This archived forum used to be called 'Peatarian' (in reference to Ray Peat).

Sucrose and Testosterone

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.

asked Jan 30, 2015 by Kasra

Anyone have the full text?

I'd ask you to consider whether the sucrose is being metabolized or converted to fat. There should be a difference in how the body reacts to each.

If a creature (rat, bat, monkey, me) is lean and has a high metabolic rate, then the sucrose is likely to be metabolized and that should be a good thing. More CO2 to the tissues, and more tissue oxidation.

If the creature is fat, or can't metabolize excess calories, then the sucrose is likely to be stored to fat, and that may not be good.

Just a thought, along Peatian lines. Peat hasn't said this outright, but I think it's implied.

It's been shown that eunuchs do live longer. I don't know if that is a path you want to take though.

1 Answer

I don't mean to derail but what's the 101 on rat studies? Rat stuff comes up all the time and I'm suspicious. I dimly recall they have very different abilities to synthesize and detoxify various stuff compared to primates. On top of that, lab rats are very weird inbred things that grow up in sterile cages. Are rat studies really worth even talking about? I suspect they're just sort of initial testing grounds for certain classes of ideas.

answered Jan 30, 2015 by 4a552f55cbb9

Similar trends can be seen in primate and human studies:

". . . 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 . . ."

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

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

if you feed anything pure fructose, or any sugar, without the corresponding nutrients that's what happens. If they fed the monkeys, or rats, or humans, fructose with potassium and b vitamins in proportion to the sugar, you would see the opposite effect, all pro metabolic effects

If you feed pure fructose (or any sugar or carb) without any nutrients it cant be processed by cells or stored as glycogen, so the body has to get it out of circulation some other way, asap, so the liver converts it into fat, and because of the high insulin needed to do that, a stress cascade happens and lowers positive hormones

that's reductionist science at its best...well, worse

they never bother to mention wild animals eating a ton of fruit never have any of those issues

Yeah that also explains the consistent epidemiological evidence in favor of fruit consumption.

I'm now very skeptical of any refined sugar though.

"If you feed pure fructose (or any sugar or carb) without any nutrients it cant be processed by cells or stored as glycogen, so the body has to get it out of circulation some other way, asap, so the liver converts it into fat"

So why does pure fructose drive this process more than pure glucose?

"they never bother to mention wild animals eating a ton of fruit never have any of those issues"

You might be interested in this article, pboy.

theres other studies showing the opposite, how spider monkeys are free of most degenerative deiseases on a diet of mostly fruit and a few insects and buds and stuff

plus I trust my taste buds above all, they are the most intiment connection with 'truth'

not to mention my results in real life

the situation with fructose is hard for a lot of people to understand, because the only sources of it in most peoples lives are either offensive in some way (unripe fruit or fruit with seeds and peels) and refined fructose. So it definitely is a volatile substance that can quickly have the same problems as loading on refined starch or something like that, or fat itself, but when properly used its probably the best substance for the human body, on par with a few of the amino your senses man! (but I know...they can be deceived by food refining and all that)
and probably 90% of the fruits available since they are unripe actually inhibit the absorption of the sugar so it doesn't do tis job properly, or if you eat the strong phenolic fruits like berries with the staining properties and seed toxins, its the same thing..they inhibit and mess with digestion and casue a stress cascade

I could easily see how for most people, avoiding most fructose would be a potentially wise tangible real life, or only using a small amount

but that doesn't change the fact that when coupled correctly or in the right foods, the body is set up to highly desire it...and its the individual best substance for promoting cellular respiration and thyroid secreting even mimics thyroid in some aspects by stimulating cells to burn energy

Pboy I know you are pro fructose and I agree it can be valauble when consumed from fruit for example. but you seem to ignore studies, in humans, like one kasra posted above showing refined fructose seems to produce worse health outcomes when compared to refined glucose. What causes this difference? Maybe this seems like a useless, overly academic question about a situation that doesn't apply to your life but i want to know how you interperet such studies. Its not a question ill pretend to have an answer to and since you seem like a well read, opinioned person so I'd love to hear your opinion (and anyone else's) if you have one.

im not sure about that one to be honest...I wouldn't imagine that to be the case, but it could be if well done studies show so. The only thing I can think of is that glucose generally is easier absorbed from the intestine....fructose usually requires the presence of glucose, amino acids, or a electrolytes so be absorbed well, so maybe the glucose is being absorbed and peed out or turned into fat more benignly, and fructose is causing some fermentation and serotonin and stuff in the intestine when taken alone like that

FWIW, taking a big dose of A, D, E with a big smoothie seems to increase testosterone because it makes me more gregarious, active and positive. Taking either supplements or smoothie alone doesn't seem to have the same effect.

@mscott, I haven't been able to find a pure fructose. Everything I see is made from genetically engineered corn using genetically engineered enzymes. The starch fragments that are left over could well cause "metabolic syndrome" all by themselves.

Glucose on the other hand if from cane sugar is relatively pure.

"Metabolic syndrome" is caused by a high insulin gradient, which in turn could be caused from lipolysis, or starch. These subjects are eating ad libitum diets from a buffet. The real culprit here (if not the fructose starch fragments) is the starch and PUFAs they are gorging themselves on.

FWIW, fructose makes you more hungry not less, so their total ad libitum intake of PUFAs and starch could be greater with fructose, as well.

Now this study will of course be misused as a pretense for some enormous governmental program, whose ultimate effect is to further reduce the already steeply declining consumption of orange juice.

Why? It's a lot cheaper to feed the masses processed food with glucose than it is orange juice.

Vision, I don't think there's any good basis for the claim that starch causes metabolic syndrome.

Hi mscott! Peat thinks there are at least three biophysical bases (that I know of): toxic starch fragments persorbed into the blood stream; rapid conversion of starch to glucose; endotoxic burden from resistant starch.

Are you concerned, as a completely separate matter, that there are no observational studies you find persuasive? I believe it's unlikely that observational studies would be funded to strike at the heart of corporate profiteering with cheap, toxic starch.