Star Fruit Health Risk
The tropical star fruit or carambola is a pretty fruit with a star-shaped cross-section. Green when unripe, it turns a lovely golden-yellow when it is ripe for eating. Juicy and sourish-sweet, it is very popular as a juice in the tropics. Star fruit is rich in antioxidants and vitamin C, and low in sugar, sodium and acid. It is a potent source of both primary and secondary polyphenolic antioxidants
Unfortunately, eating just one carambola or star fruit or drinking 100 ml of its juice can be harmful for people with illnesses like breast cancer and kidney problems. Like the grapefruit, star fruit is a potent inhibitor of seven cytochrome P450 isoforms. These enzymes are significant in the first pass elimination of many medicines, and thus the consumption of star fruit or its juice in combination with certain medications can significantly increase their effective dosage within the body. Research into grapefruit juice has identified a number of common medications affected, including statins which are commonly used to treat cardiovascular illness, benzodiazepines (a tranquilizer family including diazepam) as well as other medicines.
The cytochrome P450 isoforms are also crucial for breaking down or metabolising estrogen. When estrogen is not metabolised, it can accumulate in the body, and this is bad news for people with estrogen-positive cancers such as most breast cancers.
Like the grapefruit, start fruit contains oxalic acid which can be poison to individuals suffering from kidney disease or undergoing kidney dialysis treatment. University Malaya Medical Centre consultant nephrologist Prof Dr Tan Si-Yen reported the case of a 66-year old Malaysian man who consumed star fruit while visiting his son in Shenzhen, China. Mr. Tang Gon Seang had a kidney ailment and fell into a coma on March 29, 2008, after eating the carambola.
According to Prof Dr. Tan: “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. In kidney patients, it cannot be removed and worsens their condition”.
“The public must be alert to reactions to star fruit. Look out for initial symptoms including hiccups, numbness and weakness, and neurological symptoms including confusion, agitation and epileptic fits,” he said.
“The risk of death is high,” he added.
Other symptoms to look out for include vomiting and nausea. Fatal outcomes have been documented in some kidney patients.