celery anyone?

[Guest guest]

What's next??? here's an interesting article on celery (and related foods) from another list.

 

norm )~~~~ raw food... simply delicious ~~~

 

 

 

 

 

Sun, 30 Jun 2002 02:21:11 -0700Greg Woolley <gregwRe: [rawlife] Carrot and celery - juicing - psoralenstom cushwa wrote:> on 6/30/02 12:19 AM, Greg Woolley at gregw wrote:>> > The body speaks it's own> > language, it's up to us to listen to what our body is saying about the foods> > we> > are ingesting... if our body is reacting in a negative manner then this> > indicates> > we are intaking the wrong foods and/or ingesting the incorrect quantity of> > that> > food.>> Duh! No, I think I'm going to drink celery juice until I fall over dead!Tom,that would be rather drastic! The issue of course is not whether a daily intake ofcarrot and celery juice could ever kill us, but simply whether it can cause anadverse reaction and the answer to that is yes it can. See below.- -----------------------------What products contain psoralens?Psoralens are found in plants like limes, celery, carrots.ConcentrationsConcentrations of psoralen are highly variable, and are dependent on the season,brand and physical condition of the food product. Celery is the main concern withregard to psoralen, and therefore the most data is available for it. However thereis no set standard as to what levels are present. According to Schlatter et al,the threshold dose for furanocoumarin mixtures is ~10 mg. In the Schlatter paper,the particular sample of celery contained 30 µg furanocoumarins / g celery. So forthis particular brand of celery, 333 g are required to reach the threshold dose.This value could be taken for total celery consumption, but is only valid for thisparticular batch of celery. Also, 333 g would bring you to the threshold dose, youwould actually want to consume less than this to be safe.Effect of Temperature and ClimateThese factors are responsible for the great variability in psoralenconcentrations, making it difficult to assign concentrations to particular foodproducts. Psoralens are synthesized in response to stimuli such as temperature andclimactic stresses presented to the growing celery. Clearly the time of year wouldaffect the temperature and climate, thereby affecting the levels of psoralens.Geography will also be related to climate, similarly impacting toxin production.Certain ³brands² of celery have been implicated in phytotoxic outbreaks, and it islikely that a given brand will produce its celery in a certain geographiclocation. Environmental conditions such as acid fog and ozone levels tend to occurmore often in certain regions, and such factors have also been shown to stimulatefurocoumarin production"http://www.ansci.cornell.edu/courses/as625/1998term/Rahul/sources.html[My note: It's relatively easy to ingest 300+ gms of celery per day when juicingit and the risk of incurring an accumulative toxicological dose would naturallyincrease if ingested on a daily basis].- ----.Finkelstein E; Afek U; Gross E; Aharoni N; Rosenberg L; Halevy S.An outbreak of phytophotodermatitis due to celery.International Journal of Dermatology, 1994 FebAbstract: BACKGROUND. Celery is known to contain psoralens, a group of substancesthat cause a toxic dermal reaction on exposure to ultraviolet A rays (UVA). Anoutbreak of phytophotodermatitis amongst 11 workers in a celery harvest insouthern Israel is reported. METHODS. Analysis of the trigger factors was carriedout. The patients were questioned regarding their working conditions. Samples ofthe celery that the workers had been harvesting were analyzed for levels of totalpsoralens by means of high performance liquid chromatography (HPLC). Levels of UVAwere measured. RESULTS. It was found that the celery harvested in the south of thecountry contained 84 micrograms/g fresh weight (f.wt.) total psoralens as comparedto 35 micrograms/g f.wt. in celery harvested in the north of the country at thesame time. The following year the celery harvested in the south contained only 26micrograms/g f.wt. total psoralens. Other risk factors noted were that thesubjects had fair skin, wore no protective clothing, and worked with moist hands.In addition, the days were clear and sunny thus ensuring maximal UV radiation forthat time of the year. CONCLUSIONS. Multiple factors contributed to the outbreakof phytophotodermatitis. A late harvest in the south of the country isincriminated as the cause of the unusually high levels of psoralens in the celeryof that year. http://pinch.com/skin/docs/medline/medline96.txt- Background: Phytophotodermatitis (PPD) is a photosensitive dermal reaction inducedby exposure to certain plants with subsequent exposure to sunlight. Bothcomponents (plant and light) are required; neither agent alone can cause PPD.Pathophysiology: PPD can occur through ingestion of the plant or, more commonly,through topical contact. Furocoumarins (psoralens) are the major photoreactivechemicals involved in PPD reaction. Plants are thought to produce furocoumarinsfor disease resistance.Members of plant families Umbelliferae, Rutaceae, Moraceae, Compositae, andRanunculaceae are noted to cause PPD reaction. Common plants included in thesefamilies are celery, giant ragweed, parsnip, fennel, dill, parsley, lime, lemon,rue, fig, mustard, and chrysanthemums.Perfume-induced berloque dermatitis is a specific form of PPD reaction; areas ofskin reaction correspond to areas exposed to perfume. Furocoumarin exposure toultraviolet light (UVA) modifies the energy and reactivity of the molecule, whichcauses it to bind to pyrimidine bases and results in epidermal cell nucleic aciddamage (type I reaction). Activated furocoumarins also can produce oxygenradicals, which cause cellular membrane damage (type II reaction).Both mechanisms result in cellular dysfunction and tissue destruction. When acute,the process is phototoxic. Chronic presentation of PPD involves a photoallergicresponse; light-activated plant products act as foreign hepatogenic compounds andproduce a cell-mediated hypersensitivity response. Psoralens may not be primarilyinvolved in this mechanism of injury.Frequency:In the US: Incidence varies per population and exposure. Individuals who handleproduce or receive significant sunlight exposure (eg, field workers, farmers,gardeners, grocery workers, bartenders, vegetarians, tanning salon patrons) are atan increased risk.Internationally: No difference exists between US and international occurrence.Mortality/Morbidity: Significant long-term skin changes (hyperpigmentation,scarring) can occur with chronic exposure.http://www.emedicine.com/emerg/topic446.htm- ---Psoralens are small molecules that wedge themselves between the two strands ofDNA and then when exposed to photons of UV light, form crosslinks that prevent DNAfrom replicating. Psoralens occur naturally in plants, including limes and celery,which use them to kill attacking insects and fungi.http://www.cchem.berkeley.edu/editor/Publications/journal/volume9/no2/hearst.htm- ----Seligman PJ, Mathias CGT, O'Malley MA, Beier RC, Fehrs LJ, Serrill S, et al.Phytophotodermatitis from celery among grocery store workers. Arch Dermatol 1987;123:1478-1482. We detected 19 cases of phytophotodermatitis during a cross-sectionalepidemiological investigation of two Oregon grocery stores that were part of thesame supermarket chain. Outdoor sunlight exposure during the workshift and tanningsalon use were identified as risk factors; the most severe cutaneous reactionstended to occur among tanning salon users. Although both stores carried the samebrands and varieties of produce, all 19 cases occurred among employees of onestore, which had held a celery sale coincident with the outbreak, resulting in aquadrupling of the usual volume of celery sold. We found elevated psoralen levelsin two of three celery samples obtained from the affected store; cutaneousprovocation tests with trimmed surfaces of these celery samples producedphototoxic reactions. Preliminary experiments with one brand of celery havedemonstrated psoralen levels as high as 25 micrograms/cm2 of trimmed surface.These observations suggest that clinical phytophotodermatitis among grocery storeworkers may be caused by healthy celery and results from a complex interaction ofexposure variables, including ultraviolet radiation from tanning salon use,frequency of handling celery, celery brand, and sporadic elevation of psoralencontent from environmental stresses.Ljunggren B. Severe photoxic burn following celery ingestion. Arch Dermatol 1990;126:1334-1336. A 65-year-old woman developed a severe, generalized phototoxic reaction followinga visit to a suntan parlor. History taking revealed that she had consumed a largequantity of celery root (Apium graveolens) 1 hour earlier. With the use ofthin-layer chromatography, methoxsalen (8-methoxypsoralen) and 5-methoxypsoralenwere identified in the extract from a similar celery root. The biologic activityof this extract, as evaluated with the semiquantitative Candida albicansinhibition technique, indicated a total psoralen dose of approximately 45 mg.Substantial amounts of psoralen may be absorbed from vegetables, such as celery,and under unusual circumstances, this may constitute a health hazard.http://www.telemedicine.org/botanica/botrefs1.htm- ---------There are chemicals in wild parsnip called psoralens (precisely, furocoumarins)that cause what dermatologists call "phyto-photo-dermatitis." That means aninflammation (itis) of the skin (derm) induced by a plant (phyto) with the help ofsunlight (photo). When absorbed by skin, furocoumarins are energized byultraviolet light (present during sunny and cloudy days) causing them to bind withnuclear DNA and cell membranes. This process destroys cells and skin tissue,though the reaction takes time to produce visible damage.The chemical in wild parsnip may be a defense mechanism, just as healthy, greencelery plants will produce higher levels of furocoumarins when they are underattack from pink-rot fungus....And there are also other plants -- such as Queen Anne's lace or wild carrot(Daucus carota) and cow parsnip or hogweed (Heracleum maximum and Heracleummantegazzianum) -- that are reported to contain psoralens that causephytophotodermatitis. http://www.wnrmag.com/stories/1999/jun99/parsnip.htm- ----------Psoralens are a class of photo-mutagenic and photo-chemotherapeutic molecules thatcovalently modify nucleic acids. They belong the family of small molecules thatintercalate into and photoalkylate double stranded DNA. The primary target ofpsoralens are thymidine residues, and these molecules form both monoadducts andinterstrand crosslinks. The reaction takes place between the 3,4 (pyrone) or 4',5'(furan) double bonds of the psoralen and the 5,6 double bond in pyrimidines .http://www.mc.uky.edu/Biochemistry/department/faculty/spielmann/psoralen.html- ----------What are psoralens?Psoralens belong to a class of compounds called furocoumarins and is produced by anumber of edible plants, including celery, carrots, and parsnips. They are knownas secondary compounds, that is, plants produce them to protect themselves frompredation or mechanical damage. The structure of psoralen is shown below:http://www.ansci.cornell.edu/courses/as625/1998term/Rahul/what.htmlThis is a general structure, the phototoxic variants found in nature can havemethoxy substitutions at the 5 or 8 position or be tri-substituted.In order to combat pathogen infection and insect herbivory leading to spoilage ofcelery crops, farmers have begun to selectively breed cultivars with resistanceagainst such predation. Not surprisingly, such breeding lines have shown higherconcentrations of furocoumarins. Specifically, levels of marmesin, the compoundresponsible for pathogen resistance during storage, are elevated in such lines.Marmesin is the precursor to psoralen, a compound which has been implicated as ascarcinogen.- --------The body doesn't lie, if it's doing fine on a particular food/diet then that'sgreat, by all means keep on eating it. If however the body is having a negativereaction to a particular food item then it would be the height of folly to ignorethat negative reaction by continuing to eat it (and/or ingesting the samequantity) regardless.Greg Woolley- -- rawlife - http://www.rawtimes.com/rawlife.html