Cashews

100g (roasted, salted): 611 calories, 50.9g fat, 0.7g salt

With as much anaemia-protective iron and immune-boosting zinc as steak, cashews are a great choice for vegetarians. One handful (25g) supplies 10 per cent of a woman’s daily maximum of cholesterol-raising saturated fat though.

Hazelnuts

100g (kernels): 650 calories, 63.5g fat, negligible salt

Highly nutritious, a handful supplies 60 per cent of the recommended daily intake of vitamin E, an important antioxidant that protects cells. They are heart-healthy too: their fat content has the same composition as olive oil.

Almonds

100g (blanched): 612 calories, 5.8g fat, negligible salt

Another great nut with as much vitamin E as hazelnuts. They are low in saturated fats and packed with bone-building calcium and magnesium too.

Brazils

100g (kernels): 682 calories, 68.2g fat, negligible salt

Nibble these to boost your magnesium and selenium intake (selenium is a mineral to bolster your defence

against viruses). Quite high in saturated fat.

Pistachios

100g (kernels, roasted, salted): 601 calories, 55.4g fat, 1.3g salt

A rich source of potassium that helps keep blood pressure healthy. Go for salt-free versions. Having to remove the shell makes it more of an effort so you are less likely to eat too many.

Peanuts

100g (roasted, salted): 602 calories, 53g fat, 1g salt

A great source of niacin, needed for energy release, and biotin, important for healthy skin. Roasting reduces vitamin E and folic acid. The saturated fat intake can creep up if you eat a lot.
Macadamia nuts

100g (salted): 748 calories, 77.6g fat, 0.7g salt

The most fattening nut and lower in nutrients than some. Still good in moderation though and a handful supplies your daily manganese needs for healthy joints and bones.

The news is based on a large randomised controlled trial (RCT) that is about to start. The research follows a successful pilot study of a treatment called peanut oral immunotherapy (OIT), in which allergic children are repeatedly exposed to strictly controlled doses of peanut protein. Its success so far shows that it has good potential and the results from the upcoming RCT are greatly anticipated.

However, it is vitally important that no attempts are made to replicate the treatment at home as severe allergic reactions can be fatal. If the treatment works it will be offered to children with peanut allergies in the safe and controlled manner that will be necessary for its success.

It should be noted that this treatment is not a cure, and several unknowns need to be addressed, including whether this treatment works in adults and the nature of its long-term effects in children.

What is the basis for these current reports?

The news stories are based on research carried out by Dr Andrew Clark and colleagues from Addenbrooke’s Hospital in Cambridge. The team has had success in previous pilot studies with a technique known as peanut oral immunotherapy. This treatment aims to desensitise the immune system to the allergen (the substance that usually causes an allergic response) by gradually increasing its exposure.

A £1 million grant has now been given to Dr Clark and his team by the National Institute for Health Research, to carry out a larger RCT in more than 100 children with peanut allergies.

The results of the pilot studies and the new trial were presented by Dr Clark at the annual meeting of the American Association for the Advancement of Science.

Has this therapy been tested before?

Dr Clark announced the results of a previous trial in 23 children between 7 and 17 years of age. These children were given a very small amount of peanut flour in yoghurt every day, and the amount was increased every two weeks until the children could eat five peanuts a day. Most of the children had some reactions when the dose was increased, including oral itching and abdominal pain. However, by the end of the trial, 21 of the 23 children could eat five peanuts a day and one could eat two peanuts a day.

More information about peanut oral immunotherapy is available from another pilot study published in February 2009. This trial, in four boys with suspected peanut allergy, was covered by Behind the Headlines. Each boy had an allergic response to between 5 and 50mg of peanut protein (a fraction of the approximately 200mg present in a whole peanut). The boys were exposed to increasing daily doses of peanut flour, up to a maximum of 800mg of peanut protein. Each boy was given a personalised dosing schedule depending on their initial tolerance levels. After six weeks of carefully tailored daily treatment, all four boys were able to eat up to 800mg of peanut protein without any serious adverse effects.

More research is needed into this treatment, and the researchers have begun a larger RCT – the best way to establish the effectiveness of a treatment.

What is the new trial?

Dr Clark presented the plans for a larger study (an RCT) during his presentation to the AAAS conference. There is only limited information publicly available about the trial, but it is known that it is a large controlled trial involving 104 participants who will be randomised to peanut OIT or no treatment. The trial will cost £1 million, sponsored by the Department of Health’s Institute of Health Research, and will run for three years. Children will be given the equivalent of up to five nuts per day in a carefully controlled dosing schedule that depends on their initial tolerance.

Are peanut allergies common?

Dr Clark reports that between 1997 and 2007 there was an 18% increase in childhood food allergy. According to Clark, approximately 1 in 50 children have a nut allergy and 10% of reactions to peanuts will be severe ones. Aside from potentially fatal reactions and the fear of them, children with peanut allergies also experience restricted food choices that can affect their social behaviour. While most children will outgrow allergies to milk, eggs, soya and wheat, peanut allergies are more persistent and an estimated 80% of children remain allergic to peanuts for the rest of their lives.

Many people believe that deaths from food allergies are common and the NHS highlights this as a frequently held misconception. This may be due to the fact that the deaths receive a lot of media coverage when they do occur, but in fact, death from food allergies is very rare. For instance, there were six deaths recorded as a result of food allergies in 2008.

Conclusion

The previous success of this treatment shows that it has good potential for treating children with peanut allergy, and the results from the upcoming RCT are anticipated with great interest. Its strong study design will provide robust answers to questions about the efficacy and safety of this treatment for children with allergies.

It should be noted that this treatment is not a cure, and several unknowns need to be addressed, including whether this treatment works in adults and the nature of its long-term effects in children.

Dr Clark said in The Times: “I think in two or three years time we will be in a position where we have a treatment that works, but we are still working on a long-term cure.

“It’s likely to be a treatment that lasts at least two or three years, and we hope that once that’s over we can withdraw the treatment and maintain long-term tolerance, but we need a long-term study to find out.”

Most importantly, these trials are taking place under carefully controlled conditions and in no way should attempts be made to replicate them at home. Several safety precautions are in place should any of the children have an allergic reaction, and the amount of peanut given is carefully measured for each child’s own personal initial tolerance levels.

The short period of two to three years until a working treatment is encouraging. Until it is available, parents should continue to manage their children’s exposure as they have been doing. Peanut allergies can be successfully managed by vigilantly avoiding exposure and by treating accidental exposures with appropriate medications – antihistamines or adrenaline as advised by your doctor.