Don't eat that, it's poisoned

Architect and Sydney Morning Herald columnist Elizabeth Farrelly worries that our food is contaminated:

There are many, many instances where food safety is not clear. Genetic modification, hormone-additives, antibiotics, preservatives, pesticides, trans-fats and allergens are just a few areas where the jury is still out.

According to Farrelly:

The standard rule-of-thumb for healthy eating is Michael Pollan's ''eat food, mainly plants''.

But Farrelly ignores that by eating plants humans expose themselves to scores of natural toxins, many of them carcinogenic:

Nature's pesticides are one important group of natural chemicals that we have investigated. All plants produce toxins to protect themselves against fungi, insects, and predators such as man. Tens of thousands of these natural pesticides have been discovered, and every species of plant contains its own set of different toxins, usually a few dozen. In addition, when plants are stressed or damaged, such as during a pest attack, they increase their natural pesticide levels many fold, occasionally to levels that are acutely toxic to humans. We estimate that 99.9% of the pesticides we eat are all natural.

Surprisingly few plant toxins have been tested in animal cancer bioassays, but among those tested, again about half (20/42) are carcinogenic. Even though only a tiny proportion of plant toxins in our diet have been tested, natural pesticide carcinogens have been shown to be present in the following foods: anise, apples, bananas, basil, broccoli, brussels sprouts, cabbage, cantaloupe, carrots, cauliflower, celery, cinnamon, cloves, cocoa, coffee, comfrey tea, fennel, grapefruit juice, honeydew melon, horseradish, kale, mushrooms, mustard, nutmeg, orange juice, parsley, parsnips, peaches, black pepper, pineapples, radishes, raspberries, tarragon, and turnips. Thus, it is probable that almost every plant product in the supermarket contains natural carcinogens.

Typically, Farrelly produces nothing more than suspicions that genetically modified foods, hormone additives, antibiotics, pesticides and preservatives negatively affect human health. The reality is that both the vanishingly small quantities of chemical residues in our food and genetic material modified by humans are not adversely affecting humans.