By LOUISE CARR, Associate Editor and Featured Columnist
You’ve heard of smart foods that supposedly raise intelligence and boost cognitive function, but what about stupid foods? Some foods have the power to lower your IQ and actually make you less intelligent. Which foods make you less smart? What do you need to remove from your diet to improve your brain power?
Modern Diets Are Making Us Stupid?
It’s no secret that the modern diet has moved away from whole foods, vegetables and grains towards processed, packaged, and high-fat and high-sugar consumption.
More and more Americans are eating junk food on a daily basis. But is this affecting our intelligence? What about children – does their diet matter?
The U.S. Department of Agriculture says that the average American eats 156 pounds of sugar a year in the form of added sugar in meals and drinks – that’s five whole shelves in the grocery store that each contain around 30 bags of sugar.
We eat around 27.5 teaspoons of sugar a day in America, according to the Centers for Disease Control and Prevention, which comes to nearly a quarter of a typical 2000-calorie-a-day diet.
Link Between Obesity and IQ
Processed foods and junk food are cheaper and easier to access than ever before, leading to an explosion in obesity.
And according to a 2012 study from the New York University School of Medicine and the Nathan Kline Institute for Psychiatric Research, New York, children who are obese are more likely to perform worse in spelling, arithmetic, and mental flexibility.
Other studies also link obesity in adults to lower mental functioning.
The sad truth is, there are certain foods that can actually make you less intelligent.
We looked at recent scientific research to find the stupid-making foods so you can cut down.
1. High Fructose Corn Syrup Makes You Stupid
Bingeing on candy and soda for as little as 6 weeks can make you stupid, according to a 2012 study from UCLA.
The culprit? High fructose corn syrup. The rat study shows that a diet consistently high in fructose hampers memory, stunts learning, and actually slows the brain.
High fructose corn syrup is a cheap sweetener that is routinely added to processed foods, soft drinks and condiments in the US.
The U.S. Department of Agriculture says that the average American consumes around 47 pounds of cane sugar and 35 pounds of high-fructose corn syrup every year.
Let's repeat that --- we're eating 35 pounds of high fructose corn syrup per year.
But there is better news – researchers say you can add omega-3 fatty acids to your diet to help minimize the damage high fructose corn syrup does to your brain.
2. Too Much Junk Food is Lowering Young Children’s IQs
Children’s diets that are high in processed foods, fat and sugar are not only harming their waistline but making them less intelligent, according to the 2011 study from the UK. The Avon Longitudinal Study of Parents and Children was a massive study that looked at 14,000 children over a number of years.
The researchers found that children’s eating habits at the age of three determined their brain performance as they grew older, despite any subsequent changes in their diet.
A diet made up of predominantly processed foods at age three results in a lower IQ at the age of eight and a half, according to scientists.
On the opposite end of the food spectrum, foods high in vitamins and nutrients during the early years helps boost IQ as the brain grows at its fastest rate in the first three years of life.
3. High Fat Diets Lower IQ
If your diet is consistently high in fat you are destroying the synapses in the brain that connect neurons and aid in successful brain functioning, according to a 2015 study from the Medical College of Georgia at Georgia Regents University.
This destruction of your synapses leads to impaired memory and learning. The team looked at mice consuming food with 10% of calories from fat and 60% of calories from fat.
After 12 weeks, the high-fat mice had not only become obese but also had reduced levels of synaptic markers and indications that the synapses were being destroyed.
Too much fat in the body leads to chronic inflammation, which can trigger brain synapse damage.
However, if you switch to a low-fat diet for two months you can counteract the brain-damaging effects of your previous diet, experts say.
4. Alcohol Lowers IQ – Or Is It the Other Way Around?
Alcohol destroys brain cells, you have heard, but researchers also believe that the link with IQ is also the other way round.
A 2015 study from the Karolinska Institutet in Sweden says that people with low IQs are likely to drink more alcohol than those with higher IQs.
The study looked at 49,321 Swedish men born between 1949 to 1951 and in active service for the Swedish military from 1969 to 1971.
The scientists concluded that "a higher IQ results in healthier lifestyle choices".
However, one way it is clear that alcohol harms intelligence is in the womb.
Even minimal exposure to alcohol in the womb can result in a lower IQ, according to a 2012 study from the Universities of Bristol and Oxford in the UK.
Conflicting opinions exist over whether it is OK for a woman to drink moderately during pregnancy, but this study asserts that a strong link was found between four genetic alternatives in genes that metabolize alcohol and lower IQ at 8 years old.
This genetic difference was only found in mothers who reported moderate drinking (1 to 6 units a week) and not in those that reported no drinking at all during pregnancy.
5. Caffeine in Pregnancy Lowers Baby’s IQ: Or Does It?
Pregnant women are advised to limit their caffeine intake for many reasons, including the risk of raising blood pressure and heart rate, but it seems that moderate caffeine consumption doesn’t’ affect baby’s IQ.
A 2015 study from the Nationwide Children's Hospital in Columbus found no evidence of an adverse association “between caffeine in pregnancy and child cognition or behavior at 4 or 7 years of age,” considering that caffeine intake was moderate, around one to two cups of coffee a day.
The researchers looked at a marker of caffeine in the blood of 2,197 pregnant women at various times between 1959 and 1974, and measured child IQ at 4 and 7 years of age.
6. Iodine Deficiency Harms Baby's IQ
A lack of one particular nutrient is making people more stupid, according to a 2013 study from Surrey and Bristol Universities in the UK.
Iodine deficiency during pregnancy may have a negative effect on babies’ IQ development, say researchers. Iodine is found in seafood and dairy products and helps fetal brain cells develop.
7. Glucose Levels in Mothers Associated with IQ in Offspring
While the results of research into glucose levels in the mother and child IQ are mixed, many experts believe that higher glucose levels in pregnancy are associated with poorer cognitive performance in young adults.
A 2010 study from Aalborg Hospital Aarhus University Hospital, Denmark showed this to be the case, with higher glucose levels linked with a drop in cognitive performance.