Cynthia Kenyon

Cynthia Jane Kenyon (born c. 1955) is an American molecular biologist and biogerontologist known for her genetic dissection of aging in a tiny worm, Caenorhabditis elegans.

Career
Cynthia Kenyon graduated valedictorian in chemistry and biochemistry from the University of Georgia in 1976. She received her PhD in 1981 from MIT where, in Graham Walker's laboratory, she was the first to look for genes on the basis of their activity profiles, discovering that DNA-damaging agents activate a battery of DNA repair genes in E. coli. She then did postdoctoral studies with Nobel laureate Sydney Brenner at the MRC Laboratory of Molecular Biology in Cambridge, UK, studying the development of C. elegans.

Since 1986 she has been at the University of California, San Francisco (UCSF), where she was the Herbert Boyer Distinguished Professor of Biochemistry and Biophysics and is now an American Cancer Society Professor.

Her early work led to the discovery that Hox genes, which were known to pattern the body segments of the fruit fly Drosophila, also pattern the body of C. elegans. These findings demonstrated that Hox genes were not simply involved in segmentation, as thought, but instead were part of a much more ancient and fundamental metazoan patterning system.

Although it was already known from the work of M. Klass that lifespan of C. elegans could be altered by mutations, in 1993, Dr. Kenyon's discovery that a single-gene mutation (daf-2) could double the lifespan of C. elegans and that this could be reversed by a second mutation in daf-16m, sparked an intensive study of the molecular biology of aging. Dr. Kenyon's findings have led to the discovery that an evolutionarily-conserved hormone signaling system influences aging in other organisms, perhaps also including mammals.

Kenyon has received many honors, including the King Faisal Prize for Medicine, the American Association of Medical Colleges Award for Distinguished Research, the Ilse & Helmut Wachter Award for Exceptional Scientific Achievement, and La Fondation IPSEN Prize, for her findings. She is a member of the U.S. National Academy of Sciences and the American Academy of Arts and Sciences. She is now the director of the Hillblom Center for the Biology of Aging at UCSF. She is also one of featured biologists in the 1995 science documentary Death by Design / The Life and Times of Life and Times.

Personal diet
Kenyon's research prompted her to make personal dietary changes. She stopped eating high glycemic index carbohydrates when she discovered that putting sugar on the worms' food shortened their lifespans.

Kenyon follows a low glycemic index diet similar to the Atkins diet and the South Beach Diet.

"No desserts. No sweets. No potatoes.  No rice.  No bread.  No pasta.  When I say ‘no,’ I mean ‘no, or not much,’ she notes.  Instead, eat green vegetables.  Eat the fruits that aren't the sweet fruits, like melon.  Bananas?  Bananas are a little sweet.  Meat?  Meat, yes, of course.  Avocados.  All vegetables.  Nuts.  Fish.  Chicken.  That's what I eat.  Cheese.  Eggs.  And one glass of red wine a day."

"But the diet is unproven, she cautions, and she's not recommending it for all. Nevertheless, she's pleased with its performance for her. 'I have a fabulous blood profile. My triglyceride level is only 30, and anything below 200 is good.'"

"You have to eat something, and you just have to make your best judgment. And that's my best judgment. Plus, I feel better. Plus, I'm thin—I weigh what I weighed when I was in college. I feel great —you feel like you're a kid again. It's amazing."

In the past, Kenyon had also briefly experimented with a calorie restriction diet for two days, but couldn't stand the constant hunger.

Gene manipulation
Kenyon's lab is focusing on extending life by killing part of a specific worm cell.

"She is going to kill this cell with a laser, so she hit it right there. You can see—yes, it's starting to look different. So she's killing it. So these are cells that we know control lifespan. So when she kills the cell, the worm will live longer.

The reason that these animals can stay young longer is that they're better able to protect themselves against damage and they're better able to repair the damage once it's taken place.

If you're 80, but you're really like a 45-year-old, if you look like a 45-year-old, I mean, you're not just healthy, but you are young, then you're not going to be susceptible to these diseases until much later.

The company she founded, Elixir Pharmaceuticals, is trying to make a pill that would slow down the process that makes people age. It would mimic gene manipulation.

And then all these diseases of aging are postponed by this pill. So how realistic is this? We already know that this can happen in these long-lived animals. We see it. It's amazing."