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.

Environmental risk factors, meaning non-genetic risk factors, may play a significant role in autism, given the fact that even identical twins that share the same DNA may not share the disease more than half the time. A variety of risk factors have been proposed: “lead, mercury, persistent organic pollutants [like PCBs, or birth] complications might cause a pro-inflammatory state and oxidative damage in the brain.” But, what’s that based on?

You see a lot of correlational studies like this, speculating about “the possibility that one of the hidden agents spurring the rise in autism” is something within the food supply, especially industrialized meat production, particularly poultry. This is based on the fact that the rise in poultry consumption, particularly parental poultry consumption, appears to correlate with the rise in autism. This suggests it’s the “massive contamination of meat” with antibiotics, growth hormones, and toxic pollutants, such as dioxin in the meat.

There’s certainly toxicological issues associated with meat production—not just the pollutants, but the cooked meat carcinogens: leukotoxins. This review in the journal Meat Science came up with a whole list. But, if anything, “[t]he main chronic toxic response of consuming…meat and meat products is [cancer, not autism].” There’s tons of confounding factors that could explain this correlation.

Same thing with fish consumption and autism. In the U.S., on a state-by-state level, “mercury-related fish advisories [were] found to be a surprisingly strong predictor of…autism rates,” suggesting that mercury-contaminated fish was to blame. But, how many people tend to even eat the fish from their own state? That in no way proves a cause-and-effect mercury-autism connection. Why would they even think to make that connection? Well, heavy metals, like mercury and lead, do cause brain damage, and there’s some similarities in terms of the symptoms they can cause. But, you don’t really know, until you put it to the test.

“‘Urine mobilization test,’ ‘challenge test,’ or ‘provoked urine test’ are all terms used to describe the administration of a chelating agent [a heavy metal binding agent] to a person prior to [the] collection of their urine to test [to see the level of heavy metal burden within their bodies].” But, pediatric, public health, and toxicology authorities recommend against the use of these tests, “based on a lack of scientific validation and a lack of demonstrated benefits to the patients”—”usually promoted by alternative practitioners as the basis for recommending, promoting, and selling to the patient questionable and often inappropriate therapies…supposedly aimed at ‘detoxification.'”

“Despite [this disapproval], the tests are still commonly used and recommended by some practitioners.” This is what the results end up looking like. Uh oh, looks like mercury is in the red. “It is easy for uninformed patients and providers to infer that a result that falls in the yellow or red background signifies [heavy metal] poisoning.” But, that’s because they’re not reading the fine print. That reference interval, that normal green range, is the level under non-provoked conditions, meaning normal urine, not urine from someone who was just given a chelating drug to provoke the response, to intentionally grab onto heavy metals in the body and pull them into the urine. That’s like giving someone a drug that raises their heart rate—like a shot of adrenaline, then taking their pulse, and being, “Like wow, you got an abnormally high heart rate!” Compared to other people who just got a shot of adrenaline? No, just compared to a regular resting heart rate. Well, duh. See, “there are no established reference ranges for provoked urine samples;” so, they’re using the wrong reference range. So, we have no idea what the results mean, and given the “potential harm” of whatever treatment the practitioner then tries to sell you on, “these tests should not be utilized.”

Most commonly, that treatment means chronic chelation therapy. A “half…million [people] with autism are subjected to chelation therapy in the US [every year],” despite “no clinical trial evidence” suggesting that there’s any benefit. Why not just give it a try, though? Because there’s potential for side effects, like death. They’re referring to this case, where doctors were like, oops, they just gave the wrong drug. Should have been given edetate calcium disodium, not just straight edetate disodium. But, this may have been “no accident.” That’s exactly what’s recommended by leading chelation proponents. “As such, it would have been surprising only if the practitioner…had not chosen [it].” So, this may “not just be a simple matter of the ‘wrong medication being administered.'” That may just be a distraction from the prospect that the killer was “quackery.”

This is not to say that heavy metals aren’t toxic. It’s just that instead of trying to give people chelation drugs after the fact, we should try to help them not get exposed in the first place. For example, in this study, they compared the blood mercury levels of physicians who ate no fish, to those who ate one or two servings a week, and to those who ate three or more. Here’s where the three or more servings a week group started out. And, after a single chelation drug dose, mercury levels dropped down to here. But, perhaps better to eat less fish, or no fish at all.

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