One of the earliest concerns raised about GM foods was that a disturbed genome would generate strange proteins to which our bodies would react.
Regulators 'addressed' this concern by assessing the potential toxicity and allergenicity of the novel protein produced by the inserted gene. This neatly side-steps a fundamental safety problem with GMOs: it ignores the potential for the production of toxins or inflammatory agents due to changes in the wider genome and the metabolism it governs.
Two unique scientific studies have been published which suggest our concerns about unexpected allergens are very valid. An early warning was sounded when a nut allergen turned up in soya which had been genetically transformed with a Brazil nut gene not known to be part of any allergen in its native form. More recently, an apparently innocuous bean gene inserted into peas not only generated an allergen, but induced cross-reactivity with other common proteins.
Whether or not similar or worse problems are present in the GM in our food chain is unknown: none have been appropriately tested pre-marketing, and post-marketing monitoring is impossible in a supply chain flooded with variable amounts of different, untracked, GM crops. Unless people develop very unusual symptoms, as happened in the case of GM tryptophan poisoning in 1989, it's unlikely that GM toxins or allergens will ever be identified except as 'more of the same' upward spiral of modern chronic disease. (See 'GM food allergies are escalating' in SCIENCE – Are there dangers in genetic modification?)
However, toxins and allergens in GM foods may not the the biggest threat to our health ...
The biggest health risk from GM food might well derive from the trillions of micro-organisms resident in our guts. These bugs will be living off a GM diet too. The only attention paid to them so far has been the consideration of antibiotic resistance genes in GM foods which might be taken up by pathogens and compromise the treatment of infectious disease. This absurdly narrow view entirely ignores the contribution of digestive tract microbes to our health.
One researcher in the field of nutrition describes the mass of microbes inside our gut as an “essential organ”. This 'organ' is reckoned to weigh two to three pounds, and plays a vital part in digestion, in protection against disease, and in gastro-intestinal tract development.
There's an increasing awareness amongst scientists of the complexity of the interactions between what we eat, the products of our digestion, the composition of our gut microbes, and our health. Think about it like this:- Our health affects our digestion. Our digestion interacts with our diet to form the products of digestion which determine our health. Our gut microbes, interacting with our diet and with the products of digestion, determine the products of digestion which in turn determine the composition of our gut microbes. The balance of good and pathogenic gut microbes supported by our diet and digeston helps or hinders health and disease. The microbe-induced products of digestion interact with our cells to help or hinder the inflammatory processes and their key role in health and disease. And around and around it goes.
It seems that an 'old-fashioned' diet of seasonal vegetables, cereals, nuts and beans provides the right conditions to promote the good little guys which aid digestion, fight off the bad little guys, and protect us from inflammatory reactions.
A diet of processed foods, whose products of digestion lack both variety and micro-nutrients also lack the ability to support a health-promoting microbial mix. The measured effects of this are an increase in inflammatory reactions such as asthma and eczema. As our diet has become increasingly processed, autoimmune disorders and inflammatory bowel disease have also increased. Obesity coupled to nutritional deficiencies is emerging as a clear part of this scenario.
The role of current commercial GM crops (soya, maize, oilseed rape, sugar beet and cotton) has always been to support an unhealthy diet. These crops are designed to feed us with too much meat, and with an infinity of uniformly processed, 'pre-digested', junk foods and additives.
Add GM foods with a host of strange proteins and other metabolic products into the above health-diet-digesta-microbe-pathogen-inflammation equation and you might well arrive at a vision of a global epidemic of chronic disease.
The Bill and Melinda Gates Foundation is pouring billions of dollars into GM crop research with the goal of developing the world's first 'superfood': a single plant which contains all the vitamins, minerals and nutrients necessary for life, needs minimal water and generates its own pest-control.
The prototype Gates 'superfood' is a GM sorghum for Africa which is easier to digest than its natural counterpart, has higher protein levels, and more essential amino acids, zinc and vitamin A.
Someone needs to explain to the Gates that 'superfoods' are a fairy tale: we don't know all the nutrients necessary for life, and never will because what's necessary depends on whatever other nutrients are present in our diet, on our digestive system, on whatever gut microbes are present, and on the health of the individual.
The novel sorghum sounds suspiciously like self-processing, self-supplementing junk food whose effect on the African gut microbes and the health of the African people could be catastrophic.
Another little something to worry about in the microbe-health-GM equation is the staggering speed at which the bugs inside you might evolve in their novel environment: the adaptive processes might not be at all to your advantage.
P.S. In case you're swallowing the latest fashion in probiotic foods with bugs added in the factory, remember that eating these along with a pile of sterile junk won't make the junk (or you) healthy. Eat whole, fresh, organic food, and the bugs in your gut will love you forever.
- Mayeno and Gleich, 1994, Eosinophilia-myalgia syndrome and tryptophan production: cautionary tale, TIBTECH 12
- Nordlee et al., 1996, Identification of a Brazil-nut allergen in transgenic soybeans, New England Journal of Medicine, March 14
- Prescott et al., 2005, Transgenic Expression of Bean α-Amylase Inhibitor in Peas Results in Altered Structure and Immunogenicity, Journal of Agricultural and Food Chemistry, 53:23
- Junk food linked to allergy risk, Telegraph 3.08.10
- Mark Harris, Gates joins quest to create world's first superfood, Sunday Times, 8.08.10
- De Fillippo et al, 2010, Impact of diet in shaping gut microbiiota revealed by a comparative study in children in 'Europe and rural Africa, www.pnas.org 30.06.10
- Do it like they do in your intestinal channel, Metro, 14.03.10
- Good Intestinal Health becomes Crucial in Promoting Your Overall Health, Mercola Advanced Nutrition, March 2008