Ornamental gourds and hybrid garden squash should not be eaten
Some cucurbits are toxic and contain cucurbitacins, substances that are highly irritating and bitter. After ingestion, these can rapidly lead to digestive pain, nausea, vomiting and (sometimes bloody) diarrhoea, or even severe dehydration requiring hospitalisation. These substances, which are not destroyed by cooking, are naturally produced by wild cucurbits to repel predatory insects such as caterpillars.
This is the case with ornamental gourds such as colocynths, all of which are considered toxic, available commercially (sometimes in the fruit and vegetable section) for strictly decorative uses, and which should not be confused with edible squash.
This is also the case with certain edible squash grown in the garden vegetable patch, which become unfit for consumption as a result of wild hybridisations. This phenomenon occurs when inedible and edible varieties coexist in the same or in neighbouring vegetable patches, and the seeds are harvested and re-sown year after year. But beware! The inedible gourds that result from this hybridisation look exactly like edible squash, except that they have a bitter taste, unlike the edible varieties, which have a neutral or slightly sweet taste.
The French Poison Control Centres (CAPs) regularly receive calls regarding poisonings associated with the consumption of inedible "squash":
In a retrospective study of inedible gourd poisonings recorded by the CAPs from 2012 to 2016, 353 people had mainly digestive symptoms, or at least a bitter taste in the mouth. While none had serious life-threatening symptoms (high severity), 4% of cases had pronounced or prolonged symptoms (moderate severity) such as bloody diarrhoea, intense gastric pain, dehydration and/or hypotension, etc. Lastly, among the cases where the supply source was known, 54% of bitter gourds came from the garden vegetable patch, with the remaining 46% purchased commercially.
In another retrospective study on confusion of toxic plants with edible plants recorded by the CAPs from 2012 to 2018, among the 1159 cases of confusion recorded, those mistaking inedible gourds or colocynths for edible squash represented the third most frequent type of confusion (8.5% of the total), after confusions of toxic bulb plants with edible bulbs (12%) and of horse chestnuts with sweet chestnuts (11%).
Tips to avoid poisoning
- Ornamental gourds (colocynths): These are all toxic and should not be consumed. Check the label or get advice from the staff at the point of sale.
- Edible squash, purchased commercially or grown in garden vegetable patches: Try a small piece of raw squash and if the taste is bitter, spit it out and throw it all away: it should not be eaten, even when cooked.
- Squash from garden vegetable patches: Do not eat "wild" squash that have grown spontaneously. Do not collect seeds from previous harvests for re-sowing. Buy new seeds each time you want to sow them in the vegetable patch.
CAUTION, in the event of poisoning:
In the event of a medical emergency, heavy digestive bleeding or loss of consciousness, etc., dial 15 (in France) or go to the hospital emergency department.
In the event of other symptoms of poisoning (digestive disorders, etc.), call a poison control centre or see a doctor. Also remember to photograph the "squash" before it is eaten to help identify the species, and to keep any meal leftovers (soup, purée, etc.) that may be useful in searching for toxic substances in the squash consumed.