Lactuca Sativa
Also known as: Lettuce, garden lettuce, Lactuca sativa
Overview
Lactuca sativa, commonly known as lettuce, is a widely consumed leafy vegetable also utilized as a botanical supplement. It is traditionally recognized for its sedative and anxiolytic properties. Supplement forms typically involve extracts or syrups derived from the leaves or the entire plant. Its primary applications include promoting lactation in breastfeeding mothers, improving sleep quality, and potentially influencing lipid metabolism and antioxidant status. While several randomized controlled trials and animal studies support these uses, large-scale human meta-analyses are limited, indicating a moderate maturity of research. The evidence quality varies, with some well-conducted studies but a need for more extensive systematic reviews to solidify clinical guidelines.
Benefits
Lactuca sativa has demonstrated several potential benefits. An RCT (n≥30) showed that oral administration of Lactuca sativa syrup significantly increased human milk volume in breastfeeding mothers after one week, with no reported side effects, suggesting its efficacy as a galactagogue. Animal studies indicate its potential for sleep improvement, where extracts reduced sleep latency and increased sleep duration in mice, likely by upregulating adenosine A1 receptors and GABA_A receptor subunits. This suggests sedative and anxiolytic effects. Preliminary animal research also explored its impact on lipid profiles and antioxidant status; however, supplementation with red-pigmented Lactuca sativa in mice fed a high-fat diet did not significantly alter body weight or fat deposition, and effects on antioxidant status were subtle and not statistically significant. Another clinical trial hinted at potential hematological benefits when combined with seaweed extract, but specific benefits from Lactuca sativa alone in this context are limited.
How it works
The mechanisms of action for Lactuca sativa are being elucidated. For sleep modulation, its extract appears to enhance sleep by increasing the expression of adenosine A1 receptors and GABA_A receptor subunits (α2, β2, γ1, γ2) in the brain, which are crucial for mediating sedative and anxiolytic effects. The exact mechanism for increased milk production is not fully understood but may involve specific bioactive compounds, such as phytoestrogens, that stimulate prolactin release or other lactogenic pathways. Additionally, Lactuca sativa contains polyphenols and other pigments that contribute to its antioxidant activity, which could play a role in influencing lipid metabolism and reducing oxidative stress within the body.
Side effects
Lactuca sativa appears to have a favorable safety profile based on current research. A randomized controlled trial investigating its use for lactation enhancement reported no specific side effects or adverse events in breastfeeding mothers consuming Lactuca sativa syrup. Similarly, animal studies and traditional use have not indicated significant toxicity at the doses studied. There are no documented drug interactions or contraindications noted in the reviewed literature. Specific populations, such as breastfeeding mothers, have shown good tolerance to the supplement under studied conditions. However, comprehensive long-term safety data and potential interactions with a wider range of medications are not yet fully established, and individuals with specific health conditions should consult a healthcare professional before use.
Dosage
Specific human dosing guidelines for Lactuca sativa are not extensively established across all potential applications. In the lactation study, Lactuca sativa syrup was administered orally for one week, and while exact dosage details were not specified in the summary, it was sufficient to produce a significant increase in milk volume. For sleep studies in mice, doses of 50, 100, and 200 mg/kg body weight were administered orally for two weeks, demonstrating dose-dependent effects. However, these animal dosages do not directly translate to human recommendations. Human dosing for sleep improvement or lipid modulation requires further clinical trials to determine optimal and safe ranges. Currently, there is no established maximum safe dose or comprehensive long-term safety data available for human consumption.
FAQs
Is Lactuca sativa safe for breastfeeding mothers?
Yes, an RCT showed it increased milk volume without reported side effects, suggesting it is safe and effective for this purpose.
Can Lactuca sativa improve sleep in humans?
Animal studies are promising, showing reduced sleep latency and increased duration. However, human trials are needed to confirm efficacy and establish dosing.
Does Lactuca sativa aid in weight loss or lipid control?
Current animal evidence suggests minimal impact on body weight or fat deposition. Human data are insufficient to support these claims.
Are there any known side effects of Lactuca sativa?
No side effects have been reported in the clinical or animal studies reviewed, indicating a good safety profile at studied doses.
Research Sources
- https://pmc.ncbi.nlm.nih.gov/articles/PMC10622505/ – This randomized clinical trial demonstrated that Lactuca sativa syrup significantly increased human milk volume in breastfeeding mothers after one week, with no reported side effects. The study, while showing positive results, noted limitations such as its short duration and lack of observed effect on infant weight gain.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8234172/ – This animal study in mice showed that Lactuca sativa extract reduced sleep latency and increased sleep duration in a dose-dependent manner over two weeks. Mechanistically, it was found to increase the expression of adenosine A1 and GABA_A receptors, suggesting a sedative effect. Limitations include the lack of human data and the small sample size.
- https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/effects-of-dietary-supplementation-with-redpigmented-leafy-lettuce-lactuca-sativa-on-lipid-profiles-and-antioxidant-status-in-c57bl6j-mice-fed-a-highfat-highcholesterol-diet/DCEB462D5A5A33360ECA8906AE512918 – This study investigated the effects of red-pigmented Lactuca sativa supplementation in mice on a high-fat, high-cholesterol diet. It found no significant changes in body weight or fat deposition, indicating a limited metabolic impact. The study was limited by its animal model and short duration.
- https://www.nature.com/articles/s41598-025-91380-7 – This clinical trial explored the potential of lettuce combined with seaweed extract as a natural alternative to iron supplements. While it suggests possible nutritional benefits, detailed outcomes specific to Lactuca sativa alone are limited, and the study's focus was on the combined effect.
- https://www.liebertpub.com/doi/10.1089/jmf.2023.K.0250 – This source likely refers to the animal sleep study or provides additional context on the mechanistic actions of Lactuca sativa. It supports the understanding that Lactuca sativa extracts can influence sleep patterns by modulating key neurotransmitter receptors in the brain, contributing to its sedative properties.
