April 3, 2017History of Medicine
Gerontology, from the Greek, geron, “old man” and -logia, “study of”; coined by Ilya Ilyich Mechnikov (in 1903) is the study of the social, cultural, psychological, cognitive, and biological aspects of aging. It is distinguished from geriatrics, which is the branch of medicine that specializes in the treatment of existing disease in older adults. Gerontologists include researchers and practitioners in the fields of biology, nursing, medicine, criminology, dentistry, social work, physical and occupational therapy, psychology, psychiatry, sociology, economics, political science, architecture, geography, pharmacy, public health, housing, and anthropology.
Gerontology encompasses the following:
The multidisciplinary nature of gerontology means that there are a number of sub-fields, as well as associated fields such as physiology, anthropology, social work, public health, psychology and sociology that overlap with gerontology. One of the world’s oldest drugs which was first mentioned by Hippocrates in the 5th Century BCE could help restore memory in Alzheimer’s patients, scientists hope. Salsalate, which comes from the same family as aspirin, was typically used to treat inflammatory conditions like rheumatoid arthritis. But a new study suggests that it can prevent the build-up of toxic proteins in the brain and even reverse damage already done, unblocking pathways and restoring memory.
In the medieval world, several physicians wrote on issues related to Gerontology. Avicenna's The Canon of Medicine (1025) offered instruction for the care of the aged, including diet and remedies for problems including constipation. He also wrote on the aches and conditions of the elderly. His scholarly work covers sleep disorders, forgetfulness, how to strengthen memory, and causes of mortality. Ishaq ibn Hunayn (died 910) wrote works on the treatments for forgetfulness (U.S. National Library of Medicine, 1994).
While the number of aged humans, and life expectancy, tended to increase in every century since the 14th, society tended to consider caring for an elderly relative as a family issue. It was not until the coming of the Industrial Revolution that ideas shifted in favor of a societal care-system. Some early pioneers, such as Michel Eugene Chevreul, who himself lived to be 102, believed that aging itself should be a science to be studied. Elie Metchnikoff coined the term “gerontology” c. 1903. However, it was not until the 1940s that pioneers like James Birren began organizing gerontology into its own field. Recognizing that there were experts in many fields all dealing with the older population, it became apparent that a group like the Gerontological Society of America (founded in 1945) was needed. Two decades later, James Birren was appointed as the founding director of the first academic research center devoted exclusively to the study of aging, the Ethel Percy Andrus Gerontology Center. The Baltimore Longitudinal Studies of Aging began in 1958 in order to study physiological changes in healthy middle-aged and older men living in the community by testing them every two years on numerous physiological parameters. In 1967, the University of South Florida and the University of North Texas (formerly North Texas State University) received Older Americans Act training grants from the U.S. Administration on Aging to launch the nation's first degree programs in gerontology, at the master's level. In 1975, the University of Southern California's Leonard Davis School of Gerontology, became the country's first school of gerontology within a university and, later, offered the first PhD in Gerontology degree. Gerontological Education has flourished in the United States since 1967 and degrees at all academic levels are now offered by a number of colleges and universities. One of the pioneering gerontologists, Robert Neil Butler, pushed for care and respect of the elderly. Several university-based centers on aging have been founded such as the Duke University Center on Aging, the University of Georgia Institute of Gerontology, the Center of Aging at the University of Chicago, and the Stanford Center on Longevity. Currently, PhD programs in gerontology are available at Miami University, the University of Kansas, University of Kentucky, University of Maryland Baltimore, University of Massachusetts Boston, and the University of Southern California.
The world is forecast to undergo rapid population aging in the next several decades. In 1900, there were 3.1 million people aged 65 years and older living in the United States. However, this population continued to grow throughout the 20th century and reached 31.2, 35, and 40.3 million people in 1990, 2000, and 2010, respectively. Notably, in the United States and across the world, the “baby boomer” generation began to turn 65 in 2011. Recently, the population aged 65 years and older has grown at a faster rate than the total population in the United States. The total population increased by 9.7%, from 281.4 million to 308.7 million, between 2000 and 2010. However, the population aged 65 years and older increased by 15.1% during the same period. It has been estimated that 25% of the population in the United States and Canada will be aged 65 years and older by 2025. Moreover, by 2050, it is predicted that, for the first time in United States history, the number of individuals aged 60 years and older will be greater than the number of children aged 0 to 14 years. Those aged 85 years and older (oldest-old) are projected to increase from 5.3 million to 21 million by 2050. Adults aged 85–89 years constituted the greatest segment of the oldest-old in 1990, 2000, and 2010. However, the largest percentage point increase among the oldest-old occurred in the 90- to 94-year-old age group, which increased from 25.0% in 1990 to 26.4% in 2010. With the rapid growth of the aging population, social work education and training specialized in older adults and practitioners interested in working with older adults are increasingly in demand.
Genetic theories of aging propose that aging is programmed within each individual's genes. According to this theory, genes dictate cellular longevity. Programmed cell death, or apoptosis, is determined by a “biological clock” via genetic information in the nucleus of the cell. Genes responsible for apoptosis provide an explanation for cell death, but are less applicable to death of an entire organism. An increase in cellular apoptosis may correlate to aging, but is not a ‘cause of death’. Environmental factors and genetic mutations can influence gene expression and accelerate aging. More recently epigenetics have been explored as a contributing factor. The epigenetic clock, which objectively measures the biological age of cells and tissues, may become useful for testing different biological aging theories. General imbalance theories of aging suggest that body systems, such as the endocrine, nervous, and immune systems, gradually decline and ultimately fail to function. The rate of failure varies system by system. Accumulation theories of aging suggest that aging is bodily decline that results from an accumulation of elements. Elements can be foreign and introduced to the body from the environment. Other elements can be the natural result of cell metabolism. An example of an accumulation theory is the Free Radical Theory of Aging. According to this theory, byproducts of regular cell metabolism called free radicals interact with cellular components such as the cell membrane and DNA and cause irreversible damage.
The idea that free radicals are toxic agents was first proposed by Rebeca Gerschman and colleagues. In 1956, Denham Harman proposed the free-radical theory of aging and even demonstrated that free radical reactions contribute to the degradation of biological systems. Oxidative damage of many types accumulate with age, such as oxidative stress that oxygen-free radicals, because the free radical theory of aging argues that aging results from the damage generated by reactive oxygen species (ROS). ROS are small, highly reactive, oxygen-containing molecules that can damage a complex of cellular components such as fat, proteins, or from DNA, they are naturally generated in small amounts during the body's metabolic reactions. These conditions become more common as we age, including diseases related to aging, such as dementia, cancer and heart disease.
DNA damage has been one of the many causes in diseases related to aging. The stability of the genome is defined by the cells machinery of repair, damage tolerance, and checkpoint pathways that counteracts DNA damage. One hypothesis proposed by Gioacchino Failla in 1958 is that damage accumulation to the DNA causes aging. The hypothesis was developed soon by physicist Leo Szilard. This theory has changed over the years as new research has discovered new types of DNA damage and mutations, and several theories of aging argue that DNA damage with or without mutations causes aging.
To demonstrate how far the interest in longevity goes, Google has a separate division called Calico to study this aspect of aging.
What is Alphabet? Alphabet is mostly a collection of companies. The largest of which, of course, is Google. This newer Google is a bit slimmed down, with the companies that are pretty far afield of our main internet products contained in Alphabet instead. What do we mean by far afield? Good examples are our health efforts:Life Sciences (that works on the glucose-sensing contact lens), and Calico focused on longevity.Fundamentally, we believe this allows us more management scale, as we can run things independently that aren’t very related. What could be better? No wonder we are excited to get to work with everyone in the Alphabet family. Don’t worry, we’re still getting used to the name too!