Japanese diet doldrums

Reducing the incidence of stroke and heart disease in Japan is the aim of a tripartite research programme at the University of Wales, College of Medicine, St Bartholomew's Hospital and Kobe Gakuin University, Japan.

The Japanese suffer up to 50 per cent more strokes than the British and their levels of heart disease have mushroomed since the second world war. The incidence of heart disease is now on a par with the United Kingdom and levels could rise even higher.

Japan has concluded that diet is one of the main reasons for this ill health. So in a bid to change the country's eating habits, Junichiro Yamamoto of the nutrition faculty at Kobe Gakuin University has inaugurated international dietetics research.

His partners are John Giddings of the University of Wales, College of Medicine, and Iren Kovacs of St Bartholomew's.

"We are comparing Japanese and British diets because the Japanese are becoming more westernised in their eating habits," explained Dr Giddings.

"They are eating more meat and sugar with the result that 55 per cent of their diet is carbohydrate, 25 per cent fat and 20 per cent protein. In Britain carbohydrates are 35 per cent of our diet, fat 45 per cent and protein 20 per cent. On paper their diet looks better, but most of their carbohydrate intake is sugar-based rather than pasta."

Their greatest sin, however, is salt and this is believed to be a significant factor in the high levels of strokes and heart disease.

"The Japanese eat soy sauce very often, and that is virtually pure salt," Dr Giddings says. "On average, the Japanese consume up to three times more salt than we do."

In addition to monitoring nutrition, the research programme is also focusing on the interaction between white blood cells, proteins and the inner surface of blood vessels. All three are believed to be significant in the cause of thrombosis and strokes.

This part of the research is being supported by the Leukemia Research Appeal for Wales, because many leukemia patients suffer blood clotting problems during treatment.

The nutrition programme is financed by the three partners, and it has already been running for five years. As part of the project nutrition students from Kobe are spending this month at the College of Medicine, Cardiff, and at St Bartholomew's.

Another diet-related disease that the Japanese are investigating is osteoporosis. Its high incidence in Japan is largely due to a shortage of calcium in the diet. Dairy products are not traditionally eaten in Japan although nutritionists are currently urging the population to eat cheese. This should have a positive effect in future.

Fortunately for the research, Kobe Gakuin University was not badly affected by the recent Kobe earthquake. The university was only five kilometres from its epicentre but the quake travelled away from it in a westerly direction.

The research is expected to continue for at least another five years, with Dr Giddings and nutritionists from the College of Medicine due to fly out to Japan to further the programme and to teach Kobe students. The students are benefiting from the changes in Japan's dietetics curriculum which took place in 1986. They now study for a national qualification in nutrition focusing on the science and biochemistry of food.