Extract from The Organic Advantage (BFA Newsletter) Ed 101 - 12th May 2008.

Newly compiled evidence supports the claim of nutritional superiority of plant-based organic foods.

Collated into one dense document on the evidence of the benefits of organic, the US Organic Centre's State of Science Review: Nutritional Superiority of Organic Food, published March 2008, summarises 97 studies, including 40 new studies, from the past six years - all proof that organic foods have a higher comparative nutritional value to conventional.

The team heading up the review used cross-study comparison to evaluate and link differences in the nutrient content of organic and non-organic food over time. 

They reported organically grown plant-based foods deliver more essential nutrients per calories consumed.

Organic plant-based foods were 25% more nutrient-dense than conventional alternatives in 75% of matched pair comparisons between organic and non-organic items.

"Organic foods within matched pairs were nutritionally superior (in the majority of cases). Organic plant-based foods are, on average, more nutritious" stated the reports key findings.

Nutrient density measures covered antioxidant capacity, total polyphenols and two key flavonoids - quercetin and kaempferol.

Polyphenols - a type of antioxidant - have been linked in recent research to the prevention of cardiovascular diseases, cancers, and osteoporosis with a suggested role in the prevention of neurodegenerative diseases and diabetes mellitus.

Quercetin, found most commonly as a compound in the red and orange pigments in vegetables and fruits (for example in the skin of red apples or in red onions), is a highly active flavonoid which has been connected with significant anti-inflammatory activity through the manufacture and release of histamines. Its intake may be recommended as a means to counter-balance allergic and asthmatic symptoms.

Kaempferol is a natural flavonoid isolated from tea, broccoli, witch-hazel, grapefruit and other plant sources associated with reduced risk of heart disease. 

In 2006 a US study linked kaempferol and quercetin from strawberries with the potential to combat cancer cells, specifically leukaemia (Zunino, 2006).

Report co-author and Organic Centre's chief scientist Dr. Benbrook says the typical American diet delivers barely half the recommended levels of these health-promoting nutrients, a figure likely to be similarly represented in other western orientated diets such as Australia. 

The Australian Government's 2003 adult dietary recommendations recognise the possible conferred benefits of substances found in plant materials - including polyphenols and flavonoids - and recommends eating a wide variety of foods "particularly plant foods"  in part because of this.

The guide stated that generally the diets of older Australians are more varied than younger groups, with males living alone eating significantly fewer food groups per day. 

Organic Centre board member, Andrew Weil says the research summary provides a welcome answer to the question "Are organic foods more nutritious?", replacing previous ambivalent and vague responses from nutritionists and agricultural scientists.

"There is now overwhelming new evidence that organic fruits and vegetables deliver more nutrients per average serving" he said.

According to the report the number of relevant organic food nutrient measurement studies has doubled since 2000, with improved sensitivity in research analysis.

"Most studies in the 1980s focused simply on mineral and vitamin levels, while almost all studies published since 2000 include measures of minerals, vitamins, and health-promoting polyphenols and total antioxidant capacity".

"Organic samples contained higher concentrations of the very important polyphenols and antioxidants. Increasing intakes of these nutrients is a vital goal to improving public health since daily intakes are currently less than one half of recommended levels," stated the report.

It also found that the major factors impacting nutrient density in terms of production are plant genetics, the method of timing and harvest (especially ripeness), climate, and after harvest handling.

"How a harvested crop is handled after it leaves the field has an enormous impact on the degree to which the nutrients in the crop at harvest remain in the food when it is eaten".

To view the original report go to http://gillesarbour.wordpress.com/2008/04/15/