Sucrose and Testosterone

[Kasra]

Based on the abstract of this study, sucrose-fed rats had more abdominal fat, greater blood pressure, more free fatty acids, less testosterone, and less nitric oxide than controls.

Castration of these sucrose-fed rats lowered blood pressure, lowered free fatty acids, and increased nitric oxide.

Administration of testosterone to these castrated rats restored the increased blood pressure, increased FFAs, and decreased NO.

The most interesting bit was that sucrose lowered testosterone in the rats, since it's literally the only mention of an effect of dietary sucrose or fructose on testosterone that I've been able to find.

The weird part is that even though sucrose feeding lowered testosterone in the rats, further testosterone reduction (via castration) seemed to protect them from some of the harmful effects of sucrose feeding.

It seems that the harms of sugar intake were promoted by the presence of testosterone. The initial reduction of testosterone by sucrose feeding could be seen as a protective adaptation to mitigate the increased blood pressure, increased FFAs, etc.

 

[dinkleberg]

That is interesting. I always thought RP said fructose increases testosterone.

This study: http://joe.endocrinology-journals.org/content/21/3/341
Find a positive correlation between testosterone in the testes and fructose levels in the seminal vesicles.

 

[natedawggh]

I think this study says more about adaptive systems than it says anything about sucrose. Not being able to read the study (since you have to pay to get it, and not just the abstract) you can't see if the rats were fed anything else, and if the diet was only or mostly sucrose, or if they were exposed to sunshine and adequate physical activity, or who the study's authors are and why they were even conducting this, if they had enough protein and vitamins or enough fat to properly synthesize other hormones.

From the symptoms it seems like these rats were not getting enough protein, rather than too much sucrose. Rat physiology is also different than ours, being that we are primates with lower metabolisms who are more adapted for the consumption mono and disaccharides than are rodents who subsist mostly on polysaccharides and also engage in hibernation, lacking the stress responses we humans have to the kinds of conditions that trigger hibernation.

 

[fyo]

Rats harmed by sucrose are likely not eating a good and/or realistic diet.

 

[jyb]

I think this study says more about adaptive systems than it says anything about sucrose. Not being able to read the study (since you have to pay to get it, and not just the abstract) you can't see if the rats were fed anything else, and if the diet was only or mostly sucrose, or if they were exposed to sunshine and adequate physical activity, or who the study's authors are and why they were even conducting this, if they had enough protein and vitamins or enough fat to properly synthesize other hormones.

The experiments were performed according to the ethical guidelines of the authors’ institution, and all animals had free access to water and food. Weanling male Wistar rats, from the animal facilities of the National Institute of Cardiology “Ignacio Chávez,” were divided into two groups and maintained under a dark-light cycle of 12 hours and controlled temperature of 22 ± 2oC. The first group received 30% sucrose in their drinking water and rodent pellets (Formulab diet 5001) during 20 weeks; they were then subdivided into four subgroups of ten rats each: sucrose-fed rats, castrated sucrose-fed rats, castrated sucrose-fed rats treated with testosterone, or estradiol. The second group received water and a normal diet; they were subdivided into four sub- groups of ten rats each: control rats, castrated control rats, castrated control rats treated with testosterone, or estradiol.

 

[natedawggh]

Still talking about rats, which are not primates. I haven't seen any study into whether rodent physiology reacts the same to sucrose as it does in humans, since in humans it seems to do all the opposite that it does to rats in this study, if the humans are in good health.

 

[Kasra]

Similar trends can be seen in primate and human studies:

http://www.ncbi.nlm.nih.gov/pubmed/21884510

". . . a high-fructose diet in rhesus monkeys produces insulin
resistance and many features of the metabolic syndrome, including
central obesity, dyslipidemia, and inflammation within a short period
of time . . ."

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2673878/

". . . These data suggest that dietary fructose specifically increases
[de novo lipogenesis], promotes dyslipidemia, decreases insulin
sensitivity, and increases visceral adiposity in overweight/obese
adults."

I've seen no human evidence directly relating dietary fructose to testosterone, although obesity, dyslipidemia, and insulin resistance are all associated with low testosterone.

 

[pboy]

"The experiments were performed according to the ethical guidelines of the authors’ institution....

they were then subdivided into four subgroups of ten rats each: sucrose-fed rats, castrated sucrose-fed rats, castrated sucrose-fed rats treated with testosterone, or estradiol. "

LOL castrating and feeding estradiol is ethical by their standards

I know its in the name of science but that's still hilarious

 

[natedawggh]

Yeah a lot of common popular and medical thinking is that fructose is harmful, but Ray Peat says it's one of the easiest foods to digest and immensely helpful for the body, so I'm just saying that I wouldn't necessarily believe any of those studies over Ray's work, especially since in my own experience it has had all the benefits he has outlined, and is especially helpful for increasing my energy output, and that there can be so many other factors that lead to those researcher's opinions that aren't even considered in the conditions of the studies.

 

[Kasra]

The only thing I would argue on the basis of these studies is that refined sugar should not be eaten in large amounts. This is a view that Peat himself expresses:

"Refined granulated sugar is extremely pure, but it lacks all of the essential nutrients, so it should be considered as a temporary therapeutic material, or as an occasional substitute when good fruit isn't available, or when available honey is allergenic." - RP

 

[jyb]

Still talking about rats, which are not primates. I haven't seen any study into whether rodent physiology reacts the same to sucrose as it does in humans, since in humans it seems to do all the opposite that it does to rats in this study, if the humans are in good health.

Well, you have to start from somewhere. It's too difficult to have a precisely controlled experiment on humans. Ray bases a lot of his ideas on rat studies btw.

 

[natedawggh]

Still talking about rats, which are not primates. I haven't seen any study into whether rodent physiology reacts the same to sucrose as it does in humans, since in humans it seems to do all the opposite that it does to rats in this study, if the humans are in good health.

Well, you have to start from somewhere. It's too difficult to have a precisely controlled experiment on humans. Ray bases a lot of his ideas on rat studies btw.

Obviously.

 

[fyo]

http://www.ncbi.nlm.nih.gov/pubmed/21884510
". . . a high-fructose diet in rhesus monkeys produces insulin
resistance and many features of the metabolic syndrome, including
central obesity, dyslipidemia, and inflammation within a short period
of time . . ."
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2673878/
". . . These data suggest that dietary fructose specifically increases
[de novo lipogenesis], promotes dyslipidemia, decreases insulin
sensitivity, and increases visceral adiposity in overweight/obese
adults."

When they say 'High-fructose diet', these diets are completely unrealistic and cause conclusions that are contrary to the actual effects of fruit and reasonable sucrose within a reasonable diet.

There are some more posts on that topic around here if you search 'sucrose' 'fructose', those sorts of things.

 

[Suikerbuik]

I think this study says more about adaptive systems. ...

The experiments were performed according to the ethical guidelines of the authors’ institution, and all animals had free access to water and food. Weanling male Wistar rats, from the animal facilities of the National Institute of Cardiology “Ignacio Chávez,” were divided into two groups and maintained under a dark-light cycle of 12 hours and controlled temperature of 22 ± 2oC. The first group received 30% sucrose in their drinking water and rodent pellets (Formulab diet 5001) during 20 weeks; they were then subdivided into four subgroups of ten rats each: sucrose-fed rats, castrated sucrose-fed rats, castrated sucrose-fed rats treated with testosterone, or estradiol. The second group received water and a normal diet; they were subdivided into four sub- groups of ten rats each: control rats, castrated control rats, castrated control rats treated with testosterone, or estradiol.

International guidelines call for laboratory mice to be kept at room temperature. Yet the rodents find that range — 20–26 °C — uncomfortably chilly, says immunologist Elizabeth Repasky of the Roswell Park Cancer Institute in Buffalo, New York. Mice, she notes, lose body heat more rapidly than humans, and, when given a choice, prefer to reside at a balmy 30 °C.

At stake might be more than just creature comforts. In a study published today by Proceedings of the National Academy of Sciences1, Repasky and her colleagues report that in mice housed at room temperature, tumour growth was faster than in those housed at 30 °C, and immune responses to cancer were suppressed.

For physiologist Ajay Chawla of the University of California, San Francisco, the results cause little surprise. Mice living at room temperature have to work overtime to maintain their body temperature, and have high heart and metabolic rates, he says.

http://www.nature.com/news/chilly-lab-mice-skew-cancer-studies-1.14190

 

[tara]

International guidelines call for laboratory mice to be kept at room temperature. Yet the rodents find that range — 20–26 °C — uncomfortably chilly, says immunologist Elizabeth Repasky of the Roswell Park Cancer Institute in Buffalo, New York. Mice, she notes, lose body heat more rapidly than humans, and, when given a choice, prefer to reside at a balmy 30 °C.

Totally OT., but I'd like to live where room temperature was normally 20-26°C, too, and I reckon my health would be better too.
And I'll confirm that mice round here like to live in the warm spot at the back of the fridge. :)

 

[paymanz]

The only thing I would argue on the basis of these studies is that refined sugar should not be eaten in large amounts. This is a view that Peat himself expresses:

"Refined granulated sugar is extremely pure, but it lacks all of the essential nutrients, so it should be considered as a temporary therapeutic material, or as an occasional substitute when good fruit isn't available, or when available honey is allergenic." - RP

maybe its potassium in fruits that have an insulin like effect in body,and helps to balance blood sugar.chimps get majority of their energy from fruits and i dont think they have illness from it.im sure at least their testosterone level is not low,they are so muscular.

 

[Suikerbuik]

The most interesting bit was that sucrose lowered testosterone in the rats, since it's literally the only mention of an effect of dietary sucrose or fructose on testosterone that I've been able to find.

bold is mine.

I don't consider science to be truth. Working in the field makes you realize that many conclusions are built upon faulty assumptions. Especially if someone mentions something to be mentioned only once in the literature. So I don't think it needs to be answered with terms that match.

Peat's work is about reducing constant activation of adaptive systems. Living in an environment that is a bit too cold leads to chronic though mild stress. Peat says that during chronic stress the body becomes less effective in oxidizing sugar and is more reliant on fat.
So maybe the sugar can't be used efficiently, meaing it becomes a burden. Ofcourse this is all theory and I have no clue about how sucrose might affect pathways involved. My intuition and experience suggest me that fructose definitely helps libido when underfed (sign of increased testosterone??). So my guess is that in some people it might reduce testosterone and some it will increase testosterone.

The temperature suggestion however is not all about theory. The effect on tumor growth and immune response is impressive if you ask me. And since immunity, metabolism and stress etc. are interrelating systems. Who knows how this affects results of researchers in particular conditions??

Things like minerals, vitamins as mentioned earlier shouldn't be forgotten too, but this is also unknown.