FACE VALUE
Is the food-skin connection real? And what’s the cost of pursuing a flawless dermis?
While more people are looking to food intolerance testing to resolve their skin issues, dermatologists are warning against them. So, why exactly are they harmful? And does our fixation with the food-skin connection need a reality check?
There are certain things we’ve all heard, repeated and quietly accepted as the truth. You won’t feel the benefit if you leave your coat on inside, a sliver of Stilton at bedtime will fill your sleep with scaries, and dairy is kryptonite for your skin. While we’ll save your outerwear habits and nightmares for another day, the latter claim has been the subject of an intervention by a body with skin in the game.
After two studies that investigated the validity of private food allergy tests were presented at the AGM of the British Association of Dermatologists last September, the organisation issued a warning that such tests may be influencing people to follow unnecessary – and potentially dangerous – dietary restrictions in their quest for healthier skin. In one study, only one of the 18 brands of online allergy tests evaluated were found to use an accredited laboratory, meaning users of the other 17 could be cutting foods out of their diets based on false information. Even if you haven’t bought into this particular trend, we suspect you, too, have made dietary tweaks in the quest for a clearer complexion. But by removing food groups from your diet with your dermis in mind, could you be doing more harm than good?
PLATE EXPECTATIONS
The skin-food connection goes back decades. In the 1960s, researchers – working on the theory that acne sufferers had an impaired tolerance of glucose – were exploring the relationship between chocolate and acne; by the beginning of this century, hormones in milk shifted the focus to dairy; and, not long after, it was sugar once again – specifically, its inflammatory properties – that people were ditching for the sake of their skin. Fast forward to 2021 and social media has made it easier than ever for anyone – qualified or not – to platform their skin-saving solutions. Compound this situation with delays that mean you can now expect to wait a staggering 18 months – as one consultant told WH – to see one of the 700 or so dermatologists working for the NHS, and you can see why more and more people are looking to take matters into their own hands.
Some are doing this by ordering an at-home allergy or intolerance test. Such tests claim to highlight what’s causing your health issue, and happy customers claim that symptoms from bloating to headaches and skin complaints have been cleared up by cutting out foods flagged as problematic. One director of operations at a company that owns some of the UK’S biggest home health testing services told WH that May to September last year were record-breaking months, with September sales alone up more than 130% on the previous year. While many brands won’t go so far as to make specific claims about your skin, with glowing testimonials claiming ‘dramatic improvements’, it’s not hard to see the appeal for those in search of a solution to psoriasis, rosacea, acne or eczema.
So what can – and can’t – they tell you? While some tests promise results for allergies, it’s intolerances – which, unlike allergies, don’t involve your immune system – that are the source of most of the concerns. One of the studies
presented to the British Association of Dermatologists last year found that 70% of the brands evaluated used something called IGG testing for food intolerance, a form of testing that has no scientific evidence to support its validity. ‘With the exception of coeliac disease, where there is a correlation, we think that IGG antibodies are simply part of the normal gut immune response to food,’ says Dr Alexa Shipman, consultant dermatologist at Portsmouth University Hospital and one of the authors of the research. ‘IGG antibodies are present in most people and not related to a disease state – in fact, IGG tests are viewed by the NHS as pointless.’ Another form of testing, used by six of the brands evaluated in the study, is even less credible. Dr Shipman describes ‘bioresonance testing’ – involving the analysis of hair samples – as ‘just nonsense’.
With some labs claiming to test over 800 food groups, this is problematic for reasons beyond wasting your hard-earned cash. What’s led both the dermatology and dietetics communities to intervene in this issue is that if you follow the recommendations of these – possibly false – results, you could end up with an incredibly restrictive diet. When one WH contributor took a test, it told her that, of the 35 foods it tested, she was highly intolerant to 19 of them, and moderately intolerant to 10. Had she taken their advice and followed an elimination diet for three to four weeks, she’d have cut out a list of foods that included cow’s milk, nuts, grains, chicken and eggs. In fact, the only source of complex carbohydrate she was left with was potatoes.
When WH put these recommendations to Renee Mcgregor, a dietitian specialising in sports and eating disorders, she had concerns. ‘I’d worry she’d end up with low energy availability,’ she told us. ‘Particularly carbohydrate availability, which is important for hormone regulation and ensuring she adapts from her training.’ Consequences include increased risk of injury and compromised immunity – and that’s before you consider how ditching dairy ramps up the potential for harm. ‘If you already have inadequate amounts of oestrogen because of low energy availability, your bone health may be compromised,’ adds Mcgregor. ‘Cut out dairy – one of the best sources of calcium – and this becomes increasingly dangerous.’ No chicken or eggs, she adds, opens our contributor up to low levels of vitamin B12, while the lack of grains slashes her access to fibre and vitamins B1 and B6, essential for both thyroid and metabolic function. ‘There’s also a concern that she could become
These likely false results are leading people to restrictive diets
so fixated on following these rules that she develops anxiety over reintroducing these foods that develops into disordered eating or a full-blown eating disorder,’ she adds. This is just one example, of course. But, warns Mcgregor, any time you cut food groups from your diet without the support of a nutrition professional, you run the risk of developing deficiencies that, left unchecked, could cause problems down the line.
FACE FACTS
All this makes for a compelling case for giving at-home tests a wide berth. But it leaves those with skin concerns no closer to finding a solution. So what do we know about the role nutrition can play in treating skincare conditions? ‘It’s very hard to do good scientific research on the relationship between food and diet,’ says Dr Jason Thomson, dermatologist and head of medical at Skin + Me, a company that provides bespoke prescription skincare. ‘To get good quality data, you have to look at a large population and get them to follow a very strict diet or
‘If your cardiologist is happy, your dermatologist will be as well’
remember what they’ve eaten historically – neither of which is easy.’ He points out that it’s true that there’s some research linking dairy, sugar and high-fat diets with acne, with researchers suspecting various factors to be involved. One is the impact of high levels of sugar on gut microbes, since low levels of the latter have been linked with changes to skin barrier function and increased inflammation. Similarly, adds Dr Thomson, spicy food and alcohol appear to be associated with rosacea flare-ups, and there’s some evidence that eczema can be improved by eliminating specific foods when an allergy is suspected. But these links aren’t strong – nor can they tell what triggered the issue – and most academics don’t believe this evidence provides grounds for eliminating these foods from your diet.
If, however, you do suspect that your diet is affecting your skin, or leaving you with other symptoms, there are things you can do. For starters, if you suspect an allergy, it’s important to seek advice from your GP or a private dietitian. Unlike an intolerance, an allergy is accepted by medical professionals as a legitimate medical issue that can be associated with a specific skin complaint, and they range from the serious and potentially fatal anaphylaxis – an immediate reaction to a substance that causes your lips to swell and breathing difficulties – to the delayed onset of symptoms. While you’ll know about it if you’ve experienced the former, it can also be identified via a blood test that looks for a specific antibody – the
IGE antibody – for a specific food. As for the latter, systemic contact dermatitis, where a food – such as tomatoes, citrus or cinnamon – can cause a skin reaction, can happen six to 72 hours after ingestion, and can be diagnosed with a patch test.
As for intolerances, they’re much harder to diagnose. You can test for both lactose and fructose intolerances, but for everything else, there isn’t any way to produce accurate results. Which leaves you... where, exactly? Dr Rajani Katta is a Texas-based dermatologist who’s written extensively on diet and dermatology. She suggests different approaches depending on the issue: for eczema, psoriasis and rosacea, she recommends keeping a food and symptom diary. ‘If you experience a flare-up, look back at the previous 48 hours,’ she says. ‘This should help you identify potential triggers and, after a few weeks, you should start to see a pattern.’
Once you’ve identified a potentially problematic food, you can try avoiding it for about a month and see what happens when you reintroduce it – though it’s worth noting that Mcgregor always recommends consulting a professional before you start cutting out foods, so they can identify any nutritional gaps or a predisposition to disordered eating. For her patients with acne, Dr Katta will tailor a topical treatment plan and then, if they want to make dietary changes, she recommends reducing added sugars (such as those you’d add in when cooking, and those found in sweets, cakes and biscuits) and processed carbs (such as bread, pizza, breakfast cereals and pastries) for three months, noting that while you may see a difference sooner, if you haven’t seen a difference within that timeframe, it’s unlikely that you ever will.
If you’re looking to improve the overall health of your skin, there are steps you can take, too. And since your skin is an organ like any other, what’s good for the rest of your body is good for your dermis; you know, plates piled high with leafy greens, a couple of portions of oily fish per week and eating the antioxidant-rich colour spectrum. As one dermatologist put it: ‘If your cardiologist is happy, your dermatologist will be as well.’ As for at-home testing kits, every medical professional that WH spoke to advised against using any of these types of tests, not least because, as Dr Thomson explains, diet can only ever be part of the puzzle. ‘The health of your skin is affected by so many things: genetics, your environment and, yes, maybe, to some extent, diet, but there’s not one magic bullet.’ If there’s one truth to digest, then quietly accept, it’s this one.