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Programme 2. - Food Allergies and Intolerance
RADIO 4
THURSDAY 08/03/07 1500-1530
PRESENTER:
BARBARA MYERS
CONTRIBUTORS:
PAMELA EWAN
PRODUCER:
PAMELA RUTHERFORD
NOT CHECKED AS BROADCAST
MYERS
Hello. Some people can and do eat anything. For others the kitchen can be a minefield - full of foodstuffs that make you feel ill, bloated or nauseous at best or can at worse be life threatening. At least two million people in this country are estimated to have true food allergies - to nuts, eggs, fish or even fruit, the very thing we're being encouraged to eat more of. Millions more people experience symptoms of food intolerance - a sensitivity to foods - which make them feel very uncomfortable; bread and dairy are two examples often quoted. And the problem seems to be growing; experts are talking about an allergy epidemic. So what can we do about it? Cutting out suspect ingredients seems like a common sense solution but you may end up excluding harmless foods and leaving yourself, or perhaps more crucially, your children with a poor diet. Young children are most at risk from food allergies, is that because of what we feed them as babies? If you're unsure what to do for yourself or for a member of the family please call us now and put your questions to an allergy expert. She's Dr Pamela Ewan from Addenbrookes Hospital in Cambridge. The number here is 08700 100 444 and that is the number that Emma has called, she's in Oxford and has had an anaphylactic episode. That's serious isn't it Emma?
EMMA
Well yes it was but at the time I didn't realise, I had no knowledge of anaphylaxis. It happened 18 years ago and my lips swelled up, my airways swelled up, my tongue swelled up but as I said I didn't know what was happening to me and therefore I didn't panic. And the symptoms did go away gradually but it's only sort of five years after that that I realised what had happened to me and how serious it was.
MYERS
And what had you eaten that caused that?
EMMA
I'd eaten a mangetout snow pea raw, a very common food but it affected me that day and I'll never forget it.
MYERS
Can I just bring Pamela in first, just to comment on this business of anaphylactic shock because if we get nothing other across to people we should emphasise that if you have that response to a certain food it can be very serious, it is life threatening.
EWAN
Oh yes it is and Emma describes a very typical reaction. What happens with food allergies when they're severe is that you get swelling up in the mouth, back of the throat and airway and it can cause extremely serious breathing difficulty. The severity varies but in some people it can be life threatening. They can also develop very severe asthma. So they may need very urgent treatment in the emergency department.
MYERS
So Emma, obviously you got over that, where are you up to now - do you avoid mangetout and any other foods at all costs?
EMMA
I do avoid mangetout but I have to say I have eaten some that have been cooked and I have allergies - certain allergies that I know of to raw peanuts with husks on, peanuts that have been cooked, salted peanuts are fine, kiwi fruit's a suspect, hairy fruits and also recently I've noticed, since I've been peeling potatoes, the fumes from the potatoes have started off a very mild asthmatic reaction and I wear gloves because I come up in hives on my hands. So I'm interested to know what is causing that.
MYERS
And I gather you've got children now so you're perhaps a bit concerned about their outlook, whether they're going to also develop these allergies?
EMMA
Yes my children are three and nearly two and I'm just concerned as to when to introduce things like peanuts and also I do watch what I give them but they haven't shown any symptoms so far.
EWAN
Well Emma's described her allergies to a whole variety of foods, some of which are related and she's getting some quite unusual allergies, which is the trend now - we're seeing unusual things like peas, mangetout, potatoes even, causing allergy. In terms of the children - that's a difficult one to answer - I think basically she should just continue with a normal sensible diet for her children. There is a slightly increased risk of allergy in a child if one parent has allergies, then the risk is slightly bigger if both parents have allergies, but it's still relatively small, so I think she should proceed with a normal diet for her child.
MYERS
Thanks for your call Emma, just to pick up on that idea of these somewhat exotic fruits, perhaps kiwi fruits and even mangetout for that matter, are we responding to these because they're not familiar to us in our diet, would that make us more sensitive to them?
EWAN
Well it seems to be the introduction of a whole range of new foods, particularly in young people, including young children, that has shown a big change in allergy and this is probably one factor in the changing environment that is responsible for the increase in allergies.
MYERS
And you are indeed one of the specialists who talks about an allergy epidemic - you really do feel that's what we're going through?
EWAN
Oh I think there's very good evidence, epidemiological evidence, to show that yes and food is the latest component of this - it was asthma, eczema, hay fever before, these have gone up hugely, now we're seeing a massive rise in food. And there are very good statistics, for example, hospital admissions have gone up 500% for food allergy.
MYERS
Let's go to another caller - Sarah Gough is waiting to speak to us, concerned because her daughter has had a reaction to nut. What's happened Sarah?
GOUGH
Well she's always tried nuts in the past as her older sisters have but recently she picked up a Brazil nut and she didn't even bite into it, she just spat it out immediately and she got very upset because her tongue swelled up and her throat was hurting her but after about an hour or two hours it went down. And I was just wondering whether I should get her tested?
EWAN
Well absolutely, I mean it sounds as if she is allergic to Brazil nuts, these are very typical symptoms and Brazil nut allergy can be severe, so I think you certainly should see your doctor and she should certainly be tested and there are ways of handling this if she is Brazil nut allergic but you need good advice on how to do this, how to avoid nuts and the appropriate medicines to have available in case of mistakenly eating Brazil nut in the future, perhaps in something, so that you can treat reactions promptly.
GOUGH
Okay.
MYERS
Thanks for that. I mean there is obviously a problem with nuts which are included in processed foods and so you're not always aware of what's actually in there. Food labelling has got rather better but perhaps needs to get even better.
EWAN
Food labelling has improved massively in recent years. The Food Standards Agency have done a lot of work on this, so it is better and it's easier for patients but it still can be very difficult and nuts are a particularly difficult one because they're hidden in things you would never expect - you can have Brazil nut in lemon meringue pie, you would never expect to have to look out for it there. So patients have to be really well educated, understand how to read labels, know the high risk areas and they can usually do really well. But we know that if you are just given the advice - just avoid nuts - there's a very high risk of further reactions and every one to two years patients will be having repeat reactions.
MYERS
We have an e-mail from Claire who says that her son has a nut allergy, they discovered it when he was six and they gave him peanut butter for the first time. The question though is, like a lot of mums, she's now blaming herself and wondering if it's something she's done, like, for example, using certain creams on him when he was a baby, could there be any connection?
EWAN
Well I don't think she should blame herself because this is an area where the answer is not yet clear but there has been a lot of interest in how children become sensitised, in other words allergic, to nuts because quite a lot of children react when first given nuts to eat and so it seems they've been sensitised earlier. And one of the theories at the moment is this maybe through skin creams, including treatments for eczema, which can contain nut oils.
MYERS
Can be absorbed through the skin?
EWAN
Yes. Now this is still the subject of research as to whether tiny, tiny quantities of nut allergen, nut protein, in these creams can be absorbed, could trigger the child to make harmful allergic antibody to nuts and hence then produce symptoms when the nuts are eaten. But she certainly shouldn't blame herself and this is still the subject of research and we really need to know the results of these trials until we know the answer.
MYERS
In fact the e-mail goes on - she's wondering if it's not that, might she have caused problems because she sterilised his bottles and his equipment when he was a baby?
EWAN
Well again of course she should have sterilised the feeding equipment but that raises an interesting question which is the role of infection generally and in relation to the huge increase in allergy. And we think - well we know allergy comes around about because of a combination of genetic susceptibility and environmental exposure and one of the big changes in our environment in the last 30-40 years is change in infection. And so perhaps having less exposure to infection is harmful and may be one of the components that's led to a lot of allergy.
MYERS
A subject for debate there. But let's go on to another caller - Jan McKeller in Cheshire who admits to being 50 and has developed an allergy at that age to what exactly?
MCKELLER
Oh yes hello. Apple peel, plum skin and hazelnuts. I've always eaten lots of fruit and nuts and I've been fine but just this last year my tongue and soft pallet and lips and gums they swell within seconds and they're very itchy. And if I don't rinse my mouth out with water straightaway and spit it out I go piggy eyed and swollen nose and it starts running.
MYERS
Oh goodness me and apples and plums are very traditional foods, so that's very worrying isn't it.
MCKELLER
Yes. I wondered if it was something that was put on the peel in the shops but I've noticed that carnauba wax I can eat that because I have eaten that on a well known confection with that on it.
EWAN
Can I ask you some questions Jan? Do you have hay fever in the spring time?
MCKELLER
Yes I do actually.
EWAN
Okay, well I think what you've got is a condition we doctors call oral allergy syndrome, which - and there's a link between the hay fever and the reaction you're getting to these fruits. And this is now becoming quite a common problem. But there are proteins in apples which are similar to a protein in pollen and in that way you react to both. I should think you would find that if you had cooked these apples you would be able to eat them - is that right?
MCKELLER
Yes I'm fine. I'm also fine if I peel it.
EWAN
Really, so you can eat the raw flesh but not the peel with a bit of flesh underneath?
MCKELLER
That's right yes.
EWAN
Well that is quite unusual but it may be because the protein you're reacting to is more concentrated under the peel.
MCKELLER
Could I just ask? Is it normal to develop allergies at my time of life when I've never really been allergic to much and will it go on, will I just start developing more food allergies?
EWAN
That's a very interesting question. I mean allergy traditionally has been - food allergy - has been particularly in children and younger adults, we are now seeing people at almost any age developing allergies, we are quite excited in our clinic when we see a 75 year old coming up with cashew nut allergy for the first time, that would have been very unusual in the past. So I think it seems that people are responding almost at any age but it's still more common in younger adults and children.
MYERS
Thanks for that call. We've got e-mails about fruit allergies, obviously really is quite widespread, but Lucy's saying that her husband has developed an allergy to fruit, fine though if the fruits are cooked and Susan says that it's okay if they're canned, she can cope with them. And Emily says well she's only okay with apples that are steamed but she points out that eating a steamed apple isn't exactly a convenience snack.
EWAN
Well this is because when these fruits are cooked or processed - canned - the proteins which cause the allergy are denatured, and so the fruit in that form is no longer capable of inducing allergy. So these patients unfortunately cannot eat a fresh apple but certainly could eat a well cooked apple.
MYERS
To the calls again. Sonia in Hertfordshire wondering about what the difference is between intolerance and allergy. Do you have problems with food Sonia?
SONIA
Yes, when I was young I had violent stomach pains when I ate mushrooms. Since then I've added to the list - avocado pear and stilton cheese, unfortunately I used to eat pounds of that, but they've had the same effect. Now as long as I don't eat those three things I'm fine but I was interested to hear one of your listeners say will I continue to get more and I'm just wondering is the list going to grow and what is the difference between food intolerance and allergy? And if I may ask one more question: my younger son, who really does have allergies, nearly died when he ate kiwi fruit, his windpipe just closed up totally and if he hadn't had the right kind of medication I think he would probably have died?
MYERS
That by the way is the second reference to kiwi fruits, which is a shame because they're extremely high in vitamin C I think and rather tasty.
SONIA
Exactly.
EWAN
Yes well kiwi fruits are becoming much more common as a cause of true allergy. But if I can go back to Sonia's starting point. The difference between intolerance and allergy is really in two ways: first of all the mechanism, the way the reaction comes about and in allergy what happens is the patient makes a harmful allergic antibody, so it's an antibody mediated reaction. In intolerance this allergic antibody is not involved, so the mechanism is a different one.
MYERS
And you can test for that, you can see that on tests?
EWAN
We can test for food allergy, food intolerance is much more difficult because the mechanism sometimes is known and may be testable but in the majority of cases is not understood and cannot be tested, so the only way you can diagnose that intolerance is by removing and reintroducing the food and looking at the effect on the symptoms. The other difference between intolerance and allergy is in the symptoms they tend to produce and food allergy has very distinct symptoms - we've heard some of them from earlier callers, these severe reactions in the mouth, throat, airway, rashes, sometimes collapse. So they're very typical quick onset, potentially severe, reactions. Food intolerance is a more grumbling slow thing, not usually so severe, tends to cause tummy problems - bloating, diarrhoea, nausea sometimes. Now Sonia describes certain foods which might actually be able to cause allergy or intolerance, so I can't tell from what she's saying which one's she's got but avocado is one of the new causes of true allergy. So without testing it's rather difficult to disentangle, she may have intolerance but I can't be sure.
SONIA
How did they start when for years, as I said, I ate loads of stilton and suddenly it was by a process of elimination, cutting it out, that I realised that was one of the causes?
EWAN
Well in the case of true allergy it starts because you generate this harmful antibody, in intolerance presumably whatever mechanism is involved has become active or some disregulation of normal physiological processes has occurred.
MYERS
Pam, am I right in thinking that although we know a lot and you know a lot more than most there's still quite a lot that we don't know about this whole subject of allergy?
EWAN
Yes, yes there is, it's enormous and even just taking food allergy, it's a huge subject, yes and we really lack a lot of information.
MYERS
And we lack a lot of experts, that is to say there are not nearly enough, if we're going to be perhaps advising people that they should get a test or perhaps want to go for a specialist opinion.
EWAN
We absolutely do, I mean we know there are huge numbers with allergy, the two million is the minimum estimate, it's probably substantially more. And for this problem, some of which is mild but a lot of which is severe, we have a handful of specialists in the NHS. So the NHS really has not caught up with the allergy problem. And patients have a real difficulty, as many of the callers probably have, you go to your GP and they don't know what to do, it's quite difficult for them.
MYERS
If one is lucky enough to get to see someone like you in the clinic though what would you do in terms of tests to help with the diagnosis and indeed treatment?
EWAN
Well the tests are quite straightforward, I mean we put a lot of emphasis on a detailed history, backed up by tests - tests alone are not terribly helpful but with the history they're good. So making a proper diagnosis because you don't want to be avoiding foods that are not - you don't have to. But thereafter you can put in place quite a good system to avoid further reactions, so people need very good advice on avoidance and it might be very simple - a kiwi is very easy to avoid but nuts are not so easy to avoid, unless you have good understanding. And in addition to that we would give patients a self management plan, which is written down for them and they have drugs according to their different needs, according to severity and risk. And they are then in a position, should they eat something by mistake, to self treat and we have evidence that this management works really well and causes a huge reduction in further reactions.
MYERS
Thank you for that. I need to move on to Sandra who's waiting very patiently and is convinced that she's lactose intolerant but not everyone agrees with you. What's the story there?
SANDRA
Right, well in mid-October, out of the blue, I suddenly began to get quite severe diarrhoea and it went on for week after week after week after week and I laugh - I say I've had my money's worth out of the NHS because then the battery of tests began. I'm 60, so the first thing they obviously were eliminating were tumours of the bowel - small and large bowel - and then a whole load of blood tests, all came back negative. And I never - I think one knows one's body - and I never really felt I had a tumour, it always seemed to be connected with food or something. And went on for a long time and it's particularly nasty after breakfast and I was eating porridge every morning made with half milk and half water ...
MYERS
And thereby lies the clue is that right?
SANDRA
That's right. I cut out then the milk and the post-breakfast diarrhoea stopped. And so then I began gradually to cut out more and more milk and I have lactose free milk and I've been clear now of diarrhoea for a number of weeks.
MYERS
So you got the answer to the problem?
SANDRA
I've been going back to the GPs and saying, you know, I think I'm lactose intolerant and they say oh no, no you get that when you're an infant or if you've had a severe infection and that's not you. So they just really sort of - a bit patronising and saying there dear, you know, if you are reacting to milk don't drink milk.
MYERS
Well let's get another opinion, since we've got an expert, is it possible for someone of middle age to develop a lactose intolerance in fact to milk, the milk in the porridge by the sounds of it?
EWAN
It is - it is possible, it would be unusual and of course this is much more common in children, young children, but it may well be that - I mean the next problem is the consequence of avoiding foods and if you have to avoid milk, long term, and completely avoid milk of course it has nutritional consequences ...
MYERS
Bad for your bones isn't it?
EWAN
Yes absolutely. So I mean milk is a very rich source of calcium but there are ways round this and you can have calcium rich foods, increase the other calcium containing foods in the diet, calcium supplements. And if patients actually have osteoporosis of course there are specific drug treatment to help prevent progression.
MYERS
If we can move to the other end of the timescale. We've got Jack on the line now talking about his baby who's quite young, 14 months old I think Jack, and is allergic to milk. Now that is problematic isn't it, is he suffering from that?
JACK
Hello.
MYERS
Hello.
JACK
Yeah he's allergic to milk and dairy products but the problem with the baby he's also allergic to wheat, bananas and other stuff that we don't know about and he's very underweight.
MYERS
Jack, I'm going to lose your line I'm afraid but I hope you will stay listening because it's a rather poor line but I think we got your point that the baby's got several allergies or intolerances and obviously is finding the right foods to build the baby up.
EWAN
Well yes I mean that - I would have liked to have asked Jack some further questions as to exactly what symptoms the baby had but this sounds like a serious problem and really one where one would expect very expert advice from a paediatric allergist and again we don't have many of these. But it's a bad enough problem if a baby has milk allergy, because milk is such an important part of their diet, but if they're at the weaning stage and a whole series of other foods are withheld it's extremely important to get an accurate diagnosis and find out precisely what needs to be avoided and also what doesn't need to be avoided and make sure the child has a nutritionally adequate diet.
MYERS
So I hope you got that Jack, I mean it is important to get some medical advice if you haven't already. But just in general terms if children, babies, children are allergic to milk or not able to tolerate it are there not lots of alternatives types of milk, other animals - sheep, goat milk, Soya milk?
EWAN
Yes, yes there are, I mean Soya milk is usually the first alternative, depending on the age and the degree of the allergy but yes there are Soya milk and there are other forms of formula where the milk protein has been digested into tiny amino acids so that it's incapable of causing the allergic reaction. But in Jack's baby's case of course we're now worrying about other foods in addition to milk.
MYERS
So well worth seeking medical specialist advice if you're happy enough to be able to get it. Thank you very much. We will have to, as usual, draw to a close a little bit early there with thanks to Pamela Ewan, our expert today, and thank you very much to all those who have phoned and e-mailed - there have been plenty of you - I hope what we have been able to say has been helpful. There is more information, as always, if you would like to call our free and confidential help line, that's 0800 044 044. You can listen to this programme again if you like on our website, that's at bbc.co.uk, just follow the prompts to Check Up.
And next week join us if you will and our subject will be osteoporosis.
Ends
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