Credible Research

[JasonLB]

Actually, this is pretty interesting stuff:

"The concentrations of serum total and free testosterone were studied in 30 healthy, middle-aged men during a dietary intervention program. When men were transferred from their customary diet to an experimental diet, which contained less fat with a higher polyunsaturated/saturated ratio (P/S-ratio) and more fibre, there was a significant decrease in serum total testosterone concentrations (22.7 +/- 1.2 vs 19.3 +/- 1.1 nmol/l SEM, P less than 0.001). Furthermore, serum free, unbound testosterone fell from 0.23 +/- 0.01 to 0.20 +/- 0.01 nmol/l SEM (P less than 0.01). The hormonal changes were reversible. This observation suggests that testosterone activity in plasma can at least partly be modified by changing the composition of the diet."
(From Hämäläinen EEK, Adlercreutz HH, Puska PP, Pietinen PP.)

[JasonLB]

Interestingly, the above study shows a link between testosterone and fat intake (though it doesn't necessarily distinguish between types of fat); however, this next study found no changes in hormonal response when men were switched to a high fat diet that was very high in monounsaturated fat but low in saturated fat:

"In addition to being very low in carbohydrates, we counseled subjects to restrict saturated fat and cholesterol levels and to emphasize monounsaturated fat through generous consumption of olive oil, canola oil, almonds, and lean meats....

Using the data from the same study, we have reported fasting and postprandial hormonal responses to a VLCKD rich in monounsaturated fat and supplemented with omega3-fatty acids (4). Fasting and postprandial total testosterone, free testosterone, cortisol, leptin, and insulin responses to an oral fat tolerance test were determined before and after the 8-week VLCKD. There were no significant changes in fasting total testosterone, free testosterone, and cortisol, but there were significant decreases in insulin (-28%) and leptin (-64%) concentration after the VLCKD. Postprandial insulin responses immediately after the fat-rich meal were significantly lower after the VLCKD."
(http://www.nature.com/oby/journal/v12/n ... 4276a.html)

These two studies, when taken together, seem to suggest that high fat, low-carb diets do increase test levels, but not so if the diet is low in saturated fat. Certainly not conclusive, but interesting nonetheless.

(On a side note, the study from the nature.com link is really interesting. It's actually 9 studies examining low carb diets.)

[Mike5840]

Actually, I think your statement is somewhat unfair. While I concede that it is my nature to dismiss out-of-hand nearly everything contained in websites such as "Bodybuilding.com" , "tmuscle.com" or "Testosterone Nation" especially since much of the advise given on such sites often runs diametrically opposite to the Stronglifts philosophy of whole body strength training and eating real food.

The purpose of my question was to obtain information, to which end I searched more than one medical journal database for any abstract containing the words saturated fat and testosterone.

My concern was and is that since there is so much hearsay and misinformation on the internet and in particular regarding nutrition and bodybuilding/strength training that one can read multiple sources saying the same thing, yet it may all based on the same original source which may or may not be correct. As well, I consider the stronglifts philosophy and web site to be the most productive and healthy for natural trainers and would not want anything to discredit it. I have directed numerous neophyte lifters to this site that they may develop real , functional strength and good technique as well as learning the basics of eating real food and not wasting money on needless supplements.

Also, In reply to the previous post which states

No offense, but it's perfectly obvious that you really aren't interested in learning anything. (And I don't mean to imply I know the truth, just that I have a feeling your "question" wasn't asked in earnest.) If you were, you'd have bothered to read the links posted by atypical1. Had you done that, you would have discovered, in the very first link, an article with numerous citations. (The article itself, by the way, despite its not being peer reviewed, is well reasoned and worth your attention.) If you had then scrolled down to the very bottom of that article, to the end notes, you would have found the following list:

Yes, I should have thoroughly read through all of the links given, my bad. However, I did notice that the article mentioned concludes with

Conclusions

After reviewing the literature and studies presented in this article, one can't say that increased consumption of saturated fat definitively increases Testosterone levels, but it may, especially in strength training individuals. It's evident, though, that a higher total intake of dietary fat (30-35% of calories) does increase Testosterone levels compared to a low fat diet.

[JasonLB]

My apologies, Mike5840. I don't remember why I felt the need to jump down your throat, but it was uncalled for.

And for what it's worth, after looking over the studies myself, I agree with the above conclusion -- there's simply been very few studies even looking at this issue, so there is no definitive evidence linking saturated fat consumption to testosterone levels. Although, I did find it interesting that, as the above conclusion mentions, high fat intake in general (meaning not just saturated fat) has been shown to increase test levels, and in the last study for which I provided a link saturated fat was restricted while monounsaturated fat was increased and there was no change in testosterone levels. So there definitely seems to be a correlation between saturated fat/cholesterol and testosterone levels -- just nothing conclusive.

[somebody]

I concede that it is my nature to dismiss out-of-hand nearly everything contained in websites such as "Bodybuilding.com" , "tmuscle.com" or "Testosterone Nation" especially since much of the advise given on such sites often runs diametrically opposite to the Stronglifts philosophy of whole body strength training and eating real food.

I recommend you take some time one afternoon and actually look through the articles on T-Nation. Yes, they shill supplements. Yes, some of them are bodybuilders and have a generally pro-steroid attitude. Yes, there are pictures of peculiarly lean retired strippers in skimpy outfits. But there's a good bit of useful stuff there. Today's article has some interesting nuggets, for example: http://www.tmuscle.com/free_online_arti ... h_training

Of course, there are idiots everywhere. This article (http://www.bodyrecomposition.com/muscle ... overy.html) hilariously takes one of the T-Nation nutrition gurus apart by comparing their post-exercise supplement drink (Surge) to chocolate milk and finding no reliable basis for preferring one over the other.

On Lyle's site, by the way, he talks about the saturated fat / testosterone "link" *a bit* in this article: (http://www.bodyrecomposition.com/nutrit ... art-2.html).

From the body of the article:

"It’s worth mentioning in this context that some research suggests that saturated fat is required for optimal hormone levels (e.g. testosterone) so trying to reduce saturated fat excessively may be a mistake for athletes in the first place."

In the comments, he has this to say:

"Jack: The issue of saturated fat and optimal testosterone levels is complicated to parse in terms of the research since any time you change the intake of one nutrient, you have to change another (and most of the studies are comparing high saturated fat/low-fiber diets to low saturated fat/high-fiber diets).
There is also some question about how relevant small changes in testosterone within the normal range are in the first place. There is also some research to suggest that even if total testosterone levels change, the body will also alter levels of the binding protein such that free test doesn’t really change anyhow.
Lyle"

Does that help? It sounds like his opinion is that there's some research to suggest that *over-restricting* saturated fact would have a negative impact on serum testosterone, which is a far cry from cow fat being a substitute for gear.

[somebody]

Oh, and if you want medical studies, go to http://www.ncbi.nlm.nih.gov/pubmed/ and type the following in the search field "testosterone saturated fat." The good stuff starts around the third entry, unless you're interested in castrated chickens.

[Mike5840]

Castrated chickens you say?.. Hmm...Tell me more...(Oops! Wrong forum. I hate when I do that.)

[vso]

Someone else has done all the research already.
Gary Taubes's book, Good calories Bad calories covers cholesterol,
high fat, low fat, low carb etc.
It can be a bit tedious because of the amount of technical information,
but worth it.