A new study has indicated there could be correlation between organically grown foods and lower rates of cancer.
The research, published by JAMA Internal Medicine in late-October, was part of the French NutriNet-Sante study, which included almost 70,000 volunteers who were free of cancer.
At the beginning of the study, each participants’ diet was assessed based on the French nutritional guidelines and their food and drink consumption recorded in three 24-hour snapshots over two weeks.
Two months into the study, the participants were asked to provide specific information about their consumption of 16 categories of organically labelled foods.
This included fruits, vegetables, soy-based products, dairy products, meat and fish.
The participants were then given an organic food score. If they chose organically produced foods in all 16 categories, they would get a maximum score of 32.
The health of each participant was assessed each year and monitored for a median period of 4.5 years.
When any cases of cancer occurred, details were independently confirmed with the individual’s hospital or treating physician.
The participants’ organic food scores ranged from 0.7 to 19.4. These were used to divide the group into equal quartiles.
The overall cancer risk was 25 per cent lower in those who had the highest organic food score.
Cancers showing the greatest correlation with decreased risk were breast cancer – especially in postmenopausal women, and lymphomas – especially non-Hodgkin’s lymphoma.
No correlation appeared with prostate or colorectal cancers, although the relatively short time frame would have made any change unlikely.
But, while there was a correlation between eating organic foods and lower rates of cancer, it doesn’t necessarily mean one caused the other.
People who choose organic foods are likely to be healthier, wealthier and better educated, all factors known to impact risk of cancer, the study explains.
Researchers note that this is the first study of its kind so the findings need to be confirmed in other studies before organic food can be proposed as a preventive strategy against cancer.
However, past research has found that higher intakes of fruit, vegetables and wholegrains – however they are grown – and lower intakes of processed and red meats can decrease the risk of cancer.
As previous studies with this group had shown people who choose organically grown products tend to have higher income, higher levels of education and healthier diets.
So the researchers adjusted for these factors.
They also made adjustments for other factors that could affect the outcome, such as age, sex, the month the participants were included in the program, marital status, physical activity, smoking status, alcohol intake, family history of cancer, body mass index, height, energy intake, and the intake of dietary fibre and also red and processed meat.
For women (who made up 78 per cent of the study group), they also adjusted for the number of children they had, oral contraception use, postmenopausal status and use of hormonal treatment for menopause.
In 2015, the International Agency for Research on Cancer classified some pesticides as “probably carcinogenic to humans”.
This means there is limited evidence of a link between pesticide use and cancer in humans, but sufficient evidence of a link between pesticide use and cancer in experimental animal studies.