Arginine is probably one of my favorite amino acids. Arginine is responsible for that famous "Pump" feeling you get after you've been working out hard. Well, that and the water pressure in muscle cells if you've been consuming a lot of carbohydrates. A lot of people knock the "pump" because it's only cosmetic. I disagree. Well first of all it may only be cosmetic. BUT SO WHAT? If something makes you feel good or gives you a positive impression (looking into a mirror, even for a non-narcissist, and seeing a bulging muscle can be very very rewarding) then that will only further help you focus in on your intention, and that in turn feeds your connection with what you're doing. But if that's all that Arginine did for us I'd probably not mention it. It has a few nifty other effects too. It enhances sexual activity, erection response and even activates the part of the brain that is aroused by sexual thought. It also constitutes the major amino acid of sperm, so there is a good replenishment going on there.
For some people arginine is a great anti-depressant. Arginine's major metabolite is agmatine. Agmatine is an NMDA antagonist. What this means essentially is that it helps calm the excitatory parts of our brain. This can be good for mental peace as well as protecting our brains from excess stimulation and also helping to curb addiction. I can speak for it's mellowing effects. I've given some arginine to a few other people as well and they all seem to come back with a resounding relaxation response to it.
But what recently caught my eye was a study done, albeit with rats, which are by no means a great replacement for humans. In this study though they found that arginine protected rats from gaining excess weight. Rats do tend to be metabolic powerhouses though. They have shorter lives and faster metabolisms. They are an exagerated version if you will of the human metabolism. If it sounds too good to be true, then it was probably done on rats is what I seem to see over and over again.
But nonetheless what they found was interesting. They took two groups of rats and fed one group a High Fat Diet (HF) and the other group eate a Low Fat diet. They kept this diet going for 15 weeks. Then they introduced arginine into their diet at the amount of 1.51% L-Arginine or Alanine (for the control group). This was added to their drinking water. At the end of the study the arginine group lost 30% of their fat in their white pads (rats have pads of white fat, humans ARE pads of white fat). AND the soleus muscle was increased by 13%!
"Serum concentrations of insulin, adiponectin, growth hormone, corticosterone, triiodothyronine, and thyroxine did not differ between control and arginine-supplemented rats. However, arginine treatment resulted in lower serum concentrations of leptin, glucose, triglycerides, urea, glutamine, and branched-chain amino acids, higher serum concentrations of nitric-oxide metabolites, and improvement in glucose tolerance. "
Now, what shocked me was how nothing really changed here in the serum. But, leptin, glucose, AND triglycerides were all lower. As we know, leptin lowering is actually a good thing in the obese. It usually means there is a return to normal sensitivity to leptin. Usually people that are overweight have developed a tolerance, or insensitivity to leptin's signals.
So what's the take home message? Well, for one thing, don't stop taking arginine. And if you aren't taking it, there's no need to rush out and buy up the store, but if you're looking for something to add to your regimen to increase overall health, and possibly help you in the pursuit of leanness then pick up some arginine. You can take it on an empty stomach preferably, or you can be your own experimental rat and put it in your drinking water.
1: J Nutr. 2009 Feb;139(2):230-7. Epub 2008 Dec 23. Links
Dietary L-arginine supplementation reduces white fat gain and enhances skeletal muscle and brown fat masses in diet-induced obese rats.
Jobgen W, Meininger CJ, Jobgen SC, Li P, Lee MJ, Smith SB, Spencer TE, Fried SK, Wu G.
Department of Animal Science, Faculty of Nutrition, Texas A&M University, College Station, TX 77843, USA.
Previous studies showed that dietary L-arginine supplementation decreased white fat mass in genetically obese rats. This study tested the effectiveness of L-arginine in diet-induced obesity. Male Sprague-Dawley rats were fed for 15 wk a high-fat (HF) (40% energy) or low-fat (LF) (10% energy) diet beginning at 4 wk of age, resulting in 18% higher body weight gains and 74% higher weights of major white fat pads (retroperitoneal, epididymal, subcutaneous, and mesenteric adipose tissues) in HF than in LF fed rats. Starting at 19 wk of age, rats in each dietary group were supplemented for 12 wk with 1.51% L-arginine-HCl or 2.55% L-alanine (isonitrogenous control) (n = 8 per treatment) in drinking water and arginine groups were individually pair-fed to alanine controls. Despite similar energy intake, absolute weights of white fat pads increased by 98% in control rats over a 12-wk period but only by 35% in arginine-supplemented rats. The arginine treatment reduced the relative weights of white fat pads by 30% and enhanced those of soleus muscle by 13%, extensor digitorum longus muscle by 11%, and brown fat by 34% compared with control rats. Serum concentrations of insulin, adiponectin, growth hormone, corticosterone, triiodothyronine, and thyroxine did not differ between control and arginine-supplemented rats. However, arginine treatment resulted in lower serum concentrations of leptin, glucose, triglycerides, urea, glutamine, and branched-chain amino acids, higher serum concentrations of nitric-oxide metabolites, and improvement in glucose tolerance. Thus, dietary arginine supplementation shifts nutrient partitioning to promote muscle over fat gain and may provide a useful treatment for improving the metabolic profile and reducing body white fat in diet-induced obese rats.
PMID: 19106310 [PubMed - in process
