Recently, I was directed toward a study of glucomannan treatment for hyperthyroid (high thyroid hormones). A woman has asked me if this fiber (glucomannan), is used to treat hyperthyroid, will it have negative consequences if used in women with hypothyroid (low)?
The paper that I'm speaking of is this: "The Use of Konjac Glucomannan to Lower Serum Thyroid Hormones in Hyperthyroid" Azezli AD et al., Journal of the American College of Nutrition. 26(6), 663-8. 2007.
In this study the investigators explain that in persons with hyperthyrodism, there is often excessive circulating or peripherially stored thyroid hormone, which leads to continued symptomology, despite prescription drug treatment (such as antithyroid drugs). In these cases, bile acid sequestrants, such as cholestiramine, the same drug used to bind cholesterol in the gut and draw it out of the body to lower blood cholesterol levels, is also useful for blocking the gut-liver exchange of thyroid hormones and thus reducing blood cholesterol concentrations (and eleviation of symptoms).
With this in mind, these investigators looked at the use of glucomannan, the most viscous soluble dietary fiber found in nature, that is also used to lower blood choletserol, to lower blood thyroid levels in persons with excess thryoid found in the gut-liver circulation.
What they found was that in 48 patients with hyperthyroid disease, after two months, has significantly lower thyroid hormones (T3, T4, FT3, FT4) that persons who took a placebo.
Thus, the conclusion was that glucomannan can be used as a safe and effective natural adjunctive treatment (i.e., used along with oral thryoid-reducing meds), for hyperthyroid diseases.
Now, with this said, you might think that is has the potential to lower thyroid levels in euthryoid or hypothroid (normal or low) persons. But this is incorrect. The reasoning being, as explained above, in persons with hyperthryoidism, there is excess thyroid spilled out into the gut, but in normal and low thyroid cases, this does not occur. Thus, if you have normal to low thyroid levels, you are not at any risk of lowering your thyroid levels if you use glucomannan.
No matter who you are though, if you are on any medications, don't take them at the same time as glucomannan or any dietary fiber, as the fiber will bind the medication and draw it out of your gut during digestion.
So, go ahead an enjoy the benefits glucomannan for satiety and weight loss.