Browsing by Subject "abstinence"

There has been a steady increase in alcohol consumption in Finland since the 1969 law reform, which allowed convenience stores to sell mild alcoholic beverages such as beer. Since then, the yearly consumption has increased from 3.6 liters in 1968 to 10.8 liters of pure alcohol per capita in 2016. Increasing levels of alcohol use tend to produce high economic and population health costs. Understanding why changes in alcohol consumption behavior occur enables development of more efficient prevention and intervention programs. Alcohol consumption is not distributed equally across the population. Liberalization of Finnish alcohol policy and culture from the 1960s onwards made alcohol more available than ever before, and especially the post-war cohorts started to use significantly more alcohol than the generations before them. Evidently, there are between-individual differences in alcohol use in addition to group level differences. According to decades of research, approximately 50% of the variation between individuals in alcohol consumption can be explained by genetic sources. In other words, the heritability of alcohol use is 50%, while non-genetic factors explain the other half. However, heritability is not a static estimate, but can be modified by social forces. While it has been established that the younger generations consume significantly more alcohol than generations preceding them, only a few studies to date have examined whether the importance of genetic influences on alcohol consumption is dependent on birth cohort or generation. The current study examined, if social control during a specific time in history (e.g. how strict is alcohol policy and the cultural climate while a generation is growing up) can affect the heritability of alcohol use in later life. Mean level differences in alcohol consumption quantity and abstinence trajectories of birth cohorts were also estimated. The older Finnish twin cohort data consists of all Finnish same-sex twin pairs born before 1958 with both co-twins alive in 1975 (n = 24 481). The data were collected in four waves in 1975, 1981, 1990, and 2011. Age of the participants at study baseline in 1975 ranged from 18 to 95. Participants were grouped into seven 10-year cohorts based on their birth year. Mean trajectories of alcohol consumption quantity and abstinence over the life course were estimated for men and women separately with hierarchical growth curve models. Cohort effects and age-by-cohort interactions were also investigated. The heritability of alcohol consumption and abstinence was estimated using structural equation modelling. Birth cohort effects on heritability of alcohol use were examined by comparing heritability estimates of different cohorts at similar ages. Mean levels of alcohol consumption quantity were the highest in the youngest birth cohorts. Women drank less than men in all cohorts. The decline in the quantity of monthly alcohol use due to aging was relatively small, and appeared to be more prominent in the older birth cohorts. The odds of abstaining became lower in every successive birth cohort. Moreover, women were more likely to be abstinent than men. The aging effect of increasing abstinence was notable only in the oldest birth cohorts. Birth cohort differences in the heritability of alcohol consumption quantity were found: heritability was 25% (CI 12–38%) in the older generation (born 1901–1920) and 48% (CI 39–50%) in the younger generation (born 1941–1957) of men at the age of 54–74. For women, heritability was 60% in the older and younger generation. In alcohol abstinence, a single model was run for men and women. The shared environmental component explained a large proportion of the variation in the older generation (43%), whereas unique environment (54%) and additive genetic influences (40%) were more important among the younger generation. The findings from the present study suggest that social control during a specific time in history may have a long-term impact on alcohol consumption behavior (i.e. how and why alcohol is used) of an entire generation growing up during that period.