Consumers are increasingly concerned about the effects of herbicides, pesticides, fertilizers, and growth-promoting hormones that are found in food. Organic food, which is grown and produced differently to food produced in conventional methods, is thought to contain fewer additives and contaminants and is also considered to be more environmentally friendly.
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The main characteristics that differentiate organic farming from conventional farming are:
- Weed, disease and pest control through crop rotations
- Relying on natural predators for pest control
- Organic manuring
- Minimal reliance on biological and chemical interventions
Nutritional differences between organic and conventional foods
Expectations around the health benefits of organic food are among the strongest motivations for consumers to buy organic produce. There are some studies that show lower levels of nitrates in organic food when compared with conventionally produced food.
As nitrates have been associated with higher risks of developing gastrointestinal cancer and methemoglobinemia in children (a blood disorder where red blood cells contain levels of methemoglobin that are higher than 1%), it is obvious why consuming fewer nitrates is attractive for consumers.
In addition, the KOALA Birth Cohort Study in the Netherlands, which included approximately 2700 newborn children, found links between lower eczema rates in children at 2 years of age and the consumption of organic dairy products.
Vitamin C, also known as ascorbic acid, is responsible for helping to protect and keep cells happy, as well as aiding the healing of wounds and maintaining healthy hair, skin, bones, cartilage and blood vessels. Higher levels of vitamin C have been reported in organic fruits and leafy vegetables like spinach, lettuce, and chard.
Higher levels of carotenoids have been reported in organic sweet peppers, yellow plums, tomatoes, and carrots. However, studies in this area have produced inconsistent results, possibly due to differences in the soil types and fertilizers and pesticides being analyzed, which are thought to have an effect on carotenoid levels.
Carotenoids function as a type of antioxidant that can prevent disease and aid the immune system. Some carotenoids can also be converted into vitamin A, which is essential in growth, the enhanced function of the immune system and overall eye health.
Levels of phenolic compounds have been shown to be higher in organic food. Phenolic compounds have antioxidant, antimutagenic, anti-inflammatory and anticarcinogenic properties. The consumption of polyphenols through fruit and vegetables has been linked to a lower incidence of coronary heart disease, and reduces oxidative stress.
A number of polyphenols have been identified for their protective effect on certain cancers including:
- Mouth cancer
- Stomach cancer
- Colon cancer
- Duodenum cancer
- Liver cancer
- Lung cancer
- Cancer of the mammary glands
- Skin cancer
Some commonly identified polyphenols include:
- Ellagic acid
- Red wine polyphenols
While these polyphenols have all been shown to have protective effect on cancer, the way in which they do this is different. Some mechanisms include antiproliferative effects on tumor cells, the induction of cell cycle arrest during apoptosis, the prevention of oxidation and the induction of detoxification enzymes, regulating the immune system, and anti-inflammatory activity.
Health risks of pesticides in conventional food
Pesticide residues are contaminants that are known to have genotoxic, carcinogenic, neurodestructive, endocrine and allergenic effects. The levels of pesticide residue are generally higher in conventionally produced food. There is evidence showing that exposure to organophosphates, which make up around 50% of the active agent in most commercial pesticides, is lower in diets consisting of organic produce.
While organic food has been shown to expose consumers to less harmful pesticides, studies concerning the health benefits of organic food versus conventionally produced food often produce conflicting results. This can have a variety of reasons including the method of crop fertilization and the amount of fertilizers used, the scale of pesticide use, plant age at the time of harvesting and even weather conditions.
The bioavailability of beneficial nutrients in organic and conventionally produced food can also be affected by factors unrelated to their status as organic or non-organic. Dietary studies are also subject to great variability, since factors such as crop varieties or animal breeds may differ significantly between cohorts of participants in nutritional studies.
All of these can affect the results of the study. As a whole, more research needs to be done to identify the health effects of consuming organic produce over conventionally produced food with greater accuracy. It should be remembered that there are many other factors that can affect a person’s overall wellbeing.