Health promotion activities in Japan.

In Japan, the spread of immunization and the development of antibiotics and antituberculosis drugs have dramatically decreased the mortality rate from infectious diseases since World War II. Alterations in health practices, such as decreasing the intake of salty foods and strict management of hypertension, have resulted in prominent decreases in the mortality rate from cerebrovascular diseases, especially from cerebral hemorrhage. However, we still have high death rates from malignant neoplasms and circulatory diseases, which may be partly prevented through improvement of health status. We discuss here about various health promotion activities recently reported in Japan, including prevention of smoking, promotion of exercise, improvement of nutrition, improvement of mental health status, and health risk appraisal. Finally we would like to stress the importance of comprehensive assessment of health status in order to encourage health promotion activities further.

In Japan, the spread of immunization and the development of antibiotics and antituberculosis drugs have dramatically decreased the mortality rate from infectious diseases since World War II. We also had a very high mortality rate from cerebrovascular diseases just after the war. Since then, alterations in health practices, such as decreasing the intake of salty foods and strict management of hypertension, have resulted in prominent decreases in the mortality rate from cerebrovascular diseases, especially from cerebral hemorrhage. The mortality rate from ischemic heart diseases has been low in Japan compared with other developed countries, probably because of a low intake of meat and saturated fat. However, a recent national survey on vascular diseases indicated elevations of serum cholesterol levels in all age groups of both sexes from 1980 to 1990. During that period, systolic blood pressure decreased, especially in the older age groups, whereas diastolic blood pressure did not change, in all age groups. Therefore, we might experience increases in the incidence and mortality rates from ischemic heart diseases in the near future.
Although the age-adjusted mortality rate from malignant neoplasms has decreased in females, that in males has slightly increased in the last three decades. This sex-difference probably reflects differences in major health practices. Smoking rates among Japanese males were as high as 80% in 1965 and have gradually decreased to about 60% in recent years. In contrast, smoking rates among Japanese females have been as low as 15% for the last three decades. Likewise, the frequency of habitual alcohol drinking is as high as 40% among adult Japanese males but is very low among Japanese females.
Dietary habits and other lifestyles of the Japanese have been changing rapidly toward European styles. We have experienced great decreases in the age-adjusted mortality from gastric and cervical cancer. On the other hand, we will have further increases in mortality from lung, colon, pancreas, prostate and breast cancer in the next one or two decades. Health promotion activities to prevent these diseases are of great importance.
Under the Industrial Safety and Health Law, enacted in 1972, all companies with 50 or more employees have an obligation to have their employees take health checkups, including measurement of blood pressure, liver function, and serum lipids, at least once a year. The health checkups have contributed to the early detection of hypertension and to the prevention of apoplexy. The law for the Health and Medical Service for the Aged, enacted in 1982, also stresses the promotion of annual health checkups for residents in the community over the age of 40

PREVENTION OF SMOKING
As in other developed countries, cigarette smoking has been shown to be a major factor in the risk for lung cancer') and myocardial infarction2) in Japan. The smoking rate among Japanese males has decreased from 80% in 1965 to slightly less than 60% at the present time. The smoking rate among Japanese females has been stable at around 15%. Although most public spaces have prohibited smoking and have provided corners for smokers, many offices have not yet completely isolated such smoking corners. Because the smoking rates are especially high among younger people, health education and consultation directed toward youth are primary issues.
Among Japanese junior high school students, Ogawa et al.3) reported smoking rates among males of 6.9% and among females of 1.2%. Kawabata et al.4) reported slightly higher rates. A recent nationwide survey5) found further increases in males (10.1%) and females (3.5%) of the same age. Principal motives for such youngsters to start smoking involved smoking by their parents and/or sibling S4) and by friends3-4). Kawabata et al.4) suggested that school teachers and parents cooperate to prevent smoking among youth. They also proposed that prevention programs be introduced in elementary schools.
At the Osaka Cancer Prevention and Detection Center, Oshima and Nakamura6) have conducted a smoking cessation contest annually since 1988. Ozasa et al.7) gave individual anti-smoking advice to male smokers visiting a health checkup clinic. Six months or one year later, cessation rates were significantly higher in the intervention group than in the control group when the participants' smoking index was less than 400 and when they had attempted to quit smoking in the past7-8). Ogawa et al.9) reported that about 36% of the participants were still successful one year after the five-day plan to stop smoking. We need to spread this kind of activity because of the persistently high smoking rate among Japanese males. PROMOTION OF EXERCISE

HEALTH RISK APPRAISAL
Health risk appraisal (HRA) tries to evaluate each individual's health risk by using previously reported epidemiological findings and the individual's lifestyle data and to recommend improvement of the lifestyle. In the United States, HRA was first developed in the 1960s, and the latest edition (Healthier People) was published in 1988. In Japan, Nakamura et al .26) developed a Japanese version of HRA, based on Japanese epidemiological data and information on personal lifestyles. Takahashi et al.27) applied HRA to obese persons. The obesity index and serum lipid levels in the HRA group tended to be lower one year after the recommendations based on the HRA were given.

COMPREHENSIVE DETERMINATION OF HEALTH STATUS
A large body of epidemiological studies has proved that lifestyle and mental stress have significant effects on the development of major adult diseases such as cerebrovascular and cardiovascular diseases, cancer, and allergic diseases. It is important to develop biomarkers that accurately predict the risk for such diseases. Morimoto28) showed that those with poor lifestyles had significantly higher levels of chromosome alterations in peripheral blood lymphocytes than did those with good lifestyles. Morimoto and Takeshita29) demonstrated that habitual alcohol drinkers with aldehyde dehydrogenase (ALDH2) deficiency had a significantly higher level of chromosome alterations than did habitual drinkers without the deficiency. Kusaka et al.30) found that those with poor lifestyles had significantly lower natural killer or lymphocyte-activated killer activities than did those with good lifestyles. This kind of study would be helpful in explaining to the public how poor lifestyles affect health status and the risk for diseases. These biomarkers would also help to confirm the effects of lifestyle changes.
In summary, it is of great importance in Japan to promote primary prevention such as a nutritionally balanced diet, obesity control, smoking cessation, moderate alcohol use, physical exercise, and control of mental stress. Japanese epidemiologists and other health professionals need to conduct further epidemiological studies related to lifestyle issues and to encourage many kinds of health promotion activities.