Agar
A natural gelling agent extracted from red seaweed, used to set desserts, jellies and dairy alternatives instead of animal gelatine.
What is it?
Agar (also called agar-agar) is a polysaccharide mixture extracted from the cell walls of certain red algae, mainly species of Gelidium and Gracilaria. It consists primarily of agarose and agaropectin. Harvested seaweed is boiled, the extract filtered, and the resulting gel dried into flakes, strips or powder. It has been used as a food ingredient in Southeast Asia for centuries.
What does it do?
Agar absorbs water and forms a firm, stable gel at concentrations as low as 1%. It sets at around 32-40 degrees Celsius and melts at around 85 degrees Celsius, which means agar gels hold their shape at room temperature and do not melt in the hand the way gelatine does. It is not digested by human digestive enzymes and passes through the gut largely intact, functioning as a soluble dietary fibre.
Where you will see it
Dessert jellies, fruit gels, confectionery, jam and marmalade as an alternative setter, dairy-free cheese and yogurt alternatives, ice cream and frozen desserts to prevent ice crystal formation, canned meat and fish in aspic-style products, and some pharmaceutical capsules and microbiological growth media. On a UK label it appears as 'agar', 'agar-agar' or 'E406'.
What the science says
Digestibility and gut transit
Agar is not broken down by human digestive enzymes and reaches the large intestine largely intact, where it is partially fermented by gut bacteria. This means it contributes bulk to stool and shortens transit time at higher intakes. Some studies using high supplemental doses have noted laxative effects, but these doses far exceed what is present in food.
Agar is resistant to human salivary and pancreatic amylase and passes into the colon, where partial fermentation by colonic bacteria produces short-chain fatty acids.
At high supplemental doses (around 180g per day in one older Japanese study), agar consumption was associated with weight loss and reduced blood glucose in overweight adults with type 2 diabetes, attributed to its bulking and satiety effects rather than any pharmacological action.
Allergenicity and sensitivity
Agar is derived from seaweed, not from common allergenic plants or animals. Documented allergic reactions to agar in food are rare. Occupational sensitisation has been reported in people who handle large quantities of dried agar powder, but this is not a food-exposure concern for consumers.
No evidence of systemic allergenic potential in the general population has been identified from dietary exposure to agar at levels used in food.
Acceptable daily intake and toxicology
EFSA reviewed agar in 2016 and concluded that no numerical acceptable daily intake was needed. The panel found no toxicological concern at the levels used in food. Agar has a long history of use as a food ingredient and no carcinogenicity, genotoxicity or reproductive toxicity has been identified.
The EFSA ANS Panel concluded there is no safety concern for the general population at refined exposure estimates for agar used as a food additive, and that no numerical ADI was necessary.
Where it stands with the regulators
Who should be careful
No specific population group needs to avoid agar on safety grounds. People with known hypersensitivity to red algae products should check for 'agar' or 'E406' on labels. Very high supplemental doses can act as a laxative, which is not relevant to food additive levels.
The honest read
Agar has been used in food preparation for several centuries, first in Japan and later across Asia and Europe. It sits firmly in the category of food ingredients with a long track record: regulators in the UK, EU and US have all reviewed it and found nothing to restrict. The 2016 EFSA re-evaluation, which is the most recent systematic regulatory review, did not identify toxicological concerns and did not set an intake limit. The science on agar at food-additive doses is not a live debate.
Related additives
Common questions
Is E406 banned in the UK?
No. Agar is approved for use in the UK under the FSA's approved additives list and the assimilated EU Regulation 1333/2008. It is one of the most widely authorised gelling agents in UK and EU food law.
Does agar affect digestion?
At the amounts present in food, agar passes through the gut largely undigested and acts as a soluble fibre. Very high doses taken as a supplement can have a laxative effect, but this is not relevant to the quantities used as a food additive.
What foods contain E406?
Agar appears in dessert jellies, fruit gels, some jams and confectionery, dairy-free cheese and yogurt alternatives, ice creams, and canned aspic products. It is also used in food supplements. Look for 'agar', 'agar-agar' or 'E406' in the ingredients list.
Is E406 vegan?
Yes. Agar is extracted from red seaweed with no animal-derived ingredients. It is widely used as a vegan and vegetarian substitute for gelatine, which is made from animal collagen.
Sources
- EFSA ANS Panel: Re-evaluation of agar (E 406) as a food additive, EFSA Journal 2016
- UK FSA: Approved additives and E numbers
- Commission Regulation (EU) No 231/2012 laying down specifications for food additives
- Maeda et al.: Agar consumption and body weight, blood glucose in obese diabetic patients, Diabetes, Obesity and Metabolism
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