Second wind for older flies - special food source can ward off memory problems

Why do spring cleaning when it's warm and you get all sweaty cleaning dirt and grime, when you can do winter cleaning right before the holidays?

Every year MOH and I prepare for our trip up North by turning our apartment inside out and doing a thorough clean. Sure we clean up every now and then, but a real good scrub down is few and far between. Things that we accumulated over the year are either removed or packed away, depending on if it's still useful. Sometimes we forget about how much dust, dirt, and junk piles up, but when the home is clean, a fog feels like it's been lifted. You can breathe a little easier, maneuver through the rooms faster, and find things easier.

Our bodies also do "winter cleaning" regularly. Through a process called autophagy, proteins or cell parts that are non-functional, defective, or not needed anymore, are removed with the help of our disposal center part of cells called the lysosome. This process is very important for regulating efficient cellular processing and often becomes defective with age and several aging disorders like Alzheimer's. Ineffective autophagy results in a massive accumulation of junk proteins hanging around the cell, gradually piling up and impeding cellular function.

Structure of spermidine, a polyamine. Polyamines contain two or more amine groups (NH2) 

Recently, scientists have discovered a food source that has the ability to slow aging memory deficits in flies by upregulating autophagy processes. In this study, scientists wanted to look at the role between a compound called polyamines and age, since polyamines have been found to be downregulated with age. Using an olfactory memory test, flies were taught to associate a particular odor as being predictive of an electric shock. When old aged flies were given a type of polyamine (spermidine), scientists found that their learning was enhanced. In addition, the extra polyamine source enhanced production of more polyamines and was able to improve memory through increasing autophagy processes in this aged group - these flies had less junk proteins lying around as a result of efficient clean up . Weirdly enough, this boost in memory was only seen in the aged flies, as the younger flies showed no improvement in memory.*

While the verdict is still out on how effective polyamines are for warding age-related cellular problems and memory loss in humans, it certainly gives some incentive to try to incorporate more foods into our diet that are high in polyamines.  Luckily, our options for sources of polyamines are quite varied and tasty! The polyamine used in this study can be found heavily in foods such as aged cheese, mushrooms, soy, legumes, and corn.

Brown criminis stuffed with goat cheese (photo courtesy of Stacy from wikimedia)

Just my luck too - this week at the Farmer's Market, MOH and I stumbled across a goat cheese stand called Soledad Goats that doubles as an animal sanctuary and cheese farm. The cute little stand had a mix up of different goat cheese spreads and an olive oil herb mix with fresh goat cheese tossed into a cute little mason jar.

Delicious mix of cheese and herbs - my new thing to put on salads

This mix goes great on a salad (especially topped with some balsamic and black pepper), but can also be a great cooking oil source.

Hope everyone's ready for the holidays - have a great time eating and spending time with family and loved ones!

Until next time, happy eating all!


References:
Gupta et al., 2013. Restoring polyamines protects from age-induced memory impairment in an autophagy-dependent manner. Nature Neuroscience.

* Age-related memory loss was tested using aversive olfactory memory test, where flies learned to associate a particular odor as predictive of an aversive stimulus. Aged flies that were given spermidine showed improved performance in the aversive olfactory task compared to their control counterparts. Scientists discovered that spermidine enhanced autophagy in aged flies by looking at an autophagy protein marker  Atg8a. Furthermore, the enhancement in learning was shown to be dependent on autophagy, as autophagy defective mutant flies showed no improvement in memory after spermidine administration.