It has been argued that a potential reduction in IQ due to formula use is either too difficult to prove, or statistically unimportant... I wonder if the same holds true for the reduction in IQ due to lead poisoning? The number of points is very similar... lead poisoning can lead to a reduction of 5-7 IQ points.
Here are a few articles that talk about the risks of lead poisoning in this area:
"What’s a Few IQ Points? It is well-established that low-level lead exposure can reduce a child’s IQ. When lead poisoning is widespread in a community, the normal distribution of IQs is shifted toward the lower end. More children in the community have developmental disabilities and fewer are intellectually gifted." http://www.ehw.org/Lead/LEAD_CommunityAgenda.htm
"A 5 point loss in IQ might not affect the ability of an individual to live a productive life. But if that loss is experienced by an entire population, the implications for that society could be profound.
Bernard Weiss, a behavioral toxicologist at the University of Rochester, examined the societal impact of seemingly small losses of intelligence.
Imagine an unaffected population numbering 260 million people (like the US) with an average IQ of 100 and a standard deviation of 15 (right, above). In that population there would be 6 million people with IQs above 130 and 6 million below 70.
A decrease in average IQ of 5 points would shift the distribution to the left (right, below). The number of people scoring above 130 would decline by 3.6 million while the number below 70 would increase by 3.4 million.
I thought it was interesting that this book is titled "Our Stolen Future".... if formula use really does have similar effects on IQ as lead poisoning, what does that tell us?
.... if formula use really does have similar effects on IQ as lead poisoning, what does that tell us?
From the link with the graph: "At least two pervasive contaminants known to impair intelligence, lead and certain PCBs, are sufficiently widespread to raise concerns.
Recent data, for example, reveal that over 60% of inner city children in Philadelphia carry lead levels above criteria established by the US CDC for lead poisoning. Lead contamination in many major cities in developing countries is much worse, with millions of children affected (see discussion in Williams 1997). Other research documents significant declines in IQ in children exposed in utero to levels of PCBs experienced by many people in the United States.
These are just two of many neurotoxic chemicals. Vast quantities are released by accident or design from industrial facilities, or released purposively (e.g., pesticides) each year."
I wonder if any studies on infant feeding and IQ have taken into account effects of lead and PCB exposure?
From the first link:
Most investigators report lower IQ scores among the more highly exposed children but these differences have not uniformly reached statistical significance (that is, p less than .05). One way to synthesize the data from different studies is meta-analysis. Recent evaluation of 24 major cross-sectional studies provides strong support for the hypothesis that children's IQ scores are inversely related to lead burden (Needleman and Gatsonis, 1990).
Here it looks like they did the same thing the ARHQ did for breastfeeding. They took all the data they had to date and did a metaanalysis, and found the results to be significant. With feeding and IQ, they took all the information they had to date and found the evidence does not support the differences are due to feeding choices. Since they are observational studies and there are so many known confounders, one study alone does not prove the risk exists or is due to one particular thing. But significant findings across studies that are well controlled, can very much suggest a cause-effect link exists. It looks like cause-effect for lead but not for formula.
I will say that IF formula feeding was shown to reduce IQ points and the science demonstrated that this finding was reliable and valid, then absolutely the impact to society of lower intelligence would be a concern. But even without any proven effects on IQ, formula feeding still is a concern for society as a whole because of all the other risks we know about.
"The last of human freedoms - the ability to chose one's attitude in a given set of circumstances. " - Viktor Frankl.
I think it's an interesting point. Cocaine use during pregnancy also affects IQ 5-7 points. Similar to lead paint, I don't see a lot of people saying, "Hey, IQ doesn't change by that many points, so cocaine and lead may have some negative effects, but IQ isn't really one of them."
I do hear that argument in terms of formula.
I think you meant to ask if kids who don't have lead poisoning are smarter then those who do? ;)
Hmm.. Jason had lead poisoning and was on formula, and he was a really smart kid - so I guess it must be safe! ;)
~*~ Catherine, mom to Jason, Michael & Joshua
No matter what decision you make in your life, or your child's life - there will always be someone just waiting to tell you what a stupid idiot you are for doing so...
Do not assume you know what the silent majority is thinking.
I think it's an interesting point. Cocaine use during pregnancy also affects IQ 5-7 points. Similar to lead paint, I don't see a lot of people saying, "Hey, IQ doesn't change by that many points, so cocaine and lead may have some negative effects, but IQ isn't really one of them."
Actually, I have heard that children exposed to cocaine in utero can "make up" for it and that the data on cocaine exposure in utero and IQ is controversial. I can't remember when I heard it, but I had met someone once who was reportedly born addicted to cocaine, so hearing this years later always stuck with me. It made me wonder how he turned out. I hadn't heard about lead and IQ, and when I googled that I didn't come up with any controversy. Here are some studies on cocaine/IQ that I found just googling:
Researchers Probe How Poverty Harms Children's Brains "The tests showed that children exposed to cocaine in the womb had a mean IQ of 79 at age 6, a full standard deviation below the average. Even more disturbing, though, were the results from the control group. The 6-year-olds who had never been exposed to drugs had virtually the same IQ as the children who had endured cocaine running through their veins while inside the womb. Dr. Hurt's data suggests that while cocaine no doubt does cause harm in utero, poverty itself presents an even graver threat to a child's intellectual development."
New evidence for neurobehavioral effects of in utero cocaine exposure "Standard analyses, based on presence or absence of cocaine use during pregnancy, confirmed effects on gestational age but failed to detect cognitive effects."
Review: prenatal exposure to cocaine does not independently affect physical growth, cognition, or language skills "9 studies examined cognitive development in infants: 5 studies showed no effect; 4 studies showed an association that could not be separated from the effects of maternal alcohol or marijuana use, other risk factors, or design flaws relating to lack of adjustment or post hoc comparisons. 6 studies that evaluated cognitive development in children 3–6 years of age showed no effect when alcohol, marijuana, or tobacco use were controlled for (3 studies); 3 studies showed no effect on intellectual quotient, cognitive test scores, or academic skills."
Long-term Growth and Developmental Outcomes in Children with in Utero Cocaine and Opiate Exposure Born to HIV-infected Women. "Cocaine-exposed infants had poorer weight, height, and head growth, as well as poorer motor and cognitive development for the first few months of life, but showed no significant long-term deficit in growth, development, or behavior."
"The last of human freedoms - the ability to chose one's attitude in a given set of circumstances. " - Viktor Frankl.
