Bone broth is a liquid derived from simmering bones and connective tissues, resulting in a nutrient-rich stock containing easily digestible proteins and minerals. Many people report a distinct feeling of relaxation or sleepiness after drinking a warm cup, particularly in the evening. This common experience is rooted in biological responses to the broth’s unique composition. The sensation of feeling tired after consumption stems from the action of a specific amino acid, along with the calming effects of certain minerals and the physiological response to a warm liquid.
Glycine: The Primary Amino Acid Linked to Sleep
The most significant contributor to bone broth’s sleep-promoting effect is the amino acid glycine, the most abundant amino acid extracted from the collagen and gelatin within the bones. Glycine functions in the central nervous system as an inhibitory neurotransmitter, meaning it helps to quiet down brain activity. This calming action helps to prepare the body for rest by reducing the time it takes to fall asleep.
This amino acid promotes sleep through a mechanism involving the regulation of body temperature. Glycine ingestion stimulates blood flow to the skin’s surface, which allows the body to dissipate internal heat more efficiently. This slight lowering of the core body temperature is a natural signal the body uses to initiate the sleep cycle.
Human studies involving the consumption of about three grams of glycine before bedtime have demonstrated improvements in sleep quality. Participants reported falling asleep faster, experiencing deeper, more restful sleep, and feeling less fatigued the following day. Glycine helps stabilize sleep states and shortens the latency to slow-wave sleep, which is the deepest, most restorative stage.
Supporting Factors: Minerals and Digestive Effort
Beyond glycine, bone broth contains other components that support a tranquil state, contributing to the feeling of sleepiness. The simmering process extracts various minerals from the bones and connective tissue, including magnesium and potassium. Magnesium plays a role in muscle relaxation and nerve function, helping to calm the nervous system.
Potassium also supports nervous system function and helps regulate muscle contractions, with adequate levels contributing to a state of physical ease. While these minerals are present in supportive amounts, their combined effect with glycine creates a biological signal for relaxation. The act of consuming a warm liquid also initiates a soothing physiological response.
The heat of the broth activates the parasympathetic nervous system, the body’s “rest and digest” division. This activation promotes psychological comfort and reduces tension, which naturally precedes sleep. Furthermore, because bone broth is a nutrient-dense liquid, the body shifts energy resources toward the digestive process, which can further contribute to a mild feeling of lethargy or relaxation.
Optimizing Bone Broth Consumption for Timing
If the sleepiness is a desirable outcome, such as when using bone broth to enhance your bedtime routine, timing is important to maximize the effect. Consuming warm bone broth approximately 30 to 60 minutes before you plan to sleep aligns with the time needed for glycine to begin influencing your body temperature and neurotransmitter activity. This timing helps to reduce the time spent trying to fall asleep and promotes a better quality of rest.
However, if the sleepy feeling is unwelcome, adjusting your consumption habits can help mitigate the effect. Consider reducing the serving size, as consuming smaller quantities delivers less glycine and fewer minerals. Pairing the broth with other foods or activities that require more mental focus can help counteract the relaxation response. Avoiding large portions of bone broth during periods when you need to be highly alert will help maintain daytime energy levels.