Flies Live Longer on Low Protein Diets
An Anti-Aktins Diet Enhances the Performance of Mitochondria
Oct 8, 2009
Researchers at the Buck Institute for Age Research published new findings in the October 2, 2009 issue of Cell regarding recent experimentation with dietary restriction in fruit flies. Led by researcher Pankaj Kapahi, PhD, the study shows that after being fed an anti-Atkins diet for a period of time, the flies’ mitochondria were functioning significantly better.
Mitochondrial Enhancement
The study, which can be seen in the Cell science journal, is one of the first to show a genome-wide portrait of what happens with protein within any eukaryote organism during a time of dietary restriction. The breakthrough that Kapahi and his fellow researchers found was quite unexpected.
When protein was restricted in the diets of their subjects, there was, of course, a decrease in protein synthesis within the flies’ mitochondria. This was expected, but what followed was a surprise; while protein synthesis was reduced within the cells, more energy was being released by the mitochondria. The specific genes involved with generating this energy were more active than the researches expected.
What the Study Shows
When protein was restricted in the flies’ diet, a rise in activity of a certain protein was observed. This protein is called d4EBP that, among other things, is involved with mediating cell growth in response to nutrient availability. The research conducted showed that this protein is crucial for extended lifespan during dietary restriction.
When this protein was taken out of the flies-and-low-protein equation, they did not live longer, even while being subjected to the same anti-Atkins diet. And to really drive it in, when the protein was increased, the flies’ lifespan was extended, even when fed a very rich diet.
The Mitochondria and the Cell
In order to understand the significance of the findings of this study, it is first important to understand the basic function of mitochondria. Most will recall from high school biology that the mitochondria are the so-called “powerhouses” of cells, and are responsible for cellular respiration. While involved in a number of different processes like regulating the cell cycle and cellular growth, they are also key players in the process of cellular death.
Mitochondria are found only in eukaryotic cells, or cells with membrane-enclosed nuclei and organelles (such as mitochondria). The majority of organisms that come to mind when people think of “living things” are eukaryotes – animals, plants, fungi, and protists.
While eukaryotes are diverse, their cellular function is extremely similar. This is the reason the recent study with the flies is so important. Even though the study only uses flies as subjects, similar effects of a dietary restriction of protein in other eukaryotes will be evident.
What This All Means
The findings of this study, most importantly, call into question the common weight loss methods of people, especially in North America, of increasing protein intake and decreasing carbohydrates consumed. While the long-term effects of these high protein diets have not really been observed in any concrete way, they are likely to be detrimental to health and life expectancy.
Again, as most eukaryotes function very similarly on a cellular level, the choice of experimental subjects is not vitally important. It seems as of now that d4EBP is crucially linked with cellular life span. This protein featured in the study is likely to play a crucial role in future life-expansion studies.
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