By Aruna Handa
December 2007/January 2008
Do the 100-mile diet! Eat local! Eat your scenery! It was with these slogans in my head that I decided to host two 100-mile Harvest Dinners this fall at my home in downtown Toronto. Sixteen people participated in each dinner, and each of us prepared a course for eight people and brought drinks to go with it. Those who were assigned the hors d’oeuvres concocted 100-mile cocktails, and the rest of us brought 100-mile wine: all of it from within Toronto’s foodshed. We enjoyed a bounty of locally-grown produce—-Concord grapes, sheep’s milk cheeses, squash-stuffed ravioli made with Ontario Red Fife wheat, sourdough breads, cream of parsnip and apple soup, smoked trout salad, herb-and-chili-marinated flank steak, celeriac and potato mash, apple pie and pumpkin pudding—-to name but a few of the dishes sampled. Most of the produce and meat was either organically produced or else grown without pesticides or herbicides, without antibiotics or growth hormones. And all of it was free of genetically modified organisms.
Or so we thought.
Illustration by Aimee van Drimmelen
Despite our best efforts, it turns out that the GMOs we assumed we were avoiding by carefully selecting our grains and our produce, by shopping at farmers’ markets and buying directly from producers, and by foraging for herbs and picking fruit from our own fruit trees had nonetheless snuck a place at our table.
The GMOs were lurking in the wine. Genetically modified grapes? No, at least not yet, not in southern Ontario. While scientists are busily trying to engineer grapevines, it looks like commercially available genetically modified grapes are still some years off.
It wasn’t the grapes that were genetically modified—-it was the yeast, which goes by the name saccharomyces cerevisiae ML01. And wine doesn’t have to come from southern Ontario to contain ML01.
So far, saccharomyces cerevisiae ML01 has been approved only in Canada and the U.S. Provided the wine is Canadian or American, with each sip we swallow we may be unknowingly participating in a science experiment testing the effects of genetically modified wine on humans. It’s a poorly conducted experiment, however, since there is no control group, no observations and no “objective” scientist.
So what’s wrong with genetically modified yeast? The answer is, nobody knows—-maybe it’s safe. But then again, maybe it isn’t.
In its assessment of ML01 for commercial use, Health Canada neither commissioned nor conducted independent tests to establish its safety for human consumption. Both the United States Food and Drug Administration and Health Canada relied entirely on data supplied by the genetically modified yeast’s developer in reaching their decisions. And the developer didn’t bother to test the safety of the yeast either, invoking the “substantial equivalence” notion first introduced by the Food and Drug Administration in 1992. The FDA ruled that genetically modified foods are “substantially equivalent” to conventional foods and thus require no special regulations.
“We conducted no tests on animals and no tests on humans because the genes we inserted were from organisms that humans have been using in winemaking for hundreds of years,” says ML01’s developer Hennie van Vuuren, professor in food biotechnology and founding director of the Wine Research Centre at the University of British Columbia.
That’s how ML01 received the U.S. Food and Drug Administration’s “generally recognized as safe” designation in June of 2003 and approval in Canada in the summer of 2006, without a single test on its safety for human consumption or its potential for harm to the environment. Moldova is the only other country where ML01 is commercially available. A decision is imminent in South Africa.
Echoing the recommendations made by the Royal Society of Canada’s Expert Panel on the Future of Food Biotechnology, retired Agriculture and Agri-Food Canada scientist Bert Christie suggests that “Health Canada should set up independent scientific panels to review all data received from petitioners.” At present, however, Health Canada employees make up the review panels. This worries Christie since the federal government often funds the development of the same genetically modified organisms it is subsequently asked to license. ML01 cost $2 million to develop, with funding from the Natural Sciences and Engineering Research Council of Canada, as well as the South African wine industry and the Lesaffre Yeast Corporation.
Christie worries about the notion of substantial equivalence that was used to secure approval of ML01. “We used to think there was a one-to-one relationship between genes and traits,” he states. However, “we know now that’s not the case. One gene typically controls several traits. What else is affected?”
According to van Vuuren’s data, the genetically modified yeast’s targeted mutations also resulted in 15 unintended mutations. It remains unclear what further mutations these genes might undergo, but the South African non-governmental organization Biowatch does not recommend taking the risk. In its objection to van Vuuren’s application in South Africa, Biowatch states, “it would be unwise to work with this uncharacterized mutant.” Eleven South African vintners signed their names to Biowatch’s objection. In van Vuuren’s reply to Biowatch, he suggests that the differences between his genetically modified strain and non-genetically modified strains are consistent with the genetic variability of the organism. The Biowatch document, however, raises a number of additional worries. Among them are the possible contamination of other yeast strains by the genetically modified yeast, horizontal gene transfer to the intestinal flora of human consumers, and the fact that its use is “likely to have disastrous consequences for South Africa’s wine industry” in light of the “overwhelming rejection of all genetically modified food and drink by consumers in Europe—-an important export market for South African wine.”
Vintners here in Canada are no less worried. “I have nothing against GMOs myself, but our customers have concerns. We have never used ML01, but I’ve heard of it,” says winemaker Martin Janz of Pelee Island Winery in Ontario. Canada’s export market for wine is still relatively small, but it is growing, and customers in Europe remain skeptical about genetic engineering.
Given the ongoing crisis in consumer confidence regarding genetic modification, what motivates the development of genetically modified yeast?
Commercial bread yeast sells for $2 per kilogram; specialized wine yeasts can retail for 70 times that amount. ML01 retails for $150/kg, which ranks it as one of the highest-priced yeasts available.
The development of genetically modified yeast could be seen in the context of a trend in winemaking away from artisanship and toward science and technology. Tannins, flavours and colours—-what Canadian food critic Thomas Pawlick in his latest book, The End of Food, calls “those little extras”—-can be added to wine to enhance mouth feel, taste and appearance, all without any mention on the label.
Van Vuuren has published a document through UBC’s Wine Research Centre, “Maloactic yeast ML01: The Facts,” in which he attests that in wines fermented with ML01, “colour properties of wine are improved, wine quality is higher and wines are more fruity and have an improved mouth feel (body).”
Traditional winemaking relies on wild yeast to bring about the alcohol fermentation, and it relies on spontaneous malolactic fermentation from naturally occurring bacteria to convert bitter malic acid to smoother lactic acid. But more and more, wineries are keen to reduce the unpredictability of winemaking by using laboratory yeasts and bacterial cultures. Viewed in this context, genetically modified yeast seems a logical progression.
ML01 permits both fermentations to occur simultaneously, thus addressing a problem faced by less-experienced winemakers: stuck malolactic fermentation. A stuck malolactic fermentation can result in a spoiled batch of wine. By hastening the process, ML01 reduces the risk of a stuck fermentation.
In a study published in the September 2007 issue of the American Journal of Enology and Viticulture, conventional yeasts and bacteria fermentations were compared with the single fermentation obtained with the use of ML01. The study found that ML01 was able to convert all the malic acid to lactic acid in 60 hours while a conventional method took 21 days. The study also found that ML01 produced three times more sulphur dioxide—-a common preservative in wine—-than one of the conventional yeasts tested and six times as much as the other.
Van Vuuren cites his reason for developing ML01: red wine headache. “I love red wine but can’t drink it,” he says. Van Vuuren estimates that 40 per cent of the population are sufferers of red wine headache, a condition so prevalent it has acquired an acronym: RWH. Distinct from hangovers and allergic reactions to sulphites, red wine headache is characterized by a raging headache that develops after just a few sips.
Van Vuuren is confident that the red wine headache culprit is biogenic amines, a well-known example of which is histamine. ML01, van Vuuren claims, reduces the occurrence of bioamines and thus the likelihood of red wine headache. For some reason, though, as Health Canada observed in its statement about ML01, van Vuuren “has not analysed for biogenic amines in the wine produced from ML01 yeast.”
It is the ability to speed up the process of winemaking rather than concern about red wine headache that features prominently in marketer Springer Oenologie’s catalogue entry for ML01. In fact, there is no mention of headaches at all. As Springer Oenologie advertises, ML01 promotes the possibility of “fast wine”: wine in a single, efficient fermentation. “Quick and reliable stability can increase the throughput of your operation by removing [malolactic fermentation] delays in cellar operation. This allows you to sulphite and bottle with a low risk of bacterial contamination, sooner than ever before.”
Van Vuuren is not responsible for “fast wine” marketing, but the jury is still out on what causes red wine headache. The February 2001 issue of The Journal of Allergy and Clinical Immunology, for instance, reports no difference in reactions among 16 red wine headache sufferers who were given low- and high-histamine wines.
But even assuming that van Vuuren is correct about the connection between red wine headache and bioamines and, further, that wines using ML01 produce fewer bioamines, his fellow sufferers would be no better off since winemakers are not about to advertise the use of ML01 on wine labels. Vintners remain reluctant to divulge whether they use ML01 or any other GMOs.
So how widespread is the use of ML01? American Tartaric, a distributor of the yeast, reports that while the customer base is not “huge,” they do have several repeat customers who have been using ML01 for a couple of years now.
Van Vuuren is putting the final touches on his application for ML01’s approval in Australia. Despite his personal enthusiasm for ML01, Paul Chambers, research manager of biosciences at the Australian Wine Research Institute, doubts the Australian wine industry will waver from its published position “that no genetically modified ingredients be used in the production of Australian wine.” Chambers is nevertheless confident that ML01 and the wines it ferments will prove safe.
Optimistic about the positive potential of genetically modified foods, Pawlick nonetheless remains skeptical about their current safety. “I myself never knowingly purchase or consume them, if the labels permit me to know that they are present. It is simply too soon to take the risk.”
When Quebec brewery Unibroue, brewers of Blanche de Chambly and Maudite, among other beers, advertised its product as GMO-free for the domestic market, the Canadian food agency revoked the GMO-free certification it had earlier bestowed, arguing that the certification was for use in export markets only.
You won’t read about genetically modified ingredients on wine labels in Canada, since there is no law here requiring products containing genetically modified ingredients to be labelled—-despite the fact that a 2003 Decima poll commissioned by the Consumers’ Association of Canada found that nine out of ten Canadians want mandatory labelling of genetically modified foods.
“People ask me if I’m for or against GMOs: I’m neither.” Christie says. “But I have a lot of questions and so far no one’s answering.”
So, what are the implications for our next 100-mile dinner? Should we invoke a version of the “Marco Polo clause” and allow wines from Europe and elsewhere in a bid to avoid genetically modified yeast? No, we’ll keep drinking wines from the Toronto foodshed at our 100-mile dinners—-but next time, we’ll purchase organic wines or else ask the vintners if they use ML01 or any other GMOs in their wines. When the word gets out, though, the easy option for consumers keen to steer clear of GMOs will be to avoid Canadian and American wines altogether.
Aruna Handa writes and lectures about food security and analytic philosophy, but not at the same time.