Vegetarians may have to observe the health of the thyroid gland, especially if iodine was deeply absorbed

A large British study shows that vegetarians, but not vegans, have a slightly increased risk of hypothyroidism and raise new questions about iodine recording and the role of the BMI when interpreting dieted thyroid results.

Study: risk of hypothyroidism in carnings, fish people and vegetarians: a population-related prospective study. Photo credits: Svazi / Shutterstock

A study published in the journal BMC medicine found that vegetarians can have a moderately higher risk of hypothyroidism compared to high carnivors, but only after taking into account the body mass index (BMI). In analyzes of hypothyroidism from vegans or pescatians, no statistically significant risk increase for vegan or pescata was observed. In the prevailing hypothyroidism at the beginning of the course, however, a statistically significant increased risk of pescatarians was observed.

background

The popularity of diets on a vegetable basis increases worldwide because documented health benefits and ecological sustainability are documented. It is known that these diets reduce the risk of various chronic diseases, including cardiometabolic diseases and cancer as well as overall mortality. These health benefits are particularly in the case of vegetable diets from high-quality foods and limit the absorption of snacks, sweetened drinks and ultra-processed food.

One disadvantage of diets on a plant -based basis is that they often lack essential nutrients such as zinc, iron, selenium, vitamin B12 or iodine. These micronutrients play an important role in the regulation of different physiological processes, including hormonal regulation.

Iodine plays a crucial role in thyroid hormone biosynthesis, and iodine deficiency can lead to goiter, thyroid nodes and hypothyroidism. The World Health Organization (WHO) recommends a daily admission of 150 µg to achieve an appropriate iodine status. A daily admission of 200 µg is recommended for pregnant and breastfeeding women.

Therefore, the global increase in the popularity of diets on a herbal basis causes concern about the risk of iodine lack and the associated thyroid complications. Apart from the fact that there is sufficient iodine, certain cross-flowers such as cauliflower or kale and soy products can reduce the bioavailability of iodine-bioavailability due to the presence of gitrogenic compounds, which further increases the risk of iodine-related hormonal complications.

In view of the limited studies on plant -based nutrition and hypothyroidism, the current study aimed to evaluate the risk of hypothyroidism between different nutritional groups, including high meat eaters, low carnivore, poultry eaters, fish eaters, vegetarians and vegans.

Study design

The Study Analyzed Data from 466,362 Individuals from the UK Biobank, a Prospective Cohort CoHort of Over 500,000 UK Resired Betee 40 and 69. The Participants Were Categorized Into Six Differ Diet Groups Based On Self-Reported Food Intake Data, Including High. Meat-Eaters, Low Meat-Eaters, Poultry-Eaters, Pescatarians (Who Eat Fish Or Shellfish But Not Any Kind of Meat), Vegetarians, and vegan (strictly vegetable food eaters).

Suitable statistical analyzes were carried out to evaluate the risk of incident hypothyroidism in all nutritional groups.

Study results

The follow-up analysis of 466,362 people over a period of 12 years showed 10,831 new cases of potential iodine-related hypothyroidism. The proportion of cases of hypothyroidism was 2% for high carnivors, 2% with low meat meals, 3% for poultry eaters, 2% for pescatians, 3% in vegetarians and 3% for vegans.

The analysis of iodine recording data from a partial sample of 207,011 participants showed that about 92% of vegans, 44% of vegetarians and 33% of poultry eaters did not achieve the recommended daily intake of 150 µg.

Based on socio -demographic characteristics, the study showed that people with incident hypothyroidism are more common women have a higher body mass index (BMI; a measure of obesity) and have a lower income.

Connection between nutritional patterns and risk of hypothyroidism

In view of the significant influence of BMI when conveying the connection between nutrition and hypothyroidism, the researchers analyzed the connection with and without adapting for this factor.

The analysis showed a significant positive connection between a vegetarian diet and the risk of hypothyroidism only after adapting the BMI, a statistical approach that the authors can observe, possibly a distortion. No statistically significant association was observed for vegans, but the number of vegan participants was very low (n = 397), which restricted power in order to recognize a difference. A positive association of basic hypothyroidism prevalence was observed with low meat diet, poultry base, pescatar nutrition and vegetarian diet. In particular for the prevailing hypothyroidism at the beginning of the course, Pescatarians had a statistically significantly increased risk after the BMI adjustment (OR = 1.10, 95% CI 1.01–19).

Examine significance

The study shows that vegetarians may have a slightly higher risk of developing hypothyroidism compared to high meat meals, but the effect size is modest and the association has only been observed after statistical adaptation to BMI. There was no increased risk of vegans or pescatarians in relation to hypothyroidism of incoming hypothyroidism, but in the prevailing hypothyroidism, pescoarians showed a slightly increased risk after the BMI was adjusted. However, this association is significantly influenced by the BMI of the participants.

In view of the strong influence of the BMI on the study results, the researchers emphasized how important it is to understand whether BMI serves as a general or disruptive factor for conveying the connection between diet type and risk of hypothyroidism.

While a disruptive factor affects both the exposure and the result, one of the two is influenced by both. Existing evidence show that genetically predicted BMI can increase the risk of hypothyroidism, which indicates that BMI can confuse the connection between diet type and hypothyroidism.

In view of the lower calorie intake among vegetarian participants, it is more likely that the diet affects the BMI to affect BMI the effects of nutrition on the thyroid functions. This underlines the role of the BMI as a camper.

Since the BMI is influenced by nutrition and hypothyroidism by metabolic changes in connection with the disease, the researchers stated that the adaptation to BMI can introduce a strain.

Since data on the health of the thyroid gland were not available in front of the BMI measurements, the researchers speculated that an un diagnosed hypothyroidism or an impaired thyroid function influenced the BMI of the participants. The authors also discuss the possibility of reverse causing, in which people with former or not diagnosed hypothyroidism could take healthier or more vegetable diets in response to symptoms such as weight gain.

Overall, the study results underline the need for future research with data on iodine status and thyroid function before diagnosis. In view of the role of iodine as a potential critical nutrient for vegetarians, researchers advise you to consider complaints to prevent the risk of thyroid diseases.

The authors emphasize that since it was an observation study, no causality can be determined and the obvious association is due to underlying differences in BMI or other non -measured factors.