Home / Articles / Q & A / Appetite For Construction - Nov 8 2002

Appetite For Construction
Nov 8 2002

By Dr. John M Berardi, Ph.D.
First published at www.t-mag.com.

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Should I Spend my Hard-Earned Money on Glutamine or Hookers?

Q: In a recent T-mag article, glutamine was described as pretty much worthless if you're already taking care of protein and post-workout protein/carb/amino needs. What's your opinion? Is glutamine overrated?

A: Well, for starters, glutamine is the most abundant free amino acid…
Aww hell; I'm not going start my response off with the standard opening line that just about everyone uses to indirectly affix grandiose importance to this amino acid! Sure, it's conditionally essential (meaning that although it's not absolutely necessary in the diet, our requirements for glutamine can exceed our production of it in certain conditions).

Yes, it makes up 2/3 of the muscle's free amino acid pool (which is a pretty damn small part of the muscle's total amino acid content anyway) and sure, glutamine has been shown to have some pretty amazing benefits in wasting conditions, postoperative patients, and in TPN (total parenteral nutrition).

But as bodybuilding/fitness writers, it's about time we put aside this useless trivia and discuss the utility of glutamine supplementation for athletes, weight lifters, etc. A few years ago there were no data and therefore we could speculate all we wanted about the theoretical potential of glutamine supplementation. But nowadays, we've got the data and the data demonstrate that our theories may have been wrong.

To this end, I applaud my good friend David Barr on his excellent articles (Glutamine — Destroying the Dogma Part I and Part II) that revealed that despite all the conjecture about how glutamine supplementation may help increase muscle mass, muscle strength, and prevent overtraining, each and every research investigation examining the effects of glutamine supplementation on exercise performance, body composition, and protein degradation has shown that it offers no benefit. Because of the great job that Dave did in his literature review, I certainly don't have to provide a reference list — they're all right there at the end of his article.

To reiterate a few of the key points that Dave brought up in his article and that I brought up at the SWIS seminar:

• A high protein diet provides a big whack of glutamine as it is. In fact, if you follow standard bodybuilding protein recommendations, about 10% of your total dietary protein intake is composed of glutamine (milk proteins are composed of somewhere between 3 — 10% glutamine while meat is composed of about 15% glutamine). This means that a high protein diet (400g/day) already provides me with about 40g of glutamine.

• While the theorists still cling to the idea that since glutamine helps clinical stress, it might help with exercise stress, it’s important to note that exercise stress has got nothin’ on surgery, cancer, sepsis, burns, etc. For example, when compared with downhill running or weight lifting, urinary nitrogen loss is 15x (1400%) greater in minor surgery, 25x (2400%) greater in major surgery, and 33x (3200%) greater in sepsis. When it comes to the immune response, it’s about 9x (800%) greater with surgery. When it comes to metabolic increase, it’s 7x (600%) greater with burn injury, and when it comes to creatine kinase release; it’s about 2x (100%) greater with surgery. As I said, exercise has got nothin’ on real, clinical stress. It’s like trying to compare the damage inflicted by a peashooter and that inflicted by a rocket launcher.

• The major studies examining glutamine supplementation in otherwise healthy weightlifters have shown no effect. In the study by Candow et al (2001), 0.9g of supplemental glutamine/kg/day had no impact on muscle performance, body composition, and protein degradation. Folks, that's 90g per day for some lifters.

• The majority of the studies using glutamine supplementation in endurance athletes have shown little to no measurable benefit on performance or immune function.

• And with respect to glycogen replenishment in endurance athletes, it's interesting to note that the first study that looked at glycogen resynthesis using glutamine missed a couple of things. Basically, the study showed that after a few glycogen depleting hours of cycling at a high percentage of VO2 max interspersed with very intense cycle sprints that were supramaximal, a drink containing 8g of glutamine replenished glycogen to the same extent as a drink containing 61g of carbohydrate.

The problem was that during the recovery period, a constant IV infusion of labeled glucose was given (i.e., a little bit of glucose was given to both groups by IV infusion). While this isn't too big of a deal on its own since the infusion only provided a couple of grams of glucose, the other problem is that during glycogen depleting exercise, a lot of alanine, lactate, and other gluconeogenic precursors are released from the muscle.

What this means is that there's a good amount of glucose that will be formed after such exercise, glucose that will be made in the liver from the gluconeogenic precursors and that will travel to the muscle to replenish glycogen. Therefore, without a placebo group that receives no calories, carbohydrates, or glutamine, we have no idea of knowing whether or not the placebo would have generated the same amount of glycogen replenishment as the glutamine group or the glutamine plus carbohydrate group. To say it another way, perhaps there's a normal glycogen replenishment curve that was unaffected by any of the treatments.

• And finally, with respect to the claims that glutamine might increase cell swelling/volume (something I once believed was a reality), we decided to test this theory out in our lab using multifrequency bioelectric impedance analysis as well as magnetic resonance spectroscopy. The pilot data that's kicking around has demonstrated that glutamine supplementation has no effect on total body water, intracellular fluid volumes, or extracellular fluid volumes (as measured by mBIA) and has no effect on muscle volume (as measured by nMRS).

Therefore, at the present time, I think it's safe to conclude that glutamine supplementation probably offers little to no benefit with respect to athletic performance or body composition when given to well-fed, healthy athletes. But I don't want to totally burst anyone's little glutamine bubble. After all, I'm not saying that glutamine supplementation is totally worthless. As Dave Barr pointed out in his article, there may be some circumstances in which glutamine supplementation is of benefit. Here are some of them:

• Steroid users who are improperly coming off a cycle might need some. When coming off a steroid cycle, blood Testosterone concentrations are dismally low while cortisol levels become quite elevated. If said steroid user continues training (which he/she must to try to preserve their muscle mass), the catabolic stimulation might be significant. It still doesn't approach clinical catabolism but it may just become bad enough that some extra glutamine might help. This is just a guess, however.

• When trying to get really lean, many bodybuilders restrict energy intake and increase exercise volume and might need some glutamine. This type of energy deficit may signal the body to begin using protein as an energy source, cutting into valuable muscle resources. In addition this catabolic stimulus will be compounded by the exercise stress and may lead to excess catabolism. Perhaps glutamine may help out in these scenarios. Again, a guess.

• In elite endurance athletes training intensely 2 or 3 times in a given day, I might prescribe some. Although I rarely recommend glutamine to my clients, my elite cross country skiers are encouraged to take it mostly during their trips to altitude camp and for glacier training. These athletes train 2-3 times per day for a week or two at a time while living in tents on a glacier at altitude. Add on the fact that nutrition on such excursions is bare bones, so that's some stress that glutamine might help with.

• When injured and trying to prevent wasting or facilitate wound/soft tissue injury, take some. Williams et al (2002) demonstrated that daily supplementation with 3g of HMB, 14g of glutamine, and 14g of arginine can lead to increased wound healing.

So when all is said and done, I pretty much agree with Dave's appraisal of the value of glutamine supplementation for well-fed weightlifters and bodybuilders. Considering how much protein most bodybuilders consume, additional glutamine supplementation are probably worthless. However, like any other question, there isn't a black and white answer. There do remain a few situations, as discussed above, that glutamine might be a supplement to consider. Personally, I only prescribe it to my skiers during altitude and glacier training, to steroid users coming "off," to bodybuilders during the last few weeks of competition dieting, and to people who are injured and trying hard to recover. And, of course, to those with legitimate wasting conditions. If you don't fall into any of these categories, spend your money on more groceries.

Toxic Schmoxic

Q: Everyone at the forefront of nutrition these days in recommending fish oil; however, they all quickly add that it's "toxic." What the heck is going on here?! Should I take fish oil or is the mercury going to kill me? Along those same lines, should I limit how much tuna I eat?

A: I've got a secret to tell you… Everything's "toxic!" That's right. Everything!
I'm not allowed to eat lean meat because it contains trace amounts of hormones; I'm not allowed to eat fish because it contains a small amount of mercury (we're talking about fractions of parts per million units, or 0.0000001 units, people!); I'm not allowed to eat fruits and vegetables because they are covered in small amounts of pesticides; I'm not allowed to have sex because the condoms I'm using may deliver a micro dose of environmental estrogens; I'm not allowed to cook my food because that renders the food indigestible; I'm not allowed to own a microwave because it sends off electromagnetic energy that will give me cancer in addition to destroying my food; I'm not allowed to drink tap water, distilled water, cold water, or even filtered water from non-glass containers because I'll be getting too much chloride, fluoride, the wrong ionization, impaired digestion, or chemicals leached from the plastic containers; and I'm not even allowed to type this freakin' article because my computer monitor is sending off both electromagnetic fields as well as toxic chemicals into the air, causing a slow erosion of my health.

I might as well go back to bed. If I stay there all day, I'll be safe — wont I?
I've gotta be honest with you. I really hate the way that the health paranoiacs brandish the word toxic as if it was a loaded gun. If I had a nickel for every person that told me that fish oil or tuna or one of a host of other foodstuffs was toxic, I'd be a wealthy man. After all, what exactly are those fear mongers saying when they use the word toxic? To me, it's nothing more than waving their magic paranoid wands over something and making it, from that day forward, synonymous with "bad." When they say fish oil is toxic, they're telling us nothing other than their opinion that it's bad. So rather than saying fish oil is bad, how about discussing what those toxins are and perhaps demystifying them?

Since fish are part of the food chain, they, like many other foods, are subject to contamination. To this end, the Canadian Food Inspection Agency, and agencies like it across the world (i.e. Britain's Food Standards Agency) take measures to quantify the level of contaminants, or "toxins" and determine whether or not the levels of these chemicals are enough to cause any serious health concern.

Remember, pretty much everything, especially every food, nowadays, has been linked to some type of cancer or malady. So don't get all worked up when I tell you that fish can contain some contaminants. After all, even if you don't get those contaminants directly from the fish, you'll be getting them from the livestock that eat the fish (fish meal and fish oil are very popular livestock feeds), or diluted in your water supply, or from the fruits and vegetables you eat. Yes, the state of affairs of our environment truly sucks. It sure sucks that our water, our air, and our food is all polluted. And I think it's important to do our own part in seeing that this state of affairs improves. But in the meantime, life must go on and we must make choices as to how to live it.

So now that we know everything we eat has some contaminants and could therefore technically be described as "toxic," and we know that this is because we have allowed our chemicals to muck up our environment, let's clarify that this description of "toxic" means that the foods contain some substances that can cause harm if consumed in high enough concentrations. With that said, let's discuss which toxins are found in fish and whether they're found in high enough concentrations to be of concern.
The contaminants usually associated with fish are dioxins and furans, PCB's, DDT, and mercury. To give you some clue of what these compounds are, here's a quick synopsis:

• Dioxins and furans are components in a group of substances (polychlorinated planar aromatic structures) which have similar physical and chemical properties and consist of 75 polychlorinated dibenzo-para-dioxins (PCDDs) and 135 polychlorinated dibenzofurans (PCDFs). Seventeen members of this group have been studied extensively and are considered "toxic".

• PCBs are also persistent pollutants, some of which resemble the chemical structure of "dioxin-like" compounds. PCBs differ from dioxins and furans in that they are manufactured for transformers, insulators, capacitors etc., while dioxins and furans are produced unintentionally, as unwanted by-products from various combustion and industrial processes and from natural events like forest fires and volcanic eruptions.

• DDT is a colorless chemical pesticide, dichlorodiphenyltrichloroethane, used to eradicate disease-carrying and crop-eating insects. Unfortunately, this chemical has been linked to the death of many other animal species, to reproductive abnormalities in wildlife, and even cancer in humans.

• Methyl mercury is a highly toxic substance; there are a number of adverse health effects associated with methyl mercury exposure. Most extensive are the data for neurotoxicity, particularly in developing organisms.
Now that's an ugly picture isn't it? Knowing that these substances are found in fish does make me a bit hesitant. But we've gotta put things into perspective here. Most of the studies I've seen indicate that many of the fish oils available on the market today as well as many of the fish meal products contain only small amounts of these 4 toxins, amounts well below the limits at which health concerns might arise. Now remember, just because a food might have some toxins in it, that doesn't mean that it will cause health problems. Just like most drugs have a minimum effective dose, so do toxins. We all know that 1mg of caffeine will do nothing to promote concentration or alertness. But take 200mg and all of a sudden, things start to happen.

Since you also asked about tuna, I'll address that as well. Yes, tuna contains some mercury. But the levels of mercury contained in tuna are about 1/3 as low as those in fish considered to present a health risk. In addition, canned tuna has much less mercury than fresh tuna, so this bodybuilding staple is probably just about as safe as the next food.
While it's easy to understand why the health paranoia proponents are cautioning us against this toxic fish or fish oil, we can't let them take the focus off what's important here. Thousands of studies have been done using fish oil (of all concentrations and "purities") and in each study the benefits of the fish oil have manifested in amazing ways. Talk about a panacea for our culture's syndrome x problems! And in the face of this overwhelming evidence in favor of fish oil, there's been very little reported in the way of negative effects.

But even if the research isn't enough to convince you, how about checking out the health histories of the people with the highest level of deep ocean fish consumption? You won't find a dramatically high incidence of "toxicity." In fact, these people are far healthier than North Americans are.
At this year's SWIS symposium, everyone recommended fish oil but most of these people also suggested that fish oil was toxic. Interesting that in the face of all of this toxicity, the studies have shown overwhelming benefits anyway, such that the experts are still recommending them.

Regardless, one thing I did take away from the SWIS symposium, something I've been championing for a long time now, was that you should be getting concentrated forms of EPA/DHA — especially if you're taking a whole lot of it. For example, Barry Sears recommended "pharmaceutical grade" fish oil, which is defined as containing > 60% EPA+DHA, isn't a bad idea. I'm also told that Biotest is coming out with a fish oil that will match or surpass that percentage of EPA +DHA.

In the end, I've heard all the arguments for and against using fish oil and my conclusion, at this point, is that even if there is potential toxicity (mercury or anything else), the benefits FAR outweigh the risks. So when health experts suggest avoiding fish oil, I think they're doing people a disservice. By creating a big toxin scare they're discouraging the use of the ultra-health promoting oils. They're "muddying the waters," so to speak, and people, in the absence of an expert consensus, do nothing proactive to take control of their health.