Maternal conjugated linoleic acid supplementation reverses high-fat diet-induced skeletal muscle atrophy and inflammation in adult male rat offspring.

A high-saturated-fat diet (HFD) during pregnancy and lactation leads to metabolic disorders in offspring concomitant with increased adiposity and a proinflammatory phenotype in later life. During the fetal period, the impact of maternal diet on skeletal muscle development is poorly described, despite this tissue exerting a major influence on life-long metabolic health. This study investigated the effect of a maternal HFD on skeletal muscle anabolic, catabolic, and inflammatory signaling in adult rat offspring. Furthermore, the actions of maternal-supplemented conjugated linoleic acid (CLA) on these measures of muscle phenotype were investigated. A purified control diet (CD; 10% kcal fat), a CD supplemented with CLA (CLA; 10% kcal fat, 1% total fat as CLA), a high-fat (HFD; 45% kcal fat from lard), or a HFD supplemented with CLA (HFCLA; 45% kcal fat from lard, 1% total fat as CLA) was fed ad libitum to female Sprague-Dawley rats for 10 days before mating and throughout gestation and lactation. Male offspring received a standard chow diet from weaning, and the gastrocnemius was collected for analysis at day 150. Offspring from HF and HFCLA mothers displayed lower muscular protein content accompanied by elevated monocyte chemotactic protein-1, IL-6, and IL-1ß concentrations. Phosphorylation of NF-κBp65 (Ser(536)) and expression of the catabolic E3 ligase muscle ring finger 1 (MuRF1) were increased in HF offspring, an effect reversed by maternal CLA supplementation. The present study demonstrates the importance of early life interventions to ameliorate the negative effects of poor maternal diet on offspring skeletal muscle development.

Effects of creatine supplementation on housekeeping genes in human skeletal muscle using real-time RT-PCR.

The present study examined the validity and reliability of measuring the expression of various genes in human skeletal muscle using quantitative real-time RT-PCR on a GeneAmp 5700 sequence detection system with SYBR Green 1 chemistry. In addition, the validity of using some of these genes as endogenous controls (i.e., housekeeping genes) when human skeletal muscle was exposed to elevated total creatine levels and exercise was also examined. For all except 28S, linear relationships between the logarithm of the starting RNA concentrations and the cycle threshold (C(T)) values were established for beta-actin, beta2-microglobulin (beta2M), cyclophilin (CYC), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). We found a linear response between C(T) values and the logarithm of a given amount of starting cDNA for all the genes tested. The overall intra-assay coefficient of variance for these genes was 1.3% and 21% for raw C(T) values and the linear value of 2(-C(T)), respectively. Interassay variability was 2.3% for raw C(T) values and 34% for the linear value of 2(-C(T)). We also examined the expression of various housekeeping genes in human skeletal muscle at days 0, 1, and 5 following oral supplementation with either creatine or a placebo employing a double-blind crossover study design. Treatments were separated by a 5-wk washout period. Immediately following each muscle sampling, subjects performed two 30-s all-out bouts on a cycle ergometer. Creatine supplementation increased (P < 0.05) muscle total creatine content above placebo levels; however, there were no changes (P > 0.05) in C(T) values across the supplementation periods for any of the genes. Nevertheless, 95% confidence intervals showed that GAPDH was variable, whereas beta-actin, beta2M, and CYC were the least varying genes. Normalization of the data to these housekeeping genes revealed variable behavior for beta2M with more stable expressions for both beta-actin and CYC. We conclude that, using real-time RT-PCR, beta-actin or CYC may be used as housekeeping genes to study gene expression in human muscle in experiments employing short-term creatine supplementation combined with high-intensity exercise.

Inadvertent doping through supplement use by athletes: assessment and management of the risk in Australia.

Many athletes report using a wide range of special sports foods and supplements. In the present study of 77 elite Australian swimmers, 99% of those surveyed reported the use of these special preparations, with 94% of swimmers reporting the use of non-food supplements. The most popular dietary supplements were vitamin or mineral supplements (used by 94% of the group), herbal preparations (61%), and creatine (31%). Eighty-seven percent of swimmers reported using a sports drink or other energy-providing sports food. In total, 207 different products were reported in this survey. Sports supplements, particularly supplements presented as pills or other non-food form, are poorly regulated in most countries, with little assurance of quality control. The risk of an inadvertent "positive doping test" through the use of sports supplements or sports foods is a small but real problem facing athletes who compete in events governed by anti-doping rules. The elite swimmers in this survey reported that information about the "doping safety" of supplements was important and should be funded by supplement manufacturers. Although it is challenging to provide such information, we suggest a model to provide an accredited testing program suitable for the Australian situation, with targeted athlete education about the "sports safety" of sports supplements and foods.

The effectiveness of popular, non-prescription weight loss supplements.

OBJECTIVES: To review the evidence for the effectiveness of popular, non-prescription weight loss supplements. DATA SOURCES: A detailed literature search including all relevant medical and supplementary medicine databases and evidence submitted from manufacturers. DATA SYNTHESIS: The theoretical basis and rationale for the use of each substance is considered along with available research in the published literature on effectiveness and potential risks. We classified the level of evidence represented by the main research studies on each substance. CONCLUSIONS: There is no good evidence for any weight loss benefits from most of the substances reviewed here. There is some support for mild effects of capsaicin, caffeine and fibre, but only in whole foods. In some cases (e.g., chitosan), there is a plausible theoretical basis for the product, but no supporting proof of effect in humans in the absence of a calorie-controlled diet. Possible synergistic effects of different ingredients cannot be dismissed, but cannot be assessed from current data. There is an absence of good quality research on many substances, which means that advertising claims may be misleading.