My previous blog, Are herbicides a cause for allergies, immune incompetence and ADHD? focused on the health risks associated with the herbicide Roundup® (glyphosate) as a possible contributing factor for allergies, immune incompetence and ADHD. The danger of using glyphosate may even be worse!
On March 20, 2015, the International Agency for Research on Cancer (IARC)–the specialized cancer agency of the World Health Organization–classified glyphosate as probably carcinogenic to humans (Group 2A). Thus, I strongly recommend avoiding glyphosate and other types of herbicide and pesticide contaminated foods. Use the precautionary principle and eat only organic foods.
The IARC defines the category Group 2A as follows: The agent is probably carcinogenic to humans. This category is used when there is limited evidence of carcinogenicity in humans and sufficient evidence of carcinogenicity in experimental animals. Limited evidence means that a positive association has been observed between exposure to the agent and cancer but that other explanations for the observations (called chance, bias, or confounding) could not be ruled out. This category is also used when there is limited evidence of carcinogenicity in humans and strong data on how the agent causes cancer.
Health food advocates have long claimed that organic foods are better for your health because they have more nutrients and fewer pesticides than non organic or genetically modified grown foods. On the other hand, the USDA and agribusiness tend to claim that organically grown foods have no additional benefits. Until now, much of the published research appeared inconclusive and meta-analysis appeared to indicate that there are no health benefits from organic as compared to non organic foods although organic foods did reduce eczema in infants (Dangour et al, 2010).
Food studies that have demonstrated no benefits of organic farmed foods as compared to non-organic or genetically modified crops should be viewed with skepticism since many of these studies have been funded directly or indirectly by agribusiness. On the other hand, independently funded research studies have tended to demonstrate that organic foods are more beneficial than non-organic foods. Sadly, the United States Department of Agriculture (USDA) and agribusiness are highly interdependent as the USDA both regulates and promotes agricultural products. On the one hand the USDA’s mission is “To expand economic opportunity through innovation, helping rural America to thrive; to promote agriculture production” and on the other hand “Enhance food safety by taking steps to reduce the prevalence of food borne hazards from farm to table, improving nutrition and health by providing food assistance and nutrition education and promotion. (For more discussion on the conflict of interest between agribusiness and the USDA, see Michael Pollan’s superb books, The Omnivore’s Dilemma: A Natural History of Four Meals and In Defense of Food: An Eater’s Manifest).
Historically, most nutritional studies have investigated the nutritional difference or pesticide residue between organic and non-organically farmed. Many studies have shown that organic grown foods have significantly lower pesticide residues than non organic foods (Baker et al, 2002; Luc, 2006). Even though agribusiness and the USDA tend to state that the pesticide residues left in or on the food are safe and non-toxic and have no health consequences, I have my doubts. Human beings accumulate pesticides just like tuna fish accumulates mercury—frequent ingesting of very low levels of pesticides residue may result in long term harmful effects. One way to measure if there is an effect of organic, non organic or genetically modified grown foods or residual pesticides is to do a long term follow up and measure the impact over the lifespan of the organism. This is difficult with human beings; since, it would take 50 or more years to observe the long term effects. Nevertheless, the effects of organically grown foods versus non-organically grown foods upon lifespan, fertility and stress resistance has now been demonstrated with fruit flies.
The elegant research by Chhabra R, Kolli S, Bauer JH (2013) showed that when fruit flies were fed either organic bananas, potatoes, soy or raisins, they demonstrated a significant increase in longevity, fertility and stress resistance as compared to eating non-organic bananas, potatoes, soy and raisins. In this controlled study, the outcome data is stunning. Below are some of their results reproduced from their article, “Organically Grown Food Provides Health Benefits to Drosophila melanogaster.”
Figure 1. Longevity of D. melanogaster fed organic diets. Survivorship curves of female fruit flies fed diets made from extracts of potatoes, raisins, bananas or soybeans (grey: conventional food; black: organic food; statistically significant changes (p,0.005) are indicated by asterisks).Median survival times of flies on conventional and organics food sources, respectively, are: potatoes: 16 and 22 days (,38% longevity increase,p,0.0001); soybeans: 8 and 14 days (,75% longevity increase, p,0.0001).doi:10.1371/journal.pone.0052988.g001. Reproduced from Chhabra R, Kolli S, Bauer JH (2013).
Figure 2. Daily egg-laying of flies exposed to organic diets. Egg production of flies fed the indicated food was determined daily. Shown are the averages of biological replicates; error bars represent the standard deviation (grey: conventional food; black: organic food; statistically significant changes (p,0.005) are indicated by asterisks; p,0.0001 for all food types). doi:10.1371/journal.pone.0052988.g002. Reproduced from Chhabra R, Kolli S, Bauer JH (2013).
Figure 3. Starvation tolerance of flies raised on organic diets. Survivorship curves of female flies raised for 10 days on the indicated food sources. Flies were then transferred to starvation media and dead flies were counted twice daily (grey: conventional food; black: organic food; statistically significant changes (p,0.005) are indicated by asterisks). Median survival times of flies on conventional and organics food sources, respectively, are: potatoes: 6 and 24 hours (p,0.0001); bananas: 24 and 48 hours (p,0.0001). doi:10.1371/journal.pone.0052988.g003. Reproduced from Chhabra R, Kolli S, Bauer JH (2013)
This elegant study demonstrated the cumulative impact of organic versus non-organic food source upon survival fitness. It demonstrated that non-organic foods decreased the overall health of the organism which may be due to the lower levels of essential nutrients, presence of pesticides or genetic modified factors.
The take home message of their research is: If you are concerned about your health, want to live healthier and longer, improve fertility and resist stress, eat organically grown fruits and vegetable. Although this research was done with fruit flies and human beings are not fruit flies since we eat omnivorously, it may still be very relevant especially for children. As children grow the ingestion of non-organic foods may cause a very low level nutrient malnutrition coupled with an increased exposure to pesticides. The same concept can be extended to meats and fish. Eat only meat from free ranging animals that have been fed organic grown foods and not been given antibiotics or hormones to promote growth.
Baker, B.P., Benbrook, C.M., & Groth III, E., & Lutz, K. (2002). Pesticide residues in conventional, integrated pest management (IPM)-grown and organic foods: insights from three US data sets. Food Additives and Contaminants, 19(5) http://www.tandfonline.com/doi/abs/10.1080/02652030110113799
Chhabra R, Kolli S, Bauer JH (2013) Organically Grown Food Provides Health Benefits to Drosophila melanogaster. PLoS ONE 8(1): e52988. doi:10.1371/journal.pone.0052988 http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0052988
Dangour, A.D., Lock, K., Hayter, A., Aikenhead, A., Allen, E., Uauy, R. (2010). Nutrition related health effects of organic foods: a systematic review. Am J Clin Nutr, 92,203–210. http://ajcn.nutrition.org/content/92/1/203.short
Luc, C., Toepel, K., Irish, R., Fenske, R.A., Barr, D.B., & Bravo, R. (2006). Organic Diets Significantly Lower Children’s Dietary Exposure to Organophosphorus Pesticides. Environ Health Perspect, 114(2), 260–263. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1367841/
Pollan, M. (2009). In Defense of Food: An Eater’s Manifesto. New York: Penguin Press. ISBN: 978-0143114963
Pollan, M. (2006). The Omnivore’s Dilemma: A Natural History of Four Meals. New York: Penguin Press. ISBN: 1594200823