Dietary Factors Associated with Plasma Thyroid Peroxidase and Thyroglobulin Antibodies

Nutritional and exercise interventions to improve conception in women suffering from obesity and distinct nosological entities

Infertility among women, particularly those living with obesity, presents a multifaceted challenge with implications for reproductive health worldwide. Lifestyle interventions, mainly focusing on weight loss, have emerged as promising strategies to improve fertility outcomes in this population. This review aims to explore the effectiveness of various lifestyle interventions, encompassing dietary modifications and exercise regimens, in enhancing fertility outcomes among women with obesity and associated conditions such as polycystic ovary syndrome, congenital adrenal hyperplasia, type 2 diabetes mellitus, premenopause, hypothyroidism and eating disorders. Methodology of study search encompass a broad spectrum, ranging from interventions targeting weight management through slow or rapid weight loss to dietary approaches emphasizing whole food groups, specific nutrients, and dietary patterns like low-carbohydrate or ketogenic diets, as well as the Mediterranean diet. By synthesizing existing findings and recommendations, this review contributes to the understanding of lifestyle interventions in addressing infertility, with an emphasis on the population of women of reproductive age with excess weight and known or unknown infertility issues, while promoting their integration into clinical practice to optimize reproductive health and overall well-being.

Low-Glycemic Load Diets and Thyroid Function: A Narrative Review and Future Perspectives

Nutrition and calorie intake are associated with subtle changes of thyroid function tests in subjects with an intact Hypothalamic-Pituitary-Thyroid axis. Iodine deficiency and extreme fluctuations in calorie intake, such as those that occur during periods of starvation or overfeeding could lead to alterations in thyroid hormones. The dietary macronutrient and micronutrient composition could also influence the thyroid function. Recently, Low-Glycemic Load (LGL) diets have become very popular and are effective in the treatment and/or prevention of several medical conditions, including diabetes, obesity, cardiovascular disease, and epilepsy. In this review, we report on the available data from the literature regarding the association between LGL diets and thyroid function or dysfunction. Several studies conducted in this field to date have yielded inconsistent results.

Associations between empirically derived dietary patterns and oxidative stress and inflammation in adults with primary hypothyroidism: a case-control study

BACKGROUND

Primary hypothyroidism is a common endocrine disorder caused by impaired production of thyroid hormones. Recent studies have shown that dietary habits, oxidative stress, and inflammation may play roles in thyroid hypofunction. Thus, the present article aimed to determine the relationship between major dietary patterns and oxidative stress and inflammation in primary hypothyroid patients and healthy people in Iranian adults.

METHODS

This matched case-control study was conducted on 200 participants (100 cases and 100 controls). The presence of primary hypothyroidism was determined by endocrinologists based on American Thyroid Association (ATA) criteria. Dietary intake was assessed using a validated 168-item, semi-quantitative food frequency questionnaire (FFQ). The principal component analysis (PCA) method was used to derive major dietary patterns. Statistical analysis was performed using logistic regression analysis, and the findings were reported using odds ratios (ORs) with 95% CIs.

RESULTS

We identified 2 major dietary patterns (i.e., healthy and Western dietary patterns). After adjusting for confounding variables, participants in the highest tertile of the healthy eating pattern had lower odds of primary hypothyroidism. Also, there was a significant relationship between total antioxidant capacity (TAC) levels and thyroid hypofunction; however, no significant correlation was seen between the Western dietary pattern and malondialdehyde (MDA) and C-reactive protein (CRP) with hypothyroidism.

CONCLUSIONS

There were statistically direct associations between healthy dietary patterns (loaded with vegetables, nuts and seeds, fruits, dried fruits, olives, garlic, black pepper, starchy vegetables, low-fat dairy, and legumes) and increased TAC levels with a decreased risk of thyroid hypofunction. However, Western dietary patterns and MDA and CRP levels did not associate with an underactive thyroid.

Associations between vitamin D levels and dietary patterns in patients with Hashimoto's thyroiditis

Introduction

Vitamin D insufficiency is a global health problem affecting healthy and diseased individuals, including patients with Hashimoto's thyroiditis (HT). Identifying dietary factors that may affect vitamin D levels and providing dietary guidelines accordingly can alleviate this problem. We therefore aimed to identify still unknown associations of dietary patterns, assessed through the Food Frequency Questionnaire (FFQ) with vitamin D blood levels.

Materials and methods

FFQ was collected from 459 patients from Croatian Biobank of Patients with Hashimoto's thyroiditis (CROHT), while total 25(OH)D was measured from their stored serum samples. We performed linear regression analysis between vitamin D levels and weekly intake of 24 food groups in 459 patients with HT (ALL), and in two disease-severity groups (MILD and OVERT).

Results

The main results of our study are observations of: (1) an inverse association between vitamin D levels and coffee consumption (ALL: β = -0.433, p = 0.005; OVERT: β = -0.62, p = 0.008); (2) an inverse association between vitamin D levels and sweets consumption (ALL: β = -0.195, p = 0.034; OVERT: β = -0.431, p = 0.006); (3) positive association between vitamin D levels and vegetable consumption (ALL: β = 0.182, p = 0.019; OVERT, β = 0.311, p = 0.009). Importantly, effect sizes of all three associations were more prominent in HT patients with prolonged and more severe disease (OVERT).

Conclusion

Further research into the functional and causal relationships of the observed associations is important to provide guidance regarding coffee/sugar intake on vitamin D status. A well-balanced diet can help prevent vitamin D deficiency and improve the quality of life of patients with HT, especially those in later stages of disease characterized by greater metabolic imbalance.

Mediterranean Diet and Thyroid: An Interesting Alliance

The Mediterranean diet, recognized as being cultural heritage by UNESCO, is mostly plant-based and includes a high consumption of whole-grain, fruit, and vegetables with a moderate consumption of alcohol during meals. Thus, it provides a small amount of saturated fatty acids and a high quantity of antioxidants and fiber. For this reason, it has been considered to have an important role in preventing cardiovascular diseases, chronic kidney diseases, type 2 diabetes mellitus, and cancer, but its relationship with thyroid function and diseases is still under debate. The aim of this review was to search for the possible correlation between the Mediterranean diet and thyroid function, and to critically evaluate the pathophysiological link between selected food intake and thyroid disorders.

Metabolic Characteristics of Hashimoto's Thyroiditis Patients and the Role of Microelements and Diet in the Disease Management-An Overview

Hashimoto’s thyroiditis (HT) is the most common autoimmune disease and the leading cause of hypothyroidism, in which damage to the thyroid gland occurs due to the infiltration of lymphocytes. It is characterized by increased levels of antibodies against thyroid peroxidase and thyroglobulin. In this review, we present the metabolic profile, the effectiveness of micronutrient supplementation and the impact of dietary management in patients with HT. For this current literature review, the databases PubMed, Cochrane, Medline and Embase were reviewed from the last ten years until March 2022. This article provides a comprehensive overview of recent randomized controlled trials, meta-analyses, and clinical trials. Many patients with HT, even in the euthyroid state, have excess body weight, metabolic disorders, and reduced quality of life. Due to frequent concomitant nutritional deficiencies, the role of vitamin D, iodine, selenium, magnesium, iron and vitamin B12 is currently debated. Several studies have underlined the benefits of vitamin D and selenium supplementation. There is still no specific diet recommended for patients with HT, but a protective effect of an anti-inflammatory diet rich in vitamins and minerals and low in animal foods has been suggested. There is insufficient evidence to support a gluten-free diet for all HT patients. Pharmacotherapy, along with appropriate nutrition and supplementation, are important elements of medical care for patients with HT. The abovementioned factors may decrease autoantibody levels, improve thyroid function, slow down the inflammatory process, maintain proper body weight, relieve symptoms, and prevent nutritional deficiencies and the development of metabolic disorders in patients with HT.

Food preferences and thyroid hormones in children and adolescents with obesity

BACKGROUND

Thyroid hormones profoundly affect energy metabolism but their interrelation with food preference, which might contribute to childhood obesity development, are much less understood. In this study, we investigated if thyroid hormone levels are associated with specific modulation of food preference and potentially linked to the level of obesity in children and adolescents.

METHODS

Interrelations between food preference and peripheral thyroid activity were examined in a population of 99 non-obese and 101 obese children and adolescents (12.8 ± 3.6 years of age, 111/89 F/M) randomly selected from the patients of the Obesity and Metabolic Disease Out-patient Research Unit at National Institute for Children's Diseases in Bratislava in a period between December 2017 and March 2020.

RESULTS

Children and adolescents with obesity had a lower preference for food rich in high sucrose and high-complex carbohydrates, while the preference for protein and fat-containing food and that for dietary fibers did not differ between obese and nonobese. In adolescents with obesity, free thyroxine (FT4) correlated positively with the preference for a high protein and high fat-rich diet, irrespective of the fatty acid unsaturation level. Moreover, FT4 correlated negatively with the preference for dietary fibers, which has been also exclusively found in obese adolescents. Individuals with obesity with higher FT4 levels had higher systemic levels of AST and ALT than the population with lower FT4. Multiple regression analysis with age, sex, BMI-SDS, and FT4 as covariates revealed that FT4 and male gender are the major predictors of variability in the preference for a diet high in protein, fat, and monounsaturated fatty acids. FT4 was the sole predictor of the preference for a diet containing saturated and polyunsaturated fatty acids as well as for a diet low in fiber.

CONCLUSION

The link between free thyroxin levels and dietary preference for food rich in fat and protein is present exclusively in individuals with obesity. Higher serum FT4 was linked with elevated AST and ALT in children and adolescents with obesity, and FT4 was the best predictor for preference for food rich in fat and low in fiber. This may indicate that FT4 could contribute to the development of childhood obesity and its complications by modulating food preference.

Determinants and Clinical Implications of Thyroid Peroxidase Antibodies in Middle-Aged and Elderly Individuals: The Rotterdam Study

Background: Thyroid peroxidase antibodies (TPO-Abs) play an important role in autoimmune thyroid disease, but are also prevalent in healthy individuals. However, it is unclear what determinants may influence the occurrence of TPO-Abs in healthy individuals and how TPO-Abs may affect health outcomes in these individuals. We aimed to identify determinants of TPO-Abs in a large, prospective population-based cohort of middle-aged and elderly individuals and to subsequently assess the association between TPO-Abs and risk of overall and cause-specific mortality. Methods: We performed binomial and multinomial logistic regression analyses to obtain odds ratios (ORs) and 95% confidence intervals [95% CIs] for the association of potential determinants based on previous literature with TPO-Ab positivity (>35 kU/L), TPO-Ab detectability (>5 kU/L), and TPO-Ab categories. Cox proportional hazards regression analyses were performed to obtain hazard ratios (HRs) and CIs for the association between TPO-Abs and mortality risk. Results: In 9685 participants (57% women, median baseline age 63.3 years, median follow-up time 10.1 years), we identified female sex (OR = 2.47 [CI 2.13-2.86]) and current smoking (OR = 3.10 [CI 2.66-3.62]) as determinants of TPO-Ab positivity and TPO-Ab detectability, respectively. Higher age (OR = 0.98 [CI 0.97-0.98]) and all categories of alcohol consumption (ORs ranging from 0.71-0.78) were associated with lower odds of TPO-Ab detectability. TPO-Ab detectability was associated with a higher risk of overall (HR = 1.09 [CI 1.01-1.17]), cancer-related (HR = 1.18 [CI 1.01-1.38]), and cardiovascular mortality (HR = 1.21 [CI 1.01-1.45]). Interestingly, this was more prominent in men compared with women (HR for cardiovascular mortality 1.50 vs. 0.99, respectively). Conclusions: In community-dwelling middle-aged and elderly individuals, female sex and current smoking are the most important determinants associated with TPO-Ab levels in the detectable and positive range, whereas alcohol consumption is associated with lower odds of TPO-Abs. The clinical importance of detectable TPO-Ab levels is illustrated by the association with an increased mortality risk, mainly in men. Our results warrant further exploration of the clinical applicability of detectable TPO-Ab levels, potentially as a marker for low-grade inflammation. The Rotterdam Study has been entered into the Netherlands National Trial Register (NTR; www.trialregister.nl) and into the WHO International Clinical Trials Registry Platform (ICTRP; www.who.int/ictrp/network/primary/en/) under shared catalogue number NTR6831.

Effects of animal protein intake during pregnancy on autoimmune thyroiditis in pregnant women with mild iodine deficiency

BACKGROUND

Iodine and animal protein may affect thyroid function. In the present study, we explored the association between animal protein intake and thyroid antibody status in pregnant women following universal salt iodisation.

METHODS

Pregnant women were enrolled using a multistage, stratified random sampling method in Shanghai. In total, 4646 eligible women were interviewed in person. We used a validated food frequency questionnaire and food composition tables to calculate the daily intakes of protein and iodine. We collected urine samples and performed thyroid antibody tests.

RESULTS

Positive thyrotropin receptor antibody (TR-Ab) rates were different among animal protein intake groups (p < 0.05). Median urinary iodine concentration (UIC) was higher in the thyroid peroxidase antibody (TPO-Ab) positive group than in the negative group (p < 0.05). The median of total protein intake, animal protein intake and UIC was higher in the TR-Ab positive group than in the negative group (p < 0.05). The median of total protein intake and UIC was higher in the TPO-Ab/TG-Ab/TR-Ab positive group than in the negative group (p < 0.05). Multivariable logistic regression results showed that insufficient iodine had a negative correlation with positive TPO-Ab and positive TR-Ab (p < 0.05). The middle third and top third animal protein intakes served as protective factors for TR-Ab (coefficient = 0.559, 95% confidence interval [CI] = 0.415-0.752, p < 0.001; coefficient = 0.0.406, 95% CI = 0.266-0.621, p < 0.001) and positive TPO-Ab/TR-Ab/TG-Ab (coefficient = 0.817, 95% CI = 0.687-0.971, p = 0.022; coefficient = 0.805, 95% CI = 0.672-0.964, p = 0.018).

CONCLUSIONS

Adequate animal protein intake protects against elevated anti-thyroid antibody levels in pregnant women with mild iodine deficiency.

Are Nutritional Patterns among Polish Hashimoto Thyroiditis Patients Differentiated Internally and Related to Ailments and Other Diseases?

There is not any diet recommended for Hashimoto's disease, despite that those patients are often undernourished. Because of the high heterogeneity of Hashimoto's patients, insight into dietary patterns might shed some light on the patient-tailored dietary approach, thus improving their treatment and helping to identify patients with the highest probability of particular nutritional deficiencies. The aim of this study was to identify Hashimoto's patients' dietary patterns and their characterization based on both socio-demographic variables and dietary self-assessment. We collected data online from patients with Hashimoto's disease. The questionnaire formula used in the study was developed based on a validated food frequency questionnaire KomPAN®. K-means pattern analyses were used to characterize patients into patterns based on the frequency of particular types of foods consumption and socio-demographic factors. Four patterns were identified. We labeled them as 'Convenient', 'Non-meat', 'Pro-healthy', and 'Carnivores' with participants proportions at approximately one-fourth per each pattern. The patients were mainly of the female gender (94.08%), with a female: male ratio of 15.9. Hashimoto's patients differed in their food product choices, food choice motives, dieting experience, nutritional knowledge, smoking habits, food allergies and intolerances, and lipid disorders, and thus represent different eating patterns. However, these patterns were not determined by comorbidities or the majority of ailments.

Fonio grains: Physicochemical properties, nutritional potential, and food applications

Fonio grains are a type of small-seeded cereals native to Western Africa and are important cereal crops for food security. The two species are white fonio (Digitaria exilis) (commonly called acha) and black fonio (Digitaria iburua) (commonly called iburu). As a novel food, fonio has attracted attention from other parts of the world due to their attractive nutritional properties (e.g., in whole grain form and being gluten free) and potential food applications. The information regarding the functional properties and applications of fonio is rather scattered. This review summarizes the chemical composition, physicochemical and nutritional properties, and diverse food applications of fonio. The nutritional composition and processing properties of fonio are similar to other cereals. Fonio has potential to be complementary to major cereals for diverse food uses. There are research opportunities to better explore fonio grains for value-added applications.

Differences in food consumption between patients with Hashimoto's thyroiditis and healthy individuals

Food is considered as important environmental factor that plays a role in development of Hashimoto's thyroiditis (HT). The goal of our study was to identify food groups, assessed by food frequency questionnaire, that differ in consumption frequency between 491 patients with HT and 433 controls. We also analysed association of food groups with the wealth of HT-related clinical traits and symptoms. We found significantly increased consumption of animal fat (OR 1.55, p < 0.0001) and processed meat (OR 1.16, p = 0.0012) in HT cases, whereas controls consumed significantly more frequently red meat (OR 0.80, p < 0.0001), non-alcoholic beverages (OR 0.82, p < 0.0001), whole grains (OR 0.82, p < 0.0001) and plant oil (OR 0.87, p < 0.0001). We also observed association of plant oil consumption with increased triiodothyronine levels in HT patients (β = 0.07, p < 0.0001), and, association of olive oil consumption with decreased systolic blood pressure (β = − 0.16, p = 0.001) in HT patients on levothyroxine (LT4) therapy. Analysis of food consumption between HT patients with and without LT4 therapy suggest that patients do not tend to modify their diet upon HT diagnosis in our population. Our study may be of relevance to nutritionists, nutritional therapists and clinicians involved in developing dietary recommendations for HT patients.

Evaluation of Qualitative Dietary Protocol (Diet4Hashi) Application in Dietary Counseling in Hashimoto Thyroiditis: Study Protocol of a Randomized Controlled Trial

The current state of knowledge related to diet in Hashimoto thyroiditis (HT) is far from satisfactory, as many HT subjects experience several disorders and report reduced quality of life. There are three aims of the study: (1) to develop a qualitative dietary protocol (QDP; 'Diet4Hashi') as a simple, graphic-text tool dedicated to TH subjects, (2) to evaluate the use of the QDP in dietetic counseling compared to conventional dietetic counseling (CDC) in HT women, and (3) to assess the impact of both the QDP and the CDC on the diet quality, quality of life, adiposity, and metabolic parameters of HT women. The QDP is based on subject self-monitoring supported with a graphic-text tool to help them in food selection and adequate food frequency consumption, while the CDC on oral explanation and printed sample menus were provided by a dietician. The QDP contains two lists: (A) foods recommended for consumption and (B) foods with limited consumption, along with indicated consumption frequency per day/week/month. Both approaches include the same dietary recommendations for HT extracted from the literature but differ in subject-dietician cooperation. To summarize the evidence regarding dietary recommendations in HT, the PubMed, Embase, and Cochrane Library databases (to March 2019) and the bibliographies of key articles were searched. The study is designed as a dietary intervention lasting six months in two parallel groups: experimental and control. In the experimental group, the QDP will be applied, while in the control group, the CDC will be applied. In total, the study will include a baseline of 100 women with diagnosed HT. The subjects will be randomly allocated into the experimental/control groups (50/50). Data related to diet quality and other lifestyle factors, nutrition knowledge, quality of life, thyroid function, body composition, blood pressure, serum fasting glucose, and lipid profile at baseline and after a six-month follow-up will be collected. This study was conducted to develop a dietary protocol (Diet4Hashi) that is easy to follow for HT subjects, and it will contribute to providing valuable data that are useful to dieticians and physicians. It is anticipated that this graphic-text qualitative dietary protocol, by improving food selection and diet quality, may reduce adiposity and improve metabolic parameters and the quality of life of HT women.

The effect of multiple nutrients on plasma parathyroid hormone level in healthy individuals

Although the effect of isolated nutrients on plasma parathyroid hormone (PTH) is somewhat familiar, the effect of multiple nutrients on plasma PTH level has not yet been studied. The aim of this study was to identify groups of food items that are associated with the plasma PTH level in healthy individuals. This cross-sectional study enrolled 1180 healthy individuals from Croatia with plasma PTH levels inside the referent values. A food frequency questionnaire containing 58 food items was completed to evaluate the dietary intake. We used principal component analysis to reduce food items into dietary groups, followed by linear regression analysis to test the association between dietary groups and the level of PTH. The results indicate that different sorts of vegetables (p = .006), sausages, salami, mushrooms, eggs (p = .033), as well as white bread (p = .009) are associated with the increase, while bran bread (p = .009) is associated with the decreased plasma PTH level.