I think you are too paranoid: first spinach, and now crucifers. If you don't have a pre-existing thyroid problem, the benefits of consuming cruciferous vegetables far out weigh any negatives. In fact, there is NO research indicating crucifers pose any sort of risk to individuals with a normal function thyroid.
From WHFoods:
"There are two general categories of foods that have been associated with disrupted thyroid hormone production in humans: soybean-related foods and cruciferous vegetables. In addition, there are a few other foods not included in these categories - such as peaches, strawberries and millet - that also contain goitrogens.
Isothiocyanates are the category of substances in crucifers that have been associated with decreased thyroid function. Like the isoflavones, isothiocyanates appear to reduce thyroid function by blocking thyroid peroxidase, and also by disrupting messages that are sent across the membranes of thyroid cells.
In the absence of thyroid problems, there is no research evidence to suggest that goitrogenic foods will negatively impact your health. In fact, the opposite is true: cruciferous vegetables have unique nutritional value, and intake of these foods has been associated with decreased risk of disease in many research studies.
Because carefully controlled research studies have yet to take place on the relationship between goitrogenic foods and thyroid hormone deficiency, healthcare practitioners differ greatly on their perspectives as to whether a person who has thyroid problems, and notably a thyroid hormone deficiency, should limit their intake of goitrogenic foods. Most practitioners use words like "overconsumption" or "excessive" to describe the kind of goitrogen intake that would be a problem for individuals with thyroid hormone deficiency. Here the goal is not to eliminate goitrogenic foods from the meal plan, but to limit intake so that it falls into a reasonable range.
Although research studies are limited in this area, cooking does appear to help inactivate the goitrogenic compounds found in food. Both isoflavones (found in soy foods) and isothiocyanates (found in cruciferous vegetables) appear to be heat-sensitive, and cooking appears to lower the availability of these substances. In the case of isothiocyanates in cruciferous vegetables like broccoli, as much as one third of this goitrogenic substance may be deactivated when broccoli is boiled in water."
I appreciate the info, Skot, and yes, I may be too paranoid, but having spent the last ten years dealing with severe depression and anxiety which have only just begun to slowly clear up the last couple of years as a result of dietary changes, I'm obsessive with having a diet that isn't going to cause mood disorders or debilitate social functioning. Also, in the last three years, I have dropped 50% of my bodyweight (through diet, exercise), so I'm a bit obsessive about not gaining too much fat. Obviously, I'd like to keep my thyroid in good working order.
I'm also pursuing a nutrition degree (although I'm not far along currently) and have a particular interest in foods that are generally considered healthy, yet can cause significant problems in some individuals.
Although the depression and anxiety have lifted significantly (slowly) through dietary changes and exercise, I still experience a major fog/depression, fatigue, and occasionally severe anxiety (social and otherwise), and, like I said, am obsessed with anything that can help, especially something as simple as dropping a certain food (dropping gluten and casein has noticeably improved my mood and social function).
Having this history (as well as an inability to handle colder temperatures most of the time) as well as the current fog/fatigue/depression state, I feel I might have a compromised thyroid. I realize all of those symptoms could be caused by a variety of other conditions, and this is exactly what I'm trying to isolate. My experiments aren't exactly scientific, but in general, I have found what makes me feel better, and what makes me feel worse.
My girlfriend didn't exactly call me paranoid when I stopped with the gluten, but she didn't understand and thought I was overreacting. The benefits are now obvious.
The study you posted does put my mind at ease.
LongeCity
