Heavy Metals

Topic summary contributed by volunteer(s): Selena

Heavy metal exposure (the toxins, not the music!) can have detrimental effects on our health. Mercury can affect brain development, cadmium and lead appear to lower male fertility, copper may be a risk factor for Alzheimer’s, and all may be associated with a higher risk of cancer.

The heavy metals present in our food supply often exceed safe limits (see also here). Some metals are hard to avoid due to their presence in cigarettes, meats (see also here, here, here and here), seafood, some brands of nutritional yeast, supplements (see also here, here, here and here) and even whole grains and vegetables. There is also aluminum found in tea, but the phytonutrients also present prevent it from being easily absorbed. Hibiscus tea does have a high amount of manganese though, and so we should limit our intake to no more than two quarts a day. Research indicates that the bioavailability of heavy metals may be lower in plant-derived foods than in animal-derived foods, despite the fact that plant foods sometimes contain higher amounts. This is likely the reason why vegetarians had lower levels of cadmium, lead and mercury even though their heavy metal intake was higher than meat-eaters (and switching to a plant-based diet lowers levels within months). Organic produce may have less cadmium than conventional produce.

The information on this page has been compiled from the research presented in the videos listed. Sources for each video can be found by going to the video’s page and clicking on the Sources Cited tab.