6 reasons why IQ scores are dropping every generation since the 1970’s
(NaturalHealth365) In a bit of unwelcome news, scientists have found that humans are becoming less intelligent. In a study published in Proceedings of the National Academy of Sciences, a pair of Norwegian researchers studied test results from over 730,000 young men and found that IQ scores were dropping – to the tune of seven points per generation.
A recent British study – which demonstrated that IQ scores have fallen by 2.5 to 4.3 points every decade since the end of World War II – helps to corroborate the results of the Norwegian research.
These findings are in sharp contrast to results from the first half of the twentieth century, when IQ scores rose steadily. (Could the barrage of pesticides and environmental toxins introduced during the second half of the century be taking their toll on human brain function? Many natural health experts think so.)
Harvard researchers warn that fluoride in water can lower IQ scores
Fact: both animal and human studies have shown that fluoride impairs learning and memory.
In a meta-analysis published by Harvard University and involving 27 different studies over 22 years, the authors found that children who live in areas with highly fluoridated water have “significantly lower” IQ scores than those living in areas with low fluoride in water.
The authors reviewed studies conducted in rural China, which have not been widely published.
One study found that every 0.5 mg/L increase in the water fluoride levels was associated with a reduction of 4.29 in IQ scores.
The authors cited a report from the US National Research Council reporting that fluoride causes neurotoxicity – with children particularly at risk. “Fluoride affects brain development at exposures much lower than those causing toxicity in adults,” the report stated.
Fluoride harms brain health by causing reductions in acetylcholine receptors, promoting the formation of beta-amyloid plaques (linked to Alzheimer’s disease), impairing antioxidant defense systems and increasing uptake of aluminum – yet another neurotoxin.
(And here’s a final, disgusting fluoride fact: the two most common types of fluoride in drinking water, sodium silicofluoride and hydrofluorosilicic acid, are end products from the fertilizer industry, and are duly classified as hazardous wastes).
Double whammy: Prenatal exposure to diazinon and chlorpyrifos associated with lowered intelligence
Researchers at the Berkeley School of Public Health at the University of California found that prenatal exposure to organophosphate pesticides – such as chlorpyrifos and diazinon – is associated with lower intelligence scores in seven-year-olds.
The team assessed IQ by using the Wechsler Intelligence Scale for Children, which includes developmental subcategories such as verbal comprehension, perceptual reasoning, working memory and processing speed.
The researchers found that children in the subgroup with the highest levels of prenatal pesticide exposure scored an average of seven points lower on standardized intelligence tests.
The U.S. Centers for Disease Control and Prevention (CDC) says that exposure to diazinon and chlorpyrifos occurs from eating foods from crops treated with these chemicals (another reason to eat organic!)
Exposure to lead increases the risk of learning disabilities
Children with high lead levels can exhibit lower IQ scores and learning disabilities, along with behavioral problems such as hyperactivity, inability to maintain attention and aggression.
The EPA notes that an estimated 1.7 million children are currently affected by lead toxicity in the United States alone – almost 900,000 of them under the age of six.
And, childhood exposure to lead can cause adverse effects that persist into adulthood. In one study, a group of 281 young adults who had been exposed to lead as children displayed significant neurobehavioral effects 20 years after the exposure.
Although lead no longer exists in the nation’s gasoline, it can still be found in lead-based paint used in older homes. (In fact, it is estimated that 5 to 15 million homes in the United States have been identified as “very hazardous” by the US Department of Housing and Urban Development).
In addition to lowered IQ, symptoms of chronic lead exposure include headaches, poor memory, inability to concentrate, aberrant behavior, irritability, insomnia and difficulties with language, visual and motor skills.
IQ losses from mercury exposure carry hefty price tag
According to a new study, the “brain drain” from exposure to mercury is hitting America in the pocketbook.
Researchers at the Mount Sinai Center for Children’s Health and the Environment concluded that lower IQ levels linked to mercury exposure in the womb costs the United States a stunning $8.7 billion a year in lost earnings potential.
(Note: The EPA estimates that about 8 percent of American women of childbearing age have enough mercury in their blood to put a fetus at risk).
Mercury jeopardizes brain health by destroying neurons (brain nerve cells) and decreasing the production of vital neurotransmitters, the brain’s “chemical messengers.”
“Silver” dental amalgams – which are composed of 50 percent mercury – are a common source of exposure, along with consumption of contaminated fish or drinking water. Mercury is also found in pesticides, laxatives and paint products.
In addition to causing poor cognitive function and lowered IQ, mercury exposure can cause headaches, hallucinations, dizziness, anxiety and depression.
Aluminum cookware can release a hodgepodge of neurotoxic metals
According to a study conducted at Ashland University, aluminum cookware made in developing countries can contain dangerous amounts of lead and cadmium – along with unhealthy amounts of aluminum.
In fact, the levels of aluminum residue that leached into cooking water were found to be six times greater than that allowed by WHO dietary guidelines. Keep in mind (no pun intended), aluminum is a neurotoxin – which has been linked to lowered intelligence. In truth, there’s not a single (biological) reason for any amount of aluminum to be inside the body.
But an additional hazard lies in the potential for heavy metal poisoning from the release of lead and cadmium.
“Lead and cadmium exposures from regular use of these pots will significantly reduce IQ and school performance among children,” warned study author Jeffrey Weidenhamer, a chemistry professor at Ashland University.
Of course, there may be other factors contributing to the drop in IQ scores worldwide. Some have pointed to more rigorous IQ testing in general, while others have blamed the primacy of video games over the old-fashioned (and brain-building) pursuit of reading books.
But one can’t rule out the toxic effects of fluoride, diazinon, chlorpyrifos, mercury, lead and aluminum.
This “dirty half-dozen” very likely have something to do with the increase in cognitive decline in adults, the rise in behavioral issues in children – and lowered IQ scores worldwide.
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