Lemon

Scientific Name(s): Citrus limon (L.) Burm. f. [medica × aurantifolia]
Common Name(s): Lemon

Medically reviewed by Drugs.com. Last updated on Nov 30, 2022.

Clinical Overview

Use

Lemon is primarily used for its vitamin C nutritional value and potassium content. Epidemiological studies associate the intake of citrus fruit with a reduction in the risk of various diseases. Antioxidant, antimicrobial, and anticancer activities have been investigated. Small clinical trials have suggested potential roles in hypocitraturic calcium nephrolithiasis, aromatherapy, and reducing glycemic response.

Dosing

Clinical data are lacking to provide dosing recommendations. Daily consumption of 120 mL of concentrated lemon juice (containing 5.9 g of citric acid) diluted in 2 L of water (mean treatment duration, 44.4 months) was used in a very small study to evaluate effects on urinary metabolic parameters and stone formation in patients with hypocitraturic calcium nephrolithiasis.

Contraindications

Contraindications have not been identified.

Pregnancy/Lactation

Lemon has generally recognized as safe (GRAS) status when used as food. Avoid dosages greater than those found in food because safety and efficacy are unproven.

Interactions

None well documented.

Adverse Reactions

Erosive effects on tooth enamel and anaphylactic allergy to lemon soap have been reported. Citrus juice is often implicated in the worsening of gastroesophageal reflux disease symptoms.

Toxicology

No data.

Scientific Family

• Rutaceae (rue)

Botany

The lemon tree is an evergreen, growing to more than 6 m in height. Its toothed leaves are light green and the citrus fruit (lemon) is oval, small, and green to yellow. Unlike other citrus varieties, the lemon tree bears fruit continuously. The plant is cultivated in Mediterranean and subtropical climates worldwide.(Chevallier 1996, Ensminger 1995, USDA 2022)

History

The lemon originated in Southeast Asia, probably in India or southern China. Its history is sometimes unclear because of the confusion with the similarly appearing citron, a closely related species. The lemon may have been depicted in Roman artwork as early as the first century AD.(Ensminger 1995)

In the 1600s, physicians became aware that daily intake of lemon juice prevented outbreaks of scurvy among sailors on long sea voyages. English ships were required by law to carry enough lemon or lime juice for each sailor to receive 1 oz daily, earning them the nickname "limeys."(Carper 1988)

The California lemon industry was established after the gold rush of 1849. From 1940 to 1965, production increased and the United States became a major provider of lemons. More than 50% of the US lemon crop is processed into juice and other drink products. The peel, pulp, and seeds are used to make oils, pectin, or other products.(Ensminger 1995)

Lemon juice has traditionally been used as an astringent, diaphoretic, diuretic, gargle, lotion, and tonic.(Ensminger 1995) Application of lemon juice in conjunction with exposure to sunlight was once thought to fade tattoos, but this theory was disproven.(Chapel 1983) Lemon has also been used externally for acne, fungus (ringworm and athlete's foot), sunburn, and warts.(Chevallier 1996)

Chemistry

Citrus fruits generally contain sugars, polysaccharides, organic acids, lipids, carotenoid (pigment), vitamins, minerals, flavonoids, bitter limonoids, and volatile components.(Ranganna 1983a, Ranganna 1983b) The lemon is a good source of potassium (145 mg per 100 g of fruit), bioflavonoids, and vitamin C (40 to 50 mg per 100 g, twice the amount in oranges).(Chevallier 1996, Ensminger 1995) Vitamin C has been isolated from lemon juice.(King 1979) Calcium (61 mg) is also present, along with vitamins A, B₁, B₂, and B₃. The fruit is also low in calories, containing 27 Kcal per 100 g.(Chevallier 1996, Ensminger 1995, Murray 1993) Other constituents of lemon include volatile oil (2.5% of the peel), limonene, alpha-terpinene, alpha-pinene, citral, coumarins, mucilage, pectins, and bioflavonoids (mostly from pith and peel).(Chevallier 1996, Fisher 2006, Manners 2007, Miyake 1999, Miyake 2007) The flavonoids eriocitrin and hesperidin have been evaluated.(Miyake 2007, Miyake 1998) Flavonoid content of commercial standardized lemon products/supplements varies.

Uses and Pharmacology

Lemon is primarily used for its vitamin C and potassium content. Epidemiological studies associate the intake of citrus fruit with a reduction in the risk of various diseases.(Johnsen 2003, Manners 2007, Pavia 2006)

Acetylcholinesterase/Butylcholinesterase inhibitory activity

In vitro data

The dried leaf powder extract of lemon demonstrated moderate inhibitory activity against both acetylcholinesterase and butylcholinesterase in vitro and was not found to be neurotoxic at low concentrations.(Amat-Ur-Rasool 2020)

Antidiarrheal activity

Animal data

In a study in mice with induced diarrhea, C. limon peel appeared to possess antidiarrheal effects via antisecretory and antimotility mechanisms.(Adeniyi 2017)

Anti-inflammatory/Analgesic activity

Animal data

In a review, anti-inflammatory and analgesic actions were reported with lemon essential oil and ethanolic peel extract, respectively, in rats; antinociceptive properties were comparable with diclofenac.(Singh 2021)

Antimicrobial and antiviral effects

Animal and in vitro data

Lemon juice and oil have been evaluated for antimicrobial action. The oil shows some bacteriostatic and antiviral action thought to be due to citral and linalool content.(Fisher 2006, Gonzalez-Molina 2010, Manners 2007) Significant activity against Escherichia coli, Bacillus subtilis, Klebsiella pneumonia, Salmonella typhi, Staphylococcus aureus, and Vibrio cholerae, including some multidrug-resistant strains, has been observed with lemon peel extracts, lemon juice, and/or essential oils.(Singh 2021) Lemon has been shown to inhibit the growth of Aspergillus mold(Ballot 1987) and the yeast-like fungus Malassezia furfur(Singh 2021), and has been used to disinfect drinking water(Alderman 1976) as well as to inactivate rabies virus.(DAquino 1994) In cats, lemon essential oil exerted activity against Microsporum canis.(Mugnaini 2012)

In vitro, antileishmanial activity of lemon essential oil was comparable with the reference drug miltefosine.(Maaroufi 2021) In vitro and/or in vivo investigations suggest extracts of lemon leaves and peels may have antihelmintic activity against Eicinia foetida and Ascaridia galli.(Singh 2021)

Antioxidant effects

German studies in the late 1980s, antioxidant effects were reported for lemon peel.(Carper 1988) The pectin fiber and lemon oil also possess antioxidant properties.(Polunin 1997)

Animal data

One group of researchers, having identified eriocitrin, hesperidin, and coumarins as antioxidants, pursued experiments in diabetic rats(Miyake 1998) and venous endothelial cells,(Miyake 2007) as well as in activated Epstein-Barr virus models.(Miyake 1999) Antioxidant mechanisms include the inhibition of radical formation and radical scavenging.(Manners 2007, Miyake 2007, Miyake 1999)

Antiulcer activity

Animal and in vitro data

A review of animal and in vitro data indicated that lemon juice, lemon essential oil, and limonene provide protection for the gastric mucosa against ulcers.(Singh 2021)

Aromatherapy

Clinical data

In a retrospective analysis, aromatherapy use of lemon essential oil provided relief from nausea and vomiting in 73% of applications in 66 patients with advanced cancer receiving palliative care.(Kreye 2022) In a controlled trial (N=46), test anxiety was reduced by a mean of 43.3% in nursing students using lemon aromatherapy compared with control, based on post-test scores on State Test Anxiety Scale and Test Anxiety Schedule.(Özer 2022)

Bladder

Clinical data

The American Urology Association's updated guideline for the diagnosis and treatment of interstitial cystitis/bladder pain syndrome (2022) states that self-care practices and behavioral modifications that can improve symptoms should be discussed and implemented as feasible, which includes avoidance of certain foods known to be common bladder irritants like citrus products (clinical principle).(Clemens 2022)

Cancer

The structure of various chemical constituents of lemon and their relationship to cancer prevention have been investigated.(Benavente-Garcia 2007, Manners 2007)

Animal data

In experiments with the flavonoid eriocitrin and its metabolites(Ogata 2000) and with coumarins extracted from lemon fruit,(Miyake 1999) apoptosis was demonstrated in acute myelomonocytic leukemia cells.

Clinical data

Quality clinical studies are lacking. A meta-analysis of epidemiological studies associates the consumption of citrus fruit with a larger protective effect against oral cancer (odds ratio, 0.38; 95% CI, 0.26 to 0.56) than with overall fruit consumption.(Pavia 2006)

Cardioprotective effects

Animal data

A study in rodents reported prolonged bleeding and thrombin time with C. limon, suggesting a cardioprotective role in preventing thrombosis.(Riaz 2014)

Diabetes

Animal and in vitro data

Beneficial effects of lemon leaf and peel extracts on glucose metabolism in diabetic rat models have been reported. In vitro assays pointed to strong alpha-amylase inhibition.(Singh 2021) In a tumor necrosis factor alpha–induced insulin resistance model in vitro, lemon extract restored adipocyte insulin sensitivity and function via increased proliferator-activated receptor gamma gene expression.(Sorrenti 2021)

Clinical data

In a small randomized, crossover study (N=10), lemon juice imbibed with a serving of bread resulted in lowered glycemic response compared with bread consumed with water or black tea. Gastric content volume was also increased, along with the rate of gastric emptying.(Freitas 2022)

Hepatoprotective effects

Animal data

Effects of lemon extracts and essential oil on hepatotoxicity induced by acetaminophen or aspirin have been studied in rats. Constituents of the extract (eg, naringenin, hesperidin) were hepatoprotective against acetaminophen.(Bouzenna 2016, Singh 2021)

Insect repellent

Animal and in vitro data

Lemon peel extract and essential oils have been reported to repel mosquitoes (Anopheles, Aedes, Culex) and other insects, including carpenter ants.(Singh 2021)

Clinical data

In a study documenting indigenous knowledge on plants used as mosquito/insect repellents in 6 selected localities, topical application of C. limon as a mosquito repellent was reported by malaria-endemic locales in Cameroon.(Youmsi 2017)

Intestinal microbiome

Clinical data

In 10 healthy male university students enrolled in a controlled study, those who drank 100 mL of 10% lemon water before each meal for 4 weeks had a significant decrease in the intestinal Bilophila species microbes (P=0.036) and non-significant changes in Adlecreutzia, Haemophilus, Megamonas, and Roseburia species compared to those who drank only water before meals. No differences were observed in the other 54 species analyzed.(Iida 2021)

Metabolic effects

Animal data

Beneficial effects on lipid parameters have been demonstrated with lemon juice in rabbits.(Singh 2021) A review reported antiobesity potential of C. limon due to various mechanisms.(Gamboa-Gomez 2015) In mice with high-fat diet–induced obesity, lemon peel fermentation supernatant inhibited weight gain.(Pan 2022)

Myocardial imaging

Clinical data

Lemon juice accelerated the transit of tetrofosmin through the liver parenchyma and improved myocardial imaging in a small study.(Cherng 2006)

Nephrolithiasis/Nephrotoxicity

Animal data

Studies in rodents suggest lemon juice has protective activity against urolithiasis.(Touhami 2007) Effects of lemon essential oil on nephrotoxicity induced by aspirin has been studied in rats.(Bouzenna 2016)

Clinical data

In a small (N=15), long-term (mean duration, 44.4 months) trial, lemon juice increased citrate levels in patients with hypocitraturic calcium nephrolithiasis; daily consumption of 120 mL of concentrated lemon juice (containing 5.9 g of citric acid) diluted in 2 L of water resulted in a clinically important reduction in stone formation.(Kang 2007, Seltzer 1996) However, few quality clinical trials are available.(Pachaly 2016)

Dosing

Clinical data are lacking to provide dosing recommendations. Daily consumption of 120 mL of concentrated lemon juice (containing 5.9 g of citric acid) diluted in 2 L of water (mean treatment duration, 44.4 months) was used in a very small study to evaluate effects on urinary metabolic parameters and stone formation in patients with hypocitraturic calcium nephrolithiasis.(Kang 2007)

Pregnancy / Lactation

Lemon has GRAS status when used as food. Avoid dosages greater than those found in food because safety and efficacy are unproven.

The sperm-immobilizing properties of lemon juice have been investigated in vitro.(Clarke 2006) Animal studies have reported reversible suppressed fertility and decreases in sperm count in male rodents subsequent to administration of extracts of lemon leaf or seeds for 1 to 2 months.(Singh 2021)

Interactions

Chloroquine plasma concentrations may be reduced if concomitantly administered with lemon, decreasing therapeutic effect.(Mahmoud 1994) Lemon juice may increase iron absorption.(Ballot 1987)

In a study in rodents, increased bleeding and thrombin time was observed with C. limon dosing. Interactions with concurrent anticoagulant medicines may theoretically occur.(Riaz 2014)

Adverse Reactions

Lemon juice may cause loss of gloss, alteration in enamel color, and irregular dental tissue on tooth enamel.(Allan 1967, Grando 1996, Pias 1972, Takaoka 1971)

Anaphylactic allergy to lemon soap has been reported, resulting from a possible cross-sensitivity of citrus seed to peanut allergen.(Glaspole 2007)

Citrus juice is often implicated in the worsening of gastroesophageal reflux disease symptoms. However, no effect on lower esophageal sphincter pressure was demonstrated in a small study, and the effects are not considered to be related to fruit juice acidity.(Kaltenbach 2006)

The sperm-immobilizing properties of lemon juice have been investigated in vitro.(Clarke 2006) Lemon seed extract produced a decrease in sperm count and fertility suppression in murine models.(Singh 2021)

Toxicology

Research reveals little or no information regarding toxicology with the use of lemon.

References

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This information relates to an herbal, vitamin, mineral or other dietary supplement. This product has not been reviewed by the FDA to determine whether it is safe or effective and is not subject to the quality standards and safety information collection standards that are applicable to most prescription drugs. This information should not be used to decide whether or not to take this product. This information does not endorse this product as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this product. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this product. This information is not specific medical advice and does not replace information you receive from your health care provider. You should talk with your health care provider for complete information about the risks and benefits of using this product.

This product may adversely interact with certain health and medical conditions, other prescription and over-the-counter drugs, foods, or other dietary supplements. This product may be unsafe when used before surgery or other medical procedures. It is important to fully inform your doctor about the herbal, vitamins, mineral or any other supplements you are taking before any kind of surgery or medical procedure. With the exception of certain products that are generally recognized as safe in normal quantities, including use of folic acid and prenatal vitamins during pregnancy, this product has not been sufficiently studied to determine whether it is safe to use during pregnancy or nursing or by persons younger than 2 years of age.

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