How sex hormones slow biological aging

While you can’t change your chronological age, it is now proven that your biological age is influenced by your testosterone and estradiol levels.

That’s according to newer studies which measure correlations between these hormone levels and chromosomal telomeres.

First, let me explain about telomeres and their important relationship to biological age…

Telomeres shorten as we age

Chromosomes are the strands of DNA that contain your genetic blueprint. Telomeres are protective caps on the ends of the strands of your DNA chromosomes much like the plastic tips of your shoelaces.

In your youth, your telomeres are approximately 8,000 to 10,000 nucleotides (DNA coding proteins) long. As you age your cells are dividing; meanwhile your telomeres are shortening with each cell division and when they reach a critically short length the cell (that it is controlling) stops dividing and dies.

Therefore, biological age can be measured by the extent of your physical health, and also your telomere length, and is largely independent of your chronological age.

We also know that lifestyle factors such as poor diet, cigarette smoking, obesity, poorly managed stress and lack of physical activity accelerate aging and have each been linked to a shortening of telomere length. But what about the effects of your sex hormone levels on telomeres and aging?

Testosterone, DHT, and estradiol regulate telomere expression

We know that testosterone is metabolized into DHT (dihydrotestosterone) by the enzymatic activity of 5α-reductase and then to estradiol (E2) by the enzymatic activity of aromatase.  It turns out that testosterone and estradiol regulate the enzyme that preserves telomeres, called telomerase.

According to the science presented at the 2019 Annual Endocrine Society Meeting in New Orleans, Louisiana, in men over 70 years, higher testosterone and estradiol levels correlate with younger biological age.

Related: Natural ways to boost testosterone

The researchers examined nearly 3,000 men aged 70 to 84 years who lived in their communities (not in long-term care facilities). These were generally healthy men; approximately a third had some form of heart disease (as you would expect for this age); 14 percent had diabetes; and they were not obese (average body mass index was 26.5).

I want to put a plug in for testosterone supplementation in men and estradiol supplementation for women to preserve telomeres and lower biological age, but that conclusion cannot yet be claimed, although it sure sounds logical. The research presented did open the door for further studies to see if hormonal intervention can slow biological aging in men.

Now here is something interesting about telomeres and biological aging in women.  Does having more children cause a woman to age faster?

Reproduction, telomere length and aging in women

We know that human pregnancy causes major changes to metabolism, immune cell proliferation, and oxidative stress. Researchers hypothesized that these changes could accelerate cellular aging. In 2018 they studied young Filipino women (aged 20-22 years) and examined the relationship of pregnancy to their telomere length (821 subjects) and also to their DNA-methylation age, another indicator of genetic illness (397 subjects).

They found that telomere length and DNA-methylation age both correlated with illness and cell death; telomere length decreased and DNA-methylation age increased the more pregnancies they had. In other words, reproduction in women came with a cost: it accelerated aging.

However, this was not demonstrated in a 2016 prospective, longitudinal study. These researchers noted that studies conducted in non-human species show a trade-off between reproductive effort and biological aging such that having more offspring accelerated cell deterioration and aging (loss of cell division and growth, aka senescence). But when they investigated the relationship between the number of surviving births and telomere length over 13 years in a group of 75 Mayan women, they found that the women who had fewer children had shorter telomeres than the women who had more children (p = 0.045).

Related: Menopause Q&A: Progestogens vs progesterone

Their explanation for this apparent “protective effect” of having more children is that having more children increases social support for mothers which reduces the physical costs of reproduction. Also, the levels of estradiol increase dramatically during pregnancy. As shown with men, estradiol in women is known to protect telomere length from the effects of oxidative stress and increases telomerase activity, the enzyme that repairs telomeres after cell division.

We need more studies in postmenopausal women to determine if hormone replacement can slow biological aging. I’m betting it will because we already know transdermal natural estrogens plus progesterone lower heart disease, breast and uterine cancer, osteoporosis, Alzheimer’s dementia, and hot flashes. I can’t imagine it does not preserve telomere length in the process.

Editor’s notes: Are you feeling unusually tired? Maybe your vision (and your bladder) is getting weaker. You may think this is normal aging, but the problem could be your master hormone. When it’s not working, your risk of age-related diseases skyrockets. To reset what some call “the trigger for all disease,” and live better longer, Click Here!

To slowing biological age and living well,

Michael Cutler, M.D.

Sources:

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2. Yeap BB. Higher Plasma Estradiol Concentration is Independently Associated with Lower Biological Age, Assessed as Leucocyte Telomere Length, in Older Men — Presented at ENDO 2019, the 101^st annual meeting of the Endocrine Society, March 23-26, 2019, in New Orleans, Louisiana
3. Ryan CP, Hayes MG, Lee NR, McDade TW, Jones MJ, Kobor MS, Kuzawa CW, Eisenberg DTA. Reproduction predicts shorter telomeres and epigenetic age acceleration among young adult women — Sci Rep. 2018 Jul 23;8(1):11100. PubMed PMID: 30038336
4. Barha CK, Hanna CW, Salvante KG, Wilson SL, Robinson WP, Altman RM, Nepomnaschy PA. Number of Children and Telomere Length in Women: A Prospective, Longitudinal Evaluation — PLoS One. 2016 Jan 5;11(1):e0146424. PubMed PMID: 26731744
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