Monounsaturated fat, nuts and testosterone

Johan, since you seem to be able to find studies easily, maybe you can help me with this. I have been searching around for data on this topic, but am having trouble finding studies. Many bodybuilding/strength site say that monounsaturated fats increase testosterone levels more than any other fat, even saturated. They mention studies done (whether they are supposed to be epidemiological, cohort, double-blind or whatnot, I don't know), which show that men with the highest nut consumption have the highest testosterone levels. They also talk of studies that show an inverse relationship between polyunsaturated fat consumption and testosterone levels, save for omega 3.

So, do you know of any? I tried PubMed with several different search terms, but didn't come up with anything. Is that what you usually use to find studies?

Nuts and Testosterone? My mind went to something totally different.

I must admit I was a little disappointed when I opened this thread.

i was disappointed too, until i read carefully.

men with the highest nut consumption have the highest testosterone levels.

Go go avo-cado!

I totally set myself up for a lot of jokes.

Sorry to disappoint.

Two conflicting studies... potentially has to do with ratio of PUFA/SFA rather than total PUFA intake.

Testosterone, sex hormone-binding globulin, calculated free testosterone, and oestradiol in male vegans and omnivores

Timothy J. A. Key, Liane Roe, Margaret Thorogood, John W. Moore, Graham M. G. Clark and Dennis Y. Wang

British Journal of Nutrition (1990), 64 : 111-119

In a subset of eighteen vegans and twenty-two omnivores for whom 4 d diet records

were available, there were statistically significant correlations between T and polyunsaturated fatty acids

( r 0.37), SHBG and fat ( r 0.43 f or total fat, 0.46 f or saturated fatty acids and 0.33 f or polyunsaturated

fatty acids), and SHBG and alcohol ( r-0.39). It is concluded that a vegan diet causes a substantial

increase in SHBG but has little effect on total or free T or on E2

...

The relationships between the hormonal variables and these dietary variables were

examined by calculating partial correlation coefficients, adjusted for age, B MI and dietary

group (vegan or omnivore) (Table 5). Total T was significantly positively correlated with

polyunsaturated fat intake.

Testosterone and cortisol in relationship to dietary nutrients and resistance exercise

Jeff S. Volek, William J. Kraemer, Jill A. Bush, Thomas Incledon and Mark Boetes

J Appl Physiol 82:49-54, 1997.

Preexercise T was significantly positively correlatedwith percent energy fat, SFA (g · 1,000 kcal21 · day21 ),and MUFA (g · 1,000 kcal21 · day21 ) and was significantly negatively correlated with the percent energy protein, the PUFA/SFA ratio, and the protein-to-carbohydrate ratio (Fig. 2). There were no significant correlations observed between any nutritional variables and preexercise C or the absolute increase in T and C after exercise.

...

In contrast to the results obtained in this study, Key et al. (15) reported a significant positive correlation (r 5 0.37) between PUFA and T in male vegetarians and omnivores. Our results showed a nonsignificant correlation between PUFA and T and a significant negative correlation between the PUFA/SFA ratio and T.

Dude I think I'm going to dissapoint you here. I don't know any specific studies done on nuts and t-levels. You have to put 1+1 together. There are studies that clearly show a trend of MUFAs raising HDL and there are other studies that clearly find a positive association between HDL levels and t-levels in men. I think the mechanism behind this is pretty clear.

I don't too much about this stuff but I know that t is a hard thing to study from an athletes point of view. For instance high t-levels in serum isn't very positive because it doesn't always mean higher protein synthesis, we are intrested in how much t goes into the muscle cells (which I don't know how you can measure exactly, it's seldomly done). For instance, some people do the mistake thinking high protein diets are bad for t-production because serum t often goes down but this could simply mean that more t goes into the muscle which would be very positive. Anyway I'm just ranting. I'm going to study a lot of endocrinology this spring so make sure to bump this thread and I might have a much much better answer.

With that first study Chris posted, I wonder if the fat overall was higher, which may account for the correlation between increased PUFA and testosterone?

It makes sense that SUFAs and MUFAs would raise testosterone if it is linked to increased HDLs. I know soluble fiber increases HDLs, so I wonder if having large amounts of soluble fiber somewhat negates the SHBG raising effect of fiber, due to the increased testosterone? That would make me feel better, since so much of my crazy high fiber intake is from soluble fiber.

I will make sure to bump this in the spring. Hopefully I will be taking some classes soon with at least some focus on endocrinology.

Yeah PUFAs shows different results depnding on how the study is designed. You can find articles that say it lowers t but also those who are stating it's raised. Most researches argue that overall fat intake matters the most, almost independent of the type of fats consumed. However there are severals mechanism involved and the relationship is far from clear.