'Organic' milk is poorer in iodine than conventional milk

July 4, 2013, Plataforma SINC
Organic farming animals depend on the mineral content in soil. / Meneer Zjeroen

Milk from organic farms has a lower concentration of elements like zinc, iodine and selenium than milk produced by conventional farming methods. The discrepancy is due to the absence of mineral substances in the diets of the cows reared. According to researchers, animals on organic farms should have their diets supplemented with natural sources of iodine such as seaweed, because it is a very important element for children and pregnant women.

The concentration of nutrients in animal food products is linked to the diets of the animals reared. Conventional production methods provide mineral diet supplements, while in animals depend on the in soil, which may not be sufficient.

For this reason, researchers at the University of Santiago de Compostela compared the mineral and of organic and conventional milk taken from over thirty farms located in the northeast of the Iberian Peninsula.

The results demonstrated that mineral element content in is low compared with conventional milk, although no differences were found in the quantity of such as cadmium, which were also detected in very low concentrations.

"Levels of the elements that are typically supplemented in the diets of livestock in conventional systems – particularly iodine, copper, selenium and zinc – are higher than those found in organic milk," Marta López, researcher at the University of Santiago de Compostela and co-author of the study, explains to SINC.

In the researcher's opinion, the fact that organic milk contains lower levels of elements such as copper and zinc is not a problem because milk is not the primary source of these elements in our diets.

"Iodine is another matter," López goes on to clarify. "The contribution of iodine to our diets in countries like Spain is covered by iodised salt; in other countries, like England, with milk. In Spain the lack of sufficient iodine in some kinds of milk is especially relevant for children, due to the importance of iodine in neurological development, but also to people with diets low in salt."

Iodine is necessary for the metabolism, especially during pregnancy and infancy. Iodine deficiency can cause scurvy, which has historically been a big problem the world over, particularly in populations at a distance from the coast, who did not eat much fish, and so milk and its derivatives were the primary source of iodine.

Seaweed as an alternative source

Nevertheless, according to López, the most relevant aspect of the study is that it brings this limitation to light and enables organic production to be improved. "There are of iodine that can be incorporated into the diet. We are trialling the use of as a source of iodine and have had good results," she affirms.

In addition, the scientists found that mineral content is higher in winter, which is when dietary supplementation is greater, as a result of the reduced availability of grass.

In any case, although one might draw the conclusion that conventional milk is more nutritious in terms of minerals, López is cautious: "Organic milk may have lower content of certain minerals, but it has other properties that are much more beneficial than those of conventional milk."

Explore further: Iodine in bread not enough for pregnant women

More information: F. Rey-Crespo, M. Miranda, M. López-Alonso. "Essential trace and toxic element concentrations in organic and conventionalmilk in NW Spain". Food and Chemical Toxicology 55 (2013) 513–518

Related Stories

Iodine in bread not enough for pregnant women

June 18, 2013
(Medical Xpress)—New research from the University of Adelaide shows that iodised salt used in bread is not enough to provide healthy levels of iodine for pregnant women and their unborn children.

Mild iodine deficiency in womb associated with lower scores on children's literacy tests

April 30, 2013
–Children who did not receive enough iodine in the womb performed worse on literacy tests as 9-year-olds than their peers, according to a recent study accepted for publication in The Endocrine Society's Journal of Clinical ...

Iodine deficiency during pregnancy may adversely affect children's mental development

May 21, 2013
A study of around 1,000 UK mothers and their children, published in The Lancet, has revealed that iodine deficiency in pregnancy may have an adverse effect on children's mental development. The research raises concerns that ...

Researchers urge awareness of dietary iodine intake in postpartum Korean-American women

July 12, 2011
Researchers at Boston University School of Medicine (BUSM) have brought attention to the potential health impacts for Korean and Korean-American women and their infants from consuming brown seaweed soup. Seaweed is a known ...

Recommended for you

Who uses phone apps to track sleep habits? Mostly the healthy and wealthy in US

January 16, 2018
The profile of most Americans who use popular mobile phone apps that track sleep habits is that they are relatively affluent, claim to eat well, and say they are in good health, even if some of them tend to smoke.

Improvements in mortality rates are slowed by rise in obesity in the United States

January 15, 2018
With countless medical advances and efforts to curb smoking, one might expect that life expectancy in the United States would improve. Yet according to recent studies, there's been a reduction in the rate of improvement in ...

Teens likely to crave junk food after watching TV ads

January 15, 2018
Teenagers who watch more than three hours of commercial TV a day are more likely to eat hundreds of extra junk food snacks, according to a report by Cancer Research UK.

Can muesli help against arthritis?

January 15, 2018
It is well known that healthy eating increases a general sense of wellbeing. Researchers at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have now discovered that a fibre-rich diet can have a positive influence ...

Your dishwasher is not as sterile as you think

January 13, 2018
(HealthDay)—Your dishwasher may get those plates spotless, but it is also probably teeming with bacteria and fungus, a new study suggests.

Study reveals what sleep talkers have to say

January 12, 2018
A team of researchers with members from several institutions in France has conducted a study regarding sleep talking and has found that most sleep talking is not only negative in nature, but involves a large amount of swearing. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.