To sort out the antioxidant properties of fruits and berries, researchers turned to fruit flies for help and found that a commercially available acai berry product can lengthen their lives when the flies lives are made short through additional oxidative stress.
Researchers at Emory University School of Medicine found that under certain conditions (a simple sugar diet) acai supplementation could triple flies lifespans, from eight to 24 days.
Acai could also counteract the neurotoxic effects of the herbicide paraquat on the flies.
Alysia Vrailas-Mortimer, lead author of the study, said she didnt start out focusing on acai. But acai worked better than several other antioxidant products such as vitamins, coenzyme Q10 and lutein.
One thing that makes our work distinctive is that we tried commercially available supplements, she said.
We went to a health food store and filled up a basket, Vrailas-Mortimer said.
She said she began the project with the help of undergraduate student Rosy Gomez, and narrowed her focus after initial success with acai.
Vrailas-Mortimer took advantage of a discovery she had made working with Subhabrata Sanyal, assistant professor of cell biology, PhD.
They had previously found that flies with mutations in the œp38 MAP kinase gene have shorter lives and are more sensitive to heat, food deprivation and oxidative stress.
P38 mutant flies lived an average of only eight days when they were given a simple sugar water diet. However, their lifespans tripled when their diet was supplemented with acai. Ginger was used as a control for the diet supplements.
Acai also protected normal flies against oxidative stress, in the form of hydrogen peroxide or paraquat.
Acai can protect against oxidative stress when flies are exposed to hydrogen peroxide before being given acai, but the protective effect does not hold up if the order is reversed.
Paraquat is an herbicide that has neurotoxic effects that resemble Parkinson disease. Under the influence of paraquat, flies sleep-wake cycles gradually become chaotic (see graph). Acai can also help soften the effects of paraquat on flies circadian rhythms.
I think this is important, Vrailas-Mortimer said.
We show that whatever is in acai that is lengthening lifespan, it can also keep the flies functioning better for longer when faced with paraquat exposure. It is maintaining quality of life rather than just preventing them from dying, she said.
When flies were fed a more enriched diet of a standard cornmeal/molasses mush, the effects of supplementation with acai were more pronounced in males than in females.
Males lifespans were almost doubled with acai (20 to 40 days) but the effects on females were not as strong (30 to 34 days). On an enriched diet, male flies were more sensitive to paraquat than females as well.
Acai berries contain a variety of antioxidant and anti-inflammatory compounds, such as anthocyanins.
The study has been published by the journal Experimental Gerontology.