10 replies to this topic

[alternativista]

This has come up a bit in the discussions on DIM and estrogen dominance and related research. This is just from Wikipedia:

A glycoprotein that binds to sex hormones, specifically testosterone and estradiol.

These sex hormones circulate in the bloodstream, bound mostly to SHBG and to some degree bound to serum albumin. Only a small fraction is unbound, or "free," and thus biologically active and able to enter a cell and activate its receptor. The SHBG inhibits the function of these hormones. Thus bioavailability of sex hormones is influenced by the level of SHBG.

SHBG production

SHBG is produced by the liver cells and is released into the bloodstream. Other sites that produce SHBG are the brain, uterus, and placenta and vagina. In addition SHBG is produced by the testes; testes-produced SHBG is also called androgen-binding protein. The gene for SHBG is located on chromosome 17.

[edit] Control

SHBG levels appear to be controlled by a delicate balance of enhancing and inhibiting factors. Its level is decreased by high levels of insulin and insulin-like growth factor 1 (IGF-1). Also, high androgen levels decrease SHBG, while high estrogen and thyroxine levels increase it.

However, recent evidence suggests that it is the livers production of fats that reduces SHBG levels,[3][4] not any direct effect of insulin and specific genetic mechanisms have been found that do this.

[edit] Conditions with high or low levels

Conditions with low SHBG include polycystic ovary syndrome, diabetes, and hypothyroidism. Conditions with high SHBG include pregnancy, hyperthyroidism, and anorexia nervosa. There has recently been research to link high SHBG levels with breast and testicular cancer as well.

Note that many people have mentioned having clear skin during pregnancy.

And here's a study on diet and PMS in which women were put on a low-carb, low-fat diet, which is about increasing SHBG.

http://www.greenjournal.org/cgi/content/full/95/2/245

[sie]

Thank you. This is very important. I need to digest it.

[rakbs]

I think SHBG is an important factor in acne, as it binds to both testosterone and estrogen, both of which are harmful in their own ways when there's enough of it.

But do we really have high IGF-1? I don't really have any symptoms of high IGF-1--but I have several symptoms of low IGF-1.

[ryudoadema]

Awesome finding! All the more reason to keep up with the low glycemic diet. Ill have to see if low fat really increases SHBG cuz i do have quite a bit of that and protein since I workout like a fiend,lol...

[alternativista]

I think SHBG is an important factor in acne, as it binds to both testosterone and estrogen, both of which are harmful in their own ways when there's enough of it.

But do we really have high IGF-1? I don't really have any symptoms of high IGF-1--but I have several symptoms of low IGF-1.

Well, the wikipedia article says there has been at least one study that showed the fat lowered SHBG, and there used to be at least one person around here that always claimed a high fat diet led to acne, although that could have been about the fact that testosterone is made from cholesterol. And the study on diet and PMS, which was about increasing SHBG, was an extreme low carb and low fat diet. Even plant fats like avocados were prohibited.

Also, hypothyroidism is mentioned as lowering SHBG.

Partway down this page, there is a bit called Factors affecting SHBG levels with references to studies and articles to follow up:
http://www.nature.com/ijir/journal/v15/n4s...l/3901031a.html

Diet advice you may or may not want to follow, sites the same study from my first post.
http://www.vegsource.com/talk/health/messages/19225.html


And I think it's Fruitcocktail that's always talking about SHBG:
http://www.acne.org/messageboard/index.php...t&p=2210830

And this one is a study done on men:

http://jcem.endojournals.org/cgi/content/full/85/1/293

http://www.hairloss-research.org/GreenTearaisesSHBG.html

[ryudoadema]

I'm pretty sure I have hypothyroidism since for probably 7 years ive been eating 6 or 7 times a day and waking up at night and eating AT LEAST once early morning. Cuz of weight lifting and eating so close to bed i would get super hungry through the night and it would never get a rest. This supposedly causes hyperthyroidism where you thyroid is working overtime. If it stays in this state for an extended period of time it becomes hypothroidism and practically shuts down. I think thats the equivalent of adrenal fatigue...

[InquisitiveCreature]

That would explain problems with dairy:

Its level is decreased by high levels of insulin and insulin-like growth factor 1 (IGF-1) (see:milk).

And we all know milk is bad news for acne.

[InquisitiveCreature]

What bothers me is that in order to increase SHBG they recomend a vegan/vegetarian diet. But those diets have a reliance on grains. With all those carbohydrates you'll be eating higher GL meals and that can lead to acne. And now I'm confused because I cut out grains and went paleo to see if it would help me and it really did. My skin is less oily but still oily, I break out a lot less and my complexion is brighter.

[InquisitiveCreature]

I thought this was another good link to add

http://herkules.oulu.fi/isbn9514264266/html/x967.html

[alternativista]

That would explain problems with dairy:

Its level is decreased by high levels of insulin and insulin-like growth factor 1 (IGF-1) (see:milk).

And we all know milk is bad news for acne.

There are many problems with dairy. That's just one. For that matter, there are many problems caused by IGF1.

[alternativista]

What bothers me is that in order to increase SHBG they recomend a vegan/vegetarian diet. But those diets have a reliance on grains. With all those carbohydrates you'll be eating higher GL meals and that can lead to acne. And now I'm confused because I cut out grains and went paleo to see if it would help me and it really did. My skin is less oily but still oily, I break out a lot less and my complexion is brighter.

What's recommended for SHBG levels is the same diet that helps acne in many ways, a blood sugar stabilizing, nutrient dense, anti-inflammatory diet that doesn't include anything you have an intolerance for.
http://www.acne.org/messageboard/Good-Acne...es-t230714.html

Edited by alternativista, 19 July 2010 - 09:35 AM.