Scientists warn changing diets could hit our IQs: 'Iodine deficiency is potentially a rising problem as we move towards plant-based diets'

By Katy Askew

- Last updated on GMT

Iodine deficiency can impair cognitive development / Pic: GettyImages-FarmVeld
Iodine deficiency can impair cognitive development / Pic: GettyImages-FarmVeld

Related tags Iodine Iodine deficiency Cognition brain development

Iodine deficiency is a growing threat - and one that could result in the 'cognitive underperformance of communities at a large scale', scientists warned this week.

We need iodine, a mineral found in some foods, to make thyroid hormones that control the body's metabolism and support proper brain and bone development during infancy. People who don't get enough iodine in their diet cannot make sufficient amounts of thyroid hormone. According to the US National Institute of Health (NIH) this can result in developmental issues including arrested fetal and infant development. Severe iodine deficiency in childhood has harmful effects on brain and nervous system development, and 'mild' iodine deficiency 'might' cause 'subtle problems with neurological development', NIH suggested.

UNICEF data suggests 89% of the global population used salt with 'some iodine' in 2020 - a fact that has been key to the reduction of iodine deficiency disorders (IDDs). However, scientists at the 2nd World Iodine Association (WIA) International conference on Iodine in Food Systems and Health warned, a shift in consumption habits could lead to a resurgence in IDDs with potential 'long-basting impact on brain development in European populations'.

The conference, which opened today in Rotterdam this week, heard that iodine is a critical 'yet largely overlooked' essential nutrient.

"Today, thanks to global awareness-raising campaigns, close to 90% of the world population use iodized salt in their diet. However, this achievement is under threat due to many factures including reduced political awareness and commitment and changes in food consumption patterns,"​ suggested Dr Werner Schultink, Executive Director of the Iodine Global Network.

The significance of this issue, Dr Schultink continued, should not be underestimated. "The cognitive underperformance of communities at a large scale has dramatic consequences on societies,"​ he warned.

Concern raised over plant-based transition

Iodine occurs naturally in seafood, dairy products and eggs. This means that, as more people switch to processed foods without iodized salt or vegan diets, there is concern that more of us won't be getting the amount of iodine we need in our diets.

"Iodine deficiency is potentially a rising problem as we move towards a more plant-based diet since we know that there is less iodine in plant sources,"​ explained Dr Sarah Bath, a lecturer in public health nutrition at the University of Surrey.

"Plant-based food alternatives - like milk alternatives - would benefit from being fortified with iodine to provide vulnerable populations - such as pregnant women, teenagers and young adults - with a source of iodine if they are following a predominately plant-based diet,"​ the public health expert continued.

Agronomic biofortification 'highly effective'

According to Professor Dr Ismail Cakmak, from Sabanici University in Istanbul, the agronomic biofortification of food and feed plants with iodine is a 'highly effective' solution - and one that scientists suggest European policymakers should consider.

"Available published data show that the use of iodine-containing fertilizers is a quick and cost-effective strategy to deliver iodine to food systems,"​ Professor Cakmak suggested. "Such enrichment strategy could be a way forward in reducing IDDs in human populations."

Increased awareness needed in EU policy

The WIA wants to see an increase in awareness among European policy makers of the risks - and potential solutions - related to insufficient iodine intakes. Attilio Caligiani, Director General of the WIA and Partner of Hague Corporate Affairs, noted: “It is crucial that the scientific, medical and patient communities, as well as the industry, agree on a common strategy and jointly advocate in favour of a European policy framework which facilitates the implementation of the various solutions discussed.​"

"We call on further vigilance from European health authorities on this matter,"​ Dr Schultink added.

For Professor Dr MD Henry Völzke, of the University Medicine Greifswald, a multi-stakeholder approach to promote solutions and support education on the prevention if IDDs in Europe is needed. Alliances like EUthyroid, an EU funded project coordinated by Professor Völzke, are working to promote the implementation of a cost-effective and harmonized approach to iodine deficiency prevention in Europe.

"EUthyroid has uncovered important barriers against optimized iodine fortification programs including the low awareness of iodine deficiency-related risks in the general population. As a next step, EUthyroid will fine best practice models for accessing and informing adolescents and young women as high-risk groups about the importance of iodine intake," ​Professor Völzke said. 

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