OK, that title is slightly mischievous. When I say natural breeding, we’re not talking normal hot plant sex here, but something even hotter: bombarding the hapless veggies with gamma radiation to induce mutations.
It might not sound very natural to you and I, but according to regulators around the world, this counts as natural compared with genetic modification. If you induce a change by genetic engineering, you have to prove it’s safe. Do it by mutagenesis and no one cares.
Except a team in Portugal are now claiming that mutatagenesis results in more changes in gene expression (which genes are turned on or off) than genetic engineering. For greater changes read more potential to produce (more) toxic substances. After all, plants are primed to produce toxins to deter those that want to eat them.
In fact, history shows that even old-fashioned conventional breeding can be dangerous. The Lenape potato bred in the 1960s turned out to have dangerously high levels of solanine, the toxin found in all potatoes. The Magnum Bonum, an century-old breed from England reintroduced into Sweden in the 1990s, was similarly toxic. (“Old”; “traditional”; “natural”: gotta be good, hmm?)
The kiwi fruit bred in New Zealand from an inedible (but not toxic) Chinese berry and introduced to the US in the 1960s never underwent safety testing and caused allergic reactions in some people (recently shown to be due to a protein called actinidin). Hybrids between ordinary potatoes and related species have been found to produce a novel toxin not found in either parent called demissidine.
The list could go on and on. My point is not that genetic modification is wonderful but that we should be wary of everything we eat, however it was bred or created.