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[SANET-MG] organic foods enhance human health



April 12, 2006
Prof. Joe Cummins
Organic Foods Enhance Human Health
The following review focuses on scientific studies that have been published after 2000. The review will focus on information related to the health consequences of consuming organic food and will not deal with the many reports on people’s preferences and beliefs about organic foods. However, the growth in demand for organic food is driven by people’s beliefs about the benefits of organic food and the fact that organic foods generally taste better than conventional foods. The general reviews comparing organic and conventional foods focus on comparisons of gross composition of organic foods as compared to the gross composition of conventional foods. Those studies show that organic foods contain low to undetectable levels of pesticides, lower level of nitrates and levels of microbial toxins about the same as conventional foods. However, those reviews have not yet dealt with comprehensive data on the health of those consuming organic foods in comparison to those consuming conventional food. The current review will deal with evidence that organic foods are richer in cancer fighting secondary metabolites, on evidence that lower pesticide levels are beneficial and on evidence that microbial toxins are not substantially elevated in organic food as has been claimed by those opposing organic food. New studies showing that organic strawberry extracts inhibit growth of cancer cells are a landmark in scientific research, showing that organic food provides a defense against cancer. Two recent reviews from Harokopio Universty, Athens Greece have been skeptical of about the value of organic food in comparison to conventional food. The most consistent difference was the low level of nitrate and elevated vitamin C levels in organic as compared to conventional food. Numerous other measurements such as mycotoxin level or environmental pollutants were not different in the two types of food. Even though pesticide levels were much higher in convetional foods than in organic food those elevated pesticide levels were deemed acceptable (1,2) Christine Williams of Reading University,UK pointed out that there are no studies in the literature of controlled intervention studies of humans subjects and comparison of people habitually consuming organic as compared to conventional diets are flawed by confounding factors. Older animal studies are poorly designed and give conflicting results (3). The above reviews failed to consider the importance of health promoting secondary metabolites that accumulate once synthetic plant protection agents are eliminated. Bengt Lundegardh and Anna Martensson of the University of Agricultural Sciences , Uppsala , Sweden stressed the benefits of organic culture in (a) an activation of the plant defence mechanisms by excluding synthetic plant protection agents, (b) an active soil life where plants and microbes interact, exchanging certain metabolic compounds and (c) a balanced mineral nutrient uptake where excesses of easily available nutrients are avoided (4). Bioactive compounds in foods, especially the plant phenolic antioxidants, are well known to prevent cancer and cardiovascular disease.(5).Of course, phenolics are present in many crops , particularly fruits, but it has grown very clear that organic foods are richer in cancer fighting antoxidants (6,7). Strawberries have been studied extensively for their cancer fighting ability and those berries have also been used to emphasize the cancer preventing advantages of organic fruit cultivation. Extracts of five organic and conventional cultivars were compared for their ability to inhibit proliferation of human colon and breast cancer cells. The anti-cancer extracts were rich in vitamin C and plant phenolics , the extracts from organically grown strawberries had a higher antipropiferative activity than the conventionally grown berries for both breast and coloncancer cells (8). Compost as a soil supplement increases the level of antioxidant compounds in strawberries (9). Strawberry extracts were found to interfered with mitogen-activated protein kinase (MAPK) signaling cascade and to suppress cancer cell proliferation and transformation (10).Organic yellow plums were found to were found to be richer in phenolic acids when grown on natural meadow or with a ground cover of clover than conventional plums (11). Plum and clover extracts induced apoptosis and contributed to reduced cell viability in human liver cancer cells (12). Rats fed conventionally grown wheat had a higher risk for lymphocyte function than did organically grown wheat. Lymphocyte proliferation represented an animals response to toxicity (13,14). A number of recent studies show that there is solid scientific basis for the theory that organic culture practices produce crops that prevent cancer and modulate toxic responses. Along with the benefits of organic culture in providing secondary metabolites that are beneficial to humans the absence of pesticide residues in food and feed provides a tangible benefit from organic food. The “green revolution” has provided a high level of food production in developing countries through the deployment of high levels of pesticide and fertilizers. Investigators with the Centre for Rural Development and Technology , Dehli, India studied residues of organochlorine, organophosphorous, carbamate and pyrethroid pesticides in conventionally grown wheat and rice and found that organic wheat and rice and little or no detectable pesticide. Wheat and rice production under conventional system was higher than organic but this higher production is at the cost of health risk and also poses other hazards to flora and fauna(15). Dietary exposure intake is the major source of pesticide exposure for infants and children in the United States, this exposure may account for increased pesticide related health risks in children compared to adults. Direct controlled experiments showed that children consuming an organic diet provided dramatic and immediate protective effect against organophosphorous pesticide exposure (16). In Denmark a 1999 study on human sperm and semen quality in relation to dietary pesticide exposure and organic diet was published. A group consuming mainly organic food were estimated to have a reduced pesticide intake based on the pestide levels measured in their food. The authors of the article concluded pesticide intake in the diet did not entail a risk of impaired semen quality (17). However, the article reported that the group of men without organic food intake had a significantly lower proportion of morphologically normal sperm. Abnormal sperm is normally considered predictive of pregnancy outcome representing DNA damaged or defectively packaged DNA in the abnormal sperm (18,19). It is not clear why the significantly damaged sperm did not impair semen quality in the opinion of the Danish investigators. Mycotoxins are toxic metabolites produced by fungi. Mycotoxin poisoning has been known since the beginning of agriculture and has taken a large toll on humans and farm animals consuming contaminated crops. Mycotoxins cause immunological effects, specific organ damage, cancer, and in some cases, death. Agricultural workers may also suffer from skin and respiratory exposure during crop harvest and storage. Mycotoxin poisoning is a worldwide problem associated with maize, rice, tree nuts and peanuts along with fresh fruits and vegetables. Recently, pro-GM scientists in academia and biotech corporations have been claiming that organic food and feed is more heavily contaminated with mycotoxins than conventional and genetically modified foods, on grounds that organic production does not use chemical fungicides, and are hence more likely to be infected. But the United Nations Food and Agriculture Organization (FAO) states that, "studies have not shown that consuming organic products leads to a greater risk of mycotoxin contamination." Peer reviewed publications showed that organic foods are not more hazardous sources of mycotoxin than conventional foods (20). Recently the terms nutrigenomics and nutrigenetics have been coined to probe the relationship between genes and diet. With that approach the diet will be personalized (21). Presently, in organic agriculture , nutrigenomics and nutrigenetics are probably not as valuable to farmer as would a couple of tones of horse manure compost. Nevertheless, the breakthroughs associated with the discovery that organic strawberry extracts inhibit cancer cell growth through identifiable pathways show that organic agriculture provides science based health benefits.

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