6 theories of aging with substantial support
Notes from Roc Ordman updated January, 2020
based initially on a presentation by Dr. Christian Leeuwenburg
at the American Aging Association, June, 2004
Life expectancy in the US was 77.4 in 2002, 77.2 in 2001, while it is 80 in Japan and 82 in Okinawa where they consume 40% fewer calories than in the US. The longest person has lived to 122.
Having studied nutrition and human aging for more than 40 years, I am delighted by the opportunity to inform readers of ways that they can maintain their health as they get older. There has been tremendous progress as scientists have explored why we get older. This essay explains known causes of age-associated declines, and how to slow them through easy and inexpensive measures of prevention. With 6 children and 7 grandchildren, I want the world to be a healthier place with fewer people like me clogging our medical facilities with diseases and injuries that could be easily prevented with more public education about safe and proven methods to stay healthier. Over 70 years old, I still feel like a youngster, looking forward to a long and productive life ahead. Please join me and learn how to become and stay healthier. I welcome your questions and comments.
Below are 6 theories of aging with substantial support well documented in the literature, with specific actions one can take to lessen their progression. Further explanation is provided at the links.
1. The free radical theory of aging: Developed by Denham Harman, a host of diseases are attributed to free radicals (see Table 1). To lessen free radical damage, one can consume vitamin C 500 mg twice a day, vitamin E 400IU twice a week, and eat a diet of colorful fruits and vegetables that contain a variety of antioxidants.
2. Inflammation (or “Inflammaging” ): Another cause of chronic disease, including plaque in the arteries, cancer, etc. To reduce inflammation, one can consume fish oil, avoid 4-legged meat, reduce stress by exercising and avoiding the media, by treasuring friends, meditating and doing yoga.
3. Telomere shortening. The length of telomeres, which are caps on the end of the DNA, preserve our genetic information to allow longevity. Actions that shorten telomeres include stress and high metabolic rate. Consuming antioxidants, staying fit, and relaxing are all useful to keep long telomeres. Note that EGCG and quercetin help maintain telomere length (1).
A fourth theory Dr. Rolf Martin and I have developed:
4. Protein misfolding - The Translational Infidelity Error Theory of Aging: The basic mechanism is that mRNA is translated incorrectly, incorporating the wrong amino acids into proteins that then fold improperly (based on the AA error theory of Wolfgang Freist). These proteins are either destroyed, causing a shortage of needed proteins, or worse, remain malfunctioning and accumulating as hazardous waste such as plaque in Alzheimer’s. Processes that may lessen functional proteins being lost in translation include: 1) increasing the availability of needed amino acids, 2) slowing the rate of translation to increase accuracy, 3) providing time for better proofreading, 4) increasing degradation of misfolded proteins, or 5) diluting the accumulated damage by half through cell division. Helpful actions likely include getting exercise, eating blueberries, drinking green tea, and adjusting the diet to include beneficial foods such as tomatoes, onions, strawberries, and cabbage, which contain less common amino acids.
5. Microbiome destruction - Antibiotics kill the life forms in the intestine, lack of fiber and other complex carbohydrates that feed the microbiome, and a diet deficient in microbial components like yogurt and coleslaw cause obesity, diabetes, and weakened immunity, among other factors contributing to aging.
6. Cellular senescence - Many cell types are programmed to lose their ability to divide. This is especially true of muscle cells.
7. Miscellaneous - Other factors contribute to or reduce aging effects. These are listed in this section.
Conclusion: How to slow your aging process
Seven Compounds tested by the National Institute of Aging to extend lifespan in mice
Pages related to aging: 1)Aging index 2) Shigeaki Hinohara 3) Roc Ordman
2022- Tony Wyss-Coray from Stanford has published two papers where through single cell RNAseq he has confirmed that there is a common pattern of changes in the proteins in our bodies that happen in the 4th, 7th, and 8th decade of life. Such predictable, synchronized changes in proteome at around same age gives evidence of a program. https://www.nature.com/articles/s41591-019-0673-2
2022- In spite of significant advances in the understanding of genetic, dietary, and pharmacological manipulations of aging in animals, known interventions retard but do not stop or reverse aging. [known interventions] For those seeking eternal youth, life-extending interventions like caloric restriction (capable of extending rodent lifespan up to 50%) and rapamycin (>20% in mice) will not be sufficient and therefore reversing aging may be essential.
2022- The Hallmarks of Aging - Aging is characterized by a progressive loss of physiological integrity, leading to impaired function and increased vulnerability to death. This deterioration is the primary risk factor for major human pathologies including cancer, diabetes, cardiovascular disorders, and neurodegenerative diseases. Aging research has experienced an unprecedented advance over recent years, particularly with the discovery that the rate of aging is controlled, at least to some extent, by genetic pathways and biochemical processes conserved in evolution. This review enumerates nine tentative hallmarks that represent common denominators of aging in different organisms, with special emphasis on mammalian aging. They are genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient-sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication.