Background

Summary of Council decision:

Two issues were investigated, both of which were upheld.

Ad description

A TV ad and website for YorkTest:

a. The TV ad, seen on 29 January 2018, featured a woman described in on-screen text as a “Nutritionist YorkTest Laboratories” standing in a kitchen in front of a range of foods, including pasta, milk, eggs, bread and vegetables. She said, “Do you suffer from migraines, IBS or joint pain? The reason could be something to do with your diet. Food intolerance may occur because our body produces so-called IgG antibodies in reaction to certain foods. And there is an easy way to find out if it could be affecting you.”

On-screen text read “YorkTest define food intolerance as a food-specific IgG reaction. Our information is intended to provide nutritional advice for dietary optimisation. YorkTest do not claim to treat or cure symptoms and recommend that you discuss any medical concerns you have with a GP before undertaking a YorkTest programme.” The ad then showed five consumer testimonials which included claims such as “I feel great, it is the best thing I have ever done taking the York Test. It has really changed my life” and “I was having digestive problems daily. I took the test, I changed my diet, and now I feel amazing”. On-screen text during each testimonial stated the person’s name and their food intolerance, for example “[NAME] Intolerant to beef & brazil nuts”. The woman from the beginning of the ad returned and said, “Simple changes to your diet can make a big difference. So order your YorkTest home to laboratory test now”.

b. The website www.yorktest.com, seen on 8 February 2018, included a pop-up on the home page that covered the whole website which stated “Click the links below to see Testimonials: Digestive Skin Tiredness & Fatigue Weight Migraine & Headaches Joints”. Each condition hyperlinked to relevant testimonials.

The home page contained an embedded video which was the same as ad (a). Text on the home page included claims under the heading “We Care About Your Food Intolerance*” and “Food intolerance tests Expert laboratory testing and analysis.*YorkTest define Food Intolerance as a food-specific IgG reaction.”

Under the heading “Customer Testimonials”, testimonials stated customer names and the health issues they suffered from, and included the claims “Digestive Problems & Bloating […] suffered from re-occurring stomach aches, bloating and frequently needed to rush to the toilet straight after eating. […] Always Tired, Brain Fog & Depression My brain fog and anxiety have disappeared – I finally have my life back”. Under the heading “Our Tests”, products called “IBS Diet Programme” and “Ideal Weight Programme” were listed.

In addition, the home page included a flow chart starting with a box that stated “FirstStep Test-ONLY £24.99 Including FREE delivery. It then branched down to “Negative You do not have food intolerances* There’s no further testing required”. The other branch read “Positive- You have food intolerances*” and then listed products that the consumer could purchase such as “Food&Drink Scan” and “IBS Diet Programme”. At the bottom of the page, text stated “YorkTest define Food Intolerance as a food-specific IgG reaction. Our information is intended to provide nutritional advice for dietary optimisation. YorkTest do not claim to treat or cure symptoms and recommend that you discuss any medical concerns you have with a GP before undertaking a YorkTest programme.”

Issue

The ASA received four complaints, including one from a medical doctor specialising in allergy:

1. One complainant challenged whether the efficacy claims about migraines in both ads and depression in ad (b) were misleading and could be substantiated.

2. Three complainants challenged whether the claim “YorkTest define Food Intolerance as a food-specific IgG reaction”, and the overall impression of both ads that the test would inform consumers if they had a food intolerance, was misleading and could be substantiated.

Response

1. & 2. YorkTest Laboratories Ltd (YorkTest) said that they did not claim that IgG testing identified general and specific food intolerances but that they provided a strategy for an elimination diet based on food-specific IgG testing, which was clearly articulated through their advertising. They said that the statement “YorkTest define Food Intolerance as a food-specific IgG reaction” had been specifically added to the website and other advertising because it was known that there was no one definitive test or definition for “food intolerance”, as the phrase had taken on many different forms. They explained that these forms included coeliac disease, enzyme deficiencies such as lactose intolerance, IgE-mediated allergies, histamine sensitivity and other chemical sensitivities. They stated that the YorkTest food intolerance programme did not provide any information about those or any other conditions. They said that the website also provided clarity about exactly what was and was not being tested. They explained that the website made clear that the information they provided was intended to be nutritional advice for dietary optimisation. They did not claim to treat or cure symptoms and they recommended that consumers speak about medical concerns with their GP before undertaking the program. They said that the YorkTest Nutritional Therapists had chosen to use the YorkTest food-specific IgG antibody test as a strategy for the elimination diets that they recommended. They explained that the presence of food specific IgG antibodies, by nature of the fact that the antibodies could only be formed if a reaction to a food or foods had occurred, indicated that the body had shown a reaction to a particular food or foods. They said many people had circulating levels of IgG antibodies to foods in their blood, but, in order to support their strategy for dietary elimination, YorkTest had defined the cut-off used to determine whether food-specific IgG antibodies were detected as 10 AU (arbitrary units) per millilitre (AU/mL) of blood, with a “borderline” result being defined as 6-10 AU/mL. They explained that the cut-off point of 10 AU was a YorkTest defined cut-off measured in YorkTest Arbitrary Units (AU). That was defined when the test for food-specific IgG antibodies was developed in 1998 and reflected the cut-off above which the specific measurement of food-specific IgG antibodies could be shown to be raised in the blood based on signal to noise ratio. They said that since 1998, many hundreds of thousands of individuals had used YorkTest food-specific IgG tests based on these 14 cut-offs as guidance for an elimination diet. YorkTest held data sets supporting >98% reproducibility between matched split samples. They explained that the YorkTest Food Intolerance Programmes measured food-specific IgG antibodies and that, should a consumer purchase a test, the test results came with further explanation of what had and had not been tested, which included the statement “This is a food and drink intolerance test, not an allergy test.” They further explained that additional information about the test and its limitations were also provided during the Nutritional Therapist consultations.

YorkTest said that the FirstStep initial test was a blood test for food-specific IgG antibodies and that it provided information to tell people whether or not they had raised levels of food-specific IgG antibodies in their blood and did not detail reactions to specific foods. They explained that the further tests available measured antibodies to each of up to 208 specific food ingredients, for example, milk specific IgG, egg white specific IgG antibodies etc. They said that it was only by measuring IgG antibodies specific to each food type that an elimination diet could be defined by the Nutritional Therapist providing the support service. They further explained that it was important to note that whole foods such as milk, wheat, lentils, etc. would contain a number of different component proteins and that each had a variable number of potential antibody forming moieties. For example, the specific antibodies present in each blood sample which was a “milk” positive result would vary between individuals depending on which milk protein or proteins or moieties on each of the proteins had triggered the IgG antibody response. They also explained that similarly the result would depend on the IgG subtypes formed and that YorkTest measured all 4 subtypes.

YorkTest explained that the parameters of specificity and sensitivity, defined by a cut-off, were relevant for a diagnostic test designed to distinguish the difference between, for example, “disease” or “no disease”, or “pregnant” or “not pregnant”. But they said that YorkTest food-specific IgG tests were not diagnostic tests of either food intolerance or food intolerance symptoms. They said that the tests were used as a guide or starting point for an elimination diet and in conjunction with Nutritional Therapist consultations. They said that in order to determine the effectiveness of using the YorkTest food-specific IgG test for a guided elimination diet, survey data had been collected since the launch of the service in 1998. The survey included a wide range of parameters, including the reasons why the YorkTest customer wanted to change their diet, how much benefit, if any, that they felt and how quickly they felt any benefit. They said that in 2007, data from 5,286 subjects were collated and independently audited by the Department of Health Sciences at the University of York and were subsequently published, showing that 76% of those who embarked on a programme said that they felt better. They provided a copy of the survey.

Further, they said a summary of YorkTest’s latest survey data from 2017 showed that 80% of individuals said that they felt better after following a YorkTest programme and changing their diet. They provided a copy of the summary. They stated that surveys from 2018 and 2019 also supported similar levels of benefit. They said that there were randomised controlled trials and other studies that had shown the benefit of food-specific IgG-guided elimination diets in some conditions, and the science and immunology behind these trials and studies supported the approach, however, YorkTest did not claim to treat or cure symptoms or conditions. They explained that many individuals suffered from symptoms as wide ranging as digestive problems, irritable bowel syndrome (IBS), migraines and headaches, fatigue, depression and low mood, and joint pains, which had been associated with “food intolerance”. They said that it was a fact of life that there was often no medical explanation for symptoms such as these and that medically unexplained symptoms accounted for up to a fifth of all GP consultations in the UK. They said their evidence clearly showed that people felt better, regardless of symptoms, when they made supported dietary changes using their programmes.

YorkTest said they had allowed the TV ad to be broadcast, in good faith, after Clearcast approval and review by Clearcast scientific experts. They said they had stopped using the ad as soon as they received a complaint from the ASA. YorkTest said they no longer offered the following testing service brands referred to: “Food&Drink Scan”, “Modern Living FoodScan”, “Food Scan”, “Food Scan Junior”, IBS Diet Programme” and “Ideal Weight Programme”. They said that the “First Step” test, was also no longer offered; YorkTest no longer offered any food-specific IgG guided programmes that had multiple steps. YorkTest submitted a number of studies and articles. Clearcast said that the wording of ad (a) included an explanation of what YorkTest considered a food intolerance to be, clearly stated that they did not claim to treat or cure symptoms and recommended that consumers talk to their GP before undertaking the programme. They further said that the YorkTest definition of food intolerance had been added to the ad in good faith to ensure that there was absolute clarity for the viewer about exactly what was being tested. They said that they agreed with the advertiser’s comments on food intolerance taking different forms and that the ad directed viewers to the YorkTest website which provided further clarity for the viewer about exactly what was and was not being tested. They said that in terms of substantiation of whether a food-specific IgG guided elimination diet could be effective, supporting evidence was provided to Clearcast as part of an ongoing dialogue during the production of the ad. They said it included substantiation regarding the link between diet and IBS, migraines and joint pain.

Assessment

The ASA understood from the NHS Choices website that the NHS considered a food intolerance to be “difficulty digesting certain foods and having an unpleasant physical reaction to them”, and that there currently (at the time the ad was seen) were no blood tests to diagnose food intolerance that were supported by scientific evidence.

We understood that the best way to identify the source of a food intolerance was to eliminate specific foods from the diet and to monitor symptoms. We understood that the full programme offered by the advertiser at the time the ad appeared involved an initial blood test designed to show whether the user had raised levels of immunoglobulin G (IgG), a type of antibody produced by the immune system (though without specifying what was thought to have caused that), followed by an additional test of IgG levels against a range of specific foods, and an elimination diet informed by the results of the second test.

1. Upheld

The blood tests offered by YorkTest were registered as Class I medical devices, sold on a self-declaration basis. A CE certification did not constitute evidence for the purposes of rule 12.1 of the CAP Code, and advertisers were required to hold documentary evidence to support efficacy claims. In their response YorkTest said that the test was not diagnostic and that they did not claim to treat the medical conditions referenced in the ads. However, we considered that consumers would understand the references to migraines and depression in ads (a) and (b) to mean that by taking the tests and following the elimination diet available from YorkTest would alleviate the symptoms of both conditions. For example, in ad (b), one of the testimonials read “Always Tired, Brain Fog & Depression My brain fog and anxiety have disappeared- I finally have my life back”. We considered that consumers would interpret this claim as meaning that by taking a test and following a diet informed by it could act as treatment for depression. We noted that the ad contained text which stated “YorkTest do not claim to treat or cure symptoms and recommend that you discuss any medical concerns you have with a GP before undertaking a YorkTest programme.” However, we considered that this did not counteract the overall impression of the ad that the YorkTest programme could ‘treat’ or alleviate the symptoms and experiences described.

We reviewed the evidence submitted by YorkTest and took expert advice. YorkTest submitted five studies in relation to migraine (a claim that appeared in both ads (a) and (b). A cross-over, double-blinded, randomised controlled trial of a six-week elimination diet versus a six-week provocation diet, following IgG antibody testing, measured the number of headache days and the migraine attack count in 35 participants. The study had a small sample size and moderate to high risk of bias as a result of its design. A mixed-methods study compared levels of IgG antibodies to 108 food allergens in a group of people who had at least monthly migraines that were unresponsive to normal treatments to the levels of IgG in those in an age- and sex-matched healthy control group. That was followed by a six-month open-label uncontrolled trial of an elimination diet. Although the results of the case-control study reported a strong association between food antigens and migraine, the design used was not appropriate to demonstrate causality or food intolerance. In the intervention study, there was a high risk of bias due to the uncontrolled design. A double-blind, cross-over, randomised controlled trial of 21 patients with both migraine and IBS measured the effects of IgG-test-guided elimination diet. The sample size was very small, there was no neutral control (the comparator diet was chosen as a provocation diet, not just a normal diet) and a number of participants were excluded post-randomisation. There was no information about how the intervention was blinded. The authors presented within-group changes rather than between-group comparisons. Though the results tended to favour the intervention group, all these factors put the study at moderate to high risk of bias. A single-blind randomised controlled trial of elimination versus sham diet included volunteers with self-reported migraine-like headaches. The study was funded by YorkTest. Overall, the methodology was considered to be of good quality and at a low risk of bias. However, the results did not demonstrate any impact of testing and elimination diet on the risk of migraines.

An open-label uncontrolled intervention trial involved GP practice patients with migraine. The intervention was a two-month elimination diet informed by a YorkTest IgG test. The study was sponsored by YorkTest. Although the results were consistent with the hypothesis that IgG testing may identify foods that exacerbate migraine in some people, the open, uncontrolled design and large number of drop-outs meant that regression to the mean, attrition bias and placebo effects could not be excluded as the cause of any observed changes. We considered that most of the studies were not of sufficiently robust design and conduct to be able to substantiate the impression given by the ads that testing for IgG, followed by elimination diet, would help to treat or alleviate the symptoms of migraine. YorkTest provided two pieces of evidence in relation to depression (a claim that appeared in ad (b) only). A case-control study compared levels of IgG against 39 food antigens in patients with major depressive disorder (MDD), IBS, and healthy controls. The study suggested a considerable dissimilarity in immune responses against food proteins in people with MDD compared to controls but provided no evidence to support the claim that an elimination diet for the reactive foods identified in IgG testing would be effectives in reducing disease severity. An editorial review by a YorkTest staff member was not a research study and provided no evidence for the health claims made.

We considered that the evidence submitted did not support the impression given by ad (b) that an elimination diet informed by IgG testing would be effective in alleviating symptoms of depression. We concluded that the ads breached the Code.

On that point ad (a) breached BCAP Code rules 3.1 (Misleading advertising), 3.9 (Substantiation) and 11.4 (Medicines, medical devices, treatments and health). On that point ad (b) breached CAP Code (Edition 12) rules 3.1 (Misleading advertising), 3.7 (Substantiation) and 12.1 (Medicines, medical devices, health-related products and beauty products).

2. Upheld

TV ad (a) began with a YorkTest nutritionist listing a number of health conditions that viewers might suffer from and stated that the reason they did could be something to do with their diet. She then said, “Food intolerance may occur because our body produces so-called IgG antibodies in reaction to certain foods. There is an easy way to find out if it could be affecting you.” On-screen text stated, “YorkTest define food intolerance as a food-specific IgG reaction”. Five customers gave testimonials, which included claims such as “Taking the YorkTest has really changed my life” and “I was having digestive problems daily, I took the test, I changed my diet and now I feel amazing”. We considered the testimonials gave the impression that customers had changed their diet following a single test.

The ad concluded with the nutritionist saying “Order your YorkTest home to laboratory test kit now” and a shot of several products, which included names such as “IBS Diet Programme”, “Food Scan”, “Food Scan Junior” and “Modern Living Food Scan”. We considered that the overall impression of ad (a) was that consumers would purchase and take a single test and that the results they received would state if they had had a reaction to a specific food or foods. This would indicate whether or not they had an intolerance to those foods. The definition of a food intolerance used by YorkTest, as stated in ad (a), differed from that of the NHS, and suggested a food intolerance could be identified through testing alone. It was also not clear from the ad that the YorkTest programme actually involved an initial test to determine whether the user had had an (unspecified) IgG reaction, followed by additional, more expensive tests against specific food antibodies, and an elimination diet, in order to receive results that the advertiser believed demonstrated that individual’s specific food intolerances. We therefore considered that the ad was misleading on that basis.

Ad (b), which comprised claims on YorkTest’s own website, included a video that was identical in content to ad (a) under the heading “We Care About Your Food Intolerance”. Further down the page text stated “Take The First Step Today Our FirstStep test is a simple home to laboratory test that gives you a positive or negative result on your food intolerance (defined as a raised level of food specific IgG antibodies)”, which tested against specific foods. Although the page included some further information indicating that the programme featured multiple steps, the impression of the most prominent information at the top of the page, such as the video and the button labelled “take the test”, was the same as that created by TV ad (a) – namely that a single test would indicate whether they had an intolerance to specific foods. As that was not the case, we concluded that the ad was misleading on that basis.

That notwithstanding, we assessed whether the full YorkTest programme (specific food antibody tests and resulting elimination diet) had been substantiated to be able to diagnose specific food intolerances. We took expert advice.

In relation to the studies assessed against the efficacy claims against migraines and depression, we understood that none of the studies submitted were sufficient to establish that the IgG-test-informed elimination diet could identify specific food intolerances, for the reasons laid out at point one. YorkTest had also submitted other studies on participants with different health conditions, which we understood could indicate, theoretically, whether the IgG-guided elimination diet could identify specific food intolerances. We assessed those studies in detail. A randomised controlled trial of 150 patients with IBS divided participants into one group who were given an elimination diet based on their IgG testing, and a control group whose food exclusions were not based on those for which they had raised IgG antibodies according to the test. IBS symptoms were scored on a scale of 0 to 500. At 12 weeks, participants’ scores in the intervention group had reduced by 100 points and in the control group by 61.5 points. Although there were some concerns regarding the adequacy of the blinding and the control, overall it was a well-conducted study that suggested testing IgG antibodies could have a role in helping IBS patients identify candidate foods for elimination, and the approach was worthy of further research.

An open-label, uncontrolled study involved 20 people with IBS who were told to undertake an elimination diet informed by IgG testing. The size and study design were such that it could not act as evidence to demonstrate that testing could help identify specific food intolerances. Placebo effects, regression to the mean, other healing over time, and the effects of other interventions could not be excluded as the causes of any positive changes observed. A case control study testing for IgG antibodies to 14 food antigens in 77 patients with diarrhoea-predominant IBS and 26 healthy controls was followed by an open-label uncontrolled 12-week elimination diet in IBS patients who tested positive. A number of symptoms were measured. The findings were consistent with IgG testing followed by an elimination diet being useful, but the high risk of bias of the uncontrolled study design meant that it was not sufficient to substantiate the claims. An article on the role of IgG-guided elimination diets in IBS, written by a YorkTest staff member, contained no original research and was therefore not applicable to supporting the claims. An open-label uncontrolled trial in 25 patients aimed to evaluate the effect of an exclusion diet based on IgG testing on IBS symptoms. There were large losses to follow-up. The study was consistent with, but did not provide evidence for, the effectiveness of IgG-guided elimination diet in people with IBS. An abstract reported on two studies in people with IBS. Although insufficient detail was provided to make a full assessment, the open-label, uncontrolled design meant it was not possible to know if any reported improvements in symptoms were due to the intervention. A mixed-methods study included a case-control study of food IgG in 79 patients with Crohn’s Disease compared to 20 healthy controls. That was followed by a double-blind cross-over trial using an elimination and sham diet, with 40 participants. There was no wash-out period and plus a high loss to follow-up, meaning there was high risk of bias.

A case-control study compared IgG antibodies of 79 participants with Crohn’s disease and 33 with ulcerative colitis and 266 healthy controls. IgG antibodies were detected in 75.9% of patients with Crohn’s disease, 63.6% of patients with ulcerative colitis and 33.1% of healthy controls. We understood that the study demonstrated that patients with inflammatory bowel disease had substantially more IgG antibodies to food antigens than healthy controls. However, it did not substantiate claims that an IgG-guided elimination diet could identify specific food intolerances.

A study of 145 patients with Crohn’s disease tested participants’ response to common foods using an IgG test. They were randomised into an intervention group, which followed a diet that excluded the four foods with the highest antibody titres, or a sham diet group that excluded the four food types with the lowest antibody titres. Overall it was a well-designed randomised controlled parallel trial, but with a relatively small sample size and high drop-out rate. There were also some reporting discrepancies and post-hoc adjustments for imbalances in baseline values in the questionnaire to achieve statistical significance in the primary outcome, resulting in moderate risk of bias. The trial provided some evidence that IgG testing followed by elimination diet could identify specific food intolerances and improve symptoms in people with Crohn’s disease. However, we understood, in line with the authors’ conclusions, that verification was needed through a large, randomised, controlled trial. A mixed-methods study involved a case-control study of 3.1 patients with inflammatory bowel disease and 178 healthy controls who were tested for food-specific IgG against 14 foods. This was followed by an open-label uncontrolled study of an antibody-based medication in 31 Crohn’s disease patients. Crohn’s disease patients had a significantly higher level of food-specific IgGs than the other two groups. The open-label study was uncontrolled and at a high risk of bias. The evidence was consistent with the claim that IgG testing might identify a food intolerance, but was not sufficient to substantiate it. A case-control study investigated antibodies against a commonly-used yeast in a group of 104 patients with primary Sjogren’s syndrome, compared to 36 healthy controls. It demonstrated that a food-specific antigen occurred in 4.8% of Sjogren’s syndrome patients but not in healthy controls, but provided no evidence that IgG-guided elimination diet could identify specific intolerances or relieve symptoms. A paper on the effect of a diet on body composition and fat distribution was disregarded as it did not relate to IgG testing or food intolerance. A case-control study aimed to investigate the immunological link between gut immunity and rheumatoid arthritis, measuring antibodies to food antigens in 14 rheumatic arthritis patients and 20 healthy controls. There was nothing in the paper to substantiate the idea that IgG testing for food antigens was diagnostic or that an exclusion diet based on IgG reactivity would be helpful for arthritis sufferers.

An open-label uncontrolled intervention trial in 10 patients with primary Sjogren’s syndrome and abdominal symptoms similar to IBS tested participants for food specific IgG, following which they were put on an elimination diet. The small sample size and uncontrolled design put this trial at high risk of bias. Two case reports noted patients improving on elimination diets. Due to the nature of the design they did not provide any evidence to support the claims. A postal survey of people who had taken the YorkTest FoodScan test claimed to be of 5,286 people, however the information needed to determine the response rate, which was vital in order to draw conclusions from surveys, was unclear. However, we did not consider that subjective results from a consumer survey were adequate to support efficacy claims, in the absence of adequate clinical evidence.

Overall, we understood that while many studies were of an inappropriate design to support the claims, some of the evidence from randomised clinical trials supplied in relation to IBS and inflammatory bowel disease provided partial support with respect to the idea that an IgG-guided elimination diet might be able to identify specific food intolerances in people with those particular health conditions. However, that evidence came from two randomised controlled trials featuring a number of issues – for example, poor design or an underpowered sample size. We understood it was important to ensure that inflammatory bowel disease was considered separately as it included well-characterised diseases that required specific medical therapy. Confirmatory research was required to verify the results and they were not, of themselves, sufficient evidence to support advertising claims about the treatment of those conditions. Taking into account the full body of evidence, we concluded that the ads were misleading on that point.

On that point ad (a) breached BCAP Code rules 3.1 (Misleading advertising), 3.9 (Substantiation) and 11.4 (Medicines, medical devices, treatments and health). On that point ad (b) breached CAP Code (Edition 12) rules 3.1 (Misleading advertising), 3.7 (Substantiation) and 12.1 (Medicines, medical devices, health-related products and beauty products).

Action

The ads must not appear again in the formed complained about. We told YorkTest Laboratories Ltd not to state or imply that an elimination diet informed by their testing could help to alleviate symptoms of migraines or depression. We told them to ensure they made the extent of the programme clear and not to imply that consumers would obtain specific results from a single initial test. We also told them to ensure that in future they did not imply that the YorkTest IgG test, whether alone or in combination with further tests and an elimination diet, could diagnose specific food intolerances.