T Nation

Any one heard of this?

Got an e-mail from VitaminBlvd today (I get at least two a week – mostly ads) that I found interesting. First off, it’s one of those thinly veiled ads for Trim Spa, but one paragraph just blind-sided me:

"Let’s start with Trim Spa’s unique blend of thermogenic agents. Right off the bat, you’ll notice that Trim Spa includes the thermogenic maximizer glucosamine. It’s believed that glucosamine lets you store more food as energy, instead of storing it as fat. Glucosamine is not usually found in other nationally sold weight loss products; it seems that Trim Spa is the first to recognize the value of this clinically proven ingredient."

WTH? Glucosamine is a thrmogenic? News to me. Any one else heard this? Comments?

No I’ve never heard that and I doubt if it works that way however it has been proven to increase leptin levels which can effect fat loss.

Glucosamine as a thermogenic? Hmmmm, where’s my snake oil?

“It’s believed that glucosamine lets you store more food as energy, instead of storing it as fat.”

Maybe I’ve just been living it a cave for 21 years, but I’ve always considered fat a stored form of energy. Hmmmm…

Sounds like they’re calling it a partitioning agent actually. I can neither confirm or deny.

isn’t glucosamine supposed to make you less sensitive to insulin, so are they saying that the nutrients would flow around the blood for a longer time since you would not release as much insulin to rush them into the cells? i don’t know, just an idea. laters pk

STAY AWAY FROM GLUCOSAMINE! Am J Physiol Endocrinol Metab 2001 Mar;280(3):E428-35 Related Articles, Links

Effects of cellular ATP depletion on glucose transport and insulin signaling in 3T3-L1 adipocytes.

Kang J, Heart E, Sung CK.

Department of Physiology and Biophysics, University of Southern California, Keck School of Medicine, Los Angeles, CA 90089, USA.

Glucosamine induced insulin resistance in 3T3-L1 adipocytes, which was associated with a 15% decrease in cellular ATP content. To study the role of ATP depletion in insulin resistance, we employed sodium azide (NaN3) and dinitrophenol (DNP), which affect mitochondrial oxidative phosphorylation, to achieve a similar 15% ATP depletion. Unlike glucosamine, NaN3 and DNP markedly increased basal glucose transport, and the increased basal glucose transport was associated with increased GLUT-1 content in the plasma membrane without changes in total GLUT-1 content. These agents, like glucosamine, did not affect the early insulin signaling that is implicated in insulin stimulation of glucose transport. In cells with a severe 40% ATP depletion, basal glucose transport was similarly elevated, and insulin-stimulated glucose transport was similar in cells with 15% ATP depletion. In these cells, however, early insulin signaling was severely diminished. These data suggest that cellular ATP depletion by glucosamine, NaN3, and DNP exerts differential effects on basal and insulin-stimulated glucose transport and that ATP depletion per se does not induce insulin resistance in 3T3-L1 adipocytes.

Help! I just started taking glucosamine for a cartilage problem in my right shoulder. After a week, I’ve gotten slight improvement but I think I need to take it for 2 months or so to regenerate cartilage (or so says Colgan). Anyway, if I take creatine, will that mitigate my loss of ATP??

take chondrotin sulfate instead. laters pk

Im not really worried about the energy issue as my personal experience (6 months straight)and in conversations with others, this has not been noticable.But the insulin sensitivity issue does worry me though.Stick with chondroitin instead.

Ok, adipocytes are fat cells; but what exactly is a 3T3-L1 adipocyte? And why is insulin resistance in these cells a bad thing? Thanks.

Here is another study from the same authors and the same journal:

Glucosamine-induced insulin resistance in 3T3-L1 adipocytes

Here is a quote from this particular paper in reference to glucosamine-induced insulin resistance in skeletal muscle:

Presently, it is unclear whether insulin signal transduction is altered by glucosamine treatment of cells. In isolated muscles, glucosamine was reported not to alter insulin receptor number and activation of insulin receptor tyrosine kinase.

Maybe I'm not understanding this fully, but it seems as though glucosamine may indeed induce insulin resistance in adipocytes, but not skeletal muscle (similar to many's hypothesis on caffeine).

Hey, Joel. Wouldn’t that be a good thing? I’m thinking that making the adipocytes insulin resistant (while not affecting skeletal muscle) would be a good thing post-training.

That’s what I was thinking.

If I remember correctly, Lyle McDonald stated, in a post on misc.fitness.weights, that insulin resistance was not a big issue with glucosamine. I agree and I personally never noticed any problems I used it.

It seems that glucosamine may actually be a worthwhile supplement if it can acutely increase leptin levels (chronic increased levels of leptin can actually lead to leptin resistance, similar to insulin), and promote acute insulin resistance in adipocytes. The dosage neccesary to produce such an effect, or if glucosamine can yield the above benefits acutely would def. be worthwhile information…

3T3-L1 adipocytes are a particular type of adipocyte. In this case, they worked with the adipocyte in a cell culture. TO stop taking glucosamine because of invitro work is stupid.

And it works better for arthritis than chondrotin sulfate.