Plant Antinutrients- Glucosinolates
Glucosinolates (GLS) are natural, sulfur, and nitrogen-containing compounds present in plants. These are secondary metabolites found in the Brassicaceae or Cruciferae family of vegetables and certain fruits. In your diet, representatives of the family Brassicaceae of particular importance are vegetables like Cabbage (white and red), Brussels sprouts, Broccoli, Cauliflower, Radish, Turnip, Rocket or Arugula, Kale, Papaya, Moringa, Garden cress, Mustard seasonings, and sources of oil such as Rapeseed and Canola oil.
While GLS degradation products have also been reported in food products outside the plant kingdom, for example, in cow milk.
GLS has been studied for their toxic and anti-nutritive properties and goitrogenic activity. They are formed as a part of defense mechanisms in plants. When a plant perceives danger, the glucosinolates get converted to isothiocyanates (ITCs), which are toxic byproducts or breakdown products (BPs) of glucosinolates metabolism. Isothiocyanates and other byproducts are precursors of ‘bad’ compounds which may interfere with thyroid hormone (T4) production, absorption of iodine, thereby drastically reducing iodine supply to the thyroid gland, and resulting in the development of goiter and other associated problems.
Administration of glucosinolate-rich foods for a long time can lead to the enlargement of the liver, kidney, and thyroid gland. A few studies have found a small but significant increased risk of heart disease and type 2 diabetes and with higher intakes of glucosinolates. However, the possible relationship is not understood.
Several GSL-containing plants are commonly consumed foods. Based on their toxic properties or pungent taste, GSLs are often classified as antinutritional factors.
However, the importance of GSLs is even higher because most of these compounds have been associated with many beneficial effects to human health, such as anticancer, antibacterial, antidiabetic, antiobesity, antifungal, and antioxidant activities among others.
Certain processing techniques may help toward decreasing these toxic compound content. Treatments such as soaking, fermentation, storage at high temperatures, cooking, and drying have been reported to decrease the content of such toxic compounds. Apart from these, the impact of freezing is remarkable: the standard practice of freezing-thawing has been reported to reduce by more than 30 % the total GLS content in various Brassica vegetables.
The potentially complicated effects of glucosinolates and their metabolites are suggested by mixed evidence. We would recommend avoiding the consumption of glucosinolate-rich foods if you are already suffering from thyroid problems, heart diseases or Diabetes, or any other inflammatory condition. If you are having symptoms that you can’t explain and would like to understand what’s going on in your body, reach out to us and we’ll help you out.
References-
1) https://sci-hub.tw/10.1016/B978-0-12-816493-8.00001-9
2) https://sci-hub.tw/10.2174/1381612823666170120160832
3) https://link.springer.com/referenceworkentry/10.1007%2F978-3-319-26479-0_4-1
5) https://sci-hub.tw/10.1093/ajcn/nqy003
6) https://sci-hub.tw/10.2147/CLEP.S164497
7) https://www.hsph.harvard.edu/nutritionsource/anti-nutrients/
