Protein and testosterone

[boxer08]

I read an article a while back about high intake of protein can lower natural test levels. What you guys think about this and is it true.

[brjrj0000]

this should go in the supplement section

[smokethedays]

can you post that article?

[boxer08]

I will try and find it now smoke

[boxer08]

Part One of this article discussed that a high protein intake raises growth hormone levels. But when it comes to testosterone , it is difficult to draw a firm conclusion from the evidence. Some studies find that a high protein intake lowers T levels. For instance, in the following study, a "r=" that is negative (-) means the item was associated with lower T levels, while a "r=" that is positive means it is associated with higher T levels.

Significant correlations were observed between preexercise T and percent energy protein (r = -0.71), percent energy fat (r = 0.72), saturated fatty acids (g.1,000 kcal-1.day-1; r = 0.77), monounsaturated fatty acids (g.1,000 kcal-1.day-1; r = 0.79, the polyunsaturated fat-to-saturated fat ratio (r = -0.63), and the protein-to-carbohydrate ratio (r = -0.59). (Volek).

So a positive association was seen with total fat and saturated fat, while a negative association was seen with protein and polyunsaturated fat. However, studies such as this one only look at total T levels. When free T is considered, a somewhat different picture emerges.

For instance:
Testosterone concentrations in seven normal men were consistently higher after ten days on a high carbohydrate diet (468 +/- 34 ng/dl, mean +/- S.E.) than during a high protein diet (371 +/- 23 ng/dl, p less than 0.05) and were accompanied by parallel changes in sex hormone binding globulin (32.5 +/- 2.8 nmol/l vs. 23.4 +/- 1.6 nmol/l respectively, p less than 0.01). By contrast, cortisol concentrations were consistently lower during the high carbohydrate diet than during the high protein diet (7.74 +/- 0.71 micrograms/dl vs. 10.6 +/- 0.4 micrograms/dl respectively, p less than 0.05) (Anderson).

So the high carb diet raised total T levels and lowered cortisol levels. These are both beneficial effects. However, the raising of SHBG is problematic. This is discussed further in the next study.

A 2001 study was conducted that looked at the relationship of protein intake to SHBG, "Using data from the Massachusetts Male Aging Study we examined cross-sectional relationships between dietary components and SHBG levels in 1552 men (aged 40-70 yr) for whom these factors were known." The study found that the higher the protein intake the lower the levels of SHBG.

The researchers concluded, "Thus, diets low in protein in elderly men may lead to elevated SHBG levels and decreased testosterone bioactivity. The decrease in bioavailable testosterone can then result in declines in sexual function and muscle and red cell mass, and contribute to the loss of bone density" (Longcope).

So a high protein intake lowers total T levels and raises cortisol levels. These are both detrimental effects. However, protein lowers SHBG and increases GH secretion. These are both beneficial effects. Given these conflicting effects of protein on hormone optimization, the best recommendation would probably be to keep protein intake at a moderate level. But before discussing what "moderate" would be, another issue in regards to protein needs to be addressed

[TheSentinal]

this should go in the supplement section

Not necessarily. I don't remember test being a supplement or protein. This is a legitimate question on protein synthesis and whether it is altered by testosterone . Since this synthesis is critical to muscle building, it would seem appropriate to post here so the majority of members with knowledge can offer advice. I am interested.