So a friend of mine is hell bent on proving to me that the juice of raw papaya leaves can cure dengue. I have been presented with the following two links as evidence,
From the Sunday Observer article it seems that the study is not a true one as he knows the result of the group taking the juice and the group taking placebo. What i need though is serious debunking because this friend has a medical background and is generally very smart but seems to be taken in with Ayurveda and the like.
Maybe it's already been covered at Respectful Insolence or Science Based Medicine? If not, you could email them the links...
I did a search on JStor and Science Direct for academic journals articles regarding the same. I found no result.
And the only hit I found in PubMed was this, hardly what this guy is claiming. Maybe you could ask your friend for the proper citation. But even then, these abstracts can be misleading, the devil is in the details and you'd need someone qualified to comment on them.
Thrombocyte counts in mice after the administration of papaya leaf suspension.
Sathasivam K, Ramanathan S, Mansor SM, Haris MR, Wernsdorfer WH.
AIMST University, Kedah, Malaysia.
Following up a popular use of crude leaf preparations from Carica papaya for the treatment of dengue infections, a suspension of powdered Carica papaya leaves in palm oil has been investigated for its effect on thrombocyte counts in mice, administering by gavage 15 mg of powdered leaves per kg body weight to 5 mice. Equal numbers of animals received corresponding volumes of either palm oil alone or physiological saline solution. Thrombocyte counts before and at 1, 2, 4, 8, 10, 12, 24, 48 and 72 hours after dosing revealed significantly higher mean counts at 1, 2, 4, 8, 10 and 12 after dosing with the C. papaya leaf formulation as compared to the mean count at hour 0. There was only a non-significant rise of thrombocyte counts in the group having received saline solution, possibly the expression of a normal circadian rhythm in mice. The group having received palm oil only showed a protracted increase of platelet counts that was significant at hours 8 and 48 and obviously the result of a hitherto unknown stimulation of thrombocyte release. The results call for a dose-response investigation and for extending the studies to the isolation and identification of the C. papaya substances responsible for the release and/or production of thrombocytes.
08-Jan-2011, 11:38 AM
(This post was last modified: 08-Jan-2011, 11:40 AM by Ajita Kamal.)
(08-Jan-2011, 09:26 AM)unsorted Wrote: And the only hit I found in PubMed was this, hardly what this guy is claiming. Maybe you could ask your friend for the proper citation. But even then, these abstracts can be misleading, the devil is in the details and you'd need someone qualified to comment on them.
Sunil, do you know what journal the study was published in? I couldn't find this info.
Here's what I can tell from reading the abstract: 5 mice is a ridiculously small sample size and I'd really have to read the paper to know how they are so damn certain that their results are statistically significant. Also, this seems like a fishing expedition, and there is no indication that the experiments were double-blinded
"Fossil rabbits in the Precambrian"
~ J.B.S.Haldane, on being asked to falsify evolution.
It's hidden in the "LinkOut" link at the bottom of the page -- appears to be a German publication called "Wiener klinische Wochenschrift", which when I googled it, apparently is "Middle European Journal of Medicine":
There are some other papaya-related studies there which could be relevant - studies about how certain chemicals in papaya add to the plant's defence system. So this might be a typical case of bait-and-switch alternative medicine - take some genuine science (the bait) and then say it can cure xyz (the switch).
However there could be something there, who knows. Which is why rahul you should press your friend for the paper and then send it to Orac and SBM - and hope they'll take it on.
(08-Jan-2011, 11:51 AM)unsorted Wrote: However there could be something there, who knows. Which is why rahul you should press your friend for the paper and then send it to Orac and SBM - and hope they'll take it on.
That's a great idea!! don't know why i didn't think about it earlier!!!! I'll put the onus of proof on her and see what she comes up with. (So far all i have heard from her on the matter are third person testimonies.)
I find this whole thing really distressing since two people who have been to medical school get so easily seduced by what seems to be a new old wives tale (if i could expand this term).
Oh and sorry for the late reply guys, been busy with work the last few days, i'll let you know what i find out because i'm determined to come up with something one way or another (but of course not unscientifically).
One more thing to say (and you might have done so already): tell your friend that it's the consensus of medical experts that is to be trusted - not what one doctor says, not what "some doctors" say. And that consensus is reached after proper study, via research followed by clinical trials. At this point your friend might give a look of shock and horror as one of my doctor friends did, as if clinical trials were the work of the devil. (And she'll probably throw in the Big Pharma gambit as well, and the "natural" vs. "chemical" false dichotomy.) You should be persistent simply ask the following questions -
1) If you think trials are bad, what alternative do you have that is more rigorous - one that takes into account various forms of bias, chance, false positives etc.
2) Even if Big Pharma is the monster you say it is, it doesn't invalidate medical science and it doesn't address the question raised in (1).
The Dengue-Papaya hoax stated way back in 2005 when chain emails spread claiming that leaf extracts can be used in the treatment of Dengue except it was making the claims for a completely different plant:
Pegaga Juice - Cure for Dengue.
In due course Pegaga was changed to Pepaya. Since then many scientific investigations were made but scientists neither were able to identify any substance with pro platelet properties nor was it tested in laboratories. Not to speak of any placebo controlled double blind studies.
The advocates of Papaya juice harp on the scientific fact that 100% of Dengue patients will have a dramatic rise of platelet counts starting from the 6th day of their illness. This is a documented physiological phenomenon only.
The scientific reasons are many.
1. Hyperactivity of bone marrow in response to the low platelet count
2. Appearance of IgM antibodies which will neutralize the antiplatelet effect of the virus. This happens around the 6th day of the illness.
3. In the recovery phase of dengue, there is rapid resorption of the leaked fluid into the bloodstream which causes a dramatic increase in platelet counts and improvement in the health of the patient.
If you take papaya juice or pine apple juice or any other juice the effect will be the same.
“Effect of papaya leaf extract on platelet count in dengue fever: a randomized controlled trial (PLEAD Trial)
M. Z. K. Assir, H. Mansoor, T. Waseem, H. I. Ahmed, S. K. Bukhari, J. Akram; Allama Iqbal Medical College/ Jinnah Hospital Lahore, Department of Medicine, Lahore, PUNJAB/PK
Background: Thrombocytopenia is a prominent feature of dengue fever and dengue hemorrhagic fever. Papaya leaves have been used by many patients due to their perceived beneficial effect on platelet count. However, scientific data on this beneficial effect is lacking.
Methods: A single centre, single blinded, randomized placebo controlled trial was conducted at the Department of Medicine, Jinnah Hospital Lahore. Adult patients admitted with diagnosis of dengue fever (DF) or dengue hemorrhagic fever (DHF) and platelet counts ≤50×109/L were eligible for the study. After obtaining written informed consent participants were randomly assigned to either treatment or control group. 5ml of papaya leaf extract in syrup form was given twice daily for four days to treatment group and placebo solution was given to control group. Platelet counts were checked on daily basis. Outcome was measured in terms of platelet increments from baseline.
Results: Thirty-nine (39) patients were enrolled and 28 (72%) were male. 19 (48.7%) patients received papaya leaf extract. Mean baseline platelet counts of treatment and control group were comparable, 36.2×109/L and 34.1×109/L respectively. Mean platelet counts at the end of treatment were 142.3×109/L and 116.5×109/L in treatment and control group respectively (p=0.182). Platelet count normalized (i.e. ≥150×109/L) in 9 (47.4%) patients in treatment group and 5 (25%) patients in control group (p=0.191). Similarly, no significant differences in mean platelet count increments from baseline were found between treatment and control group on day 2 (23.7×109/L vs 15.9×109/L, p=0.242), day 3 (42.6×109/L vs 35.1×109/L, p=0.424), day 4 (71.6×109/L vs 58.4×109/L, p=0.309) and day 5 (106×109/L vs 82.3×109/L, p=0.189). No significant adverse event occurred in either group.
Conclusion: Papaya leaf extract, in this study, did not show any effect on platelet count in dengue fever.”http://www.xcdsystem.com/icid2012/58.016.html