The blogger's note: Further to an article entitled 'Is Star Fruit Kidney Poison?' (see previous post of this blog: http://taionn.blogspot.com/2012/04/is-star-fruit-kidney-poison-dr-jb-lim.html and queries from e-buddies, Great Sifu Dr JB Lim elaborates as follows:
Monday, 7 May, 2012 8:46 PM
From: lim juboo
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Dear all,
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Dear all,
Thank you for all your letters, inquiries and all the confusion added.
I have already explained little about star fruit earlier, but there seems to be still some doubts. Now two papers are sent to me for mention. So let me comment.
The Specific Neurotoxin:
Show me where in both the journals quoted, was it mentioned the very specific neurotoxin present in star fruit that caused renal failure? Show that sentence or paragraph to me. Highlight that particular neurotoxin – the specific chemical name, the identity, the isolation, the molecular and chemical structure, its molecular weight, the toxicological studies done both in tissue culture, cell-line assays, LD 50 studies, liver and kidney biopsies and histopathology, how that specific neurotoxin acts (toxico- dynamics), its toxicological kinetics (absorption, distribution,. metabolism, excretion, etc), its chemistry on the kidney, and its mode of action on the neurological system.
Show it to me where all these were stated from the journal e-mailed to me.
The Papers Published:
In this journal quoted:
It mentioned about other ‘neurotoxins from blue-green algae present in certain foods or water that can accumulate in proteins that might cause brain diseases like Alzheimer's after many years’. Where were the words ‘neurotoxin’ found specifically in ‘star fruit’ mentioned in this paper?
Don’t simply quote irrelevant papers which have no connection with specific neurotoxins in star fruit and disease entity to me. In research we are very critical and decisive in what we read.
Having said that, now let's turn to the other paper published by Miguel Moyses Neto et al in the other journal here:
Where in this second paper was the specific neurotoxin named by these authors. I want the name and chemical identity of the toxin named by these authors? Please highlight and make it in very BOLD and in LARGE letterings the specific name of the ‘neurotoxin’ together with the toxicological studies done by these authors (researchers).
Give the Identity of the Neurotoxin:
Where, show it to me? I want the name of the so-called ‘neurotoxin’ these clinicians ‘identified’ and ‘isolated’ from star fruit? Where was this mentioned in their paper? I need the specific and exact name of the toxin, not the speculation it was a ‘neurotoxin’. Show that to me in the both the papers you simply took from the Internet, copy and paste and send them to me.
I think people who blindly ‘copy and paste’ from, the Internet need to know what they are copying and pasting in the first place before sending it to others.
Disorders that Mimic in Symptoms:
In medicine, please note that you cannot use what is described in a textbook of medicine to diagnose or identify a disease based only on clinical symptoms (what the patient feels) and the signs (what a doctor can see or elicit). A text book of medicine only gives a guide to diagnosis based on the usual symptoms, signs, and other features of a disease. But you need to investigate further to differential diagnose.
There are many, many conditions that share the same symptoms and even signs, and a doctor need to differential diagnosis by lab and other elaborate investigations, such as haematological, serological (immunological), biochemical, urine, stool, microbiological, radiological (x-rays, MRI, CT, PET, Tech scans, nucleotide, positrons, etc, etc), ultrasonography, histopathology (biopsy), beside the most basic and first step above all these – by listening carefully what the patient tells you, then taking a detail medical history before proceeding to a clinical or physical examination (auscultation, palpation, percussion for percussion notes, reflexes, blood pressure measurements, instrumental examinations, etc, etc)
Simple Diagnosis:
The simple traditional method of listening to the patient carefully, questioning, taking history, followed by a physical examination can provide over 80 % accuracy in identifying the problem of a patient without even all those elaborate blood tests, all those unnecessary this scans and that scan.
There is no need to go for all those unnecessary money-making scans unless his hands, ears and eyes cannot palpate, percuss, auscultate, or see.
There are of course many diseases that mimic each other in symptoms and signs and even in syndromes (group of signs and symptoms occurring together, characteristic of a specific disease / condition / disorder). So a clinician need to differentiate one from the other by questioning, history taking, clinical examinations, and if necessary, using various appropriate lab tests and even scans.
Because the classical signs and symptoms may be absent (sub-clinical), what is more important is to use your clinical judgment (not on text-book knowledge) on signs and symptoms but the actual presentations (clinical features) as shown by a patient. From there you work on to make a diagnosis based on medical history, the patient’s complaints, clinical examination and all other lab tests.
I emphasize again – many conditions mimic each other in signs, symptoms, and even in syndrome. So you make a differential diagnosis as a physician.
Now, having explained all that let me now get back to Dr. Miguel Moyses Neto and his colleagues paper.
The authors very clearly said this:
‘neurotoxic effects of star fruit intoxication in uraemic patients’
As professionals, they did NOT commit themselves by saying it was any specific neurotoxin. They only said, it showed a ‘neurotoxin effects’ and nothing more. Once again, they did NOT identify it as any specific neurotoxin.
‘Neurotoxic effect’ literally translated, means it has an effect similar to an agent that elicits symptoms similar to any agent that may have a mimic effect on the neurological system. That does not mean it is a poison to the neurological system.
This is ENTIRELY different from an agent that is actually a neurotoxin – one that actually acts on the nervous systems by known neuro-chemical dynamics and damage it. This is a world of difference. Once again, they did NOT say star fruit contains a chemically known and already identified neurotoxin. They only describe in their paper as having a ‘neurotoxic effect’, meaning symptomatically (like many diseases sharing the same symptoms – I repeat).
Then they repeated their description with this statement:
“Certain patients with renal failure display behavioural and cognitive alterations compatible with neurologic effects after ingesting star fruit (Averrhoa carambola).
Non-committing:
That’s all they committed themselves, and no further. They have never said star fruit has a specific, identifiable neurotoxin known by a certain chemical name, with a specific molecular structure, a specific molecular weight, with a certain specific gravity, a certain colour and structure. Neither did the authors describe its solubility, chemical reactivity, a specific mode of action…etc, etc. Did they say that in their paper?
Clinicians are not Chemists or Toxicologists:
Analytical Chemist Skills:
This analytical procedure requires the professional skills of a highly trained analytical chemist. What do renal clinicians who publish that paper know about identifying chemical toxins without an analytical chemist help? Of course they did not!
They will require highly qualified and experienced toxicological chemists to handle that kind of job with identification. The clinicians need to work hand-in-hand with a chemist and a toxicologist for that.
Research these days are multidisciplinary, requiring teamwork efforts of other scientists in various areas of specialization and expertise.
The clinician cannot work alone and claim all the glory for himself. So they did NOT identify it, except describe its ‘neurological effect’ which they are professionally eligible.
The Pharmacologist:
If they still want to know its toxicity, they will pass on this substance to a toxicologist who will do very sophisticated and elaborate toxicological studies such as determining its LD 50, cell-line and culture studies, histopathology, liver, kidney and other systems functions, bioassays, microbiological, etc, etc .
These are the expert jobs of pharmacologists and a toxicologist, and certainly not for clinicians who are not qualified or expected to do these very intricate and very specialized studies. Clinicians can only report on clinical cases of toxicity, and with the help of other medical scientists they may be able to identify the so called mysterious ‘neurotoxin’ (whatever that is?) in star fruits.
But so far, they have not. In the first place, the authors were ethical by not committing themselves by ‘pin-pointing’ any specific toxin in star fruit. Once again, they only said it has ‘a neurotoxic effect’. That did NOT mean there was a specific neurotoxin in star fruit.
Multidisciplinary Expertise:
Miguel Moyses Neto the senior author, was probably the chief renal physician, but he did not publish it by himself. He did it with several colleagues and counterparts, including a scientific team from other departments. Yet they did NOT identify any specific ‘neurotoxin’ in their papers. It is not easy. This is not a newspaper for wrapping nasi goring, nasi lemak and goring pisang. It was a research paper.
Nutritional Effects:
Just to let you know even certain foods and vitamins do have ‘neurotoxin effect’. Example, MSG has been reported to cause Chinese restaurant syndrome such as:
• Chest pain
• Flushing
• Headache
• Numbness or burning in or around the mouth
• Sense of facial pressure or swelling
• Sweating
• Tingling sensation over the arms
So does nicotinic acid (one of the B vitamins) that may cause flashing effect, tingling sensation, and numbness (paraesthesia) over the upper and lower extremities (arms and legs) if taken in pure and in high doses. These are called ‘niacin flush’ and may be presented as:
• Warm flushing
• Tingling
• Puritus (itching) and redness of the skin in the face, trunk or from head to toe.
• Rapid heartbeat
• Chills,
• Shortness of breath (dyspnea)
• Sweating
• Dizziness
• Syncope (fainting)
Niacin causes flushing by dilating (expanding) the blood vessels on the surface of the skin.
So we can see, even niacin, a member of the B group of vitamins we need daily can also cause ‘neuro’ effects.
These are just two examples among dozens how even ordinary daily food can have ‘neurotoxic effect’ to some food intolerant individual. You need to undergo a 4-year university course in nutrition to understand more.
Oxalic Acid:
Oxalic Acid Not A Neurotoxin:
These insoluble calcium oxalates may block the fine renal tubules and loops through which the kidneys are trying to excrete. But oxalic acid is NOT a neurotoxin. It does not affect the brain or neurological functions as far as I know.
Actually if you eat almost any vegetable you will also ingest some oxalic acid. This acid is present in almost all fruits and vegetable to varying degrees.
In fact if you do a simple urinary FEME (Urine Full Examination, Microscopy Examination) which can easily be done by a trained Medical Lab Technologist, you will find oxalate crystals in the urine under a microscope as they are excreted out from the diet you eat every day. So what is the problem?
If you eat star fruit in excess, you will probably see more oxalate crystals coming out in your urine (under a microscope). So what is the problem with star fruit for a person with healthy kidneys? I do not know what the fuss is all about?
Oxalic Crystals in Urine:
In fact a urinary FEME is so simple and easy to do that it can be done in an ordinary GP office with just a microscope. This test itself can show many things (cast cells, blood cells, crystals, bacteria, etc) in the urine, and that itself can tell a lot about the health of your kidneys even without all those elaborate and difficult tests (renal function tests) I described in my e-mail yesterday. However, renal function tests can only be done in a well-equipped chemical pathology laboratory.
Other renal diseases (example Wilms' tumor, squamous cell carcinoma and other cancers of the kidney) will not show up with ‘renal profile tests.’ You need ultrasound, MRI and biopsy and histopathology for this.
It is now dinner time for me. I assure you there is no neurotoxin in my food.
ju boo lim