Organic foods offer twice as many antioxidants
Thursday, 26 June 2008
New study finds organic foods offer up to twice as many antioxidants
A new study throws light on just how much healthier organically grown foods are compared to mass produced foods - up to 97 per cent richer in certain antioxidants.
And with more nutrient content by weight, organic foods can provide more health benefits for your money.
The findings, presented today in Rotorua, are based on a 10 year study of tomatoes.
Dr Alyson Mitchell, a food chemist from the University of California, Davis, has led the research, which concludes that organically grown tomatoes have between 79 and 97 per cent higher levels of beneficial antioxidants called flavonoids.
"Consumption of these flavonoids has been linked to reducing rates of heart disease, blood pressure and strokes and forms of cancer and dementia", says Dr Mitchell.
While her research has focused on tomatoes, Dr Mitchell says the findings offer new opportunities for organics in general.
"Food scientists have been looking at organics for a while. Other recent studies have found significantly higher levels of beneficial compounds in organics, but they haven't necessarily been linked to specific agricultural practices. So, the answer to the question 'why' organic foods are healthier has been elusive."
Dr Mitchell says the antioxidants are naturally produced when plants face pest and environmental stress which are more likely in organically grown produce.
Local organics industry leader, Purefresh Organic's General Manager, Ana Aloma says the findings are a bonus for organics in New Zealand.
"We know people are getting more health conscious and this provides a simple way to understand a key benefit of organics. Basically, if growing foods battle the elements, without the help of agrichemicals, their defence systems have to work harder, resulting in plants with a stronger immune system, and the resulting produce is healthier," says Ms Aloma.
"Organics cost a little more but have more nutrients by weight. Interestingly, the higher nutrient content also translates to better taste." Ms Aloma says they have also recognised there is a high level of waste in produce people buy from supermarkets everyday. New Zealand families are throwing away up to 30 per cent of the fresh produce they buy each week. "Paying a bit more for organics means not only higher nutrients by weight but also that people will assign a higher value to that food and will more likely ensure it is eaten. It's a question of quality over quantity."
"Therefore the organics proposition is value for money, better taste, less waste and more healthy nutrients!" she says.
Ms Aloma says the demand for organics is growing in double digit figures in New Zealand as it is worldwide.
Apart from a review published several years ago, no studies have focused on New Zealand organics. Similarly Ms Aloma says this was the first robust study done internationally in this area.
As a well known nutritionist and TV presenter, Nikki Hart MSc, has welcomed the findings of this latest study. She said that until now there has been no evidence-based nutrition information on organic food. It's important however to appreciate that eating a tomato whether organic or conventional is better than not eating a tomato at all - but to now have documentation that organic tomatoes have higher levels of protective antioxidants than conventional tomatoes is very useful with regards to future disease prevention strategies for the general public.
While the study is a plus for organic foods, Dr Mitchell says her work is about improving individual nutrition and health. "I want to apply this work to enhancing understanding of how we can improve the nutritional value of all foods," she says.
Ms Aloma says organic tomatoes were just going out of season but that organic onions, carrots, broccoli, potatoes, apples and kiwifruit are all in season now and locally grown. Purefresh Organic produce is available in selected supermarkets, nationwide.
Dr Mitchell's trip has been funded by the Ministry of Research Science & Technology (MoRST) and Ministry of Foreign Affairs and Trade (MFAT) under the direction of Organics Aotearoa New Zealand (OANZ). This support allows Dr Mitchell to be a guest speaker at the New Zealand Institute of Food Science and Technology Conference, being held in Rotorua, 24-26 June, 2008.
The 10-year study, based at the University of California Davis' Long Term Research on Agriculture Systems project (LTRAS), found:
* The pre-and post-harvest conditions produce was exposed to (including growing conditions, fertiliser and pest control treatment, and soil fertility) affected the levels of natural compounds including beneficial antioxidants * The levels of flavonoids increased over time in samples from organic treatments, whereas the levels of flavonoids did not vary significantly in conventional treatments * Statistically higher levels of flavonoids quercetin and kaempferol in organic tomatoes.
The conference session on organics, which concluded this afternoon, included presentations by Gillian Butler (QualityLowInputFood, UK), Chris Morrison (Phoenix Organics), Jean Margerison (Massey University), Ana Aloma (Purefresh Organic), Andrew Baines (AsureQuality), Michelle Glogau (BioGro NZ), and Derek Broadmore (OANZ).
As part of her presentation, Dr Mitchell also referenced two other studies:
1. A 3-year study comparing levels of ascorbic acid, total phenolics, percentage of soluble solids and the flavonoids quercetin and kaempferol in two varieties of tomatoes grown under defined organic and conventional conditions
2. A recent study comparing levels of ascorbic acid, flavonoids and carotenoids in 10 commercial brands of organic and conventional processed tomato sauce.