Can lettuce help you sleep?

Now you might be wondering, “Well, I’ve never felt drowsy after eating a salad,” and that is because for medicinal purposes the lettuce plant is harvested at a later stage. If you’ve ever grown lettuce at home, it’s the stage where the plant ‘bolts,’ in other words flowering and going to seed. While gardeners usually hope to avoid veggies bolting, this stage is crucial for unlocking the full potential of lettuce as a sleep remedy. Once it has flowered, the plant produces a milky sap (officially called Lactucarium – again with the Latin!) that is really soothing for the nervous system.

Historical use of Lettuce as a sleep remedy

To harness the sleep-inducing power of lettuce, it's essential to wait until the plant has flowered. This is when the milky sap is at its peak potency. This is how it has been used by herbalists for centuries. Lettuce was noted in the early days of the United States, in the Transactions of the American Philosophical Society, which documented the well-known sleep-inducing properties of cultivated lettuce, and emphasised its effectiveness, particularly in older plants[1]. Tincture of Lactucarium, the dried latex of both wild and domestic lettuces, is described in the 1893 Pharmacopoeia of the United States; and historical mentions are Lettuce as a sleep aid are found in manuscripts from the medieval period in Europe, such as the Tacuinum Sanitatis, revealing its traditional use for combating insomnia[2].

Modern research on Lettuce’s sleep-inducing properties

Fast forward to the present, and scientific research is catching up with ancient wisdom, unravelling some of the molecular magic behind lettuce's sleep-inducing reputation. A 2017 study demonstrated that an extract significantly increased sleep duration, shedding light on the plant's potency in promoting restfulness.[3] In another groundbreaking outcome, lettuce extract was found to elevate the levels of gamma-aminobutyric acid (GABA), a sedative neurotransmitter, by inhibiting its enzymatic degradation.[4] This revelation opens a window into the intricate mechanisms through which lettuce contributes to a peaceful night's sleep.

Another study found that an orally-administered water extract of Lactuca sativa demonstrated a reduction in inflammation in human trials, providing another glimpse into the multifaceted health benefits this unassuming plant may offer.[5]

How does Lettuce help you sleep better?

Behind its mild flavour and crisp texture lies a complex composition of bioactive compounds that contribute to lettuce’s sleep-inducing properties. As mentioned above, it is the milky sap of the mature lettuce plant that holds the sleep magic of this plant. The compounds responsible for the sedative effects include the sesquiterpene lactones lactucin and lactucopicrin, which have been found to have a mild hypnotic action on the central nervous system.

Additionally, as mentioned above, scientific research has uncovered the way that lettuce, when harvested at a specific stage, exhibits an increase in the levels of gamma-aminobutyric acid (GABA), a neurotransmitter with calming and sedative properties.[4] The plant's ability to inhibit the enzymatic degradation of GABA showcases the sophisticated interplay of chemical components within lettuce.

Furthermore, the presence of triterpenoids and saponins in lettuce not only supports its traditional use for pain relief, but also suggests potential anti-inflammatory and analgesic activities.

How to use Lettuce to aid sleep

The milky sap can be extracted by gently scoring the stems of the lettuce plant. Once collected, the sap can be ingested or used to prepare herbal remedies. If this seems a bit tricky, don’t worry! You can find this herb in many health foods shops, as part of sleep-aiding herbal products. It's important to note that the sedative effects of lettuce are milder than those of prescription sleep medications, making it a gentle and natural option for those seeking a more holistic approach to improving sleep. The gentler effect also comes with an absence of addictive qualities, no morning grogginess, and no loss of efficacy with ongoing use.

In conclusion, lettuce transcends its role as a salad staple, and unveils itself as a herbal remedy with a rich historical background and some recent scientific studies. From centuries-old manuscripts to contemporary laboratories, the story of lettuce as a sleep aid continues to evolve. So, the next time you find yourself enjoying a fresh salad, appreciate the hidden potential of this humble vegetable—one that, left to mature, might just be the secret to a restful night's sleep. Sweet dreams, courtesy of the humble lettuce!

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