What is mTOR, Rapamycin, and the Engine of Aging?

Do you want to slow down mTOR, the engine of aging?

When you’re young, mTOR promotes healthy growth. But after development, mTOR speeds up the aging process.

Overactive mTOR, mammalian target of rapamycin, can promote obesity, diabetes, cancer, and Alzheimer’s Disease.

Some people, however, use mTOR for bodybuilding. Is there an ideal balance?

Learn the foods that inhibit mTOR and how to activate it when needed.

A turtle under water, headline "How Can You Slow Down Aging?

Table of Contents



What is mTOR?

mTOR, “mammalian target of rapamycin,” is a serine/threonine kinase responsible for metabolism and cell growth (1, 2). mTOR (TOR) is also known as the mechanistic target of rapamycin. It is activated in response to nutrients, growth factors, energy, and stress.

The discovery of mTOR changed the way we understand cellular growth. Before, cellular growth was thought to be a random process that happens when nutrients are available. It is believed to be a highly regulated process controlled by mTOR pathways.

mTor is believed to play a key role in aging.


How To Slow Down Aging: mTOR 

Aging is (3) like a speeding car without brakes. In childhood, mTOR is an engine of growth. But in adulthood, TOR is an engine of aging.

You start life racing through the aging process to reach reproductive age. When aging speeds past development, your body breaks down.

Theoretically, the over-activation of the mTOR pathway causes aging. Aging damages organs, eventually leading to death.

Traditional medicine increases the years spent in poor health. Conversely, rapamycin may slow TOR activation and, thereby, the aging process. How can you naturally slow down TOR and slow down aging?


mTOR and Fasting

“The only thing  that’s been proven in the history of science to radically improve lifespan is moderate caloric restriction in an environment of micronutrient excellence.” Dr. Joel Fuhrman


Caloric restriction slows (4) down growth and aging, possibly by inhibiting mTOR. It appears to be activated (5) by a complex mechanism involving Glutamine binding to Pib2.

Glutamine is one of the 20 amino acids in the diet used to make proteins. When glutamine is available, cells grow. When it is unavailable, cells start the process of autophagy.

Further Reading: Intermittent Fasting Times and Benefits for Weight Loss


mTOR and Autophagy

Autophagy is a Greek word, auto meaning “self” and phagy meaning “to eat.” Autophagy literally means to eat oneself.

When your body determines that there isn’t enough food to eat, it goes into survival mode. It starts searching your cells, looking for anything you don’t need. Damaged or useless cells are converted into fuel or materials to renew cells.

Caloric restriction is praised as a fountain of youth and can extend (6) the human lifespan by up to five years.

Caloric restriction has many potential health benefits, along with some potential problems.

Symptoms of caloric restriction include (7):

  • very low blood pressure
  • loss of libido
  • infertility
  • menstrual irregularities
  • bone loss,
  • cold sensitivity
  • loss of strength
  • slower healing
  • depression
  • irritability.

You can get many benefits from caloric restriction with protein restriction without the side effects.


Protein Restriction Vs. Caloric Restriction

The benefits of caloric restriction may come from protein restriction. Further, protein restriction is easier to sustain as you don’t have to cut your total food intake.

A comprehensive comparative meta-analysis of dietary restriction found that the proportion of protein intake is (8) a better indicator of longevity than the degree of caloric restriction.

Protein restriction may be (9) even more effective than dietary restriction because it suppresses TOR and IGF-1. These are two factors believed to be responsible for the benefits of caloric restriction.

Not all proteins have the same effect on mTOR. What proteins speed up the aging process?

Further Reading: 10 Best Vegan Protein Sources For Weight Loss and Muscle


Leucine and mTOR

One amino acid, leucine, has been shown to have (10) the greatest effect on mTOR.

Leucine is found (11) primarily in animal products, including meat, dairy, eggs, and fish. Conversely, plant foods, including fruits, vegetables, beans, and grains, have much less leucine. You would need to eat (12) about 9 pounds of cabbage, or 100 apples to get the same amount of leucine.

Leucine restriction helps explain (13) why the longest-living populations, such as Okinawan Japanese, eat a plant-based diet primarily. Only 1% of their diet consists (14) of meat, dairy, or fish. Or about one serving of meat per month.

The longest-living population, however, is (15) the Adventists of Loma Linda, California, who also eat a plant-based diet.

What are other risk factors for high TOR activity?


mTOR and Cancer Promotion

mTOR appears to play a prominent role in cancer growth as it is (16) responsible for regulating cellular growth and proliferation.

  • mTOR is inhibited by rapamycin, which is used (17) to prevent the rejection of kidney transplants.  Thereby patients receiving rapamycin had a decrease in cancer incidence.
  • Fifteen patients diagnosed with Kaposi’s Sarcoma, a type of skin cancer, were placed on rapamycin for a kidney transplant. Within three months of being on rapamycin, the skin lesions disappeared (18) in all 15 patients.
  • High TOR activity is (19) found in 100% of advanced prostate cancer patients.
  • TOR (20) appears to play a role in breast cancer. High TOR expression is associated with much more aggressive breast cancer and a lower survival rate.


Mitochondria and mTOR

When TOR activity is (21) inhibited, mitochondria become elongated. Conversely, when mTOR is activated, mitochondria become fragmented. Increased fragmentation of mitochondria is a possible risk factor for some cancers.

Learn more about mitochondria health in the article How to Maximize Your Mitochondria.


mTOR and Acne

Acne is (22) prevalent in about 85% of teenagers in industrialized countries. In the US, half of men and women still have acne in their twenties. Conversely, in non-industrialized locations like Okinawa, Japan, acne is rare or non-existent.

Acne appears to be a symptom of overactive mTOR signaling. Overactive mTOR signaling is a risk factor for serious common  Western diseases. Therefore, acne could be an early warning sign of more serious health problems.

Excessive mTOR stimulation induced by the Standard American diet first appears as premature puberty and acne. But later in life, it may promote obesity, diabetes, cancer, and Alzheimer’s Disease.


Milk and TOR

Milk consumption is a major contributing factor to mTOR activity.

Mammalian milk is (23) an endocrine signaling system unique to each specific species.  Milk activates mTOR, promotes cell growth and proliferation, and suppresses autophagy.


Why does milk consumption promote growth and aging?

Milk is designed primarily for infants who need higher mTOR activity to signal cells to grow and divide constantly. What happens when a person consumes milk throughout their entire lifespan?

In those who continue to drink milk, mTOR activity remains high. They continue aging fast past maturity and have higher rates of cancer.

Cow’s milk, three times more leucine than human milk, is designed for an infant cow. Infant cows grow up to 40 times faster than human infants and will weigh several hundred pounds.

Cow’s milk, with 3 times more leucine than human milk, is specifically designed for an infant cow. Infant cows grow up to 40 times faster than human infants and end up weighing several hundred pounds. Click to Tweet


Foods That Inhibit mTOR

Plant-based diets are not only low in mTOR-promoting proteins, but they can also inhibit (24) mTOR activity.

Many plants have natural inhibitors of mTOR. These include:(25)

  • broccoli
  • green tea
  • soy
  • turmeric
  • grapes
  • onions
  • strawberries
  • blueberries
  • mangos
  • cucumbers

mTOR inhibition may explain why plant-based diets are (26) associated with lower risk for many cancers.


Sulforaphane and mTOR

Sulforaphane-rich vegetables, like broccoli, are possibly the best foods for slowing down mTOR activity. Sulforaphane is (27) a potent inhibitor of cancer cells because it targets downstream elements of the TOR pathway.

Sulforaphane has also been shown to help with the following:(28)

  • oxidative stress
  • lower antioxidant capacity
  • mitochondrial dysfunction
  • brain inflammation in children with ASD.
  • It can even cross the blood-brain barrier to exert its protective force.


What is the best source of sulforaphane?

Broccoli sprouts have (29) at least ten times more sulforaphane than mature broccoli. Conversely, broccoli supplements do not have any significant sulforaphane. Broccoli sprouts can be grown at home easily and are a bargain for their health benefits. Why not give it a try?


What is mTOR Body Building?

mTOR is often touted for its growth-promoting abilities for physical training. One method is temporarily restricting protein by either fasting for 24 hours or practicing protein fasting.

Protein fasting initiates autophagy and recycles cellular waste. Then after protein fasting, you promote mTOR activation and growth by eating more mTOR-promoting protein. You reduce your risk of chronic disease, and your body grows more efficiently.

To learn more about protein fasting, read What Is Bulletproof Protein Fasting – And How To Fast Correctly.


How Will You Use mTOR?

  • We need the right amount of mTOR activation for normal growth.
  • Protein restriction is easier and as effective as a caloric restriction at down-regulating mTOR.
  • Animal protein should be limited if your priority is reducing your risk of cancer or other chronic diseases.
  • mTOR-promoting proteins should be used only when your body needs growth. If you are finished developing and inactive, mTOR will likely promote cancer.
  • If your goal is health and longevity, then consider eating a vegan diet.
  • What about mTOR interests you? What do you want to learn?


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Sources Cited

  1. https://www.ncbi.nlm.nih.gov/pubmed/1102508
  2. https://www.ncbi.nlm.nih.gov/pubmed/19100909
  3. https://www.ncbi.nlm.nih.gov/pubmed/19923900
  4. https://www.ncbi.nlm.nih.gov/pubmed/21157483
  5. https://www.sciencedaily.com/releases/2018/05/180502094652.htm
  6. http://www.scirp.org/journal/PaperInformation.aspx?paperID=24485#.UypXGccnxn1   
  7. https://www.ncbi.nlm.nih.gov/pubmed/16226298
  8. https://www.ncbi.nlm.nih.gov/pubmed/22268691
  9. https://www.ncbi.nlm.nih.gov/pubmed/20395504       
  10. https://www.ncbi.nlm.nih.gov/pubmed/22342805    
  11. https://www.ncbi.nlm.nih.gov/pubmed/19419870   
  12. https://www.ncbi.nlm.nih.gov/pubmed/22442749
  13. https://www.ncbi.nlm.nih.gov/pubmed/22524452
  14. https://www.ncbi.nlm.nih.gov/pubmed/20234038 
  15. https://www.ncbi.nlm.nih.gov/pubmed/11434797  
  16. https://www.ncbi.nlm.nih.gov/pubmed/22214661
  17. https://www.ncbi.nlm.nih.gov/pubmed/21138990
  18. https://www.ncbi.nlm.nih.gov/pubmed/15800227>
  19. https://www.ncbi.nlm.nih.gov/pubmed/22891897
  20. https://www.ncbi.nlm.nih.gov/pubmed/23503572  
  21. https://www.sciencedaily.com/releases/2017/10/171005125025.htm
  22. https://www.ncbi.nlm.nih.gov/pubmed/12472346   
  23. https://www.ncbi.nlm.nih.gov/pubmed/22891897   
  24. https://www.ncbi.nlm.nih.gov/pubmed/22686629      
  25. https://www.ncbi.nlm.nih.gov/pubmed/23517912   
  26. https://www.ncbi.nlm.nih.gov/pubmed/21862237  
  27. https://www.ncbi.nlm.nih.gov/pubmed/23389114
  28. https://www.ncbi.nlm.nih.gov/pubmed/27071792
  29. https://www.ncbi.nlm.nih.gov/pubmed/16569031

5 thoughts on “What is mTOR, Rapamycin, and the Engine of Aging?”

  1. While reducing mTor through protein reduction may reduce cancer risk at 72 years old I worry that reducing protein may also support sarcopenia. Your thoughts ? Thanks, John

    1. Thank you for your question, John. Only animal protein promotes excessive mTOR activation, not plant protein. You can get all the complete protein you need on a vegan diet. Please refer to my post 10 Best Vegan Protein Sources. But you don’t have to go vegan. Consider the Blue Zones, where people live longer than average and excellent health. In these regions, some people eat meat occasionally while others avoid it altogether.

  2. mTOR is one, and only one factor in cancer, and probably not the most important. This article too closely equates MTOR to cancer development. Vegans get cancer, too.

    There are times you want to activate mTOR. Exercise activates mTOR. Get protein to build muscle when you do resistance exercises. I read that mTOR is active for two hours, so get your nutrition to build muscle right after exercising.

    1. Thank you, Burt! Yes, mTOR has a purpose. But the link between high levels of mTOR and cancer are well documented. Please check out my sources. And yes vegans get cancer too, but at much lower rates. Please check out Dr. Gregor at Nutritionfacts.org to learn more. He’s dedicated his life to helping people improve their health with diet and exercise.

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