Recent research conducted by the University of Barcelona in Spain discovered thatorganic tomatoes contain higher levels of antioxidants in the form of phenolic compounds than do tomatoes grown with pesticides.
When the scientists examined the situation further, they discovered that it had mostly to do with the development of the plant's 'immune system'. Without pesticides and nitrogenous fertilizers, plants must mobilize their own defence mechanisms
and, when activated, these defence systems increase levels of all phenolic compounds, which ultimately raise the antioxidant content of the plant.
"The more stress plants suffer, the more polyphenols they produce," says Rosa Lamuela, the head researcher.
Polyphenols, which are natural plant-based antioxidants, have sparked a great deal of interest as their high consumption is asso-ciated with a reduced risk of cardiovascular and generative diseases, including certain cancers. Tomato plants are rich in such polyphenols as flavonones, flavonols, hydroxycinnamic acids, carotenoids and fatty-acid derivatives.
Using a special system combining liquid chromatography with mass spectrometry, the University of Barcelona researchers were able to accurately assess the level of available phenolic compounds available to individuals who ate the tomatoes. In total, the researchers discovered 34 different phenolic compounds in the organic tomatoes studied (J Agric Food Chem, 2012; 60: 4542-9).
The researchers, who comprise the university's Natural Antioxidant Group, decided to study organic tomatoes after finding higher levels of phenolic compounds in organic tomato juice and organic ketchup than in ordinary non-organic varieties. Because the process of producing ketchup and juice are known to lower levels of phenols present in the fruit, the researchers wished to study whether the higher levels of phenolic compounds found in these tomatoes had anything to do with an absence of pesticides or whether another factor was responsible.
In fact, the study clearly demonstrated that the higher phenolic content had solely to do with the plant being allowed to experience the 'stress' of fending off insects, bacteria, fungi and other invaders. This, in turn, essentially made for healthier-and more health-giving-plants.
The Spanish scientists' discovery is supported by other research by the University of California at Davis showing that levels of flavonoids increase over time in organic tomatoes, but remain static in tomatoes grown with fertilizers. Furthermore, the researchers discovered, the higher the level of organic matter in the soil and lower the amount of fertilizer, the larger the number of nutrients in the plants (J Agric Food Chem, 2007; 55: 6154-9).
Together, these studies show that a certain amount of exposure to all living matter and potential threats in a full-bodied soil only strengthens an organism and increases its nutritional benefit. The longer a tomato is left to grow naturally and fend for itself, the healthier it becomes.
This suggests that with plants, as with humans, whatever doesn't kill you makes you stronger. It also offers strong support for a plant version of the so-called 'hygiene hypothesis'.
This theory was developed by epidemiologist David Strachan of the London School of Hygiene and Tropical Medicine after noticing that children with a large number of siblings who were exposed to greater amounts of dirt, animals, bacteria and infections tended to have a lower incidence of eczema (BMJ, 1989; 299: 1259-60).
Strachan came to believe that early exposure to infections enabled the young immune system to develop and flex its muscles, and so develop greater strength to fight off disease as the child grew.
As other evidence shows, vaccination supposedly to protect babies and children from disease tends to overstimulate the immune system, leaving a child more prone to allergies and autoimmune diseases such as eczema, diabetes, ulcerative colitis, multiple sclerosis and irritable bowel syndrome. For instance, it's been shown that children given the whooping-cough (pertussis) jab are more likely to develop allergies (Thorax, 1998; 53: 927-32).
A similar situation occurs with antibiotics, which also prevent the body from mounting its own strong immune defence (Clin Exp Allergy, 2000; 30: 1548-53).
Conversely, the greater the child's exposure to a number of illnesses, such as measles, the less likely he is to have eczema (Lancet, 1996; 347: 1792-6). Children exposed to more dirt and animals, more dust and
less constant handwashing or bacterial 'decontamination' also suffer from fewer allergies.
Indeed, exposure to a wide variety of infections early on in a child's life appears to act as a powerful kickstart to the immune system, ultimately creating a robust defence against disease.
The evidence in both humans and plants suggests that living organisms attain full health and the ability to prevent disease only by being repeatedly challenged early on. By preempting that process, whether through vaccina-tion, early intervention with antibiotics, excessive washing and pesticides, we are inadvertently interfering with and possibly destroying good health.
This latest finding is even more sobering when you consider the latest report by the Environmental Working Group (EWG), which just published its latest survey of pesticides in non-organic foods.
EWG researchers found pesti-cide residues-including chemi-cals banned for use in agricul-ture-in some 68 per cent of the food they sampled. Of particular concern were the organophos-phates and other pesticide residues found in baby food that are known to interfere with brain development.
In the EWG's 2012 Shopper's Guide to Pesticides in Produce (www.ewg.org/foodnews/), which exposes the 'Dirty Dozen', the very worst offenders topping the list were apples, followed (in order) by celery, peppers, peaches, strawberries, nectarines, grapes, spinach, lettuce and cucumber.
The 'Clean 15'-those fruits and vegetables with the least amount of chemicals-included onions, sweetcorn, pineapple, avocado, cabbage, sweet peas, asparagus, mango, aubergine and kiwi fruit.
Although green beans, collard greens and kale didn't make it into the Dirty Dozen category, they did show evidence of
high levels of organophosphate insecticides, known to be toxic to the nervous system. And although they have been mostly removed from agriculture in the last 12 years, they aren't strictly banned and are still found in some crops of food.
This latest connection showing the need of plants to be stressed and the subsequent beneficial effect on a plant's nutrients is a tough counterpoint to the many recent claims by news organizations that it's not necessary to eat organic.
Factfile: The secret life of plants
According to the Soil Association, the most important determinant of human health in farming is a healthy soil. Soil is a living thing that requires other lifeforms-from earthworms and beetles to fungi and bacteria-to provide all the food, air and water necessary for healthy plant growth.
A plant's nutrition derives from a wide variety of minerals from the earth as well as from dead plants and tiny animals. The plant depends on insects and organisms, such as bacteria that live in the soil, to convert the raw nutrients in soil into a form that can be used by the plant. The plant, in turn, feeds these tiny animals by secreting sugars and enzymes into the soil.
The more minerals and other nutrients available in the soil, the more nourishing it is for the plant, and the more nutrition is ultimately available for the animals and humans who consume it. In addition to polluting food, artificial fertilizers interfere with this symbiotic process by killing much of the diverse life in the soil necessary for the healthy life of plants.
Instead, organic farming concentrates on providing healthy soil by:
- prohibiting artificial chemical fertilizers
- adding organic compost or manure, and pulling nitrogen from the atmosphere by growing clover
- allowing fallow periods so that the soil can recover
- severely restricting pesticides and relying on animal life to control pests
- growing a diversity of crops on the farm and rotating them over several seasons, a method known to break pest cycles and enhance soil fertility
- banning genetically modified (GM) crops and ingredients.