Listening to Your Body

Listening to your Body
Craig Nelson

In trying to understand how we can best improve our health, our athletic performance, our overall sense of physical well-being, the Enlightened Hedonist will defer to what the scientific literature tells us is true. Unfortunately that scientific literature has only addressed a tiny percentage of potential questions that we’d like answered. Most issues on diet and supplementation and training and recovery and injury prevention have simply never been studied.

In lieu of good science the next best thing we can do is simply listen to our bodies. Through trial and error discover what works and what doesn’t for us as individuals. Eventually we’ll figure out for ourselves how to optimize our physical health and performance. If we closely monitor our bodies, listen to what the body is telling us, we will eventually discover the truth. But there is yet another problem…

In April, 1968 The New England Journal of Medicine published a letter by a physician in which he described a previously unknown food sensitivity. Symptoms included sweating, heart palpitations, headache, numbness and tingling in the hands or feet, and a variety of other disorders. The culprit was deemed to be monosodium glutamate (MSG) and was most frequently associated with eating in Chinese restaurants were MSG was commonly used as a flavoring agent.

MSG?

The letter did the 1968 equivalent of going viral. The story was picked up by most news services and the letter was reprinted in newspapers and magazines. The phenomenon was quickly dubbed “Chinese Restaurant Syndrome.” Soon thousands, then tens of thousands of people came forward and announced that they too had Chinese Restaurant Syndrome. Many professed how relieved they were to find out that their problem was real and that others suffered from it as well.

The restaurant industry quickly responded to the consumer demand and “No MSG” options soon found their way onto menus. Although the syndrome was generally not considered a medical emergency, it was an intriguing problem and researchers soon set off to better understand the syndrome. Questions remained: What was the exact biological mechanism of the syndrome? What levels of MSG were necessary to cause the problem? Was there a lower level of MSG that would be safe for all? Could high levels of MSG be life threatening?

Various studies were conducted to answer these questions in which volunteers with the syndrome were given various doses of MSG, or no MSG, and their symptoms tracked, their blood analyzed, their heart rhythms recorded. Over time a clear pattern emerged—Chinese Restaurant Syndrome did not exist. Research subjects were unable to differentiate between the presence or absence of MSG in their food. There was no correlation between varying doses of MSG and reported symptoms. There were no physiologic responses that could be attributed to the ingestion of MSG. To date, among the many thousands of people who claim to have the syndrome and have been the subject of study, not one has been shown to actually have the problem. It is safe to conclude at this point that it simply does not exist.

What happened? In retrospect this sequence of events is entirely understandable:

1. The original report of the syndrome in the letter was simply wrong. There was no study. They physician who wrote the letter was simply reporting what he thought to be a relationship between MSG and these symptoms. He was wrong.
2. The symptoms themselves are vague and non-specific and could be caused by thousands of other factors including anxiety. Everyone has some combination of these symptoms at some point in their life.
3. The concept of “Chinese Restaurant Syndrome” somehow struck some unknown cultural nerve and achieved instant and widespread acceptance. Some have suggested racist motives in our ready acceptance of the syndrome—an alien cuisine is poisoning us. Who knows?
4. Once established the idea of the syndrome was unshakable. New suffers are added every year.

Now, 40 years after figuring out that the syndrome is not real it persists in the popular culture. Few people are aware of the science. Restaurants continue to advertise the absence of MSG. Most people who claim to have the syndrome cannot be persuaded that MSG is safe.

Note: Glutamates are naturally occurring compounds. Glutamic acid is one of the more abundant amino acids. There are many salts of glutamic acid including monosodium glutamate. Glutamates are found in high concentrations in foods like aged cheeses, soy sauce and other fermented products. Whether as a naturally occurring compound or as a flavoring agent, MSG enhances the flavors of savory foods conferring what is called the “umami” taste profile.

Although it is one of the more spectacular examples of the phenomenon, the MSG story is not unique. There are many other examples of such mass mis-attributions of dietary or other factors to specific health problems. (I’m looking at you, gluten.)

Here’s the problem (or problems) with listening to our bodies…our bodies will lie to us. Or, we are too dim to accurately interpret what our bodies are actually saying. In either case the communication is garbled and we fail to understand what is really happening. In general, our expectations, fears and hopes will distort our perceptions of bodily sensations such that we will conclude whatever it is that we hope to be true.

But what choice do we have? We can’t really decide to ignore our body’s signals to us. Some of these signal are valid and important. We have to come to some understanding about how best to use our bodies’ signals. Herewith, some guidelines for listening to your body:

• Simply keep in mind the problem discussed here. Be aware that it is difficult to perform an experiment on yourself and accurately interpret the results of that experiment.
• If the effects you’re trying to monitor are subtle (greater or lesser energy, greater or lesser joint mobility, etc.) I don’t like your chances of getting the right answer. It’s too easy to misinterpret these subtle effects. I recently did my own experiment with fish oil for joint pain. It did nothing for me. A friend objected, “Of course you didn’t notice any effects. You don’t believe that anything works.” Fair enough. But if an effect is large enough, I’ll notice it. Vicodin works.
• If the question is the value of some supplement, the effects of which have not been studied, I would approach this from the perspective of extreme skepticism. It is possible that the claims made for the supplement are true, but very unlikely. If you experiment on yourself take the position of—“Prove to me that it works.” That is, look for definitive, concrete and substantive effects. If such are lacking, forget about the supplement.
• Common sense is of some value here. If your experience is: “I noticed that when I stopped drinking a 12-pack of beer each night I felt much better the next day,” I would be inclined to take this at face value. Similarly there are many aspects of working out at the gym (frequency, intensity, type of activity) that are probably reliable indicators of effectiveness or the opposite.
• It’s OK and inevitable to get the wrong answer to your self-experiments. It’s likely to be harmless. I read somewhere that chocolate milk and tart cherry juice are good recovery drinks. This is excellent news…I love chocolate milk and tart cherry juice. If they turn out they have no value as recovery aids, oh well.
• On the other hand if you’re contemplating some dramatic dietary or lifestyle change (like giving up bread and pasta) on the basis of some self-experiment I would make every effort to be as rigorous as possible in your self-evaluation. Possibly even do as the MSG studies did—find a way to have someone give you the substance in question, or not, without your knowledge.

Good luck.