Secrets of Aging Unlocked by Yeast

Research recently conducted by Concordia scientists shows that yeast mutants shed light on the mysteries of the aging process. Two studies pinpointed mechanisms that decrease longevity. These mechanisms can be targeted by natural chemicals to boost health and prolong human lives.

The Surprising Power of Yeast

Most people think of yeast as a fungus with few purposes. However, yeast provides valuable insight into how people age. Aging in yeast cells, as well as humans, results from more than regular wear and tear. It is also determined by an active process stimulated by a particular set of genes. Some of these genes hinder aging while other genes hasten it. Concordia researchers including Vladimir Titorenko, a biology professor from the school's Faculty of Arts & Science, delved into the specifics of slowing and accelerating these genes with the goal of determining what they mean for human beings.

The Study

Titorenko and his fellow researchers exposed yeast to lithocholic acid. A previous study found that this natural molecule delays aging. The use of this molecule generated long-lasting yeast mutants the research group refers to as “yeast centenarians”. These mutants lasted five times longer than the regular ones. This can be attributed to the fact that the yeast mutants' mitochondria acquired more oxygen and generated more energy than regular yeast. Mitochondria is the section of the cell responsible for energy production and respiration. It is also worth noting that centenarians were comparably resistant to oxidative damage, a process that induces aging.

The Results

According to Titorenko, his group is the first to ever provide irrefutable evidence for the presence of genetic mechanisms that put limitations on lifespan. Lithocholic acid, which is generated in a natural manner in the environment, does not delay the aging of yeast. Yet it can force the evolution of yeast that has aged for an extensive period of time.

The Significance of the Findings

The production of excessively aged yeast mutants and the fact that Titorenko cultured them separately from regular yeast is proof that centenarians reproduce and grow with efficiency equal to that of non-centenarians. This confirms the merit of programmed aging theories. Such findings are quite significant, especially from the viewpoint of Titorenko and his fellow researchers. The findings are meaningful for yeast as well as humans.

Titorenko was able to prove that active mechanisms limit all organisms' longevity. This is the first experimental evidence to prove that lifespan-limiting mechanisms are in existence and can be actively manipulated by natural molecules to enhance health and delay the aging process.

Where We go From Here

The next step is to use yeast centenarians to gauge two styles of aging theories. The first, programmed aging theories, argues that organisms are programmed at the genetic level to have a finite lifespan as aging is inherent to evolution. This means there are active mechanisms that induce aging and consequently, put a cap on lifespan.

The second theory is “non-programmed” meaning aging does not exist for an evolutionary purpose. As a result, an evolved mechanism with the primary goal to induce aging or cap lifespan cannot exist. This theory claims that organisms that have lived for an extensive period of time will grow slower and reproduce in an inefficient manner than an organism with a lifespan that is capped at a specific age.