Category: Intelligence

Study of over 7,000 finds diet linked to IQ.

People fed a healthier diet from an early age have a higher IQ, research reveals.

Children who were breastfed and later given plenty of fruits, vegetables and other healthy foods had IQs up to two points higher at age 8.

Dr Lisa Smithers, the study’s first author, said:

“Diet supplies the nutrients needed for the development of brain tissues in the first two years of life, and the aim of this study was to look at what impact diet would have on children’s IQs.

We found that children who were breastfed at six months and had a healthy diet regularly including foods such as legumes, cheese, fruit and vegetables at 15 and 24 months, had an IQ up to two points higher by age eight.

The results come from a study of over 7,000 children whose eating habits were analysed at ages 6 months, 15 months and two years.

They were followed until age 8.

Set against the benefits of healthy eating, children fed junk food had lower IQs, Dr Smithers said:

“Those children who had a diet regularly involving biscuits, chocolate, sweets, soft drinks and chips in the first two years of life had IQs up to two points lower by age eight.

We also found some negative impact on IQ from ready-prepared baby foods given at six months, but some positive associations when given at 24 months.”

Eating well is particularly important in the formative years, said Dr Smithers:

“While the differences in IQ are not huge, this study provides some of the strongest evidence to date that dietary patterns from six to 24 months have a small but significant effect on IQ at eight years of age.

It is important that we consider the longer-term impact of the foods we feed our children.”

The study was published in the European Journal of Epidemiology (Smithers et al., 2012).

The foods boosts fluid intelligence, which is the speed at which the brain works.

Eating organic food is linked to a higher IQ, a study finds.

School-age children who ate more organic food had higher scores on tests of fluid intelligence and working memory.

Fluid intelligence refers to the speed at which the brain works.

It is like the raw power of an engine or the speed at which a computer can process information.

Working memory, meanwhile, is vital to holding pieces of visual, verbal or other information in your mind while you manipulate them.

Better working memory has been linked to improved learning, attention and other vital outcomes.

The higher levels of nutrients in organic foods may account for the boost to IQ, said Dr Jordi Júlvez, study co-author:

“Healthy diets, including organic diets, are richer than fast food diets in nutrients necessary for the brain, such as fatty acids, vitamins and antioxidants, which together may enhance cognitive function in childhood.”

In contrast, eating fast food, being exposed to tobacco smoke and house crowding were all linked to lower scores on tests of fluid intelligence.

Children’s brains are sensitive

The results come from over one thousand children aged 6 to 11-years-old in six different European countries, including the UK and Spain.

The research examined 87 factors that the unborn child might be exposed to along with another 122 factors that could affect them during childhood.

The brain is still developing in childhood, so it is particularly sensitive to toxicity.

Low levels of toxicity that may have little affect on the adult brain can still influence children’s brains.

Dr Jordi Júlvez, study co-author, explained the main predictors of higher IQ:

“In our study, we found better scores in fluid intelligence and working memory with higher organic food intake and lower fast food intake.”

As for the predictors of lower IQ, Professor Martine Vrijheid, study co-author, said:

“We observed that several prenatal environmental pollutants (indoor air pollution and tobacco smoke) and lifestyle habits during childhood (diet, sleep and family social capital) were associated with behavioral problems in children.”

The study is notable because of its comprehensive approach to a huge range of variables, said Professor Vrijheid:

“One of the strengths of this study on cognition and the earlier study on behavioral problems is that we systematically analyzed a much wider range of exposure biomarkers in blood and urine to determine the internal levels in the model and that we analyzed both prenatal and childhood exposure variables.”

→ Other dietary changes linked to high IQ include nuts, a diet low in sugars, fats and processed foods, fruits and vegetables,

The study was published in the journal Environment International (de Bont et al., 2021).

The study of almost 10,000 people used MRI scans to measure abdominal fat and blood flow through the brain.

Higher body fat is linked to the brain being slower to process information — a critical component of IQ.

The more abdominal or ‘belly fat’ that people have, the lower their scores on tests of cognitive function.

The study of almost 10,000 people used MRI scans to measure abdominal fat and blood flow through their brain.

Professor Sonia Anand, the study’s first author, explained the results:

“Our results suggest that strategies to prevent or reduce having too much body fat may preserve cognitive function.

The effect of increased body fat persisted even after adjusting for its effect on increasing cardiovascular risk factors like diabetes and high blood pressure, as well as vascular brain injury, which should prompt researchers to investigate which other pathways may link excess fat to reduced cognitive function.”

A healthy body weight is key to a healthy brain, said Dr Eric Smith, study co-author:

“Preserving cognitive function is one of the best ways to prevent dementia in old age.

This study suggests that one of the ways that good nutrition and physical activity prevent dementia may be by maintaining healthy weight and body fat percentage.”

Nutrition and cognitive function

Nutrition is often linked to cognitive function by research.

For example, a study on rats found that high-fat foods can reduce intelligence in just 9 days.

Cognitive performance was reduced by 20 percent in just over a week after eating a high-fat diet.

The study on rats fed them a diet equivalent to human junk food.

Another rat study also found that diets high in saturated fats can slow brain function.

In contrast, healthier diets have repeatedly been linked to better cognitive function, higher IQs and a lower risk of dementia.

For example, people fed a healthier diet from an early age have a higher IQ, one study found.

Even eating organic food in childhood is linked to a higher IQ.

Finally, the MIND diet could lower the risk of developing Alzheimer’s disease by over 50 percent and improve your brain health.

The study was published in JAMA Network Open (Anand et al., 2022).