fermented with Bacillus subtilis. It is popular especially as a breakfast food. Nattō may be an acquired taste because of its powerful smell, strong flavor, and slimy texture

Could this actually work for humans?  If so, it would be an amazing breakthrough!