Patterns of dietary supplement use among older men and women in the UK: findings from the Hertfordshire Cohort Study

The balance between food and dietary supplements in the general population

In the past, vitamins and minerals were used to cure deficiency diseases. Supplements nowadays are used with the aim of reducing the risk of chronic diseases of which the origins are complex. Dietary supplement use has increased in the UK over recent decades, contributing to the nutrient intake in the population, but not necessarily the proportion of the population that is sub-optimally nourished; therefore, not reducing the proportion below the estimated average requirement and potentially increasing the number at risk of an intake above the safety limits. The supplement nutrient intake may be objectively monitored using circulation biomarkers. The influence of the researcher in how the supplements are grouped and how the nutrient intakes are quantified may however result in different conclusions regarding their nutrient contribution, the associations with biomarkers, in general, and dose-response associations specifically. The diet might be sufficient in micronutrients, but lacking in a balanced food intake. Since public-health nutrition guidelines are expressed in terms of foods, there is potentially a discrepancy between the nutrient-orientated supplement and the quality of the dietary pattern. To promote health, current public-health messages only advocate supplements in specific circumstances, but not in optimally nourished populations.

Fish oil supplement use in New Zealand: A cross-sectional survey

OBJECTIVE

The aims of the survey were to determine: (i) the percentage of fish oil supplement users in a sample population; (ii) why people take fish oil supplements; (iii) where fish oil supplements are stored as well as the average daily dosage; (iv) what dietary and lifestyle behaviours are associated with fish oil supplement use.

DESIGN

An online cross-sectional survey.

SETTING

New Zealand.

RESPONDENTS

A total of 334 New Zealand residents over the age of 18.

RESULTS

Fish oil supplements were taken by 21.9% of respondents. Reasons for taking fish oil supplements were - 72.6% for 'general well-being', 54.8% to 'improve brain function', 31.5% for 'pain/inflammation', 12.3% to 'lower cholesterol levels' and 11% for 'a dietary insufficiency'. Approximately 26% of fish oil users reported taking a dose of fish oil supplements that would meet the recommended daily intake of 400-600 mg combined docosahexaenoic acid and eicosapentaenoic acid, and only 6.8% of fish oil users reported storing their fish oil supplements in the refrigerator. After controlling for other characteristics including age, gender, ethnicity and body mass index, fish oil supplementation use was most likely among respondents who already eat oily fish and least likely in respondents who regularly eat nuts and seeds.

CONCLUSIONS

Fish oil supplements are a commonly used supplement in New Zealand, yet questions remain about the role of these supplements in improving health outcomes. Safety issues related to manufacturing and storage conditions indicate that there is an urgency in answering these questions.

Characterisation of vitamin and mineral supplement users differentiated according to their motives for using supplements: results of the German National Nutrition Monitoring (NEMONIT)

OBJECTIVE

To characterise German vitamin and mineral supplement users differentiated by their motives for supplement use.

DESIGN

Data were obtained from the German National Nutrition Monitoring (2010/11) via two 24 h dietary recalls and a telephone interview. Motive-based subgroups of supplement users were identified by factor and cluster analysis. Sociodemographic, lifestyle, health and dietary characteristics and supplement use were examined. Differences were analysed using χ 2 tests, logistic and linear regression models.

SETTING

Germany, nationwide.

SUBJECTS

Individuals (n 1589) aged 18-80 years.

RESULTS

Three motive-based subgroups were identified: a 'Prevention' subgroup (n 324), characterised by the motive to prevent nutrient deficiencies; a 'Prevention and additional benefits' subgroup (n 166), characterised by motives to prevent health problems and improve well-being and performance; and a 'Treatment' subgroup (n 136), characterised by motives to treat nutrient deficiencies or diseases. Members of the two prevention subgroups had a higher Healthy Eating Index score and tended to be more physically active than non-users. Those in the 'Prevention and additional benefits' subgroup supplemented with a greater number of micronutrients. Members of the 'Treatment' subgroup tended to be older and have a lower self-reported health status than non-users, and supplemented with a smaller number of micronutrients.

CONCLUSIONS

The majority of supplement users take supplements for preventive purposes and they are more health conscious than non-users of supplements due to their concerns about developing health problems. Those supplementing for treatment purposes may have underlying health indications and may be more likely to benefit from supplementation than those supplementing for preventive purposes.

Prevalence of Glucosamine and Omega-3 Fatty Acid Use and Characteristics of Users among Mid-Age Women: Analysis of a Nationally Representative Sample of 10,638 Women

BACKGROUND

There has been a dramatic increase in the use of dietary supplements over the last few decades and both omega-3 fatty acids and glucosamine are two of the best-selling dietary supplements in many countries. An understanding of omega-3 fatty acids and glucosamine consumption is of significance to health care providers and for future health promotion activities.

METHODS

This research involved analysis of data collected from a nationally-representative sample of Australian women as part of the Australian Longitudinal Study on Women's Health (ALSWH). Participants' use of omega-3 fatty acids (FA), glucosamine, their demographics, health status and health care utilisation were measured. Analysis included logistic regression modelling.

RESULTS

Of the 10,638 women in the study, 26.8% reported use of omega-3 FA and 15.9% glucosamine. Women with osteoarthritis (OR=2.529; 95% CI: 2.190, 2.921), other arthritis (OR= 1.618; 95% CI: 1.375, 1.905), and joint pain (OR= 2.699; 95% CI: 2.305, 3.160) were more likely to use glucosamine (all p<0.001). In contrast, those with diabetes (OR= 0.471; 95% CI: 0.343, 0.646) or depression (OR= 0.764; 95% CI: 0.657, 0.887) were less likely to use glucosamine (both p<0.001). Women with osteoarthritis (OR=1.481; 95% CI: 1.297, 1.691) and joint pain (OR= 1.456; 95% CI: 1.306, 1.622) were more likely to use omega-3 FA (all p<0.001).

CONCLUSIONS

Substantial prevalence rates for use of glucosamine and omega-3 FA amongst mid-aged women highlights the need for health practitioners and policymakers to be mindful of the possible significant role of such supplement use as part of patient health-seeking behaviours.

Hepatotoxicity of green tea: an update

Green tea (GT), obtained from the leaves of Camellia sinensis (L.) Kuntze (Fam. Theaceae), is largely used for its potential health benefits such as reduction in risk of cardiovascular diseases and weight loss. Nevertheless, it is suspected to induce liver damage. Present work reviews the hepatic adverse reactions associated with GT-based herbal supplements, published by the end of 2008 to March 2015. A systematic research was carried out on PubMed, MedlinePlus, Scopus and Google Scholar databases, without any language restriction. Moreover, some accessible databases on pharmacovigilance or phytovigilance were consulted. The causality assessment was performed using the CIOMS/RUCAM score. Nineteen cases of hepatotoxicity related to the consumption of herbal products containing GT were identified. The hepatic reactions involved mostly women (16/19); the kind of liver damage was generally classified as hepatocellular (16/19). The causality assessment between consumption of herbal preparation and hepatic reaction resulted as probable in eight cases and as possible in eleven cases. In seven cases, patients used preparations containing only GT, while twelve reactions involved patients who took multicomponent preparations (MC). The reactions induced by GT had a generally long latency (179.1 ± 58.95 days), and the outcome was always resolution, with recovery time of 64.6 ± 17.78 days. On the contrary, liver injury associated with MC had a shorter latency (44.7 ± 13.85 days) and was more serious in four cases that required liver transplantation and, when resolution occurred, the recovery time was longer (118.9 ± 38.79). MC preparations contained numerous other components, many of which are suspected to induce liver damage, so it is difficult to ascribe the toxicity to one specific component, e.g., GT. Present data confirm a certain safety concern with GT, even if the number of hepatic reactions reported is low considering the great extent of use of this supplement. The mechanism of GT hepatotoxicity remains unclear, but factors related to the patient are becoming predominant. A major safety concern exists when GT is associated with other ingredients that can interact between them and with GT, enhancing the risk of liver damage. Patients should be discouraged from using herbal or dietary supplements containing complex mixtures and should be encouraged to use herbal and dietary supplement possibly under supervision of healthcare professionals.

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

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.

Concurrent use of drugs and supplements in a community-dwelling population aged 50 years or more: potential benefits and risks

BACKGROUND

The use of vitamin and mineral (VMs) and non-vitamin/non-mineral supplements (non-VMs) in the general population and the older population in developed countries has increased. When combined with drugs, their use can be associated with benefit and potential risks.

OBJECTIVE

The aims of this study were to determine the extent and associated factors of the combined use of drugs and VM/non-VM supplements, and to examine the potential major drug-supplement interactions

METHODS

Cross-sectional analysis of first-wave data of TILDA, The Irish Longitudinal Study on Ageing, nationally representative a cohort including 8,081 community-dwelling persons aged ≥50 years. Prevalences including 95 % confidence intervals (CI) were weighted to the population. Group differences in drug and supplement use were assessed using Pearson's Chi-square test, and associations between concurrent drug-supplement use and covariates were assessed using logistic regression. Potential interactions between drugs and supplements were assessed using relevant sources.

RESULTS

Every seventh respondent (14.0 %; 95 % CI 13.1-15.0) reported regular concurrent use of drugs and supplements; 7.9 % (95 % CI 7.3-8.6) took only VMs, 3.9 % (95 % CI 3.4-4.4) took only non-VMs, and 2.2 % (95 % CI 1.8-2.6) took at least one of each concurrently with drugs. Concurrent use was more prevalent in women and in the oldest (≥75 years) group. Chronic disease, female sex, third-level education and private medical insurance were associated with an increased likelihood of use of both supplement types, whereas those classed as employed were much less likely to use any supplements. Supplements were combined with drugs in all of the commonly prescribed therapeutic groups, ranging from just under 60 % with drugs for bone diseases to 15.7 % with drugs for diabetes. Potential major drug-supplement interactions were detected in 4.5 % (95 % CI 3.4-5.8) of concurrent drug-supplement users, and were more prevalent in older respondents.

CONCLUSIONS

Concurrent use of drugs and supplements among those aged over 50 years in the Irish population is substantial and increases with age. There is considerable variation in usage, and the outcome of this approach is evidence of unmet need and therefore unrealised benefits among some subgroups, and of exposure to avoidable and potential serious drug interactions among others.

Cod liver oil supplement consumption and health: cross-sectional results from the EPIC-Norfolk cohort study

Supplement users (SU) make healthy lifestyle choices; on the other hand, SU report more medical conditions. We hypothesised that cod liver oil (CLO) consumers are similar to non-supplement users, since CLO use might originate from historical motives, i.e., rickets prevention, and not health consciousness. CLO consumers were studied in order to identify possible confounders, such as confounding by indication. The European Prospective Investigation into Cancer (EPIC) investigates causes of chronic disease. The participants were 25,639 men and women, aged 40–79 years, recruited from general practices in Norfolk, East-Anglia (UK). Participants completed questionnaires and a health examination between 1993 and 1998. Supplement use was measured using 7-day diet diaries. CLO was the most common supplement used, more prevalent among women and associated with not smoking, higher physical activity level and more favourable eating habits. SU had a higher occurrence of benign growths and bone-related diseases, but CLO was negatively associated with cardiovascular-related conditions. Although the results of SU characteristics in EPIC-Norfolk are comparable with studies worldwide, the CLO group is different from SU in general. Confounding by indication takes place and will need to be taken into account when analysing prospective associations of CLO use with fracture risk and cardiovascular diseases.

Press releases issued by supplements industry organisations and non-industry organisations in response to publication of clinical research findings: a case-control study

Background

Dietary supplement use is increasing despite lack of evidence of benefits, or evidence of harm. Press releases issued by the supplements industry might contribute to this situation by using ‘spin’ (strategies to hype or denigrate findings) to distort the results of clinical studies. We assessed press releases issued in response to publication of clinical studies on dietary supplements.

Methods and Findings

We analyzed 47 supplements industry press releases and 91 non-industry press releases and news stories, generated in response to 46 clinical studies of dietary supplements published between 1/1/2005 and 5/31/2013. The primary outcome was ‘spin’ content and direction. We also assessed disposition towards use of dietary supplements, reporting of study information, and dissemination of industry press releases. More supplements industry press releases (100%) contained ‘spin’ than non-industry media documents (55%, P<0.001). Hyping ‘spin’ scores were higher in industry than non-industry media documents for studies reporting benefit of supplements (median ‘spin’ score 3.3, 95% CI 1.0–5.5 vs 0.5, 0–1.0; P<0.001). Denigratory ‘spin’ scores were higher in industry than non-industry media documents for studies reporting no effect (6.0, 5.0–7.0 vs 0, 0–0; P<0.001) or harm (6.0, 5.5–7.5 vs 0, 0–0.5; P<0.001) from a supplement. Industry press releases advocated supplement use in response to >90% of studies that reported no benefit, or harm, of the supplement. Industry press releases less frequently reported study outcomes, sample size, and estimates of effect size than non-industry media documents (all P<0.001), particularly for studies that reported no benefit of supplements. Industry press releases were referenced by 148 news stories on the websites of 6 organizations that inform manufacturers, retailers and consumers of supplements.

Conclusions

Dietary supplements industry press releases issued in response to clinical research findings are characterized by ‘spin’ that hypes results that are favourable to supplement use and denigrates results that are not.

The use of dietary supplements among older persons in southern Germany - results from the KORA-age study

OBJECTIVES

Current population-based surveys in Europe on the prevalence of dietary supplement (DS) use in older individuals are scarce. The aim of the present study was to investigate patterns, prevalence and determinants of non-herbal DS use in aged subjects. Furthermore, the intake amounts of vitamins and minerals from supplements were assessed.

DESIGN

Cross-sectional.

SETTING

Data on supplement use were available from an age- and sex-stratified random sample of the German population-based KORA (Cooperative Health Research in the Region of Augsburg)-Age study.

PARTICIPANTS

1,079 persons who were born in or before the year 1943.

MEASUREMENTS

Use of dietary supplements and medications during the last seven days was recorded in a face-to-face interview in 2009. Participants were asked to bring all packages of ingested preparations to the study center. Not only vitamin/mineral supplements, but also non-vitamin non-mineral non-herbal supplements and drugs containing vitamins and minerals were coded as DS.

RESULTS

The age-standardized prevalence of DS intake was 54.3% in women and 33.8% in men, respectively. The most commonly supplemented mineral and vitamin, respectively, was magnesium (31.9%) and vitamin D (21.5%) in women and magnesium (18.0%) and vitamin E (12.0%) in men. The highest intakes, compared to the German Dietary Reference Intakes, were reported for biotin, vitamin B6 and B1. Excessive intakes (equal or above the European Tolerable Upper Intake Levels (UL)) were observed especially for magnesium and vitamin E. 20.2% of the women and 32.5% of the men who took magnesium supplements regularly exceeded the UL for magnesium. In case of vitamin E this was true for 8.0% of the women and 13.6% of the men. Determinants of DS use were sex, education, smoking, physical activity, neurological diseases, and stroke.

CONCLUSION

A high proportion of the general population aged 65 years and older in Southern Germany uses DS, especially supplements containing vitamins/minerals. The supplementation of vitamin D can be regarded as favorable in this age group, whereas the excessive intakes of vitamin E might be a cause of concern.

Age-related macular degeneration patients’ awareness of nutritional factors

Age-related macular degeneration (AMD) is the leading cause of visual impairment in older adults in the United Kingdom. This study sought to characterise AMD patients who seek the services of the Macular Society, and determine the level and source of their dietary knowledge. A questionnaire was designed, validated, and administered to 158 participants. The questions covered demographic data and knowledge of nutrition and supplementation. The mean age of participants was 79 years; 61% of them were female, and 27% were registered visually impaired. Only 55% of the participants thought diet was important for eye health, 63% felt that they had not received enough information about AMD. The participants reported that their information mainly came from non-professional support groups. Most participants identified healthy food, but could not say why, and were not able to identify carotenoid rich foods. The results of the study will inform design of education and dissemination methods regarding dietary information.

Nutritional supplements for diabetes sold on the internet: business or health promotion?

Background

Diabetes is one of the most widespread chronic disease. Although many medications are available for the treatment and prevention of diabetes, many people turn to nutritional supplements (NSs). In these years, the online sales have contributed to the growth of use of nutritional supplement. The aim of the research was to investigate the type of information provided by sales websites on NSs, and analyse the existence of scientific evidence about some of the most common ingredients found in available NSs for diabetes.

Methods

A web search was conducted in April 2012 to identify web sites selling NSs in the treatment of diabetes using Google, Yahoo and Bing! and the key word used was “diabetes nutritional supplements”. Website content was evaluated for the quality of information available to consumers and for the presence of a complete list of ingredients in the first NS suggested by the site. Subsequently, in order to analyze the scientific evidence on the efficacy of these supplements a PubMed search was carried out on the ingredients that were shared in at least 3 nutritional supplements.

Results

A total of 10 websites selling NSs were selected. Only half of the websites had a Food and Drug Administration disclaimer and 40% declared clearly that the NS offered was not a substitute for proper medication. A total of 10 NS ingredients were searched for on PubMed. Systematic reviews, meta-analyses or randomized control trials were present for all the ingredients except one. Most of the studies, however, were of poor quality and/or the results were conflicting.

Conclusions

Easy internet access to NSs lacking in adequate medical information and strong scientific evidence is a matter of public health concern, mainly considering that a misleading information could lead to an improper prevention both in healthy people and people suffering from diabetes. There is a clear need for more trials to assess the efficacy and safety of these NSs, better quality control of websites, more informed physicians and greater public awareness of these widely used products.