Objective There has been a dramatic increase in the use of dietary supplements in Western societies over the past decades. Our understanding of the prevalence of Ω-3 fatty acid supplement consumption is of significance for future nutrition planning, health promotion and care delivery. However, we know little about Ω-3 fatty acid supplement consumption or users. This paper, drawing upon the largest dataset with regard to Ω-3 fatty acid supplement use (n=266 848), examines the use and users of this supplement among a large sample of older Australians living in New South Wales.

Design A cross-sectional study. Data were analysed from the 45 and Up Study, the largest study of healthy ageing ever undertaken in the Southern Hemisphere.

Setting New South Wales, Australia.

Participants 266 848 participants of the 45 and Up Study.

Primary and secondary outcome measures Participants’ use of Ω-3, demographics (geographical location, marital status, education level, income and level of healthcare insurance) and health status (quality of life, history of smoking and alcohol consumption, health conditions) were measured.

Results Of the 266 848 participants, 32.6% reported having taken Ω-3 in the 4 weeks prior to the survey. Use of Ω-3 fatty acid supplements was higher among men, non-smokers, non-to-mild (alcoholic) drinkers, residing in a major city, having higher income and private health insurance. Osteoarthritis, osteoporosis, high cholesterol and anxiety and/or depression were positively associated with  Ω-3 fatty acid supplement use, while cancer and high blood pressure were negatively associated with use of Ω-3 fatty acid supplements.

Conclusions This study, analysing data from the 45 and Up Study cohort, suggests that a considerable proportion of older Australians consume Ω-3 fatty acid supplements. There is a need for primary healthcare practitioners to enquire with patients about this supplement use and for work to ensure provision of good-quality information for patients and providers with regard to Ω-3 fatty acid products.