I’ve seen a lot of advertised botanical supplements that have ignored a lot of these issues; I’ll probably briefly breakdown an example that was recommended by naturopaths later on in a separate post.
Here’s a botanical treatment article shared by the international Naturopathic Medical Student Association’s (NMSA) Facebook page that has some of those issues. These include assuming that plant chemical profiles are uniform despite differing genetic strain/hybrid/handling/source (multiple studies don’t even bother to state what kind of lime was used or where they were grown), vague or incalculable dosages/amounts, poor study design (missing control, etc.), insufficient supporting research, incorrect portrayal of study results, unproven overreaching assumptions about in vivo performance based on an in vitro study, etc. Anyhow I’ll just point out a couple of examples. To be fair, a few of these particular problems may not necessarily be unique to herbal/botanical medicine, but I constantly see them associated with it.
The
NMSA Facebook post & the linked article: “
Lime Juice Could Save 100's of Thousands of Lives Each Year” by
Sayer Ji, purveyor of quackery and the founder of GreenMedInfo where
“Education Equals Empowerment.”
1. Example of Misreporting the Results of a Cited Study and Exaggerating about the Capabilities of a Plant
From Ji’s Article:
“While billions of dollars are poured into research and development for pharmaceutical drugs, the humble lime has been proven to mitigate and even cure diseases that cause millions to suffer and hundreds of thousands to die each year worldwide. […] An impressive array of research on lime juice from the National Library of Medicine indicates that it could either cure or greatly accelerate healing time from a variety of life threatening illnesses including: [...]
Bacterial Agents In Food: A recent study found that the popular food known as ceviche, naturally containing pathogenic agents from fish, could be completely sanitized with lime juice. Both Vibrio parahaemolyticus and Salmonella enterica (two common causes of food poisoning) were all reduced to below detection limits through the addition of lime extract.[2]
Disinfecting water: Lime has been found to enhance the disinfection of water, by both killing norovirus as well as Escherichia coli.[3] Lime has also been found to kill the cholera pathogen, which is believed to affect 3–5 million people and causes 100,000–130,000 deaths a year as of 2010.[4]”
From the abstract of one of the articles Ji cited: (Effect of lime juice on Vibrio parahaemolyticus and Salmonella enterica inactivation during the preparation of the raw fish dish ceviche.)
“Confirmed cases of cholera in Peru, New Jersey, and Florida have been associated with ceviche.”
“Tilapia (Oreochromis niloticus) fillet pieces were inoculated with Vibrio parahaemolyticus and Salmonella enterica (>7 log CFU/g) and incubated at 25 and 4°C for 30 or 120 min in the presence of fresh lime juice at concentrations typical for the preparation of ceviche. Similar levels of cells were also inoculated into fresh lime juice without tilapia. Surviving cells were enumerated on selective (xylose lysine Tergitol 4 and thiosulfate-bile-citrate-sucrose) and nonselective (tryptic soy agar) media. V. parahaemolyticus levels were reduced to below detection limits (~5-log reduction) under all conditions studied. Salmonella strains on tilapia were much more resistant to inactivation and were only slightly reduced (~1- to 2-log reduction). Salmonella and V. parahaemolyticus inoculated directly into lime juice without tilapia were all reduced to below detection limits (~5-log reduction). A typical ceviche recipe reduces V. parahaemolyticus risk significantly but is less effective for control of S. enterica.”
2. Example of Ignoring the Variation due to the Genetics, Handling, and Source of Plant Matter:
The standard US grocery store lime is a Persian lime (
Citrus latifolia), which is actually a triploid (thus almost always seedless) natural hybrid that probably arose from the cross of a key lime (aka Mexican lime,
Citrus aurantifolia) with a lemon (
Citrus limon) and a citron (
Citrus medica) and is
frequently imported from Mexico. Since they are sterile triploids, Persian limes are propagated from different types of clones. It’s been photoshopped, but the lime pictured in the article looks like a seedless Persian lime. It’s less acidic, less bitter, and significantly larger than the key lime (also called the Mexican lime) which is more round and only 1 to 2 inches in diameter. The fertile Mexican lime is seedy, has a thin rind, and is one of the most acidic citrus fruit. The Persian lime is also less aromatic than the Mexican lime so it probably has less of the volatile compounds that would be affected by storage and transport time; vitamin c and other compounds will still degrade with age and other conditions.
The chemical profile and physical characteristics of a lime can vary significantly with genetics and environmental factors as seen in this chapter of “
Citrus Oils: Composition, Advanced Analytical Techniques, Contaminants, and Biological Activity,” this nature article, “
Characterization of limes (Citrus aurantifolia) grown in Bhutan and Indonesia using high-throughput sequencing,” and this article, “
Temperature Effects on Vitamin C Content in Citrus Fruits.” For example, a lime’s ascorbic acid levels are higher when grown in a region with cooler nights. Its furocoumarin profile also varies significantly with growing conditions. Furocumarins are some of the compounds found in limes that may produce unwanted effects (
pharmacology info for Mexican Limes, C. aurantiifolia); lime juice/oil shouldn’t be applied topically because lime oil contains the phototoxins 5-methoxypsoralen and oxypeucedanin as well as many other furocoumarins which can cause phytophotodermatitis (
“Margarita photodermatitis”) upon exposure to sunlight.
Variety of Limes and Preparation Methods Used in the Studies Cited by the Article:
“Sickle cell anemia (SCA):” (Source cited by article:
CDC Sickle Cell Disease (SCD) - Data and Statistics ) *The source of the lime study data was
not cited.
“Malaria:” (Source cited by article:
Effects of lime juice on malaria parasite clearance.)
- Limes used: Mexican limes (C. aurantifolia Swingle) that I’m guessing were locally harvested from Yoruba land in Southwestern Nigeria in West Africa during July and September of 2009.
- Preparation: 10-15mL of lime juice given 3 times daily in conjunction with oral artemether (4mg/kg daily for 3 days) and camoquinine (10mg/kg daily for 3 days).
“Bacterial Agents In Food:” (Source cited by article:
Effect of lime juice on Vibrio parahaemolyticus and Salmonella enterica inactivation during the preparation of the raw fish dish ceviche.)
- Limes used: No listed type or source other than “purchased at local supermarket.” They are probably Persian limes (C. latifolia) imported from Mexico, because they were purchased from a store presumably in New Brunswick, New Jersey during an unspecified time of the year; Persian limes are the dominant lime in US grocery stores and Key Limes (Citrus aurantifolia) aren’t widely available year round in the US.
- Preparation: Refrigerated until use, freshly squeezed the day of the experiment, and used in the ratio 1mL lime juice per 1.5g of fish; distribution and exposed surface area may have varied a little bit (fish cubes measuring ~2.5cm along each side shaken in juice).
“Disinfecting water:” (Sources cited by article:
Protection from cholera by adding lime juice to food - results from community and laboratory studies in Guinea-Bissau in West Africa. &
Effect of lime juice on Vibrio parahaemolyticus and Salmonella enterica inactivation during the preparation of the raw fish dish ceviche.)
- Limes used: No listed type or source. I’m guessing they are local limes (probably C. arantifolia?) from Guinea-Bissau in West Africa that were collected and used in 1996, but their size and variety were not specified.
- Preparation: The authors state that their previous case-controlled study (Rodrigues et al. 1997) demonstrated that “lime juice in sauce eaten with rice was protective,” but that they performed this newer study “Since a more specific message was needed on the quantity of lime to be used.” However, no formal measurements are used in this study either. The amount of food that was prepared and divided into three samples, the amount of lime juice used, and the size of the limes are all unclear. From the study, “Peanut sauce was prepared and divided into three portions for 8-10 persons each. One portion was prepared without lime juice, one with the juice of two limes, and one with five limes. Portions of rice with the three peanut sauces and one with curdled milk were homogenized to a paste with a mechanical homogenizer; 15 g of each portion was weighed, transferred to polypropylene tubes, and inoculated with 1.5 x 10^3 cells/gram food from the overnight culture. The inoculated food was incubated in a humid environment at 29+/- 1C.” Also if heat was used in the preparation of the lime juice (not specified of course), temperature sensitive compounds would have been destroyed. Any protective effects were probably due solely to a less hospitable pH and organic acids; since Persian limes are less acidic than Mexican limes, they would probably be less effective which is why specific information about which limes were used is important.
“Killing pancreatic cancer:” (Source cited by article:
Bioactive compounds from Mexican lime (Citrus aurantifolia) juice induce apoptosis in human pancreatic cells.)
- Limes used: Mexican lime (Cirtus arantifolia Swingle) from the Texas A&M University-Kingsville Citrus Center Orchard, Walesco, TX that were collected during December of 2006.
- Preparation: The juice was freeze dried and stored at -20C until 462.4 g of freeze dried juice were extracted using a Soxhlet-type apparatus with 2000mL of chloroform at 55-60C for 8 hrs. The chloroform extract was filtered and the residue in the Soxhlet apparatus was re-extracted using acetone, MeOH, and MeOH water (8:2). All extracts were then concentrated, freeze dried, and stored at -20C until they were dissolved in various solvents for analysis by HPLC, the DDPH method for radical-scavenging activity, ABTS assay, MTT assay, cell lines/culture, and cell count assay.
“Stopping Smoking:” (Source cited by article:
Efficacy of fresh lime for smoking cessation. )
- Limes used: Mexican limes (Citrus aurantiifolia). Unknown source because I can’t find the full article, but the study was completed by the medical faculty at Srinakharinwirot University, Nakhon Nayok, Thailand.
- Preparation: Unknown because I can’t find the full article; I don’t know where the author Ji accessed it if he even did.
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