X-Message-Number: 16020
Date: Sat, 7 Apr 2001 22:52:28 -0700 (PDT)
From: Doug Skrecky <>
Subject: 36'th update on fly longevity experiments
This is the 36'th update of my fly longevity experiments. In this run
I investigated the longevity promoting effect of Knudsen elderberry
nectar. To see if more was better, some of this nectar was partially
frozen, and the ice slush was decanted to yield a fluid that was roughly
double strength. Since the main ingrediant of elderberry nectar is apple
juice, both antioxidant-rich Santa Cruz apple cider (with apple skins), as
well antioxidant poor Sun-Rype apple juice (without skins) were
tested. Since elderberry nectar also has a small amount of boysenberry
juice, another juice (Santa Cruz berry nectar), which also has a small
amount of this juice was tested. Black Cherry juice was retested since the
last surviving fly in Run #12 (65 days) was fed this juice.
Sun Rype apple juice had been tested back in Run #11, where it offered
a minor benefit. However this was before I started adding citric acid to
eliminate pathogen growth in the fly food. The result with this juice this
time is rather hard to believe. In the present experiment an average
longevity of about 40 days for the controls was doubled to about 80 days
with Sun Rype apple juice. Maximum lifespan was also dramatically
increased by 47% from 73 days for the controls, to 107 days for the apple
juice. This breaks my previous record for maximum longevity, which was set
in Run #7 at 88 days. Extreme effects like will have to be replicated
before I will put much credence to them. The modest benefit with
antioxidant-rich apple cider, indicates that antioxidants are unlikely to
be the active ingrediant in Sun Rype apple juice.
This time elderberry nectar performed about the same as in the past,
with a good increase in average longevity, without any significant effect
on maximum survival. I taken by surprise by the effect of double strength
elderberry nectar, which like Sun Rype apple doubled average longevity to
80 days, and increased maximum survival even more (62%) to 118 days. A
further census at day 124, found that this last sole survivor had at long
last perished.
In Run #18 I found that survival was better with 1/4 tsp citric acid
added to 20 gm 4-24 fly food, than 1/8 tsp. It what may be a major slip
up, I failed to test yet higher dosages of citric acid. No evidence of
pathogen growth was noted at the lower dosage of citric acid, yet this
does not mean that pathogens are not still limiting the survival of the
flies. When the flies die, their corpses are not removed from the milk
bottles that house them. Possibly some juices lengthen fly lifespan, by
providing additional acid, without inducing toxicity. Experiments are in
progress examining this possibility.
Run #36 Percent Survival on Day
supplement 39 43 46 49 55 61 68 73 78 85 90 96 100 107 112 118
____________________________________________________________________
control 56 47 47 42 33 22 19 6 0 - - - - - - -
apple 93 89 89 85 78 78 67 59 59 41 37 19 11 4 0 -
apple cider 68 64 64 59 45 45 27 14 9 0 - - - - - -
berry nectar 54 54 50 50 46 25 17 8 8 8 0 - - - - -
black cherry 94 94 94 94 94 78 61 55 44 11 0 - - - - -
elderberry 84 74 74 68 63 37 37 0 - - - - - - - -
elderberry 200% 85 77 77 77 77 74 64 64 54 41 33 26 23 18 3 3
In Freezer Run #8, I tried a slightly different experimental
protocol. For long term longevity experiments I use milk bottles to house
the flies, and add 20 grams of fly food, with 5 tablespoons of water. Such
a large amount of fly food is used, to delay the time it takes to dry the
food enough to adversely affect the flies. For this freeze experiment I
used 5 grams of fly food, and used plastic bags as containers. Flies were
treated to various supplement conditions for 5 days, before being placed
in the freezer. The time in the freezer was reduced because flies would be
under greater temperature stress when not protected by milk bottles.
I retested pycnogenol, as a positive control, though this time no
significant benefit was observed. Two sources of additional protein were
tested to see if extra amino acids offer any benefit. The null result with
soy, indicates that the benefit of whey protein is not due to amino acids.
Green tea polyphenols offered a significant benefit, which even eclipsed
that of whey.
Freezer Run #8 Percent Survival After
supplement/20 gm food 0 30 46 minutes
_________________________________________
control 100 12 0
betaine hydrochloride 2000 mg 93 14 0
green tea polys 300 mg 100 44 25
oleuropein 272 mg 93 20 0
pycnogenol 300 mg 100 15 0
resveratrol 400 mg 100 7 0
soy protein 4 tsp 96 8 0
whey protein 4 tsp 100 39 4
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