Can zinc pills help my spotty skin?

By JANE CLARKE

Last updated at 13:03 04 March 2008

Every Tuesday, Britain's leading nutritionist explains how to eat your way to health. This week, Jane offers advice on treating rosacea and the safe way to freeze vegetable soup...

I suffer from rosacea on my cheeks and nose. I understand zinc sulphate is beneficial - is there anything I can eat to relieve it?

Susan Kirby, Swansea

Rosacea is a chronic skin disease often misdiagnosed as adult acne because of its characteristic rash of pimples. Other symptoms include general redness, red lines on the nose, cheeks, chin and forehead, and around the eyes.

Middle-aged women are most at risk, although it can affect anyone between the ages of 30 and 60.

We don't really know what causes it and the condition is incredibly tough to treat. Some people find that antibiotics work for some of the time. For others, certain lifestyle changes, such as avoiding hot baths and extremes in temperature can provide some temporary relief.

As for supplements, zinc sulphate has been showing some interesting results. A recent trial found that people given doses of 300mg a day experienced an improvement in symptoms. However, this a very large dose of zinc - the body needs just 9mg a day and most supplements are around the 20mg mark.

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Large doses of zinc supplements can cause stomach problems such as cramps, indigestion and diarrhoea.

However, you cannot get 300mg from food sources alone, so it may be a case of weighing up the benefits. But don't take such large doses without talking first to your GP or dermatologist, because this strong therapy does not suit everyone.

Other supplements that have been shown to help include nicotinamide (the synthetic version of vitamin B3), copper and low-dose zinc supplements (note: these are not the same as zinc sulphate). But again, discuss these with a medical professional first as the doses of these nutrients needed are far higher than you could glean from food.

Otherwise, a classic healthy diet will help - that means plenty of wholegrains, vegetables and fruits. Aim for medium-to low-glycaemic foods which release their energy slowly; I'm not sure why, but it can work. Remember that some fruits, such as pineapple, have a high GI so should be avoided.

Occasionally, specific foods can be triggers. This can sometimes be due to an allergic reaction, but more commonly it's because the food has a vasodilatory effect, making the blood vessels swell and the skin flush, producing the classic rosacea symptoms.

Use a food, drink and symptom diary to identify your trigger foods. Record everything you eat and drink for a couple of weeks and note alongside how your skin is to see if you can spot any patterns.

The classic triggers are vinegars, hot spices such as chilli, various other spicy seasonings, hot sauces, pepper and shop-bought meat marinades. Others include tomatoes, citrus fruits and their juices, bananas, red plums, raisins, figs, pasta, cheese and chocolate. Some people also find that liver, yoghurt, sour cream, vanilla, soy sauce, yeast extract, aubergines, avocados or spinach can affect their rosacea - so, as you can see, there are a few things to check out.

Although time-consuming, a diary is well worth sticking with, as it allows you to keep tabs. As for how long it takes to trigger the blood vessels to dilate and the symptoms to appear, it can usually happen within a few hours, so this is the time-frame to watch.

Also try to make sure you're not dehydrated - aim to drink 2.5 litres of fluid, ideally water or herbal tea, a day - as this can help improve the appearance of your skin.

The odd tea or coffee isn't a problem at all, but so many of my patients notice that their complexion looks and feels better when they get their 2.5 litres from water or herbal infusions, as these are incredibly hydrating.

And since stimulants such as coffee, tea and cigarettes are all vascular dilators, they're the last thing you need. As with hot baths, hot drinks can also aggravate the condition so leave them until they are just warm. Also let icy drinks reach room temperature.

Talking of drinks: you may notice that a particular wine or spirit aggravates your rosacea.

Alcohol is also a diuretic - that is, it pushes water out of body cells, causing increased urine production and resulting in dehydration.

So if you do fancy a drink, keep it to a minimum and make sure you have plenty of water at the same time to help counteract the dehydrating effect. I've also noticed that when patients find an effective way of keeping stress levels to a minimum their condition responds really well.

I often make soups from frozen mixed vegetables sold in supermarkets. Then, if I make too much, I freeze it for another time. How much of the nutrients and vitamins survive all this?

Kathy McCabe, Bournemouth.

There can be just as many nutrients such as vitamins and minerals in frozen vegetables as in fresh because they are picked and stored within hours, preserving the nutrients.

In terms of your soup-making, by the time you've defrosted the vegetables, cooked them and then frozen and defrosted them again you will have very little, if any, vitamin C left.

This is a very fragile, heat and time-sensitive vitamin, but this shouldn't stop you from cooking this way, as you will still have a good and valuable amount of other nutrients such as betacarotene.

The body actually absorbs beta-carotene more easily from cooked carrot than from raw. So carrot soup is a good way to glean some of this useful antioxidant, which helps fight heart disease and cancer. You will also still have some useful fibre in the soup, which can be very good for the gut - especially if you incorporate lentils and beans.

My only concern is food hygiene. Defrosting and refreezing increases the bacterial content of food. You should really only freeze the soup once, then after it's defrosted, consume it all or ditch the leftovers.

This is particuarly true as you grow older, as your defences against bugs become less efficient.

You might then find it better to change your habits so that you're not re-freezing previously frozen food.