Friday Favorites: How Much Lead Is in Organic Chicken Soup (Bone Broth)?

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

“Lead poisoning still occurs the United States despite extensive prevention efforts and strict regulations.” Ayurvedic supplements, for example, specifically marketed to pregnant women, exceeded safety levels by up to 4 million percent, making “Ayurvedic medicine use and lead poisoning…a continued concern in the United States.” “[H]eavy metals are intentionally added” to the supplements. But, don’t worry, Ayurvedic practitioners claim, the lead has been detoxified with cow pee.

“Calcium supplements [can be] an additional source of lead contamination”—something we’ve known about for half a century now. Calcium supplements made from bone may have the highest lead levels. But just regular calcium supplements were found contaminated too, including a number of big national brands.

Diet-wise, the greatest contribution to the lead intake of children and their parents may be dairy, but the most concentrated source may be wild game shot with lead-containing ammunition. Concerns have been raised by hunters, though, that lead-free bullets wouldn’t have the same “wounding capacity.” But, CT scans of kills show just as much damage is inflicted—demonstrating that lead-free bullets have equivalent “killing effectiveness” even against “ballistic soap,” which evidently has a similar density to vital organs.

Workers in battery plants can be exposed to a lot of lead, but the #1 “noccupational lead exposure” is shooting firearms. Not eating lead-laden meat, just taking target practice in indoor firing ranges; 75% of target shooters have elevated lead levels in their blood. Even outside, airborne lead released by the friction of the bullet against the barrel, or lead-containing primers, can lead to substantial lead exposure both in people and in local wildlife—as well as the soil, with lead levels higher than those found next to an industrial lead factory. Most lead in urban soil, though, is from the decades of leaded paint and gasoline, raising concerns about urban gardens. Most of the lead doesn’t get taken up by the plants, though, but can stick to the leaves and roots. This is bad news in that even crops from raised beds using clean soil may get contaminated in an urban environment, but the good news is that the lead can presumably just be washed off. The health benefits of gardening and fresh produce would “likely…more than…compensate for the risk at most sites.”

Eggs from backyard chickens, however, should be tested for lead, since the lead gets inside the eggs; and so, it can’t be washed off. Most of the lead ends up in the birds’ skeletons, which raises the question: What happens when you try to make chicken soup? There may be an upswing in people boiling bones due to encouragement from paleo diet advocates. The problem is that lead is a neurotoxin, and, not just a neurotoxin. It also adversely affects the bone marrow, and digestive tract, and kidneys, and circulatory system, and hormones, and reproduction. Symptoms of too much lead exposure include impaired cognition, anemia, abdominal pain, kidney problems, high blood pressure, miscarriages, memory problems, constipation, impotence, depression,  poor concentration, etcetera.

And, we know from human studies that lead is sequestered in the bones. When there’s a lot of “bone turnover,” like at menopause or during pregnancy, lead levels in the blood can go up. This bump can be minimized during pregnancy by getting enough calcium and lowering sodium intake. When astronauts lose bone in space, the lead is released into their bloodstream. But, ironically, since they’re no longer exposed to all the lead on Earth, their overall lead levels may go down. Bones are so good at sucking up lead, they can be sprinkled on firing ranges to prevent lead from leeching further into the environment.

These researchers were concerned that the boiling of farm animals’ bones might release lead into the broth. So, they made three types of organic chicken broth—one with the bones, one with just the meat, and one with the skin and cartilage. All the soups exceeded the maximum allowable dose level for lead, even the boneless. Surprisingly, the skin and cartilage was the worst, exceeding the safety level per one cup serving by like 475%.

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Image credit: Mariuszjbie via Wikimedia. Image has been modified.

Motion graphics by Avocado Video.