Americans' views on the use and regulation of dietary supplements

This article presents the views of Americans on what the government's future role should be in regulating or overseeing the growing sales of dietary supplements for health purposes. Based on results of multiple national opinion surveys, including the views of both users and nonusers of supplements, we found that a substantial percentage of Americans surveyed reported that they regularly take dietary supplements as a part of their routine health regimen. However, they reported that they do not discuss the use of dietary supplements with their physicians because they believe that the physicians know little or nothing about these products and may be biased against them. Many users felt so strongly about the potential health benefits of some of these products that they reported that they would continue to take them even if they were shown to be ineffective in scientifically conducted clinical studies. However, there also was broad public support for increased government regulation of these products. We found that a majority of Americans surveyed supported the following: to require that the Food and Drug Administration review the safety of new dietary supplements prior to their sale; to provide increased authority to remove from sale those products shown to be unsafe; and to increase government regulation to ensure that advertising claims about the health benefits of dietary supplements are true.     

Advising patients who use dietary supplements

Public use of dietary supplements is quite prevalent, with an estimated 1 of 5 patients using such substances in an effort to maintain or promote their health. Despite their popularity, patients and physicians are often unaware of the limited regulation of these products as well as their potential risks and benefits. Lack of physician knowledge in these areas has the potential to strain the doctor-patient relationship. In this review, we present a 6-step approach to advising patients who are considering use of dietary supplements. Our framework includes a discussion of regulatory issues, efficacy and safety, potential supplement-drug interactions, and monitoring for adverse events and therapeutic effects.     

Metabolic responses to dietary supplements of bran

During a metabolic ward study, the addition of dietary fiber in the form of wheat bran biscuits to the diet of five volunteer subjects resulted in an increase in the stool wet weight and fecal solids. The excretion of fecal solids was highly correlated with the intake of unavailable carbohydrates, and fecal losses of water were similarly correlated with fecal excretion of these consituents. The major component of the increase in fecal solids was due to the noncellulosic polysaccharide fraction of dietary fiber. There was an increased fecal excretion of nitrogen fat and energy by most subjects when the supplement was eaten. However, the increased loss of energy in the feces was only 40–80 kcal/day, and therefore a large supplemental intake of dietary fiber had only minor effects on energy metabolism. Supplemental fiber is thus unlikely to induce a useful loss of calories in the management of obesity. The addition of dietary fiber caused an increased excretion of most inorganic constituents, particularly sodium and phosphorus; increased excretion of iron and megnesium was also found in two subjects.     

The impact of dietary changes and dietary supplements on lipid profile

With a growing number of dietary interventions that claim to improve lipid profile, it is important to ensure that these claims are evidence based. The objective of this study was to make recommendations for dietary regimens by analyzing their effectiveness and the level of evidence. We searched MEDLINE as well as the Cochrane Database of Systematic Reviews for nutritional studies. Meta-analyses and randomized controlled trials published in English and including data on the effect on blood lipid levels were used. Randomized controlled trials were included if they were at least 4 weeks in duration and had a minimum of 50 participants. We identified 22 different dietary interventions and reviewed 136 studies published between January 1990 and December 2009 that met our inclusion criteria. Our literature review showed that to improve lipid profile, the following regimens can be recommended fully: Mediterranean and Portfolio diets; low-fat diet; diet high in soy protein, fibre, or phytosterols; whole grain foods, and omega-3 fatty acid supplementation. The consumption of nuts, a diet high in carbohydrates and protein, green tea, and red wine, as well as the supplementation with policosanol and red yeast rice extract, can be considered for improvement of the lipid profile, while the supplements of guggulipid, garlic, chromium, vitamin C, magnesium-pyridoxal-phosphate-glutamate, tocotrienols, and absorbitol cannot be recommended.     

Interactions between dietary supplements in hospitalized patients

Inpatient consumption of dietary and herbal supplements (DHS) has recently received research attention, particularly due to potential DHS–drug interactions. Nevertheless, DHS–DHS interactions have seldom been evaluated among hospitalized patients. We evaluated potential DHS–DHS interactions among inpatients. The study was a cross-sectional prospective study, conducted at Bnai Zion Medical Center (Haifa, Israel) in 2009–2014. A multi-disciplinary team of researchers constructed a questionnaire aimed at detecting DHS use among inpatients. The Natural Medicine Database was used to examine identified DHS for potential DHS–DHS interactions. Then, medical files were reviewed to identify side effects potentially caused by such interactions and rate of documentation of DHS use. Univariate and multivariate logistic regression analyses were conducted to characterize potential risk factors for DHS–DHS interactions among hospitalized DHS users. Of 927 patients who agreed to answer the questionnaire, 458 (49.4 %) reported the use of 89 different DHS. Potential DHS–DHS interactions were identified in 12.9 % of DHS users. Three interactions were associated with the actual occurrence of adverse events. Patients at risk of DHS–DHS interactions included females (p = 0.026) and patients with greater numbers of concomitant medications (p < 0.0001) and of consumed DHS (p < 0.0001). In 88.9 % of DHS users, DHS use was not reported in medical files and only 18 % of the DHS involved in interactions were documented. Potential DHS–DHS interactions are common in inpatients, and may lead to hospitalization or worsen existing medical conditions. The causal relationship between potential interactions and actual adverse events requires further study.     

Review of liver injury associated with dietary supplements

Dietary supplements (DS) are easily available and increasingly used, and adverse hepatic reactions have been reported following their intake. To critically review the literature on liver injury because of DSs, delineating patterns and mechanisms of injury and to increase the awareness towards this cause of acute and chronic liver damage. Studies and case reports on liver injury specifically because of DSs published between 1990 and 2010 were searched in the PubMed and EMBASE data bases using the terms ‘dietary/nutritional supplements’, ‘adverse hepatic reactions’, ‘liver injury’; ‘hepatitis’, ‘liver failure’, ‘vitamin A’ and ‘retinoids’, and reviewed for yet unidentified publications. Significant liver injury was reported after intake of Herbalife^® and Hydroxycut products, tea extracts from Camellia sinensis, products containing usnic acid and high contents of vitamin A, anabolic steroids and others. No uniform pattern of hepatotoxicity has been identified and severity may range from asymptomatic elevations of serum liver enzymes to hepatic failure and death. Exact estimates on how frequent adverse hepatic reactions occur as a result of DSs cannot be provided. Liver injury from DSs mimicking other liver diseases is increasingly recognized. Measures to reduce risk include tighter regulation of their production and distribution and increased awareness of users and professionals of the potential risks.     

Orthomolecular medicine: the therapeutic use of dietary supplements for anti-aging

Dietary supplements at high doses as part of medical therapy have been controversial, but the evidence suggests that they play a significant role in prevention and treatment of diseases as well as protection from accelerated aging that results from oxygen free-radical damage, inflammation, and glycation. This literature review examines several supplements that have documented roles in medical therapy, including vitamins C and E, coenzyme Q10, alpha-lipoic acid, chromium, L-carnitine, and quercetin. The evidence shows benefits in diabetes, cardiovascular disease, hypertension, congestive heart failure, age-related deterioration of brain function and vision, and immune function, as well as other age-related health problems.     

Hepatic venocclusive disease associated with the consumption of pyrrolizidine-containing dietary supplements

Venocclusive disease, a form of Budd-Chiari syndrome, was diagnosed in a 49-yr-old woman. The patient had portal hypertension associated with obliteration of the smaller hepatic venules. A liver biopsy specimen showed centrilobular necrosis and congestion. Analysis of food supplements the woman regularly consumed showed the presence of pyrrolizidine alkaloids. The major source was a powder purporting to contain ground comfrey root (Symphytum sp). We calculated that during the 6 mo before the woman was hospitalized, she had consumed a minimum of 85 mg of pyrrolizidine alkaloids (15 micrograms/kg body wt X day). The clinical and analytic findings were consistent with chronic pyrrolizidine intoxication, indicating that low-level, chronic exposure to such alkaloids can cause venocclusive disease.     

Perceptions of dietary supplements among older women with diabetes

PURPOSE: The purpose of this qualitative study was to explore the meaning of taking dietary supplements from the perspective of being an older woman with type 2 diabetes. METHODS: Nine women over the age of 65 with type 2 diabetes participated in a single, in-depth semistructured interview that focused on use of, views of, and methods of hearing about supplements. Interviews were audiotaped, transcribed verbatim, and analyzed using phenomenological methodology. RESULTS: Eight of the 9 participants used some form of dietary supplement daily. Respondents described methods of hearing about supplements ranging from their daughters to the media to "people talk." Individual supplements were used primarily to prevent or treat conditions related to aging, such as osteoporosis, arthritis, and vision loss. They were also taken to prevent or lessen conditions associated with diabetes, including heart disease. CONCLUSIONS: The older women with type 2 diabetes in this study used dietary supplements. However, taking supplements was not perceived as a means of controlling blood glucose and, as such, supplements were not taken as part of their diabetes treatment regimen.     

Danger of high-protein dietary supplements to persons with hyperphenylalaninaemia

A 16-year-old adolescent with mild hyperphenylalaninaemia was given a high-protein 'body building' supplement twice daily, causing headaches, decreased school performance and mild depression. All symptoms disappeared after cessation of the supplement. The phenylalanine hydroxylase mutation H170D/IVS1nt5G>T was found to be responsive to tetrahydrobiopterin with significant decrease in blood phenylalanine concentration and increase in tyrosine blood content. A brain phenylalanine level of 0.5 mmol/L was initially documented, which decreased to the normal carrier range of 0.2 mmol/L within one month of discontinuance of the protein supplement. At present, the patient is on a normal diet without phenylalanine restriction. This revised version was published online in August 2006 with corrections to the Cover Date.     

Acceptability of dietary supplements of the national Mexican program "Oportunidades"

OBJECTIVE: To identify cultural beliefs and practices to evaluate the acceptability of dietary supplements of Oportunidades Program. MATERIAL AND METHODS: Ethnographic study with in-depth interviews (n=43)--mothers of children less than five years of age and pregnant and breasfeeding women (PBW)--, key informants (n=9); focus groups (n=8) and direct observation, in four communities from North, Central, South and Southwest of Mexico. RESULTS: The supplement was prepared in several different ways.The liquid preparation was best accepted; generally the supplement was mixed with milk. Initially, the supplement caused nausea, vomiting and diarrhea, but these symptoms disappeared with continued consumption. Acceptance was highest among PBW. CONCLUSIONS: The supplement tends to replace milk as a food product in the daily diet. There is a necessity to develop culturally specific evaluations in regions with different food intake practices. The study results should be interpreted in the context of other program components, such as health care and education.