Horror of horrors! "Human genes in your food! Rice crops to be genetically modified with human DNA" screams the front page of today's Daily Mail
If this disturbing news made you swallow in shock, you just got a dose of the products of two of the human genes in question. One is lysozyme, an enzyme that kills some bacteria by breaking down their cell walls. The other is lactoferrin, an iron-binding protein that helps us absorb the metal while starving bacteria of it. It also attacks viruses and bacteria in several other ways.
Both molecules are found in our saliva, tears and other secretions, including breast milk. You also consume somewhat different animal versions of these proteins with just about every meal - eggs are rich in lysozyme, for instance, while cow's milk contains both proteins.
Thanks to their antimicrobial and other benefits, some health food companies already sell lysozyme and lactoferrin supplements. But it's babies who need these proteins most - human milk is rich in lysozyme and lactoferrin. Infant formula contains neither, which may be one of the reasons why breastfeeding is so much healthier. Hence the interest in adding lysozyme and lactoferrin to formula
and related products such as the rehydration fluids given to young children with diarrhoea
Unsurprisingly, the human versions of these proteins appear to do more for babies than the bovine versions
. The problem is making them cheaply - you cannot cook up such big, complex molecules in a conventional drug factory and since mass milking of women isn't practical, companies have had to turn to genetic engineering. One, Ventria Bioscience of Sacromento, has created two rice strains whose grains contain human lysozyme and lactoferrin, respectively.
A third rice strain created by Ventria produces human serum albumin, the most abundant protein in our blood. The protein is needed to make up the media used to grow microbes in labs. If you eat any kind of meat, you already consume large amounts of animal serum albumin.
The US Department of Agriculture
has just given the preliminary go-ahead for these three rice strains to be grown commercially in Kansas, sparking the hysterical coverage in the Daily Mail
. The paper, which specialises in nasty knee-jerk reactions, rolled out the usual anti-GM campaigners to condemn the news.
Even the Washington Post
led its story with the claim that the approval is "reigniting fears that biomedically potent substances in high-tech plants could escape and turn up in other foods".
Now there's no doubt that contamination is a real risk. There are numerous instances of non-GM crops being fertilised by GM strains, or of GM strains being planted instead of non-GM varieties
There are also some drugs that could be grown in food crops that would pose a risk if they got into the food chain. It's more sensible to engineer non-food crops such as tobacco to produce such substances
However, it's hard to imagine any substances that are less likely to cause a problem than lysozyme, lactoferrin or serum albumin, whatever food they turn up in.
Opponents have focused on the theoretical risk of allergic reactions
. A tiny number of people do have immune reactions to the animal versions of serum albumin if they eat meat that hasn't been thoroughly cooked. But I've yet to hear any calls for all meat products to be banned on this basis.
And plant breeders are free to introduce new plant strains created by deliberately inducing genetic mutations without any regulatory hurdles - the risk posed by Ventria's carefully scrutinised creations are minuscule in comparison.
Let's not forget that the idea is to feed relatively large quantities of lysozyme and lactoferrin to young kids, for heaven's sake. If it's safe for them, why should the rest of us panic about the possibility that there might be trace amounts in rice?
What's more, I don't know how you like your rice, but I tend to boil mine for at least 10 minutes. And boiling breaks down proteins such as albumin. I wouldn't hesitate to eat the lysozyme or lactoferrin-containing rice if Ventria is kind enough to send me some. The fact is that the potential benefits of these genetically modified rice strains hugely outweighs any risk they pose.
What really appals some people, I suspect, is simply the idea of adding human genes to plants. Yet there isn't some magical separation between humans and other living organisms. We all share the same origins. In fact, we're half bananas - around 50% of our genes have close equivalents in plants. We share even more genes with creatures such as cows. In other words, there already are "human" genes in our food. Lots of them.Michael Le Page, biomedical features editor