Aging refers to the physiological changes we experience during our lifespan. It’s also an inevitable part of life. But why does this happen? For decades, scientists have been studying the subject. Here are some theories on why we age, and how you can slow down the effects.
Cellular aging
Cellular aging is due to intrinsic factors. It’s related to the biological aging of cells.
- Your cells are programmed to divide, multiply, and perform basic biological functions, but the more cells divide, the older they get. In turn, cells eventually lose their ability to function properly.
Damage-related and environmental aging
Environmental aging refers to how our surroundings and lifestyle affect how we age
- Everyone experiences both types of aging, and each form of aging varies from person to person
- It’s generally accepted that aging is caused by multiple processes, rather than one reason
- Some prominent theories include:
Evolutionary theory of aging
Natural selection refers to the adaptive traits of an organism. These traits can help the organism adjust to their environment, so they are more likely to survive.
- Aging is based on natural selection. It says that an organism begins aging after they have reached their peak of reproduction and have passed down adaptive traits.
Programmed theories of aging
Gene theory: This theory suggests that specific genes turn “on” or “off” over time, causing aging.
- Endocrine theory: Aging is caused by changes in hormones produced by the endocrine system
- Immunological theory: The idea that the immune response is designed to decline, and the result is disease and aging.
How to Slow Aging
Eat a nutritious diet: Focus on fruits, vegetables, whole grains, and lean protein
- Stay active: Aim for 30 minutes a day, 5 days a week
- Avoid tobacco: Tobacco speeds up aging
- Drink alcohol in moderation: Alcohol increases your risk of chronic disease
- Know your family history: Discuss your family’s health history with your doctor to have appropriate screening or get early treatment for potential chronic diseases
- Engage your brain: Protect your cognitive function by doing brain exercises
- Wear sunscreen: Sunscreen protects your skin from UV radiation
Error theories of aging
Damage theories are the opposite of programmed theories
- They hypothesize that aging is caused by cellular changes that are random and unplanned
- Wear and tear theory: cells break down and become damaged over time
- Genome instability theory: aging happens because the body loses its ability to repair DNA damage
- Cross-linkage theory: Aging is due to the buildup of cross-linked proteins which damages cells and slows biological functions
- Rate-of-living theory: Proponents say that an organism’s rate of metabolism determines its lifespan, but the theory lacks solid and consistent scientific evidence
- Free radical theory: A variation of the free radical theory, this theory says that mitochondrial damage releases free radicals and causes aging
Genetic theory of aging
The genetic theory proposes that aging primarily depends on genetics
- Our life expectancy is regulated by the genes we got from our parents
- Telomere theory: telomeres protect the ends of chromosomes as they multiply
- Programmed senescence theory: cells stop dividing and growing, but don’t die
- Stem cell theory: Stem cells can turn into other cells, which helps repair tissue and organs
- Longevity gene theory: Certain genes extend lifespan
