What causes aging? If we knew how and why cells start aging, science might be able to stop or at least slow it down. We know that older people get chronic diseases before they die. But instead of curing each illness, could it be possible to stop aging itself?
One of the most common misperceptions, as it relates to aging, is that the body is in a constant state of degeneration. This has misled many to believe that preventable diseases cannot be improved through dietary and lifestyle change. Even the conventional medicine establishment has asserted that once brain cells die, they are gone forever.
Fortunately, the scientific literature disagrees. ~ Dr. David Perlmutter, author Grain Brain, Brain Wash
The Longevity Solution
I’ve been reading an informative book called the Longevity Solution: Rediscovering Centuries-Old Secrets to a Healthy, Long Life by Dr. James DiNicolantonio and Dr. Jason Fung. Here’s what I’m learning:
On a cellular level aging involves several things:
- Changes in appearances.
- Loss of functioning.
- Loss of cellular response to hormones.
The declining efficiency of an aging body results in higher rates of illness. Age exponentially increases the risk for disease and death.
Aging is not a disease itself (although some scientists disagree with this and propose there is a single root cause of aging). Aging raises the chances of developing diseases which debilitate and eventually cause death. That’s why scientists want to know more about the aging process so that they can target it and stop, slow or even reverse chronic diseases..
Possible Answers to What Causes Aging
Why do organisms age at all? Aging is the accumulation of damage. Long-lived, healthy populations around the world that eat few processed foods show us the possibility of slowing the aging process.
Autophagy: An important damage repair mechanism (Yoshinori Ohsumi was awarded the 2016 Nobel Prize in Medicine for his discoveries of mechanisms for autophagy). In autophagy, cellular parts called organelles are broken down and recycled periodically as part of a wide-ranging quality control system. This damage control process is heavily influenced by the foods we eat.
Theories of Aging
Theory of antagonistic pleiotrophy: genes have different effects at different stages of life. A gene that increases growth and fertility but increases the risk of cancer in old age means more children but a shorter life span. Survival of a gene is always given priority over longevity of an individual. A particular gene would spread in a given population because evolution favors survival of the gene, not the longevity of an individual life. One gene might have two different, unrelated effects (pleiotropy) that are seemingly at odds with one another (antagonistic).
Insulin-like growth factor 1 (IGF-1): High levels of IGF-1 promote growth, allowing organisms to grow larger, reproduce faster, and repair wounds better (an advantage for survival in order to have children}. However, in old age, high IGF-1 contributes to cancer, heart disease, and early death, but by that time, the gene for it has already passed into the next generation.
When growth/reproduction comes up against longevity, evolution favors reproduction and high IGF-1 levels. This is the natural balance between growth and longevity. Cells are either reproducing or repairing themselves to stay healthy.
The fight against the ravages of aging is a fight against nature itself. Aging is completely natural, living and eating completely in tune with nature does not prevent aging. Nature and evolution do not care about your longevity; your genes’ survival is their only concern. So we must look beyond nature to slow or prevent aging.
Disease Causes Aging
Before the modern industrial era with its advances in sanitation and medicine, infectious diseases were the main natural causes of death.
In the US in 1900, life expectancy was 46 years for a man and 48 for a woman (due largely to high infant and childhood mortality.
The top three causes of death in 1900 were all infectious diseases: pneumonia, tuberculosis, and gastro-intestinal infections.
Causes of Death
Today the top two causes of death are cardiovascular disease and cancer and they correlate tightly with age. Cardiovascular diseases include heart disease and stroke and is the number-one cause of death in the US, accounting for 1 in 4 deaths. Its incidence increases dramatically with age. By age 65 most of us have some form of CV disease.
The story is the same for cancer. Children and young adults each account for only about 1 percent of new cancer cases each year. People aged 50 and older account for around 89 percent of all new cancer cases.
Other diseases with clear links to aging include cataracts, osteoporosis, type 2 diabetes, Alzheimer’s, and Parkinson’s. These diseases are responsible for approximately 2/3s for the roughly 150,000 deaths that occur around the world every single day.
One reason that explains this is that infectious diseases like smallpox have been successfully eradicated. There are more many more older people alive today, and they have a high risk for chronic diseases. But that’s not the whole story.
Obesity and Lowered Lifespan
The obesity epidemic is putting our health at increasing risk of cancer and heart disease.
There are many dietary and lifestyle modifications that can reverse our risk of chronic disease. The obesity problem is contributing to a lower life expectancy in the US for the first time in a century.
To summarize, aging is the slow accumulation of cellular damage due to a decreasing ability of cells to repair themselves. This results in a chronically low level of inflammation, along with oxidative stress (a condition in which free radicals—highly reactive molecules with an unpaired electron—overpower the body’s internal antioxidant system). Oxidative stress damages cellular DNA.
Extend Your Healthspan
You can make lifestyle changes that can increase your odds of healthy aging, extend not just your lifespan, but your healthspan, the number of healthy years in old age.
I believe this is important to understand so that we can sustain lifestyle changes for the better. We know a lot about the steps seniors can take to extend their lifespan. What should we do to extend our healthspan? Stay tuned next week for more on this topic!
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