Association between fish consumption and all-cause and cause-specific mortality in Japan: NIPPON DATA80, 1980-99

A Japanese diet and 19-year mortality: national integrated project for prospective observation of non-communicable diseases and its trends in the aged, 1980

Few studies have examined the association between Japanese diet and mortality outcomes. We analysed the relationship between a healthy Japanese diet and all-cause and cause-specific mortality using the database from the National Integrated Project for Prospective Observation of Non-Communicable Diseases and its Trends in the Aged, 1980. At baseline in 1980, data were collected on study participants aged > or =30 years from randomly selected areas in Japan. We defined a measure of a healthy reduced-salt Japanese diet based on seven components from FFQ. The total score ranged from 0 to 7, with 0 being least healthy and 7 being most healthy. Participants were divided into approximate tertiles of dietary scores (0-2, 3 and 4-7 scores). After excluding participants with co-morbidities, we followed 9086 participants (44 % men) for 19 years. There were 1823 all-cause and 654 cardiovascular deaths during the follow-up. With the dietary score group 0-2 serving as a reference, the Cox multivariate-adjusted hazard ratios for groups with scores 3 and 4-7 were 0.92 (95 % CI 0.83, 1.04) and 0.78 (95 % CI 0.70, 0.88) for all-cause mortality (trend P < 0.0001), and 0.91 (95 % CI 0.75, 1.10) and 0.80 (95 % CI 0.66, 0.97) for cardiovascular mortality (trend P = 0.022). Adherence to a healthy reduced-salt Japanese diet was associated with an approximate 20 % lower rate of all-cause and cardiovascular mortality.

Fish, omega-3 polyunsaturated fatty acids, and mortality from cardiovascular diseases in a nationwide community-based cohort of Japanese men and women the JACC (Japan Collaborative Cohort Study for Evaluation of Cancer Risk) Study

OBJECTIVES

The objective of our study was to test the hypothesis that fish or omega-3 polyunsaturated fatty acids (PUFA) intakes would be inversely associated with risks of mortality from ischemic heart disease, cardiac arrest, heart failure, stroke, and total cardiovascular disease.

BACKGROUND

Data on associations of dietary intake of fish and of omega-3 PUFA with risk of cardiovascular disease among Asian societies have been limited.

METHODS

We conducted a prospective study consisting of 57,972 Japanese men and women. Dietary intakes of fish and omega-3 PUFA were determined by food frequency questionnaire, and participants were followed up for 12.7 years. Hazard ratios and 95% confidence intervals were calculated according to quintiles of fish or omega-3 PUFA intake.

RESULTS

We observed generally inverse associations of fish and omega-3 PUFA intakes with risks of mortality from heart failure (multivariable hazard ratio [95% confidence interval] for highest versus lowest quintiles = 0.76 [0.53 to 1.09] for fish and 0.58 [0.36 to 0.93] for omega-3 PUFA). Associations with ischemic heart disease or myocardial infarction were relatively weak and not statistically significant after adjustment for potential risk factors. Neither fish nor omega-3 PUFA dietary intake was associated with mortality from total stroke, its subtypes, or cardiac arrest. For mortality from total cardiovascular disease, intakes of fish and omega-3 PUFA were associated with 18% to 19% lower risk.

CONCLUSIONS

We found an inverse association between fish and omega-3 PUFA dietary intakes and cardiovascular mortality, especially for heart failure, suggesting a protective effect of fish intake on cardiovascular diseases.

Fish consumption and its motives in households with versus without self-reported medical history of CVD: a consumer survey from five European countries

Background

The purpose of this study was to explore the cross-cultural differences in the frequency of fish intake and in motivations for fish consumption between people from households with (CVD+) or without (CVD-) medical history of cardiovascular disease, using data obtained in five European countries.

Methods

A cross-sectional consumer survey was carried out in November-December 2004 with representative household samples from Belgium, the Netherlands, Denmark, Poland and Spain. The sample consisted of 4,786 respondents, aged 18–84 and who were responsible for food purchasing and cooking in the household.

Results

Individuals from households in the CVD+ group consumed fish more frequently in Belgium and in Denmark as compared to those in the CVD- group. The consumption of fatty fish, which is the main sources of omega-3 PUFA associated with prevention of cardiovascular diseases, was on the same level for the two CVD groups in the majority of the countries, except in Belgium where CVD+ subjects reported to eat fatty fish significantly more frequently than CVD- subjects. All respondents perceived fish as a very healthy and nutritious food product. Only Danish consumers reported a higher subjective and objective knowledge related to nutrition issues about fish. In the other countries, objective knowledge about fish was on a low level, similar for CVD+ as for CVD- subjects, despite a higher claimed use of medical information sources about fish among CVD+ subjects.

Conclusion

Although a number of differences between CVD- and CVD+ subjects with respect to their frequency of fish intake are uncovered, the findings suggest that fish consumption traditions and habits – rather than a medical history of CVD – account for large differences between the countries, particularly in fatty fish consumption. This study exemplifies the need for nutrition education and more effective communication about fish, not only to the people facing chronic diseases, but also to the broader public. European consumers are convinced that eating fish is healthy, but particular emphasis should be made on communicating benefits especially from fatty fish consumption.

Low-risk profile for cardiovascular disease and mortality in Japanese

BACKGROUND

Some studies focusing on low-risk profiles for cardiovascular disease have been reported in Western countries. Yet, few reports have examined, with substantial longevity, the low-risk profile for cardiovascular disease in the Japanese population. This study examines whether having a favorable risk factor profile yields lower all-cause mortality and whether the proportion of those with a low-risk profile is larger in the Japanese population.

METHODS AND RESULTS

A total of 8,339 men and women aged 30-69 years without a history of cardiovascular diseases for 19 years, who had participated in the 1980 National Survey on Circulatory Disorders after being randomly selected from throughout Japan, were followed. Low risk was defined as having all of the following baseline characteristics: blood pressure (BP) <120/80 mmHg; no antihypertensive medication; serum cholesterol 160-240 mg/dl (4.14-6.22 mmol/L); no history of diabetes; and non-smoker. The long-term mortality of the low-risk group was compared with that of others using the Cox proportional hazard model. The prevalence of low risk was 9.4% of all participants. The multivariate-adjusted hazard ratios for low-risk individuals compared with others were as follows: 0.33 (95% confidence intervals (CI), 0.15-0.74) for cardiovascular disease and 0.63 (95% CI, 0.46-0.88) for all-cause mortality. The most attributable risk factor for all-cause mortality was high BP (>or=120/80 mmHg).

CONCLUSION

Japanese individuals with favorable cardiovascular disease risk profiles had lower mortality from cardiovascular disease and all-causes than those without.

Impaired glucose tolerance is a risk factor for stroke in a Japanese sample--the Funagata study

Impaired glucose tolerance (IGT) is a known risk factor for cardiovascular disease, which includes stroke as well as coronary heart disease (CHD). We investigated whether IGT is a risk factor for stroke. The incidence of stroke and CHD in a cohort population (n = 2938) consisting of participants of the 1990-1997 Funagata study was assessed through interviews with the participants and their family members and reviews of death certificates and residence transfer documents through 2002. Glucose tolerance at the baseline was classified according to the criteria of the 1998 World Health Organization (normal glucose tolerance, n = 2189; IGT, n = 320; and diabetes, n = 286). The cumulative incidences among the groups were compared using the Kaplan-Meier product-limit method, and the risks of these conditions were evaluated by person-year and Cox proportional hazard methods. During the 147-month (mean, 116.5 months) follow-up, 158 (normal glucose tolerance, IGT, and diabetes: 94, 35, and 29, respectively) participants experienced a stroke and 94 (54, 16, and 24, respectively) experienced CHD. By the person-year method, IGT and diabetes were shown to be significant risk factors for stroke and CHD (odds ratio, 1.87 [95% confidence interval, 1.73-2.03] and 3.57 [3.21-3.98] for stroke; 1.53 [1.31-1.78] and 3.47 [2.91-4.14] for CHD, respectively). Cox proportional hazard analysis showed that IGT was a risk factor for stroke (age-, sex-, and hypertension-adjusted hazard ratio: 1.51 [95% confidence interval, 1.02-2.24], P = .039) but not for CHD (1.21 [0.69-2.313], .509). Impaired glucose tolerance is a risk factor for future stroke in a Japanese population.

Does self-reported history of hypertension predict cardiovascular death? Comparison with blood pressure measurement in a 19-year prospective study

OBJECTIVES

Hypertension as assessed by blood pressure (BP) measurement is one of the most important risk factors for cardiovascular diseases (CVD). Self-reported history of hypertension (self-reported HT) is an easy way to obtain information on BP and is known to have a certain sensitivity and high specificity for hypertension confirmed by BP measurement (confirmative HT). Thus, it might predict CVD mortality, but few studies have reported on this relationship.

METHODS

We followed 6427 participants aged 30-59 years without a history of CVD for 19 years. The multivariate-adjusted hazard ratio (HR) of CVD mortality was estimated by the Cox proportional hazard model.

RESULTS

The sensitivity and specificity of self-reported HT for confirmative HT were 52-65% and 95%, respectively. The multivariate-adjusted HR of self-reported HT for CVD death was 2.49 [95% confidence interval (CI) = 1.72-3.61]. Compared to participants with neither self-reported HT nor confirmative HT, those with confirmative HT showed a consistently higher HR for CVD mortality. Self-reported HT without confirmative HT was also significantly related to CVD mortality (HR = 2.10, 95% CI = 1.04-4.26). These tendencies were unchanged when we further adjusted for systolic BP (SBP) level. The age-adjusted mortality rate of individuals with self-reported HT corresponded to the age-adjusted mortality rate of individuals whose SBP was 160-179 mmHg.

CONCLUSION

Self-reported HT could screen one-half of the participants for confirmative HT and was significantly associated with CVD mortality. These results indicate that self-reported HT can be a useful tool to screen for individuals with high BP if it is difficult to perform BP measurements continuously among all members of a community.

Intake of fish and long-chain n−3 fatty acids and the risk of coronary heart mortality in men and women

This prospective study investigated the relationship between the consumption of fish and intake of long-chain n−3 fatty acids and the risk of coronary heart mortality in 2775 men and 2445 women aged from 30 to 79 years who were free of CHD and had participated in a health examination survey from 1967 to 1972. In total, 335 men and 163 women died of CHD during a follow-up until the end of 1992. A dietary history interview method provided data on habitual consumption of fish and other foods over the preceding year at baseline. The intakes of long-chain n−3 fatty acids were calculated on the basis of food composition values of Finnish foods. Higher consumption of fish was associated with a decreased risk of CHD among women, whereas no significant association was seen among men. The relative risk between the highest and the lowest quintile for fish consumption was 1·00 (95% CI 0·70, 1·43; p for trend 0·83) for men and 0·59 (95% CI 0·36, 0·99; p for trend 0·02) for women in analysis adjusting for age, energy intake, geographical area, BMI, serum cholesterol, blood pressure, smoking, occupation and diabetes; however, after adjustment for dietary confounders this association was no longer significant. The intake of n−3 fatty acids was not significantly associated with the risk of CHD in either men or women. In conclusion, our results for women are in line with the suggested protective effect of fish consumption against CHD but a similar association was not, however, found in men.

Life expectancy among Japanese of different smoking status in Japan: NIPPON DATA80

BACKGROUND

The life expectancy is an important measure for describing health status among population. Several studies from the United States and Europe showed the harm of smoking by describing the life expectancies with different smoking status. No such study is examined in Japan, the country with the world's highest life expectancy irrespective of high smoking rate among men.

METHODS

The abridged life table method was applied to calculate the life expectancies of men and women among different smoking status from age 40 until age 85. Age-specific mortality rates stratified by different smoking status were obtained from follow-up data from random sample in Japanese population (NIPPON DATA80).

RESULTS

Proportion of current smokers was 62.9% in men and 8.8% in women at the baseline survey in 1980. The life expectancies of 40-year-old never smokers, ex-smokers and current smokers were 42.1, 40.4, and 38.6 years in men and 45.6, 45.9, and 43.4 years in women. The life expectancy of 40-year-old men who smoked less than one pack per day was 39.0 and was longer than that of those who smoked one or two packs (38.8) and more than two packs (38.1).

CONCLUSION

Life expectancy decreased gradually as the grade of smoking increased in the Japanese population.

Dietary patterns and cardiovascular disease mortality in Japan: a prospective cohort study

BACKGROUND

Although ecological observations suggest that the Japanese diet may reduce the risk of cardiovascular disease (CVD), the impact of a Japanese dietary pattern upon mortality due to CVD is unclear.

METHODS

We prospectively assessed the association between dietary patterns among the Japanese and CVD mortality. Dietary information was collected from 40 547 Japanese men and women aged 40-79 years without a history of diabetes, stroke, myocardial infarction or cancer at the baseline in 1994.

RESULTS

During 7 years of follow-up, 801 participants died of CVD. Factor analysis (principal component) based on a validated food frequency questionnaire identified three dietary patterns: (i) a Japanese dietary pattern highly correlated with soybean products, fish, seaweeds, vegetables, fruits and green tea, (ii) an 'animal food' dietary pattern and (iii) a high-dairy, high-fruit-and-vegetable, low-alcohol (DFA) dietary pattern. The Japanese dietary pattern was related to high sodium intake and high prevalence of hypertension. After adjustment for potential confounders, the Japanese dietary pattern score was associated with a lower risk of CVD mortality (hazard ratio of the highest quartile vs the lowest, 0.73; 95% confidence interval: 0.59-0.90; P for trend = 0.003). The 'animal food' dietary pattern was associated with an increased risk of CVD, but the DFA dietary pattern was not.

CONCLUSION

The Japanese dietary pattern was associated with a decreased risk of CVD mortality, despite its relation to sodium intake and hypertension.

The relationship between serum total cholesterol and all-cause or cause-specific mortality in a 17.3-year study of a Japanese cohort

No study has shown a positive relationship between hypercholesterolemia and all-cause mortality in the Japanese population. Therefore, a cohort study of 17.3 years' duration was conducted on 9216 participants aged 30 years or older, selected randomly from throughout Japan. In both the lowest (<4.14mmol/L, 160mg/dl) and highest (>or=6.71mmol/L, 260mg/dl) total cholesterol (TC) groups, there was a positive association between TC and risk of all-cause mortality (hazard ratio (HR) 1.19; 95% confidence interval (CI), 1.03-1.37 and 1.36 (95% CI, 1.05-1.77), respectively). The lowest TC group had an increased risk of liver disease (HR 3.03; 95% CI, 1.70-5.43), whereas the highest TC group had an increased risk of coronary heart disease (HR 3.81; 95% CI, 1.70-5.43). After exclusion of deaths due to liver disease during the entire follow-up period and all-cause deaths within the first 5 years of follow-up, the increased HR in the lowest TC group disappeared (HR 1.05; 95% CI, 0.89-1.24). Although the cut-off point seemed to be higher than that for Western populations, hypercholesterolemia was shown to be positively associated with all-cause mortality in Japan.

n-3 Fatty acids from fish or fish-oil supplements, but not alpha-linolenic acid, benefit cardiovascular disease outcomes in primary- and secondary-prevention studies: a systematic review

Studies on the relation between dietary n-3 fatty acids (FAs) and cardiovascular disease vary in quality, and the results are inconsistent. A systematic review of the literature on the effects of n-3 FAs (consumed as fish or fish oils rich in eicosapentaenoic acid and docosahexaenoic acid or as alpha-linolenic acid) on cardiovascular disease outcomes and adverse events was conducted. Studies from MEDLINE and other sources that were of > or =1 y in duration and that reported estimates of fish or n-3 FA intakes and cardiovascular disease outcomes were included. Secondary prevention was addressed in 14 randomized controlled trials (RCTs) of fish-oil supplements or of diets high in n-3 FAs and in 1 prospective cohort study. Most trials reported that fish oil significantly reduced all-cause mortality, myocardial infarction, cardiac and sudden death, or stroke. Primary prevention of cardiovascular disease was reported in 1 RCT, in 25 prospective cohort studies, and in 7 case-control studies. No significant effect on overall deaths was reported in 3 RCTs that evaluated the effects of fish oil in patients with implantable cardioverter defibrillators. Most cohort studies reported that fish consumption was associated with lower rates of all-cause mortality and adverse cardiac outcomes. The effects on stroke were inconsistent. Evidence suggests that increased consumption of n-3 FAs from fish or fish-oil supplements, but not of alpha-linolenic acid, reduces the rates of all-cause mortality, cardiac and sudden death, and possibly stroke. The evidence for the benefits of fish oil is stronger in secondary- than in primary-prevention settings. Adverse effects appear to be minor.

Treatment of Hyperlipidemia from Japanese Evidence

The treatment of hyperlipidemia is aimed at preventing cardiovascular disease (CVD) and coronary heart disease (CHD). As the incidence of CHD in Japan is about one-third lower and that of stroke is two-fold higher compared to Western countries, and the doses of lipid-lowering drugs used in foreign randomized controlled clinical trials (RCTs) are much higher than in general use in Japan, it remains unclear whether the results of RCTs conducted in Western countries could be extrapolated to Japanese patients. Recently, two major large-scale, prospective, RCTs in Japanese hypercholesterolmic patients, the Management of Elevated Cholesterol in the Primary Prevention of Adult Japanese (MEGA) study and the Japan EPA Lipid Intervention Study (JELIS), have been reported. Japanese epidemiological studies and Japanese clinical studies are reviewed. The evidence suggests that hypercholesterolemia, hypertriglyceridemia, and low HDL-cholesterol are strongly associated with increased CHD risk. Lipid-lowering medication shows beneficial effects even in low-risk populations; however, the data did not support that lower cholesterol is better. The safety and efficacy of hyperlipidemia treatment in Japanese patients are discussed.

Dietary approaches that delay age-related diseases

Reducing food intake in lower animals such as the rat decreases body weight, retards many aging processes, delays the onset of most diseases of old age, and prolongs life. A number of clinical trials of food restriction in healthy adult human subjects running over 2-15 years show significant reductions in body weight, blood cholesterol, blood glucose, and blood pressure, which are risk factors for the development of cardiovascular disease and diabetes. Lifestyle interventions that lower energy balance by reducing body weight such as physical exercise can also delay the development of diabetes and cardiovascular disease. In general, clinical trials are suggesting that diets high in calories or fat along with overweight are associated with increased risk for cardiovascular disease, type 2 diabetes, some cancers, and dementia. There is a growing literature indicating that specific dietary constituents are able to influence the development of age-related diseases, including certain fats (trans fatty acids, saturated, and polyunsaturated fats) and cholesterol for cardiovascular disease, glycemic index and fiber for diabetes, fruits and vegetables for cardiovascular disease, and calcium and vitamin D for osteoporosis and bone fracture. In addition, there are dietary compounds from different functional foods, herbs, and neutraceuticals such as ginseng, nuts, grains, and polyphenols that may affect the development of age-related diseases. Long-term prospective clinical trials will be needed to confirm these diet-disease relationships. On the basis of current research, the best diet to delay age-related disease onset is one low in calories and saturated fat and high in wholegrain cereals, legumes, fruits and vegetables, and which maintains a lean body weight. Such a diet should become a key component of healthy aging, delaying age-related diseases and perhaps intervening in the aging process itself. Furthermore, there are studies suggesting that nutrition in childhood and even in the fetus may influence the later development of aging diseases and lifespan.