Catechin induced modulation in the activities of thyroid hormone synthesizing enzymes leading to hypothyroidism

Long-Term Consumption of Green Tea Can Reduce the Degree of Depression in Postmenopausal Women by Increasing Estradiol

Postmenopausal women face a higher risk of depression due to a combination of social and physiological factors. As a beverage rich in a variety of bioactive substances, green tea has significant effects on metabolism, inflammation and endocrine, and may reduce the risk of depression, but few studies have looked at the effects of green tea on postmenopausal women. Therefore, we designed this study to investigate the effects of long-term green tea consumption on inflammation, endocrine and depression levels in postmenopausal women. We investigated a tea-producing village and eventually included 386 postmenopausal women, both in the tea drinking and control groups. The results showed that there were significant differences in the degree of insomnia, degree of depression, BMI, SII and estradiol between the two groups. And, green tea consumption may reduce the risk of depression through the mediating pathway of sleep, SII and estradiol. In summary, long-term green tea consumption can reduce the risk of depression in postmenopausal women by reducing inflammation and increasing estradiol. This kind of living habit deserves further promotion.

Plant constituents and thyroid: A revision of the main phytochemicals that interfere with thyroid function

In the past few decades, there has been a lot of interest in plant constituents for their antioxidant, anti-inflammatory, anti-microbial and anti-proliferative properties. However, concerns have been raised on their potential toxic effects particularly when consumed at high dose. The anti-thyroid effects of some plant constituents have been known for some time. Indeed, epidemiological observations have shown the causal association between staple food based on brassicaceae or soybeans and the development of goiter and/or hypothyroidism. Herein, we review the main plant constituents that interfere with normal thyroid function such as cyanogenic glucosides, polyphenols, phenolic acids, and alkaloids. In detail, we summarize the in vitro and in vivo studies present in the literature, focusing on the compounds that are more abundant in foods or that are available as dietary supplements. We highlight the mechanism of action of these compounds on thyroid cells by giving a particular emphasis to the experimental studies that can be significant for human health. Furthermore, we reveal that the anti-thyroid effects of these plant constituents are clinically evident only when they are consumed in very large amounts or when their ingestion is associated with other conditions that impair thyroid function.

Detoxification effects of phytonutrients against environmental toxicants and sharing of clinical experience on practical applications

According to the Food and Health Bureau and Trade and Industry Department of the Hong Kong Government, 90 % of the total food supply in Hong Kong was imported from the Mainland China. In addition, the hidden or illegal use of prohibited pesticides, food adulteration (e.g., using industrial salt in food processing, using gutter oil as cooking oil), and pollutions were periodically reported by the media. Excessive exposure to toxic heavy metals or persistent organic pollutants (POPs) from diet or environmental is inevitable amid industrialization and pollution. Understanding of the detoxification ability among nutrients in plant-based food (i.e., phytonutrients in green tea, onion, garlic, coriander, and turmeric) offers therapeutic and preventive effects against the poisoning effects due to these pollutants. Oxidative stress and pro-inflammatory actions are the common mechanisms for heavy metals or POPs toxicities, while phytonutrients counteracts these cellular insults by anti-oxidation, upregulation of anti-inflammatory pathways, and chelation.

Correlations Between Nutrition Habits, Anxiety and Metabolic Parameters in Greek Healthy Adults

BACKGROUND

Anxiety combined with nervousness and apprehension consist a focal response to different life conditions. Lifestyle habits, anxiety and biochemical markers are in a constant interaction.

AIM

To investigate the prevalence of anxiety in healthy adults and its possible association with biochemical factors-lipid profile, liver markers, thyroid hormones-and lifestyle habits.

METHODS

Quantitative descriptive correlation study. A total of 100 healthy adults participated in the research. A specially designed questionnaire and Hamilton's scale were used. Anthropometric and biochemical analyses were performed.

FINDINGS

Overall, 61% of the participants presented moderate to very serious anxiety. The average score on the Hamilton scale was 13.82 (±9.000), with men exhibiting less stress than women. For p ≤ 0.05: Stress was positively correlated with impaired thyroid and hepatic function. Hepatic function was affected by both sugar products and water melon, which were positively correlated with total bilirubin and AST/SGOT respectively. Tomato, peppers and legumes were negatively correlated with AST/SGOT. Deep fried food was positively correlated with GGT and triglycerides. Legumes and fish were negatively correlated with CPK. Regarding the lipid metabolism, it was found that food cooked with oil was positively associated with uric acid, but non-cooked olive oil was negatively correlated with the risk for CAD. Thyroid function was negatively correlated with non-homemade food and pasta consumption and positively correlated with consumption of whole grains and green tea. Participants with subclinical hypothyroidism seemed to consume less vitamin B12, folic acid and vegetables.

CONCLUSION

No direct correlation between lifestyle habits and anxiety was found. Nevertheless, eating habits influenced biochemical markers-especially the thyroid hormones-which may be indirectly responsible for anxiety and related moods.

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 Greek herbal tea consumption on thyroid cancer: a case-control study

BACKGROUND

Although in the last decade several studies have addressed the protective role of black and green tea on several diseases, including cancer, there are only few and controversial studies on the effect of tea on benign and malignant thyroid diseases.

METHODS

An age and gender group matched case-control study conducted in Athens, Greece, was designed. 113 Greek patients with histologically confirmed thyroid cancer and 286 patients with benign thyroid diseases along with 138 healthy controls were interviewed with a pre-structured questionnaire in person by trained interviewers.

RESULTS

An inverse association between chamomile tea consumption and benign/malignant thyroid diseases was found (P < 0.001). The odds of chamomile tea consumption, two to six times a week, after controlling for age, gender and BMI, were 0.30 (95% CI: 0.10-0.89) and 0.26 (95% CI: 0.12-0.5) for developing thyroid cancer and benign thyroid diseases, respectively when compared with not consumption. The duration of consumption was also inversely associated with the diseases. Thirty years of consumption significantly reduced the risk of thyroid cancer and benign thyroid diseases development by almost 80%. Similar, although weaker protective association, was found for sage and mountain tea. Adjustment for smoking, alcohol and coffee consumption did not alter the results.

CONCLUSIONS

Our findings suggest for the first time that drinking herbal teas, especially chamomile, protects from thyroid cancer as well as other benign thyroid diseases.

Flavonoid rutin increases thyroid iodide uptake in rats

Thyroid iodide uptake through the sodium-iodide symporter (NIS) is not only an essential step for thyroid hormones biosynthesis, but also fundamental for the diagnosis and treatment of different thyroid diseases. However, part of patients with thyroid cancer is refractory to radioiodine therapy, due to reduced ability to uptake iodide, which greatly reduces the chances of survival. Therefore, compounds able to increase thyroid iodide uptake are of great interest. It has been shown that some flavonoids are able to increase iodide uptake and NIS expression in vitro, however, data in vivo are lacking. Flavonoids are polyhydroxyphenolic compounds, found in vegetables present in human diet, and have been shown not only to modulate NIS, but also thyroperoxidase (TPO), the key enzyme in thyroid hormones biosynthesis, besides having antiproliferative effect in thyroid cancer cell lines. Therefore, we aimed to evaluate the effect of some flavonoids on thyroid iodide uptake in Wistar rats in vivo. Among the flavonoids tested, rutin was the only one able to increase thyroid iodide uptake, so we decided to evaluate the effect of this flavonoid on some aspects of thyroid hormones synthesis and metabolism. Rutin led to a slight reduction of serum T4 and T3 without changes in serum thyrotropin (TSH), and significantly increased hypothalamic, pituitary and brown adipose tissue type 2 deiodinase and decreased liver type 1 deiodinase activities. Moreover, rutin treatment increased thyroid iodide uptake probably due to the increment of NIS expression, which might be secondary to increased response to TSH, since TSH receptor expression was increased. Thus, rutin might be useful as an adjuvant in radioiodine therapy, since this flavonoid increased thyroid iodide uptake without greatly affecting thyroid function.