At any given time, there are articles or books circulating that suggest that a particular nutrient is the root of all disease. Oxalates, phytates, lectins, and goitrogens (plant products that negatively affect the thyroid) have all come under fire.

An article entitled “Is There Such a Thing as “Anti-Nutrients”? A Narrative Review of Perceived Problematic Plant Compounds,” published in the medical journal Nutrients, does a nice job of reviewing the literature on this subject. The literature review for each compound is a bit challenging to read, but the summaries at the end of each section are useful.

For each of these “anti-nutrients,” a few individuals may have trouble with their metabolism. For most people, though, eating a reasonable diet with a variety of properly prepared foods, there is no reason to worry about these “anti-nutrients.”

Excessive intake of a food that is perceived as “healthy” can cause problems. As an example, spinach is high in oxalates, but in the usual ways it is eaten raw, such as in a salad, it is hard to eat enough to be an issue for most people. I don’t recommend that anyone juice spinach or put it into a smoothie, because a lot more spinach is ingested that way, too much oxalate for anyone to handle, especially if done frequently.

SOURCE: http://news.bbc.co.uk/2/hi/asia-pacific/1780541.stm

The brassica family of vegetables, which includes broccoli, kale, cauliflower, cabbage, and Brussels sprouts, contains substances that can interfere with the thyroid gland, especially in patients who are deficient in iodine. Cooking them mitigates this issue. Dr. Gonzalez had a patient who ate large amounts of raw kale in a short period of time and had a temporary drop in her thyroid function, which returned to normal when she stopped it. The brassica vegetables have a host of beneficial components, so they are highly recommended - cooked.

After reading this article, I did modify the bean recipe on my website to state that if using kidney beans, extra boiling is needed to be sure the lectins are destroyed.

The article does not discuss our main objection to soy products; they contain a potent inhibitor of proteolytic enzymes. I continue to recommend avoidance of soy.