Original article
Associations of ikigai as a positive psychological factor with all-cause mortality and cause-specific mortality among middle-aged and elderly Japanese people: Findings from the Japan Collaborative Cohort Study

https://doi.org/10.1016/j.jpsychores.2008.10.018Get rights and content

Abstract

Objective

To determine whether presence of ikigai as a positive psychological factor is associated with decreased risks for all-cause and cause-specific mortality among middle-aged and elderly Japanese men and women.

Methods

From 1988 to 1990, a total of 30,155 men and 43,117 women aged 40 to 79 years completed a lifestyle questionnaire including a question about ikigai. Mortality follow-up was available for a mean of 12.5 years and was classified as having occurred in the first 5 years or the subsequent follow-up period. Associations between ikigai and all-cause and cause-specific mortality were assessed using a Cox's regression model. Multivariate hazard ratios (HRs) were adjusted for age, body mass index, drinking and smoking status, physical activity, sleep duration, education, occupation, marital status, perceived mental stress, and medical history.

Results

During the follow-up period, 10,021 deaths were recorded. Men and women with ikigai had decreased risks of mortality from all causes in the long-term follow-up period; multivariate HRs (95% confidence intervals, CIs) were 0.85 (0.80–0.90) for men and 0.93 (0.86–1.00) for women. The risk of cardiovascular mortality was reduced in men with ikigai; the multivariate HR (95% CI) was 0.86 (0.76–0.97). Furthermore, men and women with ikigai had a decreased risk for mortality from external causes; multivariate HRs (95% CIs) were 0.74 (0.59–0.93) for men and 0.67 (0.51–0.88) for women.

Conclusion

The findings suggest that a positive psychological factor such as ikigai is associated with longevity among Japanese people.

Introduction

Negative psychological factors, such as depression, anxiety, hopelessness, psychological stress, and psychological distress, are associated with increased risks of coronary heart disease [1], [2], [3], [4], [5] and cerebrovascular disease [6], [7], [8]. Recently, there is growing evidence that positive psychological factors are associated with greater longevity, reduced risk of cardiovascular disease, and reduced risk of physical disability [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], [19].

In this study, we focused on ikigai as a psychological factor that might be associated with all-cause mortality and cause-specific mortality. Ikigai is a Japanese word that is believed to be an important factor for achieving better health and a fulfilling life [20]. Ikigai is defined in Japanese dictionaries as something to live for, the joy and goal of living, a life worth living, and the happiness and benefit of being alive. It is also understood to be a comprehensive concept including not only pleasure and happiness but also the meaning of one's life and self-realization. Although there is no term fully comparable to ikigai in English [21], we considered that the concept of ikigai is similar to both hedonic and eudaimonic views of well-being; a hedonic view defines well-being in terms of pleasure attainment and pain avoidance, and a eudaimonic view defines well-being in terms of degree to which a person is fully functioning [22]. Therefore, ikigai may play an important role in health-related outcomes as well as other positive psychological factors.

Recently, some prospective studies in Japan have shown that the absence of ikigai was associated with an increased risk for all-cause mortality [23], [24], [25], [26]. However, age-, sex-, and/or cause-specific mortality risks were not estimated in most of those studies because of a relatively small study population in a certain area and a short follow-up period. The purpose of this study was to determine whether presence of ikigai is associated with decreased risks for all-cause and cause-specific mortality among middle-aged and elderly Japanese men and women, using data from the Japan Collaborative Cohort (JACC) Study, which has a larger study population and a longer follow-up period than those in previous studies.

Section snippets

Materials and methods

Data used for this study were obtained from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC study), a nationwide multicenter collaborative study sponsored by the Ministry of Education, Culture, Sports, Science, and Technology of Japan (Monbukagakusho). The methods used in the JACC study have been described in detail elsewhere [27], [28]. Briefly, a baseline survey was conducted between 1988 and 1990, enrolling 127,477 apparently healthy subjects living in 45 areas

Results

During the follow-up period (average, 12.5 years; total of 918,644 person-years), a total of 10,021 deaths (5855 men and 4166 women) were recorded. The causes of death included cancer in 2376 cases, cardiovascular disease in 1599 cases (coronary heart disease in 356 cases, cerebrovascular diseases in 724 cases), and external causes in 430 cases in men. The corresponding numbers of deaths in women were 1421, 1405 (273, 648), and 331, respectively.

Table 1 shows selected baseline characteristics

Discussion

We demonstrated that the presence of ikigai contributed to a reduction of risk for mortality from all causes among middle-aged and elderly Japanese men and women. For cardiovascular mortality, men with ikigai had a significantly lower risk and women with ikigai tended to have a lower risk than those without ikigai. We also showed that mortality risks for cerebrovascular disease and coronary heart disease tended to be lower among men and women with ikigai than among those without ikigai.

Acknowledgments

The authors express their appreciation to Dr. Kunio Aoki, Professor Emeritus, Nagoya University School of Medicine and the former chairman of the JACC study Group, and Dr. Haruo Sugano, the former Director of the Cancer Institute of the Japanese Foundation for Cancer Research, who greatly contributed to initiating the study, and Dr. Yoshiyuki Ohno, Professor Emeritus, Nagoya University School of Medicine, who was the past chairman of the study. The authors also wish to thank Dr. Akizumi

References (39)

  • PitkalaKH et al.

    Positive life orientation as a predictor of 10-year outcome in an aged population

    J Clin Epidemiol

    (2004)
  • DaltonS et al.

    Mind and cancer. Do psychological factors cause cancer?

    Eur J Cancer

    (2002)
  • HemingwayH et al.

    Evidence based cardiology: psychosocial factors in the aetiology and prognosis of coronary heart disease. Systematic review of prospective cohort studies

    BMJ

    (1999)
  • AndaR et al.

    Depressed affect, hopelessness, and the risk of ischemic heart disease in a cohort of U.S. adults

    Epidemiology

    (1993)
  • EversonS et al.

    Hopelessness and risk of mortality and incidence of myocardial infarction and cancer

    Psychosom Med

    (1996)
  • StansfeldSA et al.

    Psychological distress as a risk factor for coronary heart disease in the Whitehall II Study

    Int J Epidemiol

    (2002)
  • RasulF et al.

    Psychological distress, physical illness, and risk of coronary heart disease

    J Epidemiol Community Health

    (2005)
  • EversonSA et al.

    Depressive symptoms and increased risk of stroke mortality over a 29-year period

    Arch Intern Med

    (1998)
  • JonasBS et al.

    Symptoms of depression as a prospective risk factor for stroke

    Psychosom Med

    (2000)
  • MayM et al.

    Does psychological distress predict the risk of ischemic stroke and transient ischemic attack? The Caerphilly Study

    Stroke

    (2002)
  • PressmanSD et al.

    Does positive affect influence health?

    Psychol Bull

    (2005)
  • BlazerDG et al.

    What symptoms of depression predict mortality in community-dwelling elders?

    J Am Geriatr Soc

    (2004)
  • Koivumaa-HonkanenH et al.

    Self-reported life satisfaction and 20-year mortality in healthy Finnish adults

    Am J Epidemiol

    (2000)
  • OstirGV et al.

    Emotional well-being predicts subsequent functional independence and survival

    J Am Geriatr Soc

    (2000)
  • GiltayEJ et al.

    Dispositional optimism and all-cause and cardiovascular mortality in a prospective cohort of elderly Dutch men and women

    Arch Gen Psychiatry

    (2004)
  • OstirGV et al.

    The association between emotional well-being and the incidence of stroke in older adults

    Psychosom Med

    (2001)
  • GiltayEJ et al.

    Dispositional optimism and the risk of cardiovascular death: the Zutphen Elderly Study

    Arch Intern Med

    (2006)
  • KubzanskyLD et al.

    Is the glass half empty or half full? A prospective study of optimism and coronary heart disease in the normative aging study

    Psychosom Med

    (2001)
  • KawamotoR et al.

    Self-reported functional ability predicts three-year mobility and mortality in community-dwelling older persons

    Geriatr Gerontol Int

    (2002)
  • Cited by (0)

    The JACC Study has been supported by Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Sports and Culture of Japan (nos. 61010076, 62010074, 63010074, 1010068, 2151065, 3151064, 4151063, 5151069, 6279102, 11181101, 17015022, 18014011).

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