Eating polyamine rich food can postpone age-induced memory decline in fruit flies, reports a paper published online this week in Nature Neuroscience. Since polyamines, which are found in various food sources, are known to naturally decrease in the human brain with age, and are also known to promote longevity in other model organisms, the current findings lend further support to the idea that increasing polyamines in the diet could help hold off age-related mental declines.
Most organisms utilize polyamines to modulate a variety of cellular processes such as for cell survival and proliferation. Mammalian cells are capable of synthesizing their own polyamines, though little is known about their native molecular function. It is also known that polyamine levels in the brain decrease during aging.
As polyamines can prolong life span in invertebrate model organisms, Stephan Sigrist, Frank Madeo and colleagues explored whether age-induced memory decline in fruit flies could be reversed with dietary polyamines. They found that while older flies were less successful in learning that a particular cue predicted a mild electric shock, older flies fed a high polyamine diet had no such deficit. The older flies’ performance of the task was comparable to that of younger flies. The authors note that the beneficial effects of polyamine were mediated by their role in promoting autophagy-a process of cellular self-digestion that rids defective organelles.