Traditional fermentation increases goitrogenic activity in pearl millet

Area of Science:

• Nutritional Science
• Endocrinology
• Toxicology

Background:

• Epidemiological studies suggest a link between millet consumption and endemic goiter.
• Previous research demonstrated that fermenting pearl millet altered its effects on rat thyroid glands and hormones.

Purpose of the Study:

• To investigate the impact of a traditional fermentation process on the mineral composition of pearl millet.
• To determine how fermented millet affects thyroid gland function, mineral balance, and thyroid hormone levels in rats.

Main Methods:

• Pearl millet cultivars were traditionally fermented.
• Fermented and unfermented millet were analyzed for mineral content (ash, Mg, Zn, K, Ca, Fe, Cu).
• Rats were fed fermented or unfermented millet diets, and their thyroid gland, bone mineral content, serum thyroid hormones (T3), and selenium levels were assessed.

Main Results:

• Fermentation reduced millet's ash content by approximately 40% and significantly decreased magnesium, zinc, and potassium levels.
• Feeding fermented millet led to reduced bone magnesium and zinc content in rats.
• Dietary magnesium intake and bone magnesium correlated negatively with serum triiodothyronine (T3) levels.
• Millet-fed groups exhibited higher serum selenium levels, with fermented millet causing a further increase.

Conclusions:

• The fermentation process alters millet's mineral profile, reducing key minerals like magnesium and zinc.
• These mineral changes, along with potential chemical transformations of goitrogens, likely explain the modified effects of fermented millet on thyroid function in rats.
• Fermentation may enhance the thyroid-influencing properties of millet through mineral depletion and/or goitrogen modification.