Eulalee ThompsonHardly ever is a pot of chicken soup prepared without chunks of cho cho added for flavour and taste. But this Jamaican favourite is actually more than just food. Last year, local scientists, (Dr. L.P. Guppy et al) after noticing the local custom and listening to folk tales about the fruit's hypotensive effect, set about separating truth from myth.
Dr. Guppy, University of the West Indies' (UWI's) pharmacologist concluded, at the end of preliminary investigations of the fruit, that it did in fact, have the ability to lower blood pressure.
"The effect comes on fairly slowly, the blood pressure stayed down but came back up again. It may not affect the heart and blood vessel but it may be a diuretic and cause the blood potassium level to drop but this is actually the effect of many common diuretics that people use," he said.
These are preliminary findings, and further chronic experimentation will have to be done to determine the mechanism by which the fruit produces the hypotensive effect, to identify the fruit's active ingredient and to determine, among other things, whether the active ingredient retains its potency when it is cooked. He noted too, that while the mechanism is to be determined, it did not appear to involve direct effects on the cardiac tissue (the heart).
"We, of course, used laboratory rats in our experiment which is not directly comparable to humans but we can draw conclusions," Dr. Guppy said.
The experiments (which were published in the West Indies Medical Journal) were conducted in a random and blind fashion on two sub-species of cho cho (scientific name, Sechium edule). The sub-species of cho cho available here and used in the study are white and light-green in colour. Both the pulp and the peel were examined for hypotensive activity.
The scientists prepared water-soluble extracts from the pulp and the peel and injected them into anaesthetised rats. The scientists then measured various cardiovascular parameters including heart rate, mean arterial pressure (MAP) and several ECG intervals. They reported that all the extracts produced a fall in blood pressure ranging from 5 mmHG to 48 mmHG with little change in ECG intervals. The extract labelled B produced the least change in heart rate with a fall in MAP of about 23 mmHG (millimetres of mercury). Minimal changes in heart rate were noticed with all the extracts.
Dr. Guppy said in Jamaica and the rest of the Caribbean there is a wide variety of flora and fauna and several tales about their usefulness have been passed down from generation to generation. There might be a lot of credence in these tales of medicinal values, but the only way to gain legitimacy is to put the plants through the test of scientific research.
The researchers say they do not advocate the use of "alternative medicine" unless there is incontrovertible scientific proof that such treatment will be of benefit to the patient. They however, noted that most if not all useful medicines originated from a plant or animal source. Physicians, the researchers say, will have to balance the risk versus the benefit of any therapy they advocate.
Different names of cho cho
The cho cho goes by many different names depending on which part of the world you are located. Some names are chayote, cho-cho, chocho, christophene, christophine, chuchu, mango squash, mirliton (in the South), pear squash, vegetable pear, sousous, choko, custard marrow, pepinella, pepinello, xuxu and xoxo.
This mild-flavoured squash, that looks like a wrinkled, pale green pear should be cooked before eating and it takes a longer time than other summer squash to be cooked. You should peel a chocho before cooking it, but don't take the seed out -- it's edible and tasty. It is said to be a good low-fat substitute for avocados.
