Omega-3 fatty acids: a review of the effects on adiponectin and leptin and potential implications for obesity management.

An increase in adiposity is associated with altered levels of biologically active proteins. These include the hormones adiponectin and leptin. The marked change in circulating concentrations of these hormones in obesity has been associated with the development of insulin resistance and metabolic syndrome. Variations in dietary lipid consumption have also been shown to impact obesity. Specifically, omega-3 fatty acids have been correlated with the prevention of obesity and subsequent development of chronic disease sequalae. This review explores animal and human data relating to the effects of omega-3 fatty acids (marine lipids) on adiponectin and leptin, considering plausible mechanisms and potential implications for obesity management. Current evidence suggests a positive, dose-dependent relationship between omega-3 fatty acid intake and circulating levels of adiponectin. In obese subjects, this may translate into a reduced risk of developing cardiovascular disease, metabolic syndrome and diabetes. In non-obese subjects, omega-3 is observed to decrease circulating levels of leptin; however, omega-3-associated increases in leptin levels have been observed in obese subjects. This may pose benefits in the prevention of weight regain in these subjects following calorie restriction.

Mind-body medicine: stress and its impact on overall health and longevity.

The belief that adverse life stressors and the emotional states that can lead to major negative impacts on an individual's body functions and hence health has been held since antiquity. Adverse health outcomes such as coronary heart disease, gastrointestinal distress, and cancer have been linked to unresolved lifestyle stresses that can be expressed as a negative impact on human survival and ultimately a decrease of the human life span. Psychological modulation of immune function is now a well-established phenomenon, with much of the relevant literature published within the last 50 years. Psychoneuroimmunology and psychoneuroendocrinology embrace the scientific evidence of research of the mind with that of endocrinology, neurology and immunology, whereby the brain and body communicate with each other in a multidirectional flow of information that consists of hormones, neurotransmitters/neuropeptides, and cytokines. Advances in mind-body medicine research together with healthy nutrition and lifestyle choices can have a significant impact on health maintenance and disease prevention and hence the prolongation of the human life span.

An investigation into the acute nootropic effects of Hypericum perforatum L. (St. John's Wort) in healthy human volunteers.

Hypericum perforatum L. (St. John's Wort) is a complex herb that has been used for centuries for its putative medicinal properties, and has current therapeutic relevance as a treatment of mild to moderate depression. Recently, two studies in rodents have suggested that hypericum may also have memory-enhancing effects. It has a complex pharmacology, in that acute administration modulates numerous neurotransmitter systems that have previously been observed to either augment or impair a variety of memory processes in humans. This study aimed to examine whether acute administration of standardized hypericum extract could exert a nootropic effect in normal human subjects. The study employed a double-blind, crossover, repeated-measures design. Twelve healthy young subjects completed the Cognitive Drug Research (CDR) memory battery, following administration of placebo, 900 mg and 1800 mg hypericum (Blackmore's Hyperiforte). The findings suggested that hypericum does not have an acute nootropic effect in healthy humans at these doses. However, there was some evidence for an impairing effect on accuracy of numeric working memory and delayed picture recognition at the higher dose. This observed impairment could be due to a sensitivity of these specific tasks to modulation by neurotransmitters that have been noted to have memory-impairing effects (e.g. y-aminobutyric acid (GABA), serotonin).

A preliminary investigation on the acute pharmacodynamic effects of hypericum on cognitive and psychomotor performance.

Research has indicated that the herb St John's Wort (Hypericum perforatum) has comparable efficacy to conventional antidepressants in the treatment of depression. Although clinical studies have demonstrated that hypericum has a superior side-effect profile compared to standard antidepressants, no study has directly compared the cognitive and psychomotor effects of hypericum with those of other antidepressants. The aim of the current study was to examine the acute effects of hypericum on cognitive and psychomotor function, and to compare its effects with those of amitriptyline. Thirteen healthy volunteers received an acute dose of placebo, amitriptyline (25 mg, positive control) or hypericum (900 mg or 1800 mg) in a double-blind, placebo-controlled design. Cognitive and psychomotor tests and subjective measures of sedation were administered before and 1, 2 and 4 hours after drug administration. Amitriptyline impaired performance on a battery of psychological tests, which included critical flicker fusion (CFF), choice reaction time (CRT), digit symbol substitution test (DSST), profile of mood states (POMS) and the line analogue rating scale (LARS), while hypericum had neutral effects on performance in these tests. However, hypericum induced a dose-related impairment on DSST. Current findings suggest that clinical doses of hypericum do not impair attention, sensorimotor function or information processing.