The Mediterranean diet can provide many health benefits, but you may risk consuming too many environmental pollutants. A new study shows that organically produced food could be the answer.
Many people swear by the Mediterranean diet, which includes eating plenty of fruits, vegetables, whole grains, nuts, legumes, and fish, along with a little wine. Another advantage is that this diet contains only small amounts of saturated fats from dairy products and red meat.
But a new study by scientists at the University of Oslo and universities in other countries has made a surprising discovery: study participants who lived on a Mediterranean diet containing normally grown food ate three times more environmental pollutants. Compared to when they were eating normal Western food.
Professor Per Ole Iversen from the Department of Nutrition at the University of Oslo participated in the study, along with project director Carlo Levert, a visiting professor at the University of Oslo. According to Iversen, one of the study’s major strengths is that it took into account several factors. The participants were divided into two groups: one ate a Mediterranean diet based on organically grown foods, while the other ate a Mediterranean diet based only on organically grown foods. Before and after the period in which they kept the Mediterranean diet, the participants all ate their usual diet.
In the group living on a Mediterranean diet based on organically grown foods, the level of environmental pollutants was reduced by 90% compared to the group following a Mediterranean diet with foods grown the normal way, Iversen says.
Environmental pollutants can affect hormones in the body
The researchers tested the participants’ urine and examined what contaminants were in the food they ate.
Leifert, an assistant professor at Southern Cross University in Australia and a visiting professor at the Chinese Academy of Agricultural Sciences, reveals that many of the environmental pollutants they found are known or suspected to affect hormones in the body. There is mounting evidence that such toxins can impair our immune system and possibly also fertility. If the hormones become unbalanced, it can also have a negative effect on the growth and development of children.
Traditionally grown fruits, vegetables and whole grains are some of the main sources of environmental pollutants absorbed by our diet. Because the Mediterranean diet relies on such foods, those who ate them ate 10 times more of these pollutants than if their diet were based on organically grown foods, Levert explains.
Both farmed and wild fish can contain environmental pollutants, but usually in small amounts.
No warning from the Mediterranean diet
However, scientists weren’t about to issue a warning against living on a Mediterranean diet devoid of organically grown foods. As Iversen explained, the study is not very large and they have not yet been able to monitor the long-term health effects of such a diet.
For those who eat a non-organic Mediterranean diet, we don’t yet know what will be most decisive in the long run: eating better and healthier nutrients than if they were eating a traditional northern European diet, or absorbing more environmental pollutants. The professor says we will have to wait for the results of research studies in larger numbers of the population.
Our ingestion of environmental pollutants also comes from other sources such as the air we breathe and through cosmetics such as skin creams. This study did not adjust its results to account for these factors.
But it is unlikely that the two groups in our study differed regarding the two factors mentioned above because of the way the study was designed, Iverson believes.
For now, the University of Oslo scientist says they will continue to promote official dietary guidelines.
A new study on 200 pregnant women
With support from the University of Oslo and the ICPO Foundation, Iversen and fellow researchers will study 150 to 200 pregnant women in Norway. One group will eat organic food until the birth of their child, while the other will eat “as usual”. Both groups are recommended to follow the National Dietary Guidelines for pregnant women. Iversen and his research team will then test for environmental pollutants in the participants’ blood, urine and faeces.
We are eager to see if the first group that eats organic food will have lower levels of environmental pollutants. We will also test children’s urine with this in mind. In addition, participants will be followed up over a subsequent period of two years.”
Professor Per Ole Iversen, Department of Nutrition, University of Oslo
University of Oslo, Faculty of Medicine
Rempelos, L., et al. (2021) Diet and food type influence urinary pesticide residue excretion profiles in healthy individuals: results of the randomized controlled dietary intervention trial. American Journal of Clinical Nutrition. doi.org/10.1093/ajcn/nqab308.