X-Message-Number: 26061 References: <> From: Kennita Watson <> Subject: Re: 172'nd update on fly longevity experiments Date: Wed, 20 Apr 2005 10:59:00 -0700 Doug Skrecky <> wrote: > Subject: 172'nd update on fly longevity experiments > > ... According to one survey, cranberry has the highest oxygen > radical > absorbance capacity (ORAC) among fruits and vegetables, while cloves > have > the highest ORAC of all food items.... > To my great surprise, the current batch of clove powder turned > out to > be highly toxic. I have no idea why this turned out to be the case. > ... > Run #172 Percent Survival on Day > supplement 12 26 33 45 55 64 71 78 83 87 91 95 101 > ___________________________________________________________ > control one 95 58 53 37 26 16 5 5 5 5 0 - - > control two 88 56 44 36 36 16 8 0 - - - - - > cloves 1/8 tsp 52 0 - - - - - - - - - - - > " 1/4 tsp 29 0 - - - - - - - - - - - > ... Question: How long do flies live if you don't feed them anything at all? Could the poor results from cloves be not because they're toxic, but because flies don't consider them food? (It may also be that 1/16 or 1/32 tsp would confer benefit; I certainly don't think I'd respond well to eating a cup of cloves.) In attempting to answer this question for myself, I ran across <http://www.kabt.org/Labs/Fruit%20Fly.htm> which said " If the food becomes too dry, the animals starve. They need to watch for 'cracked' and dry food and/or lifeless larvae. If this occurs, adding one or two drops of water will moisten the food and should solve the problem. On the other hand, the environment can become too humid and the food too moist. In this case the food will become contaminated with fungi, which is also detrimental to the flies. Finally, caution students not to leave the flies in direct sunlight or other extreme environmental conditions." (FYI: the activity above was based on a set of activities detailed at http://www.is.wayne.edu/mnissani/PAGEPUB/FLIES.HTM .) I expect/hope that you've set up the room (the flies are all in one room, right?) to not be exposed to direct sunlight (heavy curtains and/or northern exposure). Could some supplements be better at wicking moisture to the surface of the food, so it dries out faster and the flies starve -- or at holding in the moisture, so fungus grows? "Longevity-enhancing Effects of Bacterial Exposure in Fruit Flies " (http://www.bioscienceworld.ca/view.html?id=361) "Bacterial exposure can increase longevity, but only when it occurs early in life. ..." The more I read, the more it seems that the experiments you report on are insufficiently controlled. A set of more controlled experiments is detailed at http://www.pnas.org/cgi/content/full/101/35/12980 . Confusion: I haven't seen anything online that discusses fruit fly lifespans longer than 80 days. Apparently it's normally about 35, and most articles talk about lengthening it with calorie restriction, lowered temperature, etc. to about 72. Where does a maximal longevity of 123 days come from, then? I should stop -- I've been at this for almost two hours. I hope I've offered some food for thought. (I wonder if a local school's biology teacher could be enlisted to have his/her class do some of the experiments?) Thanks, Kennita Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=26061