Human test aims to show if dairy food helps asthma

Dairy foods may reduce the occurrence and symptoms of asthma and other allergic diseases, a New Zealand study has found.

In an apparent contradiction to conventional wisdom, researchers at Auckland University found that mice with allergic conditions showed a reduced reaction to allergens after being fed a diet enriched with milk-derived fatty acids.

These fatty acids have anti-inflammatory properties and occur naturally in cow's milk, butter and cheese, but are missing from margarine.

The research team is looking for volunteers for a small trial using a specially enriched butter to see if the same results can be observed in human asthmatics.

"One of the striking things about asthma, or indeed all of the allergic diseases - asthma, hay fever, eczema - is how much more common they are now than if you go back to the 1950s or 1960s," said lead researcher Dr Peter Black, from the university's faculty of medical and health sciences.

"There's been a several-fold increase, with somewhere between a two-fold and four-fold increase in the number of people with asthma."

One of the main suspects was the change in the Western diet, he said. The reduction in butter consumption and the increase of margarine use had taken place at the same time as allergic diseases had become more common.

About half a dozen studies had found that higher consumption of dairy products or a decrease in margarine use was beneficial, Dr Black said.

"One of the striking things was that in Germany, prior to the fall of the Berlin wall, asthma was more common - as was eczema and hayfever - in West Germany rather than East Germany. The main difference was that they used more butter in East Germany and more margarine in West Germany."

But former Heart Foundation medical director Boyd Swinburn, now chairman of population health at Australia's Deakin University, said people needed to avoid putting too much store into the study, which was still untested on humans.

"We also have to stack up this potential hypothesis against what is already proven many, many times over on the impact of saturated fat - of which butter's a huge source - on cholesterol levels and heart disease.

"I think it's an interesting hypothesis and has some plausible elements, but I would not like to see it weighed on the scales at the moment against the issue of butter and its role in heart disease, which after all is the biggest killer in New Zealand."

Dr Black said he was mindful of the less healthy aspects of butter.

"If this was something you had to eat a hundred grams of a day for a beneficial effect, this would be a non-starter.

"We hope that 10 grams a day of butter enriched with these natural fatty acids should help control symptoms of asthma."

The amount was similar to the packets of butter found in hotels and on planes.

* Interested volunteers, particularly those with regular asthma symptoms, can contact co-ordinator Susanne Brodie on (09) 373-7599 ext 89807 or by email