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Autoimmune thyroiditis, also known as Hashimoto’s disease, is an organ-speciﬁc autoimmune disorder where your body attacks your own thyroid gland, often leading to hypothyroidism due to destruction and scarring of the gland itself. We know there’s a genetic component, since identical twins are more likely to share the disease than fraternal twins. However, even with identical twins, the concordance rate was only about 50 percent––meaning even if your identical twin with basically the exact same DNA as you has the disease, there’s only like a flip of a coin’s chance you’ll get it, emphasizing that important factors other than your genes play a role in the development of the disease. Genes load the gun, but environment may pull the trigger.
More than 90 chemicals have been noted disrupting hormonal balance or thyroid function; however, only a few such pollutants show evidence that they contribute to autoimmune thyroid disease. These include polyaromatic hydrocarbons, which smokers get a lot from their cigarettes, but in nonsmokers, exposure comes almost entirely from food. Polycyclic aromatic hydrocarbons are primarily formed when muscle meats, such as beef, pork, fish, or chicken, are cooked by high temperature methods, such as grilling. PBBs are a type of flame-retardant chemical no longer manufactured in the U.S., but still found in the aquatic food chain. PCBs are used in a number of industrial processes, and end up in people’s bodies largely through the consumption of fish as well, but also other meat and eggs.
So, one might suspect those eating plant-based diets would have lower rates of hypothyroidism, and indeed, despite their lower iodine intake, vegan diets tended to be protective. But they’ve never been put to the test in an interventional trial. A modification of the Paleolithic diet has been tried in Hashimoto’s patients, but didn’t appear to improve thyroid function.
What did, though, was Nigella Sativa. That name should sound familiar to anyone who’s read my latest book How Not to Diet, or watched my latest live presentation Evidence-Based Weight Loss. Nigella Sativa is the sciency name for black cumin, which is just a simple spice, but it is also used for a variety of medicinal purposes.
In this study, a randomized, double-blind placebo-controlled trial of eight weeks of a half teaspoon of powdered black cumin a day in Hashimoto’s patients. Not only was there a signiﬁcant reduction in body weight, which is why I profiled it in my book, it also signiﬁcantly reduced thyroid stimulating hormone, a sign that thyroid function was improving. It even lowered the level of autoimmune anti-thyroid antibodies, as well as increasing blood levels of thyroid hormone T3 in these Hashimoto’s patients. In addition, there was a significant drop in Interleukin 23, a proinflammatory cell signal thought to help promote the autoimmune inﬂammation of the thyroid, so further conﬁrming the anti-inﬂammatory nature of the plant. And what were the side effects? A 17 percent drop in LDL bad cholesterol.
Given the fact that patients with Hashimoto’s may be at particularly high risk of developing heart disease, this is exactly the kind of side effect we’d want. “Considering these health-promoting effects of black cumin, it can be considered as a therapeutic approach in management of Hashimoto-related metabolic abnormalities.”
A similar trial failed to find a benefit, though. Same dose, same time frame, but no significant changes in thyroid function. In contrast with the last study, though, they were not all Hashimoto’s patients, but rather hypothyroid for any reason, and that may have diluted the results. And it’s possible that telling patients to take the black cumin doses with their thyroid hormone replacement therapy may have interfered with its absorption, similar to other foods and drugs––which is why patients are normally told to take it on an empty stomach. Since there are no downsides—it’s just a simple spice—I figure, why not give it a try? The worst that can happen is you’ll have tastier food.
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