Opposites don’t attract: high spouse concordance for dietary supplement use in the European Prospective Investigation into Cancer in Norfolk (EPIC-Norfolk) cohort study

Abstract

Objective: Dietary supplements are commonly consumed but may not be beneficial for everyone. It is known that supplement users have healthy behaviour characteristics but until now concordance between spouses living in the same household has not been investigated and concordance may be an important behavioural determinant. Design: Prospective cohort study, cross-sectional data analysis. Setting: European Prospective Investigation into Cancer in Norfolk (EPIC-Norfolk) in the UK, recruitment between 1993 and 1998. Subjects: Married (or living as married) participants sharing a household, who attended a health examination and completed a 7 d diet diary were included in the analysis (n 11 060). The age range was 39-79 years. Results: Nearly 75 % of the households in EPIC-Norfolk were concordant in their supplement use, with 46·7 % not using supplements and 27·0 % using supplements. Concordance increased with age; the percentage of concordant couples varied less by other sociodemographic characteristics. Participants who had a spouse who used a supplement were nearly nine times more likely to use a supplement (unadjusted). Depending on participants' sex and type of supplement used, odds ratios for 'supplement use by spouse' in the prediction of participants' supplement use varied between 6·2 and 11·7 adjusted for participants' age, smoking status, BMI, social class, education level and physical activity. Conclusions: 'Supplement use by spouse' is an independent and the strongest predictor of participants' supplement use. This phenomenon can be useful in the design of studies and health interventions; or when assessing risk of excessive intake from dietary supplements. Keywords Dietary supplement Concordance Spouse Sociodemographic variablesIn the European Prospective Investigation into Cancer in Norfolk (EPIC-Norfolk), dietary supplements were reported by 44·8 % of women and 31·7 % of men in their 7 d diet diary (7dDD) (1) , of which cod-liver oil was the most commonly consumed supplement (2) . Studies in the UK have identified the characteristics of supplement users (SU) and found that SU are more likely to have a normal weight, a higher social class and show more health-conscious behaviours (3)(4)(5) . They have focused on the SU as an individual; however, people sharing a household could influence each other's behaviour, as has been shown for other types of behaviours such as smoking (6) . Concordance in the choice of using a supplement might partly explain why not all SU consistently show healthy behaviours; their spouse might have influenced them without the SU showing the known characteristics of a SU.

Spousal diabetes status as a risk factor for incident type 2 diabetes: a prospective cohort study and meta-analysis

“…The second theory alludes to spouses converging in their behaviors and lifestyle over the course of the marriage as a result of engaging in similar activities, practices, and habits [42,14,15]. In support of both theories, substantial spousal resemblance has been reported for blood pressure [43], glucose [5,6], lipids [9], physical activity [44,45], sedentary lifestyle [46], diet and eating patterns [47,48], dietary supplement use [49], sleeping patterns [50] and smoking [48]. For instance, having an obese spouse is reported to be associated with a 37% to a 2-fold risk of obesity in the other spouse [51,52].…”

Vitamin C and the Lens: New Insights into Delaying the Onset of Cataract

“…In a follow up study, the risk of age related cataract was investigated in Swedish men and revealed that the use of multiple supplements in combination with vitamin C was not associated with cataract risk, but that the use of high dose vitamin C may increase the risk of cataract [ 118 ]. The use of dietary supplements in the form of multivitamins or a specific vitamin is widespread ranging from 22% to 53% in studies conducted from USA, Canada, Korea, UK, Sweden, Germany, and France [ 119 , 120 , 121 , 122 , 123 , 124 , 125 ]. While these supplements are taken for a range of health reasons, based on findings from the above clinical trials, the long-term value of vitamin C supplementation in decreasing the risk of cataract progression is questionable, and at high doses may in fact exacerbate cataract progression.…”

Online Purchase of Health Supplements and Traditional and Complementary Medicine (T&CM) Products: A Qualitative Study

“…At the same time, the role of traditional and complementary medicine (T&CM) has also gained attention around the globe, being an alternative to the conventional medicine in healthcare system. About 40.2% of U.K. adults (1) and 52% of U.S. population (2) reported health supplements use, while 16.4% of Japanese mothers provided health supplements to their children (3). Apart from that, T&CM medicine usage is also common among the U.S. population, where 17.7% of them had used nonvitamin, nonmineral, or natural products in 2007 (4).…”