Testosterone Levels & Genetics

I've been busy this week with updating old articles -- adding new studies, making the formatting consistent, and generally working to improve Genetic Lifehacks.

One article that got a major update and redesign is on the genetic variants that affect testosterone levels. In it, I go through the pathway of testosterone synthesis, the genetic constraints on free testosterone levels, and the effects of diet and microplastics. I have also added a section on testing, timing of testing, and how diet affects testosterone levels.

Below, I've included the section from the article about recent studies on microplastics and testosterone because I thought it might be of interest to everyone. I found it very interesting that microplastics adsorb circulating testosterone.

Stay curious!

~ Debbie

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Testosterone: Genetic Variants that Impact Testosterone Levels

Key takeaways:
~ Testosterone is an essential hormone for both men and women, and imbalances can lead to health problems.
~ Genetics play a significant role in testosterone levels, with an estimated heritability of up to 70% in men.
~ Addressing lifestyle factors such as getting enough sleep, reducing microplastic exposure, eating right, and managing inflammation can help optimize testosterone levels.

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Section snippet:

Microplastics and testosterone:

Exposure to plastic is ubiquitous in our modern environment, but the full extent of the problems posed by the microscopic bits of plastic we consume is only now being uncovered.

Microplastics are a problem for testosterone in at least three ways:

1. Adsorption of free testosterone

2. Endocrine disruption

3. Testicular damage

1) Adsorption of testosterone by microplastic:
Apparently, it has been known for more than 5 decades in research labs that steroid hormones are adsorbed (adhered to) by plastic containers.[ref] If you think about storing food in plastic containers, they often will get stained by specific foods (e.g. tomatoes) or can absorb odors (e.g. onion). A similar thing happens with steroid hormones being adsorbed to plastics.

Recently, researchers looked at whether the tiny bits of plastic that ingest each day also adsorb hormones circulating in the body. First, the researchers centrifuged different types of microplastics with a solution of testosterone to see which plastics adsorbed the most hormone. They then used animals to see the in vivo effect of two different types of microplastics in two different sizes. The results showed that polyamide microplastics (e.g. from fabrics) were particularly good at adsorbing circulating testosterone like little sponges – enough to make a measurable difference in testosterone levels within hours due to the plastic particles adsorbing free testosterone. They also found that the plastic particles were taken up by the testicles within 24 hours.[ref]

2) Endocrine disruptor:
Microplastics and nanoplastics also can leach endocrine-disrupting chemicals, such as BPA and phthalates, into the body. A recent study showed that microplastics can reduce the expression of the enzymes needed for testosterone production, such as 17β-hydroxysteroid dehydrogenase (HS17B1 gene in the synthesis diagram above). Polystyrene nanoplastics have also been shown to disrupt luteinizing hormone levels (and LH is a driver of testosterone levels). Another study showed that under inflammatory conditions, the polystyrene microplastics had an even stronger negative effect on testosterone production.[ref][ref][ref]

3) Damage to the testes:
Microplastic and nanoplastic particles are absorbed in the intestines and circulate throughout the body before being taken into various organs. One place where the microscopic particles end up is in the testes. Studies show that they can accumulate in the different cell types there, including damaging the Leydig cells that produce the majority of male testosterone.[ref][ref][ref][ref]

Read the full article on testosterone here

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What I've been reading:

1.) Colon cancer, seed oils, and a lack of resolution of inflammation

There's a new study out showing that the lack of resolution of inflammation is likely driving colon cancer. The resolution of inflammation is an active process that depends on the availability of DHA and EPA along with the enzymes needed to convert them into pro-resolving mediators.

Excess omega-6 seed oils can limit the conversion enzymes. When this is combined with a lack of DHA and EPA (e.g. fish oil), specialized pro-resolving mediators aren't formed to turn off inflammation and turn on healing. The new study shows that this is part of what is driving the increase in colon cancer.

Here's more on pro-resolving mediators and the resolution of inflammation: https://www.geneticlifehacks.com/specialized-pro-resolving-mediators-getting-rid-of-chronic-inflammation/