What's Really in Your Turkey?
Contrary to popular belief, turkey meat itself does not contain hormones like melatonin or serotonin. What it does contain, however, is tryptophan, an essential amino acid. Tryptophan is a crucial building block that the body uses to create various important compounds. While this amino acid is a precursor to serotonin and melatonin, the idea that eating a few slices of turkey is enough to induce sleep is a long-standing myth. In fact, other foods like cheddar cheese, pork, and soybeans can contain just as much or even more tryptophan than turkey.
The Tryptophan-to-Hormone Connection
So, if turkey contains tryptophan, and tryptophan is a precursor to sleep-regulating hormones, why doesn't a turkey sandwich at lunch knock you out? The science behind this is more complex than the simple myth suggests. For tryptophan to cross the blood-brain barrier and be converted into serotonin and subsequently melatonin, it needs to compete with other amino acids. A large, protein-heavy meal provides a host of competing amino acids, effectively blocking the efficient passage of tryptophan to the brain. This is a key reason why the post-Thanksgiving dinner sleepiness is a misattribution.
The True Culprits of Post-Feast Fatigue
If the tryptophan in turkey isn't the reason for that post-meal 'food coma', what is? Experts point to a combination of factors related to the size and composition of the holiday meal.
- Large Meal Consumption: Eating a large volume of food diverts significant blood flow to the digestive system to aid in digestion. This reduces blood flow to the brain, leading to feelings of tiredness and reduced alertness.
- High Carbohydrate Intake: A typical holiday meal is rich in carbohydrates from side dishes like stuffing, mashed potatoes, and desserts. High-carb foods cause a rapid spike in blood sugar, followed by a subsequent crash that can leave you feeling sluggish and fatigued.
- Alcohol Consumption: Many people consume alcohol with their celebratory meals. Alcohol is a sedative and can significantly contribute to drowsiness and a feeling of relaxation.
- Circadian Rhythms: The time of day a large meal is consumed can also play a role. A heavy lunch, for example, is more likely to cause sleepiness than a breakfast because of the body's natural circadian rhythm.
Nutritional Comparison: Turkey vs. Other Foods High in Tryptophan
Understanding the myth requires comparing turkey's tryptophan content to that of other common foods. As shown below, turkey is far from the most potent source.
| Food | Tryptophan (g/100g) | Protein (g/100g) |
|---|---|---|
| Dried Egg White | 1.00 | 81.10 |
| Dried Spirulina | 0.92 | 57.47 |
| Raw Soybeans | 0.59 | 36.49 |
| Parmesan Cheese | 0.56 | 37.90 |
| Cheddar Cheese | 0.32 | 24.90 |
| Turkey | 0.24 | 21.89 |
| Chicken | 0.24 | 20.85 |
This table illustrates that, per 100 grams, several other foods contain more tryptophan than turkey. This fact strongly supports the conclusion that the sleepiness is not due to turkey's tryptophan content alone.
The Real Health Benefits of Turkey
Focusing on the hormone myth detracts from the genuine and substantial health benefits of including turkey in your diet. Turkey is a lean, protein-rich meat that offers an array of essential nutrients.
- Excellent Source of Protein: Turkey is packed with high-quality protein, essential for muscle building and repair, tissue regeneration, and overall bodily function.
- Rich in B Vitamins: It is a good source of several B vitamins, including B3 (Niacin), B6 (Pyridoxine), and B12, which are vital for energy production, nerve function, and red blood cell formation.
- Packed with Minerals: Turkey provides a healthy dose of minerals like selenium, which supports thyroid function and the immune system, and zinc, important for immune health and metabolism.
- Supports Heart Health: Replacing high-fat red meats with lean poultry like turkey can contribute to better heart health.
- Low in Fat: When consumed skinless, turkey is a low-fat protein option, particularly white meat, making it an excellent choice for weight management.
Incorporating Turkey into a Balanced Diet
Adding turkey to your diet can provide a wealth of nutrients without the perceived risk of drowsiness. For example, opting for lean cuts of turkey breast and pairing them with complex carbohydrates and vegetables can offer a well-rounded meal. Consider a turkey and veggie stir-fry, a turkey breast and salad plate, or even a simple ground turkey patty for a delicious and nutritious protein source.
Conclusion
In conclusion, the answer to "what hormone does turkey have in it?" is none directly. The widely believed myth about turkey's tryptophan content causing sleepiness is a fallacy. Instead, the fatigue associated with large meals is a result of overeating, high carbohydrate intake, and potentially alcohol. Turkey remains a healthy, protein-rich food that provides numerous nutritional benefits, including essential vitamins and minerals. Understanding the truth allows you to enjoy turkey as part of a balanced nutrition diet without falling for the holiday food coma myth. For more nutritional information, consider resources like the Sleep Foundation, which provides detailed information on tryptophan and sleep.
