The effect of the dietary supplement, Chitosan, on body weight: a randomised controlled trial in 250 overweight and obese adults

CONTEXT: Chitosan, a deacetylated chitin, is a widely available dietary supplement purported to decrease body weight and serum lipids through gastrointestinal fat binding. Although evaluated in a number of trials, its efficacy remains in dispute. OBJECTIVE: To evaluate the efficacy of chitosan for weight loss in overweight and obese adults. DESIGN AND SETTING: A 24-week randomised, double-blind, placebo-controlled trial, conducted at the University of Auckland between November 2001 and December 2002. PARTICIPANTS: A total of 250 participants (82% women; mean (s.d.) body mass index, 35.5 (5.1) kg/m(2); mean age, 48 (12) y). INTERVENTIONS: Participants were randomly assigned to receive 3 g chitosan/day (n = 125) or placebo (n = 125). All participants received standardised dietary and lifestyle advice for weight loss. Adherence was monitored by capsule counts. MAIN OUTCOME MEASURES: The primary outcome measure was change in body weight. Secondary outcomes included changes in body mass index, waist circumference, body fat percentage, blood pressure, serum lipids, plasma glucose, fat-soluble vitamins, faecal fat, and health-related quality of life. RESULTS: In an intention-to-treat analysis with the last observation carried forward, the chitosan group lost more body weight than the placebo group (mean (s.e.), -0.4 (0.2) kg (0.4% loss) vs +0.2 (0.2) kg (0.2% gain), P = 0.03) during the 24-week intervention, but effects were small. Similar small changes occurred in circulating total and LDL cholesterol, and glucose (P < 0.01). There were no significant differences between groups for any of the other measured outcomes. CONCLUSION: In this 24-week trial, chitosan treatment did not result in a clinically significant loss of body weight compared with placebo.

Health characteristics of older Australian dietary supplement users compared to non-supplement users

The aim of this study was to measure the prevalence of dietary and health supplement use among Australians aged 65 years and over, and to contrast the health differences between supplement users and non-supplement users. Data was obtained from 1,263 randomly selected older Australians, who provided general demographic data, in addition to information related to their health, symptoms experienced and uses of medication, including dietary supplements. Supplement use was reported by 43% of the sample (52% of females and 35% of males). This investigation has revealed distinct differences in the health profile of older supplement users compared to non-users. Although there was no difference in the number of visits to medical doctors or self-rated health status between supplement users and non-supplement users, supplement users were more likely to report arthritis and osteoporosis, and experience more symptoms and consume more medication than non-supplement users. In contrast, there was a reduced likelihood of taking a supplement for those with hypertension and by those using blood pressure medication and heart tablets. These results suggest that older dietary supplement users may benefit from education and professional advice to assist them make appropriate and informed choices, particularly if they expect these preparations to attenuate their health concerns.

Wading through the quagmire: Making sense of dietary supplement utilization

Since the 1980s, numerous studies conducted in the United States have attempted to estimate the prevalence of supplement use among the population (e.g., the National Health and Nutrition Survey and the National Health Interview Surveys). Despite these efforts, the true extent of supplement use is unclear. The literature pertaining to the prevalence of supplement use refers to a confusing array of ambiguous terms. Forming accurate conclusions about supplement use is confounded by differences in terminology and methodology between studies. Direct comparisons between studies are therefore inherently problematic. The emphasis in future investigations should be on standardizing the study design; recording data on daily, weekly, or even monthly use in order to establish the safety and efficacy of supplement use; and adopting a consistent, uniform definition of the term supplement.

Characteristics of older dietary supplement users: Review of the literature

Published literature reports rates of dietary supplement usage by individuals aged 60 years or more to be 16−60%. Prevalence figures are dependent on the population studied and the method of data collection. In general, older supplement users are female, Caucasian and well educated, with healthier lifestyle practices than non-supplement users, and they are less likely to be overweight or to smoke. Neither income nor self-rated health status are reliable predictors of supplement use in this group. In many cases older supplement users report higher intakes of several micronutrients from food than older non-supplement users. Current patterns of supplement use by the older person reveal that although they consume a range of products, they do not supplement with nutrients that are of particular benefit to them. The supplements most commonly consumed by individuals aged 60 years and over are multivitamins and minerals, vitamin C and vitamin E preparations. There is insufficient data to quantify the dosage, frequency and duration of supplement use by the older population. Obtaining this information and data about herbal medicine use is an important step towards minimising the risk of drug–nutrient–herbal interactions. Identifying the health professionals who monitor the appropriateness and safety of supplement use in older individuals, particularly given the already high use of medication in this population, also needs to be a focus of future utilisation investigations. This systematic review of the literature published between 1982 and 2003 aims to measure the patterns of dietary supplement use by community-living individuals aged 60 years and over and to profile the characteristics of older supplement users.

Love, that indispensable supplement: Irigaray and Kant on love and respect

Is love essential to ethical life, or merely a supplement? In Kant's view, respect and love, as duties, are in tension with each other because love involves drawing closer and respect involves drawing away. By contrast, Irigaray says that love and respect do not conflict because love as passion must also involve distancing and we have a responsibility to love. I argue that love, understood as passion and based on respect, is essential to ethics