There comes a point in everybody's life when it's time to put the brakes on. Babies arrive, the long-hours culture begins to wear you down and, well, the years roll on. With the best will in the world, you find you just can't put it away like you used to. It's what used to be called middle age.
I had to accept, as I reached my mid-thirties, that I'd become an awfully cheap date. Once an enthusiastic drinker of beer, proud to swill pints like a man, now a couple of halves was all it took to put me under the table.
But it was more than just a problem of capacity. Even after one or two drinks, it seemed the hangover would begin halfway through the evening and continue for the rest of the night. I'd get home feeling like hell - ravenously hungry, even if I'd been out to dinner, yet with evil indigestion. I'd down some water and sugary foods in an attempt at first aid, then spend a fitful night with a foggy head and a heart full of feverish anxieties. A full recovery could take several days.
So, you can imagine how much fun my social life was. Parties soon lost their pull when the consequences were so punishing. Weeks would go by without me touching a drop.
When I noticed that I also lost my voice after a night out, I assumed this was caused by the cigarettes that went with the drinks. Curiously, though, a recent rash of non-smoking parties quickly brought about just the same rasping hoarseness.
Then one day in the office here at The Independent, someone cracked open some birthday champagne. I took one sip and began to cough. A few sips later and I was coughing and wheezing like a chain-smoking, 80-year-old miner. The reaction was so sudden and dramatic that it prompted me to put a few words into an internet search engine and soon I was pretty sure I'd nailed the culprit: sulphites.
Here's what I found out. Sulphites are a group of sulphur-based chemicals, used since ancient times to preserve foods and to stop them going brown. Without them, white wine would be brownish wine. They are present in the largest quantities in wine, cider and some beers, but also in many preserved foods such as dried fruit, soy sauce, jam, deli meat and fruit juice made from concentrate - almost all foods I've instinctively avoided for years. They are used liberally on frozen potatoes, which are often used to make chips. They're put on shellfish to keep them from going bad, and in the US they used to be liberally sprinkled on salad-bar salads, until the practice was banned because too many people had bad reactions to them. Some of those people died.
So they're useful substances, but they just don't agree with everyone. Asthmatics seem to be particularly susceptible, but nobody knows exactly how many people are sulphite-sensitive. Isabel Skypala, a specialist allergy dietician at the Royal Brompton Hospital, puts the figure at about 5 per cent of asthmatics, but other studies have suggested that as many as a third of asthmatics have had attacks triggered by sulphites.
There are two schools of thought about sulphite sensitivity, Skypala explains. "The first is that when you swallow there's some sort of inhalation effect, because you're creating a bit of sulphur dioxide and that causes the wheeze and other symptoms. But also sulphites are converted into sulphates by enzymes during digestion. There is a view that there could be a group of people who have a lack of this enzyme and that's what causes their symptoms because they can't convert them. I've certainly seen a distinct group of people who don't get the asthma wheeze but they do get quite a severe gastro-intestinal reaction."
Skypala is writing a dissertation on the diagnosis of food allergies, but has found sulphite sensitivity very difficult to research, because of the risks of deliberately inducing symptoms in asthmatic people, in whom the reaction can be very severe.
Reaction to sulphites is not an allergy, strictly speaking. With an allergy, exposure to a protein in a food (or in pollen, for example) will cause the body to produce antibodies to it, so that next time you encounter the food you will have a reaction. In the case of sulphites, the mechanism is less clear, but unlike, for example, peanut allergy, it seems to be dose-related: people tend not to react to only a little sulphite.
I have a clutch of "real" allergies: eczema, hay fever, allergic rhinitis and shellfish allergy. I come from a family of atopic allergics. At one stage I underwent a patch test to try to establish what was causing a severe eczema flare-up. I was asked to bring in any suspected allergens, to be taped to my back in small quantities for a few days. The skin was then examined for reactions. Unfortunately, the patch of skin that caused the allergy doctor a sharp intake of breath was the one on which had been placed a drop of Chanel No 19, my favourite perfume. So that was goodbye to perfume. And now, does this mean goodbye to alcoholic drinks, too? Or, worse, am I just becoming a terrible hypochondriac?
Well, I may be, but Justine Bold is certainly not. Ten years ago, Bold, then in her twenties, began to get dreadfully ill. She was having severe anaphylactic reactions. She had difficulty breathing, and had vomiting and diarrhoea and peeling skin on the inside of her mouth. During one episode, her lungs filled with fluid and she had to take steroids. It took two years for doctors at the Royal Brompton to pinpoint the cause. Bold was asked to keep a food diary, then go into hospital for a series of food " challenges" under controlled conditions. "They put me on a drip and made me eat some of the things I'd been reacting to: soft drinks, beer, wine, jam, fruit yoghurt. I had a reaction from just one spoonful of strawberry jam!"
Bold was sent away with a rather depressing sulphite-free diet sheet and an EpiPen - the DIY adrenalin injection that can counter an anaphylactic reaction. "Then after one very bad attack, when my boyfriend jabbed me with the EpiPen on the way to hospital, I realised I was getting worse. My boyfriend looked at the EpiPen and realised it contained sulphites. Now I have adrenalin from the States that is preservative-free."
Bold, who then worked in advertising, was inspired by her experience to retrain as a nutritionist and wrote her dissertation on sulphites. Now she says, "If I had an asthmatic child, the first thing I'd do is take them off sulphites. But it doesn't seem to be part of asthma treatment protocol at all." She has learnt to control her condition and now enjoys a fairly normal diet.
Bold has occasionally had short shrift from doctors, including an allergy specialist at one hospital. "That certainly wouldn't have happened here [at the Royal Brompton]," says Isabel Skypala. "But I think there is still a generally held belief that foods don't cause asthma, they can only exacerbate it. But I've seen it happen and I know it happens. The problem is that there is a great lack of research evidence to support this. Adult allergies are under-researched."
It is now acknowledged by most authorities, including the World Health Organisation, that sulphites are not safe for everyone. Last year the EU introduced new rules about labelling. Foods containing more than 10mg of sulphites per kg or litre must now be labelled. There is also a maximum permitted level: for dried fruit this is 600-2,000mg per kg. For wine it's 200mg per litre. It is now one of 12 substances, including milk, wheat, nuts and fish, that must be declared.
There is also an EU "acceptable daily intake" of 0.7mg per kg. That's 42mg a day if you're a 60kg female. A medium glass of white wine contains about 26mg; five dried apricots have 80mg.
The levels of sulphites in wine will vary a good deal, and can vary from label to label, or even from year to year. I can remember a happy and consequence-free evening at a restaurant a few months ago drinking posh white wine. Good wines will generally be lower in sulphites, Skypala says. Champagne, she says, has lower amounts because it's fermented in the bottle. My wheezing episode,might have been caused by a yeast allergy, although she says yeast allergy is rare, "despite what you read in the papers". Or it might be that I was in fact drinking sparkling white wine, which is the worst of the lot.
So I've discovered the joys of gin and tonic, though Justine Bold tells me that, due to strict brewing laws, German beers such as Beck's are also very low in sulphites. It's an acquired taste and not that practical - it is rarely brought round at launch parties. But I can now get pleasantly drunk and arrive home as fresh as a daisy. So make mine a G&T.
Justine Bold, nutritionist: firstname.lastname@example.org
The sulphite problem
* A medium glass of white wine contains, on average, 26mg of sulphites. The EU recommended "acceptable daily intake" is 42mg per day for a 60kg female.
* Most red wine is lower in sulphites than white - though it still has fairly high levels - as its natural tannins help to preserve it. But it may still cause or aggravate allergies, as it contains histamines.
* Beer usually has added sulphites, as well as some formed during fermentation. However, German bottled beer, which is made according to a purity law dating back to 1516, has no added sulphites and is more likely to be tolerated by those who are sensitive.
* Cider is generally high in sulphites because apples oxidise readily.
* White spirits are the least likely to cause problems with sulphites, but beware of mixers: squashes - particularly lime cordial - are usually very high in sulphites, as are juices made from concentrate. Even tonic " with a twist of lemon" could set you off - though fresh lemon juice is fine, as is normal tonic water.
* Some organic wines will be lower in sulphites, and some will call themselves "sulphite-free", although sulphites occur naturally in wine. To be "sulphite-free" under EU regulations, a wine must contain less than 10mg per litre. In practice, few people suffer a reaction to less than 20mg of sulphites. The maximum permitted level is 200mg per litre.
* SULPHITES AS E-NUMBERS
The following e-numbers indicate the presence of sulphites: E220, E221, E222, E223, E224, E226, E227, E228, E150
* FOODS TO AVOID
Dried fruits and candied peel, especially dried apricots, bananas, apples and peaches
Sausages and other processed deli meats
Chips, unless they're made from fresh potatoes
Vinegar, ketchup, mayonnaise and horseradish sauce
Sliced breads, crumpets and other processed bakery goods, which may contain vinegar or flour treated with sulphites
Frozen seafood, and fresh prawns, usually contain sulphites
Ready-made pizza - the dough is often treated with sulphites
Fruit squashes, especially lime cordial
Bottled lemon juice, which always contains sulphites
Grape juice and fruit juices made from concentrate
Dried mushrooms and stock cubes (unless fully organic)
Other foods to watch out for are those with corn syrup, glucose syrup, corn starch, potato starch and other syrups
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