• Turkey doesn’t make you sleepy

    It may be my favorite medical myth, and it’s totally appropriate for Thanksgiving.  Please enjoy this chapter from my book:

    Myth: Eating Turkey Makes You Sleepy

    While not everyone stoops to the level of Seinfeld’s Jerry and George, who used tryptophan in turkey to lull a girl asleep so that they could play with her toys, the supposed sleep-inducing effects of tryptophan in turkey are commonly recounted at American Thanksgiving feasts and in the popular media around the holidays.

    Scientific evidence does support a connection between tryptophan and sleep. L-tryptophan has been marketed as a dietary supplement to aid with sleep.  Tryptophan also may have an effect on the immune system, with possible benefits for autoimmune disorders such as multiple sclerosis.

    The truth is, turkey is not to blame for your sleepiness.  Chicken and ground beef contain almost the same amount of tryptophan as turkey — about 350 milligrams per 4 ounce serving.  While you might have heard someone claim that turkey made them drowsy, you have probably never heard someone say that chicken, ground beef, or any other meat made them sleepy. Swiss cheese and pork actually contain more tryptophan per gram than turkey, and yet the American classic, a ham and cheese sandwich, somehow escapes blame.

    The amount of tryptophan in a single 4 ounce serving of turkey (350 milligrams) is also lower than the amount typically used to induce sleep. The recommendations for tryptophan supplements to help you sleep are 500 to 1000 milligrams. Many scientists also think the limited amount of tryptophan in turkey would be offset by the fact that it is generally eaten in combination with other foods and not on an empty stomach. While one clinical trial found comparable results for tryptophan from a food protein-source and pharmaceutical grade tryptophan, this study also used an extremely rich source of tryptophan, deoiled gourd seeds, which have twice the tryptophan content of turkey. In this trial, and in general use of supplements, tryptophan is taken on an empty stomach to aid absorption. Although we did not locate any experimental evidence to support this claim, many believe that the presence of other proteins and food in the stomach during the feasts generally associated with turkey consumption would limit the absorption of the tryptophan in the turkey.

    There are other elements of the holiday feasts that can induce drowsiness.  Large meals have been shown to cause sleepiness regardless of what is eaten because the body increases blood flow to the stomach, and decreases blood flow and oxygenation to the brain. Meals both high in proteins or in carbohydrates may cause drowsiness.  And don’t forget about the booze. One or two glasses of wine, especially for people who only drink occasionally, can increase drowsiness.

    Have a happy Thanksgiving, everyone.  Stop blaming the turkey for your sleepiness.

    DON’T SWALLOW YOUR GUM! by Aaron Carroll, MD and Rachel Vreeman, MD copyright © 2009 by the author and reprinted with permission from St. Martin’s Griffin, an imprint of St. Martin’s Press, LLC

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    • I think I am in shock. First, for nearly fifty years, I’ve believed that turkey makes you sleep. Adding to that bombshell, I find out that eating makes me stupid (I now understand what happened to me) by pulling blood flow from the brain to the stomach.

      OK, OK… Seriously, the amount of tryptophan in a turkey portion @ 350mg per 4oz still can be significant considering how we do overeat, and likely eat more than 4 oz of turkey. Along with the fact that we are probably saturated with food, isn’t it likely that the effects of the trytophan is actually enhanced due to the lack of blood flow to the brain and a close to the recommended dose?

    • Happy Thanksgiving!! I just want to make a comment concerning turkey. There is tryptophan in turkey, but there’s actually more in chicken and some other foods. It’s not the chemical that makes you sleepy after Thanksgiving dinner, it’s all the extra energy you use digesting a huge meal.One belief is that heavy consumption of turkey meat (as for example in a Thanksgiving or Christmas feast) results in drowsiness, which has been attributed to high levels of tryptophan contained in turkey.While turkey does contain high levels of tryptophan, the amount is comparable to that contained in most other meats.Furthermore, postprandial Thanksgiving sedation may have more to do with what is consumed along with the turkey, in particular carbohydrates and alcohol, rather than the turkey itself. I hope this helps everyone who is falling asleep on Thanksgiving while watching the parade!!

    • Large meals have been shown to cause sleepiness regardless of what is eaten because the body increases blood flow to the stomach, and decreases blood flow and oxygenation to the brain.

      Any student of physiology would know that this is incorrect.

      Whenever you eat a large meal (or any meal, for that matter) the parietal cells of the stomach extract chloride anions, sodium cations, carbon dioxide, and water from the blood to produce hydrochloric acid. As a consequence of this process, there is a concomitant release of bicarbonate into the plasma (the so-called “alkaline tide”) that raises the pH of the blood. It is this increase in plasma pH that makes one drowsy.

    • I don’t care what anybody says: Chicken and turkey even in very small amounts, eaten alone, make ME lethargic. Not sleepy, just energy-less and feeling heavy. And by small amounts I mean like about 3 ounces. There HAS to be something in it. I don’t get this effect from any other food.