Organic food

I see some problems with this study.

I know some people believe organic food is more nutritional.
But I'm sure I'm not alone is buying organic food for other reasons:
1. Reducing chemical pollution in the environment
2. Reducing exposure to harmful chemicals in the food I eat, which might cause long-term damage to health
3. Reducing soil degradation

Unexpectedly, after several months of eating mostly organic food I started feeling better.

I note that they acknowledge finding small nutritional differences, but assume they are not large enough to make a difference. The did not try to compare the actual health of peope who eat or do not eat a large percentage of organic food. Of course, it would be harder to do this, because of uncertainties in what proportion of one's diet was organic, and other factors. Eg., since organic food is more expensive, I would expect that people who eat a lot of organic would be better off financially, on average, and thus tend to be healthier for reasons other than eating organic. And if they found that people who ate organically were healthier, they wouldn't know if it were just because they were less exposed to poisons, or if there were a nutritional effect.

I would say the important thing is not whether or not there are nutritional differences in organic food, but whether there are health differences, from whatever cause. I would find a study of animals raised on organic or non-organic food to be much more relevant.

And the general news sites headlines and sometimes lead sentences are claiming this study proves organic food is no "healthier", which is of course is false, since as I pointed out, there are other aspects of organic food that could affect health.

http://www.eurekalert.org/pub_releases/2009-07/lsoh-of072909.php

Public release date: 29-Jul-2009
Contact: Gemma Howe
London School of Hygiene & Tropical Medicine
Organic food not nutritionally better than conventionally produced food
Systematic review of literature over 50 years finds no evidence for superior nutritional content of organic produce

There is no evidence that organically produced foods are nutritionally superior to conventionally produced foodstuffs, according to a study published today in The American Journal of Clinical Nutrition.

Consumers appear willing to pay higher prices for organic foods based on their perceived health and nutrition benefits, and the global organic food market was estimated in 2007 to be worth £29 billion (£2 billion in the UK alone). Some previous reviews have concluded that organically produced food has a superior nutrient composition to conventional food, but there has to-date been no systematic review of the available published literature.

Researchers from the London School of Hygiene & Tropical Medicine have now completed the most extensive systematic review of the available published literature on nutrient content of organic food ever conducted. The review focussed on nutritional content and did not include a review of the content of contaminants or chemical residues in foods from different agricultural production regimens.

Over 50,000 papers were searched, and a total of 162 relevant articles were identified that were published over a fifty-year period up to 29 February 2008 and compared the nutrient content of organically and conventionally produced foodstuffs. To ensure methodological rigour the quality of each article was assessed. To be graded as satisfactory quality, the studies had to provide information on the organic certification scheme from which the foodstuffs were derived, the cultivar of crop or breed of livestock analysed, the nutrient or other nutritionally relevant substance assessed, the laboratory analytical methods used, and the methods used for statistical analysis. 55 of the identified papers were of satisfactory quality, and analysis was conducted comparing the content in organically and conventionally produced foods of the 13 most commonly reported nutrient categories.

The researchers found organically and conventionally produced foods to be comparable in their nutrient content. For 10 out of the 13 nutrient categories analysed, there were no significant differences between production methods in nutrient content. Differences that were detected were most likely to be due to differences in fertilizer use (nitrogen, phosphorus), and ripeness at harvest (acidity), and it is unlikely that consuming these nutrients at the levels reported in organic foods would provide any health benefit.

Alan Dangour, of the London School of Hygiene & Tropical Medicine's Nutrition and Public Health Intervention Research Unit, and one of the report's authors, comments: 'A small number of differences in nutrient content were found to exist between organically and conventionally produced foodstuffs, but these are unlikely to be of any public health relevance. Our review indicates that there is currently no evidence to support the selection of organically over conventionally produced foods on the basis of nutritional superiority. Research in this area would benefit from greater scientific rigour and a better understanding of the various factors that determine the nutrient content of foodstuffs'.