As an older person, one wonders how much longer one will be around and what role science has played in how long people live in our country. Part of our federal government, the U.S. Census Bureau, has data that are remarkable. At the beginning of the 20th century, the average age at death was 47.3 years. By the beginning of the 21st century, the average age at death had increased substantially to 77.85 years of age. Below is a figure taken from the National Vital Statistics Reports, Vol. 54, No.14, April19, 2006. Find your age on the horizontal axis and then move up to the three curves to learn what proportion of people your age died in the years represented by each curve.
If you’d like to read the entire report that has a lot of interesting information, go to this web site: https://www.cdc.gov/nchs/data/nvsr/nvsr54/nvsr54_14.pdf.
What has made that big difference in when we might die? Human civilizations recognized very early, 8,000 to 5,000 BC, that clean water, careful disposal of human waste and basic hygiene behaviors helped people to live longer. Over the last 200 or so years, public health has helped increase the length of our lives by treating diseases, encouraging us to use behaviors like handwashing and breastfeeding, vaccines, and other ways to prevent the spread of diseases. Our health care systems’ abilities to protect us from critical diseases such as tuberculosis, dysentery, pneumonia and polio were a result of scientific findings.
The polio vaccine has protected many of us from a serious disease that probably resulted in the death of President Franklin D. Roosevelt in 1945. This vaccine was developed by Jonas Salk at the University of Pittsburgh in 1952. What Salk did for the near elimination of polio highlights the effectiveness of vaccination. Vaccines have eliminated small pox and are responsible for reducing the effects of measles, tetanus (a muscle disease), influenza, chicken pox and others. Many of us get our flu shots each year, but those viruses continue to evolve and require the development of new flu vaccines frequently.
So why do we age? One of the characteristics of cells taken from aged humans is that the number of chromosomes is sometimes not normal and these abnormalities increase with age. Scientists have found that this is a result of dysfunction of the machinery that makes our cells divide. They have also found that the genes which regulate cell division are turned off as we age. These scientists have also found that turning these genes back on makes the cell division process work better in older cells. It is possible that developing a way to turn these genes back on in older individuals may be a way to develop an anti-aging treatment. If you would like to read the scientific paper that discovered these interesting findings, go to this website: https://www.biorxiv.org/content/10.1101/261008v1.full.
Other studies of the consequences of aging have focused on our ability to think and reason as we grow older. A recent study of the short-term memory and other cognitive abilities of 45,000 people showed some fascinating results. Short term memory improved substantially from the age of 12 until people became 20 or a few years older. This and other cognitive abilities begin to decline until the age of 69 which was the oldest sample used. These scientists did find differences in the cognitive abilities of different genders, but concluded that these differences are not due to their sex but to environmental factors such as drug and alcohol use, mostly in men. Women’s cognitive abilities are affected by anxiety they experience more often than men. It is possible to reduce the effects of aging on our cognitive abilities by engaging in a lot of exercise. This study has lots of other recommendations that you can read by going to this website: https://www.biorxiv.org/content/10.1101/804765v1.full.
As we learned above, there may be ways to slow aging in people. Suppose some of these scientific procedures were effective, and people could manipulate their genes and environment to live much longer than we do now. Currently, there are about 7.7 billion people living on this planet. As we noted above, the average age that people die has increased by more than 30 years in the U.S. from the beginning of the 20th century until the beginning of the 21st century. Suppose scientists were able to modify our genes to allow us to live until the average age at death was 150. What would be the consequences for our children and other young people? Should our political systems control the work of scientists who could make these changes? Will different countries and other political systems compete with our country if we decide to restrict this kind of research? What do you think?
Rollin Richmond is an emeritus professor of biology and emeritus president at Humboldt State University. He has worked as an evolutionary geneticist at several universities during his career. Full disclosure: He happens to be responsible for 50 percent of Times-Standard publisher John Richmond’s genetic makeup. Questions or comments about this column can be sent to email@example.com.