Effect of eicosapentaenoic acid ethyl ester on hypothyroid function

Maternal plasma phospholipid polyunsaturated fatty acids in early pregnancy and thyroid function throughout pregnancy: a longitudinal study

BACKGROUND

Evidence has indicated that polyunsaturated fatty acids (PUFAs)-enriched diet could reduce inflammation because of thyroid autoimmunity in vivo, and therefore, enhance thyroid function.

OBJECTIVES

We investigated whether early pregnancy plasma phospholipid PUFAs could benefit maternal thyroid function across pregnancy, which is critical to fetal brain development and growth in pregnancy.

METHODS

Within the National Institute of Child Health and Human Development Fetal Growth Studies-Singleton Cohort, we collected plasma samples longitudinally from 214 subjects [107 with gestational diabetes mellitus (GDM) matched with 107 controls] with a singleton pregnancy. We measured 11 PUFAs at early pregnancy (10-14 wk) and 5 thyroid biomarkers at 10-14, 15-26, 23-31, and 33-39 wk, including free thyroxine (fT4), free triiodothyronine (fT3), thyroid-stimulating hormone, antithyroid peroxidase, and antithyroglobulin. Associations of PUFAs with thyroid function biomarkers and relative risk (RR) of gestational hypothyroidism (GHT) during pregnancy were assessed using generalized linear mixed models and modified Poisson regression, respectively.

RESULTS

After sample weighting because of subjects with GDM over-representing in the analytic sample with biomarkers, eicosapentaenoic acid (EPA) at early pregnancy was associated with a reduction of 0.24 pmol/L (95% confidence intervals: -0.31, -0.16) in fT3 across gestation per standard deviation (SD) increment, whereas docosahexaenoic acid (DHA) at early pregnancy was associated with an increment of 0.04 ng/dL (0.02, 0.05) in fT4 across gestation per SD increment. Furthermore, EPA and docosatetraenoic acid (DTA) were associated with lower risks of persistent GHT (EPA-RR: 0.13; 0.06, 0.28; DTA-RR: 0.24; 0.13, 0.44) per SD increment. All significant associations remained robust in sensitivity analysis and multiple testing.

CONCLUSIONS

Certain plasma phospholipid PUFAs were associated with optimal levels of thyroid biomarkers and even lower risk of GHT throughout pregnancy, which might be potentially targeted for maternal thyroid regulation in early pregnancy.

CLINICAL TRIAL REGISTRY

This trial was registered at https://beta.

CLINICALTRIALS

gov/study/NCT00912132?distance=50&term=NCT00912132&rank=1 as NCT00912132.

Evaluation of Cadmium or Lead Exposure with Nannochloropsis oculata Mitigation on Productive Performance, Biochemical, and Oxidative Stress Biomarkers in Barki Rams

This study was designed to determine the lead or cadmium exposure of Barki rams and the beneficial role of Nannochlorposis oculata (N. oculata) 4% as a feed supplement, as well as its mitigating role against these elements' impacts concerning performance, biochemical markers of liver enzymes and kidney function, thyroid hormone activity, and oxidative stress markers. Six groups of 36 Barki rams (33.63 ± 1.29 kg) were divided into G1: which served as control; G2: was given 4% dietary N. oculata; G3: was given oral 1 mg/kg cadmium chloride; G4: was given 5 mg/kg/day lead acetate; G5: was given oral 1 mg/kg cadmium chloride and 4% dietary N. oculata, and G6: was given oral 5 mg/kg/day lead acetate and 4% dietary N. oculata; and treatments were continued for 60 days. Cadmium and lead-exposed groups exhibited lower and weaker weight gain as well as feed conversion ratio, respectively, than the control and other groups. Additionally, levels of T3, T4, total proteins, albumin, and glutathione (GSH) were significantly reduced in both G3 and G4 compared to control. However, urea, creatinine, ALT, AST, total cholesterol, triglycerides, protein carbonyl content (PCC), and malondialdehyde (MDA) were significantly increased (P ≤ 0.05) in cadmium and lead-exposed groups. Dietary N. oculata (4%) improves serum proteins, creatinine, urea, T4, and oxidative stress indicators as compared to the control group. Finally, 4% dietary N. oculata greatly enhances the investigated parameters in terms of performance, thyroid hormones, serum biochemical, and antioxidant activity and may assist in reducing the endocrine disrupting effects of Pb and Cd.

Relationship between thyroid hormone parameters and exposure to a mixture of organochlorine pesticides, mercury and nutrients in the cord blood of newborns

The fetus is prenatally exposed to a mixture of organochlorine pesticides (OCPs), mercury (Hg), docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and selenium (Se) through maternal seafood consumption in real-life scenario. Prenatal exposure to these contaminants and nutrients has been suggested to affect thyroid hormone (TH) status in newborns, but the potential relationships between them are unclear and the joint effects of the mixture are seldom analyzed. The aim of the study is to investigate the associations of prenatal exposure to a mixture of OCPs, Hg, DHA, EPA and Se with TH parameters in newborns. 228 mother-infant pairs in Shanghai, China were included. We measured 20 OCPs, total Hg, DHA, EPA and Se in cord blood samples as exposure variables. The total thyroxine (TT4), free thyroxine (FT4), total triiodothyronine (TT3), free triiodothyronine (FT3), and thyroid-stimulating hormone (TSH) levels and the FT3/FT4 ratio in cord serum were determined as outcomes. Using linear regression models, generalized additive models and Bayesian kernel machine regression, we found dose-response relationships of the mixture component with outcomes: among the contaminants, p,p'-DDE was the most important positive predictor of TT3, while HCB was predominantly positively associated with FT3 and the FT3/FT4 ratio, indicating different mechanisms underlying these relationships; among the nutrients, EPA was first found to be positively related to the FT3/FT4 ratio. Additionally, we found suggestive evidence of interactions between p,p'-DDE and HCB on both TT3 and FT3, and EPA by HCB interactions for TT3, FT3 and FT3/FT4 ratio. However, the overall effects of the mixture on thyroid hormone parameters were not significant. Our result suggests that prenatal exposure to p,p'-DDE, HCB and EPA as part of a mixture might affect thyroid function of newborns in independent and interactive ways. The potential biological mechanisms merit further investigation.

Fish and the Thyroid: A Janus Bifrons Relationship Caused by Pollutants and the Omega-3 Polyunsaturated Fatty Acids

Benefits of the omega-3 polyunsaturated fatty acids (PUFA) on a number of clinical disorders, including autoimmune diseases, are widely reported in the literature. One major dietary source of PUFA are fish, particularly the small oily fish, like anchovy, sardine, mackerel and others. Unfortunately, fish (particularly the large, top-predator fish like swordfish) are also a source of pollutants, including the heavy metals. One relevant heavy metal is mercury, a known environmental trigger of autoimmunity that is measurable inside the thyroid. There are a number of interactions between the omega-3 PUFA and thyroid hormones, even at the level of the thyroid hormone transport proteins. Concerning the mechanisms behind the protection from/amelioration of autoimmune diseases, including thyroiditis, that are caused by the omega-3 PUFA, one can be the decreased production of chemokines, a decrease that was reported in the literature for other nutraceuticals. Recent studies point also to the involvement of resolvins. The intracellular increase in resolvins is associated with the tissue protection from inflammation that was observed in experimental animals after coadministration of omega-3 PUFA and thyroid hormone. After having presented data on fish consumption at the beginning, we conclude our review by presenting data on the market of the dietary supplements/nutraceuticals. The global omega-3 products market was valued at USD 2.10 billion in 2020, and was projected to go up at a compound annual growth rate of 7.8% from 2020 to 2028. Among supplements, fish oils, which are derived mainly from anchovies, are considered the best and generally safest source of omega-3. Taking into account (i) the anti-autoimmunity and anti-cancer properties of the omega-3 PUFA, (ii) the increasing incidence of both autoimmune thyroiditis and thyroid cancer worldwide, (iii) the predisposing role for thyroid cancer exerted by autoimmune thyroiditis, and (iv) the risk for developing metabolic and cardiovascular disorders conferred by both elevated/trendwise elevated serum TSH levels and thyroid autoimmunity, then there is enough rationale for the omega-3 PUFA as measures to contrast the appearance and/or duration of Hashimoto's thyroiditis as well as to correct the slightly elevated serum TSH levels of subclinical hypothyroidism.

Pilot assessment of omega-3 fatty acids and potassium thiocyanate in sickle cell anemia patients with conditional peak systolic cerebral artery blood velocity

OBJECTIVE

The purpose of this pilot study was to explore the effect of omega-3 fatty acids and potassium thiocyanate on conditional peak systolic cerebral artery blood velocity in children with sickle cell anemia (SCA).

METHODS

Transcranial doppler ultrasonography (TCD) was done on 232 SCA children, and 21 found with conditional peak systolic blood velocity (PSV) of 200-249 cm/s in internal carotid, middle or anterior cerebral arteries. These were randomized to receive omega-3 fatty acids and potassium thiocyanate with standard treatment of SCA (test group, N = 14), or standard treatment only (control group, N = 7). After 3 months of treatment, PSV was measured again.

RESULTS

Right middle cerebral artery PSV was significantly reduced in the test relative to the control groups (p = 0.04). PSV returned to normal in 79% of the test versus 43% of the control group; and increased to abnormal in one member of the control group, but none of the test group.

CONCLUSIONS

The pilot data suggest that in SCA, omega-3 fatty acids and potassium thiocyanate might reduce conditional blood velocity to normal, or prevent progression to abnormal values. A larger, randomized, clinical trial is required to further address the current gap in management of conditional TCD blood velocity.

Thyroid Function Disruptors: from nature to chemicals

The modern concept of thyroid disruptors includes man-made chemicals and bioactive compounds from food that interfere with any aspect of the hypothalamus-pituitary-thyroid axis, thyroid hormone biosynthesis and secretion, blood and transmembrane transport, metabolism and local action of thyroid hormones. This review highlights relevant disruptors that effect populations through their diet: directly from food itself (fish oil and polyunsaturated fatty acids, pepper, coffee, cinnamon and resveratrol/grapes), through vegetable cultivation (pesticides) and from containers for food storage and cooking (bisphenol A, phthalates and polybrominated diphenyl ethers). Due to the vital role of thyroid hormones during every stage of life, we review effects from the gestational period through to adulthood, including evidence from in vitro studies, rodent models, human trials and epidemiological studies.

Various Possible Toxicants Involved in Thyroid Dysfunction: A Review

About 300 million people across the world suffer from thyroid gland dysfunction. Environmental factors play an important role in causation of autoimmune thyroid diseases in susceptible individuals. Genetics contributes to 70% of the risk. In order to reduce the risk, we need to understand the association of environmental agents with thyroid dysfunction. These factors are especially relevant for those at increased risk due to positive family history. The ideal study to see the impact of a thyroid toxicant consists of directly measuring the degree of exposure to toxicant in an individual with his thyroid status. Knowledge of various factors influencing thyroid dysfunction can help in interpreting the results of such studies in a better way. This article is an attempt to highlight the various possible toxicants affecting thyroid function so that adequate measures can be undertaken to control excessive exposure in future to reduce the prevalence of thyroid disorders.

The effect of omega-3 on cognition in hypothyroid adult male rats

Thyroid hormones and omega-3 are essential for normal brain functions. Recent studies have suggested that omega-3 may protect against the risk of dementia. The aim of this study was to investigate the effect of hypothyroidism on spatial learning and memory in adult male rats, the underlying mechanisms and the possible therapeutic value of omega-3 supplementation. Thirty male rats were divided into three groups; control, hypothyroid and omega-3 treated. Hypothyroidism induced significant deficits in working and reference memories in radial arm maze, retention deficits in passive avoidance test and impaired intermediate and long-term memories in novel object recognition test. Serum total antioxidant capacity (TAC) and hippocampal serotonin and γ-aminobutyric acid (GABA) levels were decreased in the hypothyroid group as compared to the control group. Moreover, the hippocampus of hypothyroid rats showed marked structural changes as diffuse vacuolar degeneration and distortion of the pyramidal cells. Immunohistochemistry showed that the expression of Cav1.2 (the voltage dependent LTCC alpha 1c subunit) protein was increased in the hypothyroid group as compared to the control group. Omega-3 supplementation ameliorated memory deficits, increased TAC, decreased the structural changes and decreased the expression of Cav1.2 protein. In conclusion omega-3 could be useful as a neuroprotective agent against hypothyroidism-induced cognitive impairment.

Mercury and thyroid autoantibodies in U.S. women, NHANES 2007-2008

Associations between positive thyroid autoantibodies and total blood mercury in women were evaluated using the National Health and Nutrition Examination Survey (NHANES), 2007-2008. Women are at increased risk for autoimmune disorders, mercury exposure has been associated with cellular autoimmunity and mercury accumulates in the thyroid gland. We used multiple logistic regression to evaluate the associations between total bloodmercury and thyroglobulin autoantibody antibody positivity and thyroid peroxidase autoantibody positivity in non-pregnant, non-lactating women aged 20 and older not currently using birth control pills or other hormone therapies, adjusted for demographic factors, menopausal status, nutrient intake and urine iodine (n=2047). Relative to women with the lowest mercury levels (≤0.40 μg/L), women with mercury >1.81 μg/L (upper quintile) showed 2.24 (95% CI=1.22, 4.12) greater odds for thyroglobulin autoantibody positivity (p(trend)=0.032); this relationship was not evident for thyroid peroxidase autoantibody positivity. Results suggest an association between mercury and thyroglobulin autoantibody positivity.

Total blood mercury and serum measles antibodies in US children, NHANES 2003-2004

BACKGROUND

Environmental toxins, pathogens and host susceptibility cofactors may interact to contribute to disease. In vitro mercury exposure inhibited antiviral cytokines in human cells; however, little is known about the relationship between mercury and viruses in children. Children are susceptible to mercury toxicity; lower vitamin B-12 and folate levels and higher homocysteine levels may represent susceptibility cofactors. This study aimed to evaluate associations between total blood mercury (Hg) and measles antibodies in children, and the influence of these susceptibility cofactors.

DESIGN

Cross-sectional data on serum measles antibodies, Hg, homocysteine, methylmalonic acid (MMA, indicator of B-12 deficiency), and folate were obtained from the 2003-2004 NHANES for children aged 6-11 years with measles seropositivity (n=692). We used linear regression to evaluate relationships between measles antibodies and Hg, stratified by sex, MMA ≥, folate <, and homocysteine≥sample medians, adjusted for demographic, nutritional and environmental cofactors.

RESULTS

Hg (range: 0.10-19.10μg/L) was inversely associated with measles antibodies (range: 1.00-28.24 units) in non-stratified analysis (n=692), yet positively associated among the subset of boys with higher MMA and lower folate (n=98). Among this subset with higher homocysteine levels (n=61), correlations were positive across all Hg quartiles relative to Q1 (Hg≤0.20μg/L): Q2:β=6.60 (3.02, 10.19); Q3:β=8.49 (6.17, 10.81); Q4 (Hg>0.80μg/L):β=4.90 (2.12, 7.67) (p(trend)=0.077).

CONCLUSION

Stratification by susceptibility cofactors revealed opposing directionality for correlations between Hg and measles antibodies, with positive effect estimates at lowest exposures only among boys with higher MMA, lower folate and higher homocysteine levels.

Therapeutic potential of argan oil: a review

Objectives

The therapeutic benefits of argan oil consumption have been claimed by natives of Morocco and explorers for more than eight centuries. However, argan oil has remained unresearched for a long time. Traditionally, argan oil has been well known for its cardioprotective properties and it is also used in the treatment of skin infections. Argan oil is principally composed of mono-unsaturated (up to 80%) and saturated (up to 20%) fatty acids. As minor components, it contains polyphenols, tocopherols, sterols, squalene, and triterpene alcohols. Together with the mono-unsaturated fatty acids, these minor components are likely to be responsible for its beneficial effects. This review aims to present an overview of the known pharmacological properties of argan oil.

Key findings

Antiproliferative, antidiabetic, and cardiovascular-protective effects of argan oil have been particularly actively evaluated over the last 5 years in order to build on phytochemical studies that indicate the presence of large amounts of possibly pharmacologically active compounds.

Summary

This review shows that a lack of clinical data constitutes a serious weakness in our knowledge about argan oil, therefore it is difficult to correlate the reported pharmacological activities to any potential clinical relevance.

Effects of highly purified eicosapentaenoic acid on erythrocyte fatty acid composition and leukocyte and colonic mucosa leukotriene B4 production in children with ulcerative colitis

BACKGROUND

n-3 Polyunsaturated fatty acids (PUFAs) have been suggested as a treatment for ulcerative colitis (UC). However, the efficacy of n-3 PUFAs against UC has not been examined in children. Therefore, the authors investigated the effects of eicosapentaenoic acid (EPA) on fatty acid composition and leukotriene (LT) production in children with UC.

METHODS

For 2 months the authors administered highly purified EPA ethyl ester (EPA-E) (1.8 g/d) to children with UC in remission. Colonic mucosal histology, fatty acid composition of erythrocyte membrane phospholipids, and LTB4 production by leukocytes and colonic mucosa were measured before and 2 months after the initiation of EPA-E treatment.

RESULTS

No patients relapsed during the study period, and no significant differences were detected in laboratory findings obtained before and 2 months after the initiation of EPA-E ingestion. There were no significant differences in mucosal histologic scores before and 2 months after EPA-E treatment. The EPA levels in erythrocyte membranes 2 months after the initiation of EPA-E treatment were significantly higher than before treatment, but the other fatty acids showed no significant changes. LTB4 production by leukocytes and rectal mucosa after 2 months of EPA-E treatment was significantly lower than before treatment.

CONCLUSION

EPA-E treatment increased the levels of EPA in erythrocytes and decreased LTB4 levels produced by leukocytes and colonic mucosa. To assess the concomitant clinical changes, we should examine the long-term effects of EPA-E ingestion on the maintenance of remission in children with UC.