A new study of 1,370 teenagers in Kuwait found that having healthy levels of four important minerals in their blood was linked to better thinking skills and higher grades in school. The minerals—copper, manganese, selenium, and zinc—help the brain work properly. Teens with higher levels of these minerals scored about 5 points higher on thinking tests and had better academic performance than those with lower levels. Since many teenagers don’t eat well enough to get these minerals naturally, the researchers suggest that schools and health programs should help young people get the right amounts of these nutrients.

The Quick Take

  • What they studied: Whether the amount of four specific minerals (copper, manganese, selenium, and zinc) in teenagers’ blood is connected to how well they think and perform in school
  • Who participated: 1,370 teenagers between 11 and 14 years old from public middle schools in Kuwait, selected randomly to represent the country’s teen population
  • Key finding: Teenagers with higher blood levels of these four minerals scored about 5 points higher on thinking tests and had better grades than those with lower mineral levels. All four minerals showed this positive connection.
  • What it means for you: Getting enough of these minerals through food may help you think more clearly and do better in school. However, this study shows a connection, not that the minerals definitely cause better performance. Talk to a doctor or nutritionist about whether you’re getting enough of these minerals.

The Research Details

Researchers studied 1,370 teenagers from Kuwait and measured the amount of four minerals in their blood using a special lab test called ICP-MS. They also gave the teenagers a thinking skills test (called Raven’s Standard Progressive Matrices) and looked at their actual school grades. They collected information about the teenagers’ eating habits, family background, and other health factors through questionnaires.

This type of study is called a ‘cross-sectional’ study, which means researchers looked at everything at one point in time rather than following teenagers over months or years. The teenagers were chosen randomly from schools across Kuwait to make sure the results would represent all Kuwaiti teenagers, not just one group.

This research approach is important because it uses real blood tests (not just asking people what they eat) to measure mineral levels, and it combines this with actual school grades and scientific thinking tests. This gives researchers more reliable information than studies that only ask people questions. The large sample size of 1,370 teenagers also makes the results more trustworthy.

The study has several strengths: it used a large, representative sample of teenagers; it measured minerals directly from blood rather than guessing from diet; and it looked at both thinking skills and real school performance. However, because this is a cross-sectional study (a snapshot in time), we can’t be completely sure that having more minerals causes better thinking—it’s possible that teenagers who think better also eat healthier foods. The study was published in a respected nutrition journal, which suggests it went through quality review.

What the Results Show

Teenagers with mineral levels above the middle point (median) scored about 5 points higher on the thinking skills test compared to those below the middle point. This difference was statistically significant, meaning it’s unlikely to have happened by chance.

When researchers looked at each mineral separately, all four showed positive connections with both thinking skills and school grades. Copper, manganese, selenium, and zinc all followed the same pattern: more mineral in the blood meant better test scores and grades.

The study also looked at mineral levels divided into four groups (quartiles). Teenagers in the highest group for each mineral consistently had better cognitive function and academic performance than those in the lowest group. This pattern held true across all four minerals studied.

The study found that the connection between minerals and school performance was consistent whether researchers looked at the minerals individually or in combination. The teenagers’ mineral levels varied quite a bit—some had much higher levels than others—but the pattern remained the same: higher levels were better for thinking and grades.

Previous research has shown that these four minerals are important for brain health and development. This study adds to that knowledge by showing that in real teenagers, having adequate levels of these minerals is connected to better thinking skills and school performance. The findings support what scientists already knew about these minerals being essential for the brain, but now we have evidence from a large group of real teenagers.

The biggest limitation is that this study shows a connection between minerals and performance, but doesn’t prove that the minerals cause better thinking or grades. It’s possible that teenagers who eat healthier foods (which contain these minerals) also have other advantages that help them do better in school. The study was done only in Kuwait, so results might be different in other countries with different diets and lifestyles. Additionally, the study measured minerals at only one point in time, so we don’t know if these connections stay the same over months or years.

The Bottom Line

Make sure you’re eating foods rich in these four minerals: copper (found in nuts, seeds, and shellfish), manganese (found in whole grains, nuts, and leafy greens), selenium (found in Brazil nuts, fish, and eggs), and zinc (found in meat, shellfish, beans, and nuts). This is a moderate-confidence recommendation based on this study’s findings. If you’re concerned about your mineral intake, talk to a doctor or school nurse who can assess your diet.

All teenagers should care about this, especially those who eat limited diets or skip meals. Parents and teachers should also pay attention because good nutrition during teenage years affects both school performance now and health later in life. If you have a diagnosed mineral deficiency, definitely talk to a doctor before making changes.

You won’t see changes overnight. Building up healthy mineral levels and seeing improvements in thinking and grades typically takes weeks to months of consistent healthy eating. The brain develops throughout the teenage years, so starting good eating habits now can have long-term benefits.

Want to Apply This Research?

  • Track your daily intake of mineral-rich foods: log servings of nuts/seeds (copper), whole grains (manganese), fish/eggs (selenium), and legumes/meat (zinc). Aim for at least one serving from each category daily.
  • Set a weekly goal to try one new mineral-rich recipe or food. For example: add Brazil nuts to breakfast one day, try a new fish recipe another day, or experiment with beans in a meal you enjoy.
  • Every two weeks, rate your energy levels, focus during homework, and overall mood on a 1-10 scale. While this won’t measure minerals directly, these factors often improve when nutrition improves. Also track your grades or test scores over the semester to see if better eating habits correlate with better academic performance.

This study shows a connection between mineral levels and thinking skills, but does not prove that minerals directly cause better grades or thinking. Individual results vary based on many factors including genetics, sleep, exercise, and overall diet. This information is not a substitute for professional medical advice. If you’re concerned about your mineral intake or have symptoms of nutritional deficiency, consult with a healthcare provider, doctor, or registered dietitian. Do not start taking mineral supplements without talking to a healthcare professional first, as too much of certain minerals can be harmful.