Food colouring - what's all the hype about?
It’s often said “we eat with our eyes” and as such, what we taste is often closely linked to what we see. In fact, colour is believed to be the most important sensory cue when it comes to our expectation around what a specific food will taste like. However, food colouring has also been the subject of much debate, especially around it’s impact on hyperactivity and behaviour. Let’s find out more….
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Why is colour added to food?
Colouring is added to foods for a number of different reasons. It can be added to food to:
Make it more appealing
Bring back the natural colours that may have been lost during food processing
Enhance the natural colours or to make the colour’s more ‘even’
Support the taste and enhancing the flavour perception of a food
Stimulate appetite
What is the difference between natural and synthetic colours?
Food colouring with natural substances has been used since approximately 1500 B.C. Natural food colours (dyes) are generally made from the colours found in plants and minerals. Some common natural sources of food colouring include, lycopene (which gives tomatoes their red colour), anthocyanins (which gives berries their purple colour), turmeric (yellow/gold), carotenoids (the yellow in carrots and pumpkin) and betanin (the red found in beetroot).
In the 1800s, synthetic dyes emerged which were made from petroleum or coal. This sparked the regulation of synthetic food colourings across many countries in the world, to ensure they were safe to use. Over the years, some food colours have been linked to health implications and they have since been banned for use within the New Zealand market. Synthetic (artificial) colours are often cheaper and more stable than their natural dye counterparts.
What are the safe levels of artificial colours?
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All food additives, including food colours, must be assessed for safety by Food Standards Australia New Zealand before they are permitted to be added to our food. Safe levels are determined by calculating the “acceptable daily intake” (ADI). The ADI tells us how much of a specific food additive we can safely eat each day, throughout our life. The ADIs for synthetic colours has been set well below the level that could cause any adverse health effects. For artificial colours, the ADI is 40mg for each kilogram of body weight. Studies have found the average child in New Zealand eats less than 5% of the ADIs for synthetic colours. To exceed the ADI, a 70kg person would need to consume over 4 litres of soft drinks, or over a kilogram of sweets every day.
Food colouring and hyperactivity
The notion that food colouring causes hyperactivity in children, has the same origin as the claims around sugar causing hyperactivity. The Feingold diet, which eliminates artificial colours and flavourings, sweeteners (including sugar) and preservatives, was prescribed by paediatrician Benjamin Feingold, in the 1970s to help alleviate the symptoms of Attention-Deficit/Hyperactivity Disorder (ADHD). However, the Feingold diet has since been largely discredited by the medical profession and researchers, despite continuing to be a popular belief held amongst parents.
The topic of artificial colours and hyperactivity was heavily studied between the 1970s and 1980s, and then again in more recent years. However, studies have produced largely mixed and inconsistent results, mostly as a result of poor study designs. Expert reviews of the research by the European Union (2009/10) and the United States (2011) Food Safety Agencies have both concluded that results from previous studies are inconsistent and that there is no conclusive evidence to support that food colours cause hyperactivity. These findings were also supported by the Joint FAO/WHO Expert Committee on Food Additives (2016).
Despite these expert reports, whether artificial colours have any impact on hyperactivity or children’s behaviour remains a contentious issue. More well-designed trials need to be conducted to accurately determine safety and whether there are any clear links between specific artificial colours and hyperactivity.
While evidence may remain inconsistent about whether artificial colours cause hyperactivity for the majority of people, there are some small groups of the population who may experience an intolerance (rashes, irritable bowel symptoms or headaches) or change in behaviour when specific colours are included in their diet. Changes in behaviour may also occur in a small number (8%) of children who already have ADHD, and who are more sensitive to food colours than their peers.
If you believe your child has a reaction or intolerance to a food colouring, it is best to seek personalised guidance from a Registered Dietitian who specialises in this field.
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Tartrazine (yellow 102, or yellow #5)
Tartrazine is a bright lemon yellow synthetic food colour that has been linked to adverse reactions like asthma, rashes, itching/hives and headaches in a small number of people. However, it should be emphasised that these cases are rare (0.12% in the general population) and usually occur only in people who have other allergies. Tartrazine is one of the colours that is part of the Southampton 6.
The Southampton 6
The ‘Southampton Six’ are six food colours (Tartrazine (102), Quinoline Yellow (104), Sunset Yellow FCF (110), Ponceau 4R (124), Allura Red AC (129) and Carmoisine (122)) that were linked to hyperactivity in children in a study funded by the UK Food Standards Agency in 2007. The study investigated the effect of two mixtures of the food colours, and a preservative (sodium benzoate), on children’s behaviour. The study found that there was “supporting evidence suggesting that certain mixtures of artificial food colours, together with the preservative sodium benzoate, are associated with an increase in hyperactivity in children from the general population”.
A subsequent review by the EFSA, which included the evidence from the Southampton study, concluded that the available evidence did not indicate a causal link between exposure to the colours and effects on behaviour. However, in a precautionary approach, the EFSA does now require that all products containing any of the Southampton six colours, must clearly be labelled with the following statement: “may have an adverse effect on activity and attention in children”. In addition, the ADIs for three of the Southampton Six colours (E104, E124 and E110) have subsequently been lowered by EFSA.
In addition to the EFSA review, the FDA (2011) also reviewed the evidence and found that there was still no evidence to support a link between food colouring causing hyperactivity.
Do I need to avoid all food numbers?
All food ingredients used in New Zealand have been approved as safe for use. While we do need to focus most of what we eat around whole and less-processed foods (most of which won’t have any food numbers on their label), we do not need to avoid foods with numbers listed in the ingredients list all together. Food numbers can be used for both natural and artificial additives. For example, turmeric is 100, beet red is 162 and blackcurrant extract 163.If you would like to avoid artificial colours, most products will clearly state whether they contain only natural food colouring (or ‘no artificial colours’) on the front of the pack. However, even natural additives can cause an issue for some people.
If you or your child are sensitive to food colouring it is recommended that you consult with your GP and a Registered Dietititian for additional help and guidance.