Can we stop cells from aging?

Ask Dr. K

Print Article

DEAR DOCTOR K: I see advertisements about various treatments that stop your cells from aging. Is there anything to that? What happens to our cells as we age?

DEAR READER: There are no treatments that can stop our cells from aging. But in the past 10 years scientists have made giant steps in understanding what causes cells to age. That knowledge could lead to true "anti-aging" treatments.

As for what happens to our cells as we age, I'd rephrase the question: What happens to us as our cells age?

Our bodies are made up of trillions of cells. As we get older, so too do our cells. And like us, our cells do not live forever. Most of the cells in our bodies today were not with us when we were born.

From birth through adulthood, new cells are constantly forming; that's how our bodies grow larger. Cells "grow" not by getting bigger, but by dividing in two. This process is called mitosis. Normally, the two cells that result from mitosis are identical right down to the last bit of genetic information.

Once we reach adulthood, our cells don't need to divide to help our bodies grow bigger. They divide only to replace cells that have died or been damaged. This happens differently in different organs. Liver cells, for example, multiply only in response to injury. But skin cells continue to divide regularly, even if the skin hasn't been injured, though at a pace that slows over time.

Cells can split only a limited number of times. For example, fibroblasts, the collagen-producing skin cells, typically divide about 50 times. Once a cell reaches this end point, it enters a stage in which it no longer divides and finally dies. When the cell receives certain chemical signals that its time is up, the cell switches on a program called apoptosis that leads to the cell's death. In other words, a cell that learns its time has come commits suicide.

Each time a cell divides, a little bit of the telomere - DNA at the tip of each chromosome - is lost. Thus, telomeres of young cells are longer than the telomeres of middle-aged cells, which in turn are longer than the telomeres of old cells. When the telomeres become very short, the cell can no longer divide, and it dies. (I've put an illustration of cell division and its effect on telomere length on my website, AskDoctorK.com.)

Along with telomeres that get shorter, older cells also suffer increasing damage to their DNA. In addition, the mitochondria -- the little "batteries" inside each cell that supply its energy -- start to become less efficient.

The bottom line is this: We get older because our cells get older. What makes a cell age, and what could help keep a cell young, were nearly total mysteries just 25 years ago. Since then, medical research has provided many answers. Because of that research, I believe that someday we will be able to slow aging.

Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.

Print Article

Read More

Bear, cubs spotted on Canfield Mountain

July 21, 2017 at 5:57 pm | Coeur d'Alene Press COEUR d’ALENE — A black bear encounter on Canfield Mountain this week has prompted the Forest Service to warn people to beware of bears at the popular recreation site. A sow black bear with two cubs...

Comments

Read More

Fundraiser Saturday for child of man killed in Cd’A

July 21, 2017 at 1:36 pm | Coeur d'Alene Press A breakfast fundraiser to benefit the young daughter of Jeffrey Marfice, who was killed recently in downtown Coeur d’Alene, will be held Saturday, July 22, from 8 to 10 a.m. at Applebee’s in Coeur d’...

Comments

Read More

Julyamsh eagle feather in the sky

July 21, 2017 at 4:11 pm | Coeur d'Alene Press The eagle is an important part of the Coeur d’Alene Tribe’s culture. Mark Sales sent us this photo he took earlier today as the Tribe’s Julyamsh powwow is under way in Coeur d’Alene at the Kootenai C...

Comments

Read More

Council debates 9-inch fail

July 21, 2017 at 5:00 am | Coeur d'Alene Press COEUR d’ALENE — Less than a foot of encroachment from a newly built concrete ramp onto a Coeur d’Alene city sidewalk has caused some kvetching among City Council members who blame building inspectors...

Comments

Read More

Contact Us

(208) 664-8176
215 N. Second St
Coeur d'Alene, Idaho 83814

©2017 The Coeur d'Alene Press Terms of Use Privacy Policy
X
X