I am interested in taking d-limonene on a daily basis to prevent occasional nighttime acid reflux and for its potent cancer prevention properties. This is fundamentally a very inexpensive substance, being extracted from a waste product (orange peels). However, the monthly cost to take 1 gram daily would be at least $45 if consumed via Life Extension's Natural EsophaGuard, $60 via Enzymatic Therapy Heartburn Free, or $33 if consumed via Jarrow's Ultra CoQ10 gelcaps (each contains 300mg of limonene).
I didn't realize just how badly LEF and Enzymatic Therapy were gouging us until I found this site:
http://www.greenterp...rpenes_s/20.htm
Limonene is used for many applications, and apparently it makes an excellent general purpose cleaner. They are selling a gallon of 98.5% pure d-limonene (orange peel extract) for $49.99. 98.5% d-limonene orange peel extract is listed as the main ingredient of LEF's EsophaGuard and Enzymatic Therapy's Heartburn Free -- I assume they are all using the same ingredient sourced from the same original manufacturer.
Assuming Green Terpene's claim that the product is 100% orange peel extract with no additives, is there any reason I to think I couldn't use this as a supplement? Chemicals from the plastic bottles leeching into the product maybe? I would either have to dilute the limonene considerably with water to ingest or cap it somehow, but the cost savings would be worth it. I don't know how many grams of limonene are in a gallon but I would be surprised if it lasted less than a year.
We might want to turn firstimmortal onto this if we decide this is remotely practical since it is dirt, dirt cheap:
Cancer Epidemiology Biomarkers & Prevention Vol. 11, 1472-1476, November 2002
© 2002 American Association for Cancer Research
Pharmacokinetics of Perillic Acid in Humans after a Single Dose Administration of a Citrus Preparation Rich in d-Limonene Content
....
The chemopreventive efficacy of limonene during both the initiation and promotion stages of carcinogenesis has been demonstrated in chemically induced rodent skin (7) , kidney (8) , lung and forestomach (9 , 10) , and mammary (11, 12, 13) tumor model systems. In mammary carcinoma, d-limonene exhibits therapeutic effects against chemically induced mammary tumors in rats, with regression of >80% of carcinomas with little toxicity (11) . Limonene also appears to act in a cytostatic fashion. Its removal from the diet results in significant tumor recurrences (11) . The postinitiation chemopreventive/tumor suppressive activity may be due, in part, to the inhibition of isoprenylation of cell growth-associated small G proteins such as p21ras and induction of apoptosis by limonene and its metabolites (11 , 12) . The initiation-phase chemopreventive effects of d-limonene have been attributed to the modulation of Phase I (14) and Phase II (5) carcinogen-metabolizing enzymes, leading to enhanced detoxification of carcinogens.
Chemotherapeutic activities of pharmaceutical preparations of d-limonene are under evaluation in Phase I/II therapeutic clinical trials (15) . d-Limonene, as a drug, is well tolerated in cancer patients at doses that may have clinical activity. One partial response in a breast cancer patient at a dose of 8 g/m2/day was maintained for 11 months, and three additional patients with colorectal carcinoma showed stabilization of disease for longer than 6 months on d-limonene at 0.5 or 1 g/m2/day (15) . The favorable toxicity profile and the partial response supports additional clinical evaluation.
D-Limonene: safety and clinical applications.
Sun J.
Thorne Research, PO Box 25, Dover, ID 83825, USA. jidong@thorne.com
D-limonene is one of the most common terpenes in nature. It is a major constituent in several citrus oils (orange, lemon, mandarin, lime, and grapefruit). D-limonene is listed in the Code of Federal Regulations as generally recognized as safe (GRAS) for a flavoring agent and can be found in common food items such as fruit juices, soft drinks, baked goods, ice cream, and pudding. D-limonene is considered to have fairly low toxicity. It has been tested for carcinogenicity in mice and rats. Although initial results showed d-limonene increased the incidence of renal tubular tumors in male rats, female rats and mice in both genders showed no evidence of any tumor. Subsequent studies have determined how these tumors occur and established that d-limonene does not pose a mutagenic, carcinogenic, or nephrotoxic risk to humans. In humans, d-limonene has demonstrated low toxicity after single and repeated dosing for up to one year. Being a solvent of cholesterol, d-limonene has been used clinically to dissolve cholesterol-containing gallstones. Because of its gastric acid neutralizing effect and its support of normal peristalsis, it has also been used for relief of heartburn and gastroesophageal reflux (GERD). D-limonene has well-established chemopreventive activity against many types of cancer. Evidence from a phase I clinical trial demonstrated a partial response in a patient with breast cancer and stable disease for more than six months in three patients with colorectal cancer.
Edited by FunkOdyssey, 10 October 2008 - 02:57 PM.