Kale has been coined the ‘queen of greens’, the ‘vegetarian delight’. However, there are a few controversies amongst the nutrition and medical world when it comes to the consumption of kale.
Cruciferous vegetables, especially kale are called goitrogen foods and contain chemicals called isothiacyanates that may inhibit absorption of dietary iodine. A decrease in iodine in your body can worsen symptoms of hypothyroidism, a condition where your thyroid gland does not produce enough hormones. The hormones produced by your thyroid gland are essential for regulating your metabolism. Isothiacyanates are almost completely destroyed during cooking.
According to Dr Mario Skugor, The Cleveland Clinic Guide to Thyroid disorders 2009, there is no convincing evidence suggesting that cruciferous vegetables have a negative impact on health with those in absence of thyroid disease. He goes on to say that the opposite may be true where research has shown that the foods have a positive effect on an array of conditions and illnesses on a preventive level.
There are differing opinions when it comes to consuming kale in a pre-existing thyroid disease. The general consensus here is the not to over consume goitrogen foods, not to avoid it altogether due to its vast richness of health benefiting nutrients.
However, Dr Mario Skugor says that limiting these foods, in his opinion is not necessary for someone who is treating their hypothyroid. Due to their hormones being supplied synthetically, they are not at risk of developing goiter. He goes on to say, that by limiting or avoiding these foods, you may be robbing your body of important nutrients.
Where iodine is insufficient in the diet, which is not commonly the case in the develop world, goitrogen foods must be consumed in a huge amount for it to be a problem.
Kale contains, amongst other nutrients a high portion of calcium. It also contains oxalates which can interfere with calcium absorption. Oxalates can can also pose a problem with a person who is prone to kidney stones. However, due to the high amount of calcium found in kale and the fact that it is easily assimilated and absorbed, calcium deficiency should not be a risk. If you are prone to kidney stones, however, it would be a good choice to limit but not avoid, kale intake.
For further information on thyroid or cruciferous food, contact you nutritionist or naturopath.
