Clinician Fact Sheet: Medicinal Foods
(Lycopersicon esculentum)
Epidemiological studies have demonstrated an association between the lycopene found in tomatoes and a reduced risk of certain diseases and cancer.
Historical Medical Use
Orally, lycopene is used to prevent coronary heart disease, cognitive impairment, and prostate, pancreatic, cervical, and stomach cancers.
Formulation and Dosage
• 5 to 10 mg of lycopene daily
• One cup (240 ml) of tomato juice contains approximately 23 mg lycopene.
• Processed tomato products (e.g., tomato juice, paste, sauce) are better sources of lycopene than fresh tomatoes.
• Because it is lipid soluble, lycopene is better absorbed in the presence of oil or fat.
Adverse Effects
• No significant adverse effects have been reported.
Interactions
• Concomitant ingestion with beta-carotene may increase lycopene absorption.
Contraindications
• There are no known contraindications.
Clinical Research
At a 1999 meeting of the American Association for Cancer Research, researchers presented findings from a study of lycopene and men with prostate cancer.1 Supplementation with 30 mg/d lycopene resulted in cancer tissue that was less likely to extend to the edges of the prostate and precancerous tissue that was less abnormal in presentation.
In a population-based study of 317 prostate cancer patients and 480 controls, researchers in New Zealand found that lycopene intake was weakly associated with reduced risk of prostate cancer, whereas intake of beta-carotene was largely unassociated with reduced risk.2
In another recent study, Italian researchers evaluated the effect of tomato intake on total antioxidant activity in 11 healthy female subjects.3 Following seven days of a diet low in carotenoids, the subjects were given 25 g/d of tomato puree (7.0 mg lycopene and 0.25 mg beta-carotene) for 14 days. Both total lycopene and beta-carotene plasma concentrations increased significantly (P < 0.0001 and P = 0.0036, respectively); however, total plasma antioxidant capacity did not.
In a similarly designed study, some of these same researchers found that tomato puree did increase carotenoid concentrations and the resistance of lymphocytes to oxidative stress.4 Intake of 25 g/d of tomato puree for 14 days increased plasma (P < 0.001) and lymphocyte (P < 0.005) lycopene concentrations and reduced lymphocyte DNA damage by approximately 50% (P < 0.0001).
Peppermint (Mentha x piperita L. Family: Labiatae)
Orally, peppermint is used for loss of appetite; for spasms of the gastrointestinal tract, gallbladder, and bile ducts; and for flatulence, gastritis, and enteritis. Topically, the oil is used for headache, myalgias, neuralgias, toothache, oral mucosa inflammation, rheumatic conditions, pruritus, urticaria, and as an antibacterial and antiviral agent. Peppermint has spasmolytic and antiflatulent activities, and stimulates bile production.
Historical Medical Use
In folk medicine, peppermint has been used to treat nausea, vomiting, morning sickness, respiratory infections, dysmenorrhea, indigestion, sore throat, colds, toothache, cramps, and cancer.
Formulation and Dosage
• For upset stomach, the typical dose is one cup of tea (1 tablespoon dried leaf in 150 ml boiling water for 10 minutes, then strained) three to four times daily between meals.
• The usual dose of the tincture (1:5 in 45% ethanol) is 2-3 ml tid.
• The typical oral dose of peppermint oil for digestive disorders is 0.2-0.4 ml diluted in liquid tid. For irritable bowel syndrome, the usual dose is 0.2-0.4 ml tid in enteric-coated capsules between meals.
• Peppermint oil is commonly applied as 5-20% semi-solid and oily preparations, 5-10% aqueous-ethanol preparations, and 1-5% nasal ointments.
• For tension headache, a 10% peppermint oil in ethanol solution can be applied across forehead and temples, and repeated every 15-30 min.
• For inhalation, 3-4 drops of the oil are used in hot water.
Adverse Reactions
• The menthol in peppermint can cause a choking and bronchospasm in infants and small children.
• The menthol in peppermint can cause allergic reactions, including contact dermatitis, flushing, and headache.
• Theoretically, peppermint leaf and oil can exacerbate hernia symptoms by relaxing the lower esophageal sphincter.
Interactions
No interactions are known to occur.
Contraindications
• Peppermint is safe in typical food amounts. However, in concentrated forms, peppermint should be used with caution in pregnant and lactating women.
• Peppermint oil is contraindicated when the stomach is not producing hydrochloric acid.
• Peppermint oil is contraindicated in hypersensitive individuals and in those with bile duct obstruction, severe liver disease, and gallbladder inflammation.
Clinical Research
A meta-analysis of eight randomized, controlled trials indicated that peppermint oil could be efficacious for symptom relief of irritable bowel syndrome.5 However, methodological flaws associated with the studies preclude a definitive judgment about efficacy.
A recent review by Wilkinson examined the use of herbs for the relief of morning sickness during pregnancy.6 Peppermint was cited in 44% of the articles reviewed and was found unsafe in 6%.
References
1. Haney DQ. "Tomato nutrient is found to fight prostate cancer." Associated Press, Philadelphia, April 12, 1999.
2. Norrish AE, et al. Prostate cancer and dietary carotenoids. Am J Epidemiol 2000;151:119-123.
3. Pellegrini N, et al. Tomato consumption does not affect the total antioxidant capacity of plasma. Nutrition 2000;16:268-271.
4. Porrini M, Riso P. Lymphocyte lycopene concentration and DNA protection from oxidative damage is increased in women after a short period of tomato consumption. J Nutr 2000;130:189-192.
5. Pittler MH, Ernst E. Peppermint oil for irritable bowel syndrome: A critical review and meta-analysis. Am J Gastroenterol 1998:1131-1135.
6. Wilkinson JM. What do we know about herbal morning sickness treatments? A literature survey. Midwifery 2000;16:224-228.
Additional Resources
McGuffin M, et al. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press; 1997.
Natural Medicines Comprehensive Database. Stockton, CA: Therapeutic Research Center, Inc.
Schulz V, et al. Rational Phytotherapy. 3rd ed. Berlin: Springer-Verlag; 1998.
The Review of Natural Products. St. Louis, MO: Facts and Comparisons.
Foster S, Tyler VE. Tyler's Honest Herbal. 4th ed. Binghamton, NY: The Haworth Herbal Press; 1999.
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