Organically Grown Food Provides Health Benefits To Drosophila melanogaster

The ‘‘organic food’’ market is the fastest growing food sector, yet it is unclear whether organically raised food is nutritionally superior to conventionally grown food and whether consuming organic food bestows health benefits. In order to evaluate potential health benefits of organic foods, we used the well-characterized fruit fly Drosophila melanogaster as a model system. Fruit flies were raised on diets consisting of extracts of either conventionally or organically raised produce (bananas, potatoes, raisins, soy beans). Flies were then subjected to a variety of tests designed to assess overall fly health. Flies raised on diets made from organically grown produce had greater fertility and longevity. On certain food sources, greater activity and greater stress resistance was additionally observed, suggesting that organic food bestows positive effects on fly health. Our data show that Drosophila can be used as a convenient model system to experimentally test potential health effects of dietary components. Using this system, we provide evidence that organically raised food may provide animals with tangible benefits to overall health

Oxidative stress resistance of <i>Drosophila</i> raised on organic food.

<p>Survivorship curves of female flies raised for 10 days on the indicated food sources. Flies were then transferred to media containing H₂O₂ and dead flies were counted twice daily (grey: conventional food; black: organic food; statistically significant changes (p<0.005) are indicated by asterisks). Median survival times of flies on conventional and organics food sources, respectively, are: potatoes: 24 and 30 hours (p<0.0001); raisins: 24 and 24 hours (p<0.0001); bananas: 30 and 30 hours (p<0.2172).</p

Starvation tolerance of flies raised on organic diets.

<p>Survivorship curves of female flies raised for 10 days on the indicated food sources. Flies were then transferred to starvation media and dead flies were counted twice daily (grey: conventional food; black: organic food; statistically significant changes (p<0.005) are indicated by asterisks). Median survival times of flies on conventional and organics food sources, respectively, are: potatoes: 6 and 24 hours (p<0.0001); raisins: 24 and 24 hours (p<0.0001); bananas: 24 and 48 hours (p<0.0001).</p

Longevity of D. <i>melanogaster</i> fed organic diets.

<p>Survivorship curves of female fruit flies fed diets made from extracts of potatoes, raisins, bananas or soybeans (grey: conventional food; black: organic food; statistically significant changes (p<0.005) are indicated by asterisks). Median survival times of flies on conventional and organics food sources, respectively, are: potatoes: 16 and 22 days (∼38% longevity increase, p<0.0001); raisins: 2 and 24 days (∼20% longevity increase, p<0.0001); bananas: 24 and 26 days (p = 0.1543); soybeans: 8 and 14 days (∼75% longevity increase, p<0.0001).</p

Effects of organic diets on <i>Drosophila</i> health parameters compared to conventional diets.

<p>Effects of organic diets on <i>Drosophila</i> health parameters compared to conventional diets.</p

Daily egg-laying of flies exposed to organic diets.

<p>Egg production of flies fed the indicated food was determined daily. Shown are the averages of four biological replicates; error bars represent the standard deviation (grey: conventional food; black: organic food; statistically significant changes (p<0.005) are indicated by asterisks; p<0.0001 for all food types).</p

Comparative transcriptional profiling identifies takeout as a gene that regulates life span

A major challenge in translating the positive effects of dietary restriction (DR) for the improvement of human health is the development of therapeutic mimics. One approach to finding DR mimics is based upon identification of the proximal effectors of DR life span extension. Whole genome profiling of DR in Drosophila shows a large number of changes in gene expression, making it difficult to establish which changes are involved in life span determination as opposed to other unrelated physiological changes. We used comparative whole genome expression profiling to discover genes whose change in expression is shared between DR and two molecular genetic life span extending interventions related to DR,increased dSir2 and decreased Dmp53 activity. We find twenty‐one genes shared among the three related life span extending interventions. One of these genes, takeout, thought to be involved in circadian rhythms, feeding behavior and juvenile hormone binding is also increased in four other life span extending conditions: Rpd3, Indy, chico and methuselah.We demonstrate takeout is involved in longevity determination by specifically increasing adult takeout expression and extending life span. These studies demonstrate the power of comparative whole genome transcriptional profiling for identifying specific downstream elements of the DR life span extending pathway

Bone-Remodeling Transcript Levels Are Independent of Perching in End-of-Lay White Leghorn Chickens

Osteoporosis is a bone disease that commonly results in a 30% incidence of fracture in hens used to produce eggs for human consumption. One of the causes of osteoporosis is the lack of mechanical strain placed on weight-bearing bones. In conventionally-caged hens, there is inadequate space for chickens to exercise and induce mechanical strain on their bones. One approach is to encourage mechanical stress on bones by the addition of perches to conventional cages. Our study focuses on the molecular mechanism of bone remodeling in end-of-lay hens (71 weeks) with access to perches. We examined bone-specific transcripts that are actively involved during development and remodeling. Using real-time quantitative PCR, we examined seven transcripts (COL2A1 (collagen, type II, alpha 1), RANKL (receptor activator of nuclear factor kappa-B ligand), OPG (osteoprotegerin), PTHLH (PTH-like hormone), PTH1R (PTH/PTHLH type-1 receptor), PTH3R (PTH/PTHLH type-3 receptor), and SOX9 (Sry-related high mobility group box)) in phalange, tibia and femur. Our results indicate that the only significant effect was a difference among bones for COL2A1 (femur &gt; phalange). Therefore, we conclude that access to a perch did not alter transcript expression. Furthermore, because hens have been used as a model for human bone metabolism and osteoporosis, the results indicate that bone remodeling due to mechanical loading in chickens may be a product of different pathways than those involved in the mammalian model