Drug interactions diet - iodine - low

Aim

To provide a diet low in iodine (<50µg/day) to promote maximal uptake of radioiodine (131I) for diagnosis and/or treatment of thyroid cancer.

Characteristics

Severely reduces iodine derived from food, avoids soy foods (due to the potential for interaction with radioiodine uptake), and avoids the following additives:

• Red 3/Erythrosine/Erythrosine Red/Erythrosine cherry red/E127 (127) – a red food colouring commonly found in glacé cherries
• Alginate/E401-405 (401-405) – a food thickener and emulsifier that may be within ice-cream, fruit and vegetable juices, and milk beverages
• Agar/E406 (406) – a food thickener that may be within soups, sauces, jams, ice-cream, and custard/puddings
• Carageenen/Carageenan gum/vegetable gum 407/ E407 (407) – a food thickener that may be within jelly and dairy products.

Where is iodine found in food?

• Foods sourced from the ocean, e.g. fish and seaweed
• Iodine-fortified foods, e.g. iodised salt and bread
• Milk and eggs – iodine is added to animal (cow and chicken) feed and is contained within some cleaning agents that may be used by the dairy industry
• Soy products – can interfere with the uptake of iodine into thyroid cells
• Some food crops – due to iodine in the soil
• Food additives derived from sources of iodine (as described above).
  
  It is not necessary to remove all traces of milk, soy or egg from the diet. That is, products labelled as ‘may contain traces of milk/soy/egg’ are suitable for inclusion if they are otherwise considered a low iodine food.

Where appropriate, clinicians may consider ordering this diet for patients:

• undergoing radioiodine treatment (ablation) for thyroid cancer
• requiring radioiodine as a diagnostic tool for thyroid cancer.

Nutritional adequacy

This diet is not nutritionally adequate - it is intended to be utilised for short-term use only.

Precautions

It is not possible to provide a full list of all permitted commercial products; the following are general guidelines only. Care should be taken to read all product ingredient lists to look for iodine within ingredients. If ‘salt’ is listed as an ingredient, it should be clarified with the manufacturer whether it is iodised.

This diet requires supervision by a dietitian if utilised >21 days.

To stay within the 50ug limit, it is important to adhere to course code maximums. In addition, this diet should not be combined with a ‘large’ or double serve/serving size without Dietitian consultation.

Paediatrics

Not suitable for use in paediatrics.

Specific menu planning guidelines

	Allowed (but check label)	Not allowed
Hot main dishes	Plain cooked beef, lamb, pork, poultry, bacon Mixed dishes containing allowed ingredients Legumes	All fish, shellfish, crustaceans or seaweed, including fish sauce, oyster sauce, fish stock and shrimp paste Dishes containing eggs or milk/cheese (e.g. quiche, frittata, omelette, risotto) Ham, corned beef, salami, sausages Crumbed meats, fish and poultry Soy products e.g. tofu, textured vegetable protein
Sauces, gravies	Sauces and gravies made without milk or soy ingredients, maximum serve size 40ml. Tomato sauce and barbecue sauce (limited to 1 tablespoon/day)	Milk or cream base sauce, e.g. white sauce, cheese sauce, bearnaise sauce, tartare sauce
Starchy vegetables / pasta / rice	Plain rice, pasta, couscous, quinoa, rice noodles Plain potato or sweet potato, steamed, boiled or roasted	Potato/pasta/rice with added milk or soy Egg noodles
Vegetables	Plain boiled/steamed or roasted vegetable, such as carrots, broccoli, cauliflower, etc.	Plain or boiled/steamed green beans or vegetable mixes containing green beans Edamame Vegetables and vegetable dishes served with milk or cream based sauces e.g. white sauce, cheese sauce, etc.
Soups	Clear broth made without soy or fish ingredients	Milk or cream based soups Fish, seafood or seaweed soups Croutons Meat extracts
Sandwiches	None
Salads, dressings	Salad using allowed ingredients Salad dressing	Egg, cheese or fish containing salad Mayonnaise
Breads, cereals	Plain rice/corn or wheat crackers/crispbreads/cakes Rolled oats made with water Rice cereal made with water Flakes of corn Puffed rice Wheat biscuits Natural muesli without bran	All bread and bread products, including gluten free (e.g. wraps, flat bread, rolls, buns, English muffins, crumpets, bagels, brioche, fruit bread) All other cereals Seaweed flavour rice crackers
Spreads	Margarine without soy ingredients Jam, regular Honey Marmalade, regular Vegemite	Butter and clarified butter (ghee) Peanut or nut butters
Hot breakfast choices	Baked beans Spaghetti	All eggs and egg based dishes Pancakes
Fruit	All other fresh, canned (inclusive of juice) or dried fruit	Processed fruits containing erythrosine (e.g. Maraschino cherries) Processed fruit salad containing cherries
Yoghurt	None	-
Desserts	Jelly (gelatine based) Sorbet	Ice-cream, cream All milk or soy-based puddings and desserts Cakes, pastries and crumbles containing milk, butter or egg
Milk and cheese	Rice, oat, coconut or almond milk: 150ml at breakfast, and within tea/coffee	Cow/goat/sheep milk or soy milk, including low lactose/lactose free milk products Cow/goat/sheep cheese or soy cheese
Beverages	Tea (black, green, herbal) and coffee Apple juice (limit of 300ml/day) Orange juice Lemonade, cola	Cow/goat/sheep milk or soy milk, including low lactose/lactose free milk products
Biscuits	Plain rice/corn or wheat crackers/crispbreads/cakes	Biscuits containing milk, butter or egg
Miscellaneous	Non-iodised salt, pepper, herbs and spices Vinegar Lemon wedge Sugar and artificial sweeteners Nuts Marshmallow Dark chocolate containing >60% cocoa solids (limit to less than 100g per day) Lollies, jelly & boiled Oil Muesli bar without chocolate or yoghurt Potato crisps, plain salted Sugar, artificial sweetener	Iodised salt Oral nutrition supplements or enteral formulae containing milk or soy ingredients Chocolate (milk, white) Cream Mayonnaise Cakes containing milk, butter or egg Soy crisps/crackers Flavoured potato crisps, e.g. salt & vinegar, cheese Corn chips (all) Soy sauce Vitamin and mineral supplements containing iodine

References

1. Dietitians Association of Australia. Nutrition manual. 9th ed. Canberra: DAA; 2014.
2. Food Standards Australia New Zealand, 2018. NUTTAB 2018 Online Searchable Database. Foods that Contain Iodine (I).
3. Food Standards Australia New Zealand, 2018. AUSNUT 2011-13 food nutrient database.
4. Food Standards Australia New Zealand, 2018. Food Additives- Alphabetical List (updated 2016).
5. Predebon Morsch E, Vanacor R, Furlanetto TW & Schmid H, 2011, ‘Two weeks of a low-iodine diet are equivalent to 3 weeks for lowering urinary iodine and increasing radioactive iodine uptake’, Thyroid, vol. 21, no. 1, pp. 61-7.

Change log

November 2020

Section updated	Change
Specific menu planning guidelines - Milk and Cheese	In Allowed, added oat, coconut or almond milk