Consuming more organic food certainly isn't the only way to improve one's nutrient intake, but it may be the safest. It's regularly claimed by the mainstream food industry that pesticide residues in foods are known to be safe on the basis of total diet surveys that supposedly find the levels of pesticide residues in our food to be very low and within acceptable safety limits. But monitoring programs consistently show that around one in three non-organic food samples tested contains a variety of pesticide residues, with far lower levels being found in and on organic produce. Conventional-food proponents also claim that rigorous safety assessments show that pesticide residues are no threat to human health. Yet consumers intuitively know this is a false assurance.

Most pesticide-residue safety levels are set for individual pesticides, but many samples of fresh produce carry multiple pesticide residues. Rules often do not take into account the "cocktail effect" of combinations of pesticides in and on foods. Research is emerging confirming the potential for such synergistic increases in toxicity of up to 100-fold, resulting in reproductive, immune and nervous system effects not expected from the  individual compounds acting alone.

Israeli researchers have linked symptoms such as headaches, tremor, lack of energy, depression, anxiety, poor memory, dermatitis, convulsions, nausea, indigestion and diarrhoea with dietary intakes  of pesticides. Belgian research has found that women diagnosed with breast cancer are six to nine times more likely to have the pesticides DDT or hexachlorobenzene in their bloodstreams compared to women who did not have breast cancer. Hawaiian researchers following 8,000 people for 34 years have found that increasing consumption of conventional fruit and juice (and the pesticide residues they carry) raises the risk of Parkinson's disease.

Dr. Vyvyan Howard, toxico-pathologist at the University of Liverpool, UK, comments on the trend towards organic food on the part of health-minded consumers:

"People are applying the precautionary principle to their own lives by purchasing food that has not been produced by industrial methods. From the simple stance of hazard avoidance, organically produced food is the best option that we have."

The British Medical Association appears to agree:

"Until we have a more complete understanding of pesticide toxicity, the benefit of the doubt should be awarded to protecting the environment, the worker, and the consumer—this precautionary approach is necessary because the data on risk to human health from exposure to pesticides are incomplete."