Case report. Efficacy of Hoodia for weight loss: is there evidence to support the efficacy claims?

Increasing rates of adult obesity and its negative health consequences are likely to become an increasing burden to the Canadian health care system. Consumers are looking for treatment options and often try the natural health products that are heavily promoted as safe, fast and effective. In this case report, MH, a 57-year-old overweight female wanted advice regarding whether she should use the natural product Hoodia to help her attain her weight loss goals. A literature search was conducted using Medline, EMBASE, the Cochrane Library, Natural Medicines Comprehensive Database and IPA from inception to March 2009. The internet, files of the authors and bibliographies of articles were searched for additional references. No published, peer-reviewed randomized controlled trials examining efficacy of Hoodia were found. Unpublished data from two small trials reported promising results with no adverse events. However, this leaves many unanswered questions regarding the use of Hoodia for weight loss such as the appropriate dose and duration, short and long term safety and use in patients with concomitant diseases. Literature suggests that some commercial products may not actually contain Hoodia at all. Additionally, Hoodia is not yet listed in the Canadian Licensed Natural Health Products Database meaning products sold in Canada may not meet Canadian regulatory standards. Upon discussing this information, MH decided not to use Hoodia, and other evidence-based recommendations were discussed.

Sequential staining: the effects of sodium fluorescein, osmolarity, and pH on human corneal epithelium.

BACKGROUND: Previous reports have suggested that sequential applications of sodium fluorescein (NaF) to the ocular surface cause loss of epithelial cells. In those experiments the solutions were free of preservatives, but delivered a hypertonic and alkaline load. It is possible that either the hyperosmolarity, NaF, and/or alkalinity may have contributed to the epithelial cell loss. Our study explored the possible impact of these three factors on epithelial integrity. METHODS: We used a paradigm in which we designed four test solutions to isolate the cytotoxic effects of the three factors. Fifteen subjects were exposed to one of the solutions on separate visits. One solution was instilled in both eyes, every 3 min, for a total of seven applications, and a slitlamp examination was performed. Staining was graded on a scale of 0 to 3 for each of five corneal sectors. RESULTS: Application of solution 1 (NaF, hyperosmotic, and alkaline) resulted in staining for all subjects. For the other three solutions (without NaF), insignificant staining occurred. CONCLUSIONS: The epithelium tolerates changes in pH and osmolarity between 7.2 to 7.8 and 290 to 350, respectively. However, NaF when applied in multiple doses may be cytotoxic.