Eczema, asthma, hayfever and diet
Juliet Gellatley, founder & director of Viva!Health looks at the link between eczema, asthma and hayfever and how diet can help you
The sun is here and for some brings with it the summertime blues. But sneezers also tend to be wheezers and scratchers – as poor old hayfever sufferers are much more likely to also have eczema or asthma, or belong to a family with one of these allergies.
One in 12 Brits have asthma; a startling one-fifth of children have eczema and 1 in 12 adults; and one quarter of us sneeze our way through the summer with hayfever.
All allergies are on the increase – hayfever has doubled in the last 20 years! There are various theories why, and they are all similar for each condition. One reason is called the ‘hygiene hypothesis’ or ‘fussy parent syndrome’! Parents’ insistence on cleanliness with babies means that when their children grow they are unable to fight bacteria. Our immune systems do not get a chance to mature and so develop an excessive reaction to ‘allergens’ – pollen in the case of hayfever, often dustmite poo or cat saliva with asthmatics and eczema sufferers, which are mistaken for a harmful invader.
Global warming is also a culprit for hayfever, as it has expanded the season, which now begins in March and April with tree pollen. Grass pollens follow in May and June.
Pollution has also been suggested as an aid to hay-fever, the theory being that when proteins from pollen grains are washed off they stick to particles in the polluted air which are inhaled. However, with asthma research carried out in places such as rural New Zealand suggests that children are just as likely to develop asthma whether they live in the middle of a metropolis or the back of beyond.
International studies have found that children in richer countries including Britain are more likely to suffer from allergies than those in poorer societies. There are two main reasons. Firstly, the richer we get, the better we insulate our homes, giving dust mites the perfect place to breed. Also because we can afford to fill our comfortable houses with TVs, gadgets and computer games, we spend more time indoors with the mites and the mould.
Secondly, and ironically, as we get wealthier more and more of our children suffer from malnutrition! June 2000 saw the publication of a national diet and nutrition survey which looked into the eating habits of young people aged 4 to 18 years in Great Britain. It probably comes as no surprise to most parents but makes for grim reading nevertheless. Roughly 80 per cent of kids are guzzling away on white bread, savoury snacks, biscuits, chips and chocolate confectionery. Roughly 60-75 per cent had not eaten any citrus fruits or leafy green vegetables during the week of the survey. My belief is that as the quality of our children’s diet declines, their immune system fails to develop healthily and allergies are one of the consequences.
WHAT LINKS THE TRIO
The underlying changes in the body are very similar with atopic (usually inherited) eczema, asthma and hayfever. All are due to allergic reactions where the immune system reacts to normally harmless substances. They are all classed as ‘type 1 hypersensitivity’.
Our immune system is composed partly of millions of antibodies and each one recognises a specific invader. For some reason that still eludes the medical establishment, in people with allergies, antibodies called IgE are formed when an individual is exposed to a ‘harmless’ invader or allergen such as pollen, cat or dog saliva, feathers, cow’s milk, eggs, shellfish and so on. These antibodies attach to mast cells which are present in large numbers in the mucous lining of the respiratory and digestive tracts and in skin tissue. On reexposure to the allergen, the IgE antibody grabs hold of it and tells the mast cell to release chemicals which provoke an allergic response. You’ll have heard of the main chemical – it’s histamine and it causes inflammation. Inflammation is normally a good thing if you are fighting a harmful invader such as bacteria but in the case of eczema, asthma and hayfever, it is an OTT response to a harmless substance.
Inflammation means that blood capillaries widen allowing more blood to flow to the area, bringing more antibodies to fight the invader. The increased blood flow causes redness and warmth. Water also seeps from the capillaries in an attempt to dilute any poisons that may be at the site – this causes swelling. Pain results from the pressure of the increased fluids on nerve endings and from chemicals such as prostaglandins irritating the nerves. Various types of exudates are formed from the fluid in the affected area – they can be watery with small bits of protein – and this is usually the case with allergies (often it’s pus with bacterial infections).
If the mast cells ‘switched on’ by the IGE antibodies are located in the mucous lining of the nose, they also cause the production of excessive mucus and so a runny nose and hayfever is the result. If the mast cells are in the lining of the lungs, the histamine and other chemicals also cause contraction of the airways and mucus production in the airways, leading to blockage, or asthma. If the allergic response happens in the skin, then it’s labelled eczema.
The tendency for all three conditions is inherited and yet if an identical twin has eczema, in one-in-five cases the other twin will not develop symptoms. This is because all allergies have triggers which differ from person to person. For example, stress is a major trigger – so if one twin avoids stress they may never develop eczema, while the other twin who burns the candle at both ends, ends up with the sore, itchy skin.
FOOD THAT PROTECT US
It’s known that some foods trigger allergies, while others protect us. In broad terms, the biggest food to spark an allergic response is cow’s milk. In almost one-third of children with eczema, food may be a trigger, and in 10 per cent, it’s the main trigger. The most common foods linked to eczema are cow’s milk and eggs, lesser triggers are fish, soya, wheat and nuts (National Eczema Society, 2003).
Some foods help protect against allergies. For example, Dutch research has shown that people who ate the most fruit and vegetables had the healthiest lung function. Vitamin C (from fresh fruit and veg) and E (from nuts and seeds, avocadoes, tomatoes, wholegrains etc) are also believed to help reduce the severity of the inflammatory response in the lungs of people with asthma. A diet that includes a high level of nutrients can also boost the immune system and help ward off colds and flu – both common asthma triggers (Asthma UK 2006).
Trials have shown that rubbing omega 3 rich oils on children with eczema helps alleviate the condition; as does consuming diets rich in omega 3s. These are the good fats found in oils from flaxseed, rapeseed and soya as well as nuts (esp. walnuts) and leafy green veg. These fats are incorporated into the skin cell membranes and so help lock in moisture.
Another example of how diet affects allergies come from Finland. Studies there have shown that if a breastfeeding mum’s diet is high in animal fats and low in omega-3, the risk of her baby developing eczema increases.
Allergies are now so common in the UK that the Royal College of Physicians is referring to them as an epidemic. Although there is a strong genetic component involved, it is essential to boost your health and immune system to minimise the chances of an attack. This means: eat a healthy vegan diet rich in fruit, veg, nuts, seeds, wholegrains and omega 3s.
Exercise! Can’t get away from that one! Exercising regularly keeps the heart, bones and digestive system healthy and helps to keep unwanted weight off. It makes us feel good and better able to cope with the stresses of everyday life. In the case of asthma, exercise also helps to strengthen the lungs and can therefore improve your asthma. Asthma UK say that ironically one in three children don’t exercise because they have asthma and yet they are most in need of exercise.
Finally stress is incredibly damaging in many ways and can trigger all allergic responses – so use your health as the perfect excuse to distress your life (easier said than done I know!).
And the last one – no excuses here – stop smoking!