Different oils used as supplement during lactation causes endocrine-metabolic dysfunctions in male rats

Environmental Factors Affecting Thyroid-Stimulating Hormone and Thyroid Hormone Levels

Thyroid hormones are necessary for the normal functioning of physiological systems. Therefore, knowledge of any factor (whether genetic, environmental or intrinsic) that alters the levels of thyroid-stimulating hormone (TSH) and thyroid hormones is crucial. Genetic factors contribute up to 65% of interindividual variations in TSH and thyroid hormone levels, but many environmental factors can also affect thyroid function. This review discusses studies that have analyzed the impact of environmental factors on TSH and thyroid hormone levels in healthy adults. We included lifestyle factors (smoking, alcohol consumption, diet and exercise) and pollutants (chemicals and heavy metals). Many inconsistencies in the results have been observed between studies, making it difficult to draw a general conclusion about how a particular environmental factor influences TSH and thyroid hormone levels. However, lifestyle factors that showed the clearest association with TSH and thyroid hormones were smoking, body mass index (BMI) and iodine (micronutrient taken from the diet). Smoking mainly led to a decrease in TSH levels and an increase in triiodothyronine (T3) and thyroxine (T4) levels, while BMI levels were positively correlated with TSH and free T3 levels. Excess iodine led to an increase in TSH levels and a decrease in thyroid hormone levels. Among the pollutants analyzed, most studies observed a decrease in thyroid hormone levels after exposure to perchlorate. Future studies should continue to analyze the impact of environmental factors on thyroid function as they could contribute to understanding the complex background of gene-environment interactions underlying the pathology of thyroid diseases.

Thyroid-Modulating Activities of Olive and Its Polyphenols: A Systematic Review

Olive oil, which is commonly used in the Mediterranean diet, is known for its health benefits related to the reduction of the risks of cancer, coronary heart disease, hypertension, and neurodegenerative disease. These unique properties are attributed to the phytochemicals with potent antioxidant activities in olive oil. Olive leaf also harbours similar bioactive compounds. Several studies have reported the effects of olive phenolics, olive oil, and leaf extract in the modulation of thyroid activities. A systematic review of the literature was conducted to identify relevant studies on the effects of olive derivatives on thyroid function. A comprehensive search was conducted in October 2020 using the PubMed, Scopus, and Web of Science databases. Cellular, animal, and human studies reporting the effects of olive derivatives, including olive phenolics, olive oil, and leaf extracts on thyroid function were considered. The literature search found 445 articles on this topic, but only nine articles were included based on the inclusion and exclusion criteria. All included articles were animal studies involving the administration of olive oil, olive leaf extract, or olive pomace residues orally. These olive derivatives were consistently demonstrated to have thyroid-stimulating activities in euthyroid or hypothyroid animals, but their mechanisms of action are unknown. Despite the positive results, validation of the beneficial health effects of olive derivatives in the human population is lacking. In conclusion, olive derivatives, especially olive oil and leaf extract, could stimulate thyroid function. Olive pomace residue is not suitable for pharmaceutical or health supplementation purposes. Therapeutic applications of olive oil and leaf extract, especially in individuals with hypothyroidism, require further validation through human studies.

Maternal coconut oil intake on lactation programs for endocannabinoid system dysfunction in adult offspring

Maternal exposure to coconut oil metabolically programs adult offspring for overweight, hyperphagia and hyperleptinemia. We studied the neuroendocrine mechanisms by which coconut oil supplementation during breastfeeding as well as continued exposure of this oil throughout life affect the feeding behavior of the progeny. At birth, pups were divided into two groups: Soybean oil (SO) and Coconut oil (CO). Dams received these oils by gavage (0.5 g/kg body mass/day) during lactation. Half of the CO group continued to receive CO in chow throughout life (CO + C). Adult CO and CO + C groups had overweight; the CO group had hyperphagia, higher visceral adiposity, and hyperleptinemia, while the CO + C group had hypophagia only. The CO group showed higher DAGLα (endocannabinoid synthesis) but no alteration of FAAH (endocannabinoid degradation) or CB1R. Leptin signaling and GLP1R were unchanged in the CO group, which did not explain its phenotype. Hyperphagia in these animals can be due to higher DAGLα, increasing the production of 2-AG, an orexigenic mediator. The CO + C group had higher preference for fat and lower hypothalamic GLP1R content. Continuous exposure to coconut oil prevented an increase in DAGLα. The CO + C group, although hypophagic, showed greater voracity when exposed to a hyperlipidemic diet, maybe due to lower GLP1R, since GLP1 inhibits short-term food intake.