I received a forward email from friend a week ago informing how harmful star fruit is that it can kill! Here is the email content:
Star Fruit Can Kill
Goes by another name….carambola
This fruit can end your life!
This is not an April Fool Joke. But a stern reminder to all my readers. We were advised to have a few servings of fruits a day in order to reap the benefits of fruits right? But obviously this is one big no-no fruit to be excluded from your fruity feast!
In Shenzen, more than 10 people who consumes the star fruit had died. And now a 66-year-old, Malaysian who has been suffering from kidney ailment fell into coma after eating the start fruits. Yes, all it takes is one fruit or 100ml of its juice and the ordinarily harmless star fruit transforms poison in a matter of hours for kidney patients. So does this mean, people without kidney problems should be fine with star fruit! My take: Not at all! Prevention is better right?
Universiti Malaya Medical Centre consultant nephrologist said that star fruits contain a neurotoxin which is not present in other fruits. It affects the brain and nerves. In healthy persons, the kidneys filter it out. But for those with kidney problems, this potent toxin cannot be removed and will worsen the consumers’ conditions.
The symptoms of start fruit poisoning include:
~Hiccups
~Numbness and weakness
~Feeling confused
~Agitation
~Epileptic fits
The risk of death is high if you are having kidney ailments! But healthy individuals should beware of this fruit’s potential toxin too. It could also cripple your vitality if you are not lucky. So don’t take it for granted. It’s better to avoid them. Please pass this news to others.
My first response to it, could it be a hoax? However doubtful, I searched from the Internet and found the original news report. Well, despite of the fact of star fruit intoxication, I can see some other information have been twisted by the person who produced the above article. Often, I hold some disbelief to this kind of forward email concerning health issues because of the way people deliver or spread the information. Some are apparently questionable and at some point misleading but people still ignorantly spread it without think.
Anyway, back to the topic, this issue did spark my interest so I decided to research more about it.
Star fruit (carambola) is indeed harmful and can be life-threatening to patients who have kidney dysfunctions particularly uraemia. Common symptoms encountered by uraemic patients after star fruit ingestion are:
- persistent and intractable hiccups
- vomiting
- disturbed consciousness of variable degrees (mental confusion, psychomotor agitation)
- decreased muscle power
- limb numbness, paresis and paresthesia
- insomnia
- seizure
- hypertension
- convulsion
According to the experts, as little as one half of the fruit can lead to the symptoms. The time from ingestion to onset of symptoms ranged from 30 minutes to several hours and in some severe intoxication cases, death resulted.
It is said that these symptoms are caused by the oxalic acid and a kind of neurotoxin contained in the star fruit. However, the claim of oxalic acid being problematic in this case is controversial as the other foods that contain higher level of oxalic acid such as spinach do not seem to cause the symptoms. Brazilian researchers Carolino et al. (2003) have proven that the AcTx, a neurotoxic compound found in star fruit, is causal to the convulsion after ingestion. For people with normal kidneys, this compound can be excreted from the blood quickly and thus they do not suffer from its effect when a reasonable portion of the fruit is consumed.
Medical treatment for star fruit intoxication is kidney dialysis. Interestingly, Neto et al. (2003) who studied the intoxication in 32 uraemic patients found those who were promptly treated with hemodialysis (HD), recovered without sequelae; those who were untreated or treated with other form of dialysis, peritoneal dialysis (PD), unfortunately did not survive.
There are always rebound effects after dialysis such as persistent hiccups and consciousness disturbance. One remarkable case study as described in Neto’s research is about a 25-year-old female uraemic patient who initially developed hiccups after consuming a star fruit. The condition was worsened after she consumed another 4 star fruits few hours later and she even vomited. She then received 2 hours of hemodialysis and the symptoms disappeared one hour after the dialysis. However, she suffered from intractable hiccups 2 hours later and the condition persisted until the next day, when she was again treated with 4 hours of hemodialysis. The hiccups were stopped but that was not the end of the story yet. When she returned home, the hiccups started again and caused her a sleepless night although she experienced 10 minutes intervals that were free of symptoms. The following morning she went through another 4 hours of hemodialysis but the hiccups continued to haunt her when she was at home. Good thing was the 10 mins hiccup-free intervals had extended. The hiccups finally disappeared after she received one more 4-hours dialysis and no sequelae has been reported afterwards. Overall, it took 14 hours of dialysis to end her nightmare. Dreadful isn’t it?
Therefore, it’s highly advisable for kidney patients to avoid eating star fruit. While people with normal kidneys have no problem with the star fruit intoxication, do beware of over consumption. My point of view is, it is unnecessary to completely shut your door to the fruit. You still can enjoy it but always keep one rule of thumb in mind: moderation is the key. And that applies to whatever you eat. 
