In the run up to and during Dietitians Week 2021, the British Dietetic Association (BDA) has been looking at the complex topic of iodine. They’ve highlighted the importance of addressing sub-optimal iodine intake in some at-risk groups and its consequent health implications.

We welcome this fully and we hope the conversation is wide, with care taken for any subsequent public awareness campaign, in order to avoid any potential unintended consequences.

Here’s our take on the issue…

 

The BDA’s campaign

The BDA’s England Board and the Maternal & Fertility Nutrition Specialist Group recently completed a project to consider the case for wider iodine fortification.

This has now developed into a campaign to increase public awareness of the essential role of iodine in the diet. (It adds further support to Professor Margaret Rayman’s group at the University of Surrey, who have been campaigning for over 10 years to place this serious issue on the UK government’s agenda.)

To date, a key focus of the BDA campaign is on plant-based drinks – giving a strong implied message that the increased consumption of plant-based drinks is the cause of poor iodine status. Their campaign aims to:

  • Promote foods that provide iodine naturally
  • Gain commitment from leading cow’s milk alternative manufacturers to ensure that all cow’s milk alternative products sold in the UK are fortified with iodine equivalent to the amounts available in cows’ milk (25-50µg per 100ml)
  • Promote understanding about the importance for those who switch wholly from cows’ milk to plant-based alternatives

We welcome this and fully support iodine fortification of plant-based drinks to the level that is found in cow’s milk. Milk is the main source of iodine in the UK diet – due to fortification via fodder and equipment sterilisation solutions – so all plant-based drinks should also be fortified with iodine to similar levels found in dairy milk.

It’s a no-brainer. Those following a vegan diet (around one million people in the UK, according to The Vegan Society) and those avoiding fish and/or dairy due to allergy or intolerance will benefit from the fortification.

But it’s not so clear cut as to suggest that adding iodine to plant-based drinks will solve problems of iodine levels in at risk groups in the UK. Additionally, the potential unnecessary and unintended consequence of such communications may be to deter support for moderating dairy intake for environmental reasons. This important concern needs to be incorporated and carefully considered to avoid this situation.

 

Fortifying plant-based milk alternatives will have minimal impact on the nation’s health

Iodine fortification of plant-based drinks will have little or no impact on the nation’s iodine status, because plant-based milk substitutes have not significantly displaced dairy in the UK diet.

  • Aside from those following a vegan diet or those with intolerances, while there has been a significant increase in the popularity of plant-based alternatives (Department of Environment, Food and Rural Affairs, Family Food Datasets), this still only amounts to an average consumption of 69ml plant-based drinks per person per week, versus an average dairy milk intake of 1.840ml per person per week.
  • Market data demonstrates that most consumers of plant-based alternatives also consume dairy. A Dineva, Rayman & Bath 2020 paper identified that just 2.2% of the National Diet and Nutrition Survey (NDNS) population drink plant-based drinks exclusively.

 

Who’s actually at risk of iodine deficiency?

There are some key groups within the population who are at risk of iodine deficiency, notably:

  • Those who avoid dairy and/or fish – either due to a vegan diet, dairy and/or fish allergies or a ‘dislike’ of eating fish
  • Women who are pregnant or young women who may become pregnant
  • Some males, especially those aged 11–18

See The National Diet and Nutrition Survey for detailed data

However, risk to the above female groups and groups isn’t because they don’t drink dairy milk – data shows variable intakes for these groups. Nor is it because they are consuming plant-based drinks that are not fortified with iodine. Rather, it’s because they’re eating an unhealthy diet overall.  Therefore, further consideration is needed for these groups. This is especially true for young and pregnant women, due the potential consequences not only for themselves but also foetal development and children’s subsequent IQ levels.

Registered Dietitian, Ursula Arens says: Iodine supports healthy foetal development, so following general healthy diet messages, especially regular intakes of fish, are especially important for mothers-to-be. For mothers-to-be who cannot, or chose not to eat fish, an iodine-containing supplement (containing not more than 150ug) provides assurance of an adequate intake.

“Most plant-based milks are now fortified with iodine, although not all. Organic versions (and organic milk) contain little. For those choosing organic or for those not achieving a healthy balanced diet, the use of an iodine supplement may need be considered to provide adequate intakes (especially in women before or during pregnancy).”

 

The tension between the iodine campaign and sustainability

The BDA, the UK government and other global organisations are committed to the promotion of sustainable diets. The government healthy eating guidelines, the Eatwell Guide (re-launched in 2016) considers sustainability for the first time alongside nutrition. The ‘dairy and alternatives’ group were almost halved compared to previous recommendations, from 15% down to just 8% of the plate, where unsweetened dairy alternatives were included and recognised as being significantly more sustainable and an ideal replacement, if fortified. Any public health message will need to ensure that this is well understood.

It should also be noted that sustainable farming focuses on grazing cattle, rather than using iodine-fortified fodder. Going forward this will need to be considered, as the more sustainable our farming practices become, the lower the iodine levels of dairy milk will become.

 

What’s the solution?

To address the current iodine concerns of the at risk groups we must give attention to the wider significant impactful changes which must come from the Government. These include:

  • Better credible monitoring of status – current measures via the National Diet and Nutrition Survey do not include the most vulnerable, pregnant women
  • Identifying an effective alternative solution to the World Health Organisation (WHO) Iodised Salt Programme, which the UK has thus far rejected
  • Reviewing the UK Dietary Reference Values to match WHO iodine intake recommendations, especially for women who are pregnant or breast feeding
  • Ensuring iodine advice is incorporated into healthy eating advice and support for the teenage years and, during ante-natal clinics any supplement recommendations to be inclusive of iodine
  • Encourage higher intake of other sources of iodine:
    • Seaweed – Create specific guidance around seaweed consumption in the UK. The iodine content of different seaweed sources is highly variable and there has been concern about the risk of consuming too much iodine. However, other countries such as Japan achieve this. Better labelling and recommendations could be part of the solution
    • Fish – what does a public awareness campaign around eating more sustainable fish look like, and could this be supported by government?
  • However, as these sources are currently more limited and have variable levels of iodine, fortification clearly needs to also be put on the agenda. It is our hope that the BDA will lobby government to take action on Iodine.

 

In summary
  • We fully agree that fortifying plant-based milk alternatives with iodine to the level currently found in dairy milk is important. This will help those avoiding dairy milk and/or fish.
  • But the majority of the UK population aren’t at risk of iodine deficiency. The at-risk groups, including some young and pregnant women, are at risk because they are failing to eat a healthy balanced diet. Fortifying plant-based drinks alone will have little impact on their iodine intakes and status and further consideration needs to be given to how best these groups can be supported. Any awareness campaigns should focus on teenage years and young and pregnant women in particular, and include support for achieving a healthy balanced diet that includes advice for iodine.
  • Any guidance around milk consumption needs to be carefully curated in consideration of planetary concerns, otherwise it may risk putting people off cutting down on dairy for environmental reasons.
  • Significant changes to iodine status in the at-risk groups will need to come from government action and we hope the BDA will be lobbying government on this issue.

 

We’d love to hear your thoughts!

Further information:

Webinar – Iodine deficiency in the UK: who is at risk? with Dr Sarah Bath, University of Surrey

Were iodine headlines scaremongering?, Nutrilicious blog, 2019

BDA Fact sheet on iodine

Iodine deficiency: Britain’s hidden nutrition crisis, Independent Nurse blog, 2018

Effect of inadequate iodine status in UK pregnant women on cognitive outcomes in their children: results from the Avon Longitudinal Study of Parents and Children (ALSPAC) , 2013