Broccoli

Hello.

In the context of plant-based calcium sources, kale, pak choi, and broccoli are becoming increasingly discussed. What is your opinion on these foods in terms of calcium? I calculated the volume of absorbable calcium in broccoli, and it performs better than cow's milk. I am also moving away from recommending poppy seeds as a quality source because its absorbability is, in reality, very low, as mentioned here: https://www.evahajkova.com/cs/jaka-je-absorbce-vapniku-z-rostlinnych-zdroju-vyjadreni-k-maku, and there is also a risk of high cadmium contamination.

Thank you.

The absorption of minerals from food is not only a complex issue but, primarily in terms of numerical expression, highly relative. Too many factors come into play for it to be meaningful to express the level of utilization of each element; therefore, be cautious not only in adopting any values but especially in applying them in practice. The bioavailability of calcium is generally significantly lower from plant sources than from animal sources, so more effort is needed in plant-based diets to optimize the whole process. Essentially, this involves reducing fiber content and avoiding higher concentrations of other antinutritional components, but it also makes sense to maintain a balance with the intake of magnesium, care for the function of the gut microbiome, which significantly contributes to calcium metabolism, ensure adequate calciferol levels, and support metabolism through physical activity. The higher the proportion of plant-based foods (and thus calcium sources) in our diet, the higher the demands we place on the body to activate adaptive mechanisms tasked with maintaining balance. An extreme in this regard is a vegan diet, where it makes sense to address every "detail," as practice shows that indeed there is a challenge in ensuring adequate calcium with all its consequences. Do not address heavy metals in the mentioned food sources, as this factor depends on soil quality and crop cultivation methods, and it does not make sense to generalize it.

Hello,

I have had a borderline thyroid condition for a long time after two childbirths. However, my doctor has not prescribed any medication yet. Would it be harmful in this situation if I regularly consumed pickles made from cabbage or kohlrabi? I also often steam broccoli for a few minutes. Do these preparations, such as fermentation or steaming, reduce the goitrogen content in cruciferous vegetables?

In the case of seeds, nuts, grains, and legumes, if I always soak them, should I also be able to eliminate the negative impact of antinutritional factors? I was a bit surprised by your answer regarding veganism and thyroid issues, where you basically do not recommend solely plant-based diets. Yet, if I follow practices like soaking, fermenting, and sprouting, I thought I could significantly eliminate the negative substances in these foods.

Thank you for your response.

Thermal treatments including soaking and fermentation reduce the amount of antinutritional factors, but not significantly in the case of goitrogens. In fact, fermented cabbage contains these compounds in unnecessarily high quantities. A vegan diet contains the highest proportion of antinutritional factors of all dietary regimens, making it unsuitable for individuals with a genetic predisposition to thyroid function disorders. In practice, this means that in such cases it is necessary to adhere even more strictly to all available guidelines that improve the digestibility of plant foods and simultaneously reduce the proportion of antinutritional factors.

In general, it is advisable not to avoid these "implicated" foods directly, but rather to keep their intake under control (= occasional consumption in moderate amounts will not harm). This is conditional on efforts to ensure an adequate intake of substances that support thyroid function (iodine, zinc, selenium, antioxidants, sufficient protein, etc.).