Researchers in Lebanon tested urine samples from teenagers to see if a mold toxin called ochratoxin A (OTA) found in some foods might be affecting their kidneys. They found the toxin or its byproducts in many teens’ urine samples and detected early signs of kidney stress in most participants, though at low levels. The study suggests that contaminated food in Lebanon may be exposing young people to this toxin, but more research is needed to understand the real health impact. This is the first study worldwide to look at this specific concern in teenagers.

The Quick Take

  • What they studied: Whether a poisonous substance called ochratoxin A (OTA) that grows on food crops in Lebanon is damaging the kidneys of teenagers aged 10-18 years old.
  • Who participated: Lebanese teenagers between 10 and 18 years old. The exact number of participants wasn’t specified in the abstract, but researchers collected and tested urine samples from multiple adolescents.
  • Key finding: The toxin or its breakdown product was found in about 60% of teen urine samples tested. Early warning signs of kidney stress were detected in most teens, but at very low levels that don’t yet indicate actual kidney disease.
  • What it means for you: If you live in Lebanon or consume food from there, this suggests you may be exposed to this toxin through contaminated crops. However, the levels found were low and didn’t show serious kidney damage yet. This is preliminary research, and more studies are needed before making major dietary changes.

The Research Details

This was a cross-sectional study, which means researchers took a snapshot in time by collecting urine samples from Lebanese teenagers and testing them all at once. They weren’t following the same kids over months or years; instead, they gathered information from different teens at one point in time. Researchers measured three different kidney stress markers (special proteins that appear in urine when kidneys are struggling) and also checked for the presence of ochratoxin A and its breakdown product. They also asked about what the teens ate to see if certain foods were connected to higher toxin levels.

This type of study is useful for spotting potential health problems in a population and understanding how common a problem might be. By testing many teenagers at once, researchers could see how widespread the toxin exposure was. However, because it’s a snapshot rather than a long-term study, it can’t prove that the toxin is definitely causing the kidney changes—it can only suggest a possible connection.

The study was published in a peer-reviewed scientific journal, which means other experts reviewed it before publication. However, the sample size wasn’t clearly stated in the abstract, which makes it harder to judge how reliable the results are. The researchers acknowledged that their estimates of how much toxin people ate from food were based on older contamination data, which could affect accuracy. The findings show only weak connections between the toxin and kidney markers, suggesting the effects are subtle.

What the Results Show

When researchers tested urine samples, they found ochratoxin A (the original toxin) in about 14% of samples and its breakdown product in about 60% of samples. This means most teens had been exposed to this toxin at some point. When they looked for kidney stress markers, they found that almost all teens had at least some of these markers in their urine, though at very low levels. One specific marker called KIM-1 was found in 86% of the teenagers tested. Another marker called NAG exceeded what doctors consider a safe level in only 1.5% of samples. The researchers found a weak positive connection between the toxin breakdown product and one of the kidney stress markers (NAG), suggesting the toxin might be causing subtle kidney stress.

The study also looked at whether certain foods the teens ate were connected to higher toxin levels. The connections found were generally weak, meaning diet alone doesn’t fully explain the toxin exposure. Researchers compared how much toxin the teens likely ate based on food consumption surveys with how much toxin was actually detected in their urine. The urine tests showed more toxin exposure than the food surveys suggested, which could mean either the food surveys underestimated consumption or the contamination in Lebanese foods is higher than previously measured.

This is the first study worldwide to specifically examine how ochratoxin A exposure affects kidney health in teenagers. Previous research has documented that OTA contamination exists in Lebanon’s food supply, but no one had studied its effects on young people’s kidneys before. The kidney stress markers found in this study are similar to what researchers have seen in other populations exposed to various toxins, but the levels were generally lower than in some previous studies of toxin exposure.

The study has several important limitations. The exact number of teenagers studied wasn’t clearly stated. The researchers used older data about food contamination to estimate how much toxin teens ate, which may not accurately reflect current contamination levels. The study only looked at one point in time, so researchers couldn’t determine whether kidney stress was getting worse or better. The connections between the toxin and kidney markers were weak, making it hard to say the toxin definitely caused the kidney changes. Finally, the kidney stress markers were all at low levels, so it’s unclear whether these early warning signs will develop into actual kidney disease.

The Bottom Line

Based on this preliminary research, there is moderate evidence that ochratoxin A contamination in Lebanese food may be a concern for teen health. However, confidence in specific recommendations is low because this is the first study of its kind. General recommendations include: (1) Supporting efforts to test and reduce mold contamination in food crops in Lebanon, (2) Encouraging teenagers to eat a varied diet with foods from different sources when possible, (3) Storing grains and nuts properly to prevent mold growth. These are sensible precautions but shouldn’t cause alarm, as the kidney stress markers found were at low levels.

This research is most relevant to teenagers living in Lebanon or consuming significant amounts of food imported from Lebanon. Parents and public health officials in Lebanon should pay attention to these findings. Healthcare providers in Lebanon may want to monitor kidney health in adolescents more closely. People in other countries should be aware but don’t need to make immediate changes based on this single study. This research is less relevant to people eating primarily locally-grown food in countries with strong food safety regulations.

If kidney stress from toxin exposure is happening, it likely develops slowly over months or years of exposure. You wouldn’t expect to see obvious symptoms quickly. The kidney stress markers found in this study suggest very early, subtle changes. It could take years of continued exposure for serious kidney problems to develop, or the body might adapt and prevent further damage. More research over several years is needed to understand the real timeline.

Want to Apply This Research?

  • If you live in Lebanon or consume Lebanese food products regularly, track your intake of grains, nuts, dried fruits, and coffee (common sources of mold toxins). Log these foods weekly and note any symptoms like changes in urination, fatigue, or swelling. This creates a personal record to discuss with your doctor.
  • Users can set a weekly reminder to check food storage conditions at home—ensure grains, nuts, and dried foods are kept in cool, dry places in sealed containers to prevent mold growth. Users can also log when they purchase foods and note the source (local vs. imported) to track their exposure patterns over time.
  • For long-term tracking, users should record kidney health markers if they have regular medical checkups (creatinine levels, protein in urine). Set quarterly reminders to discuss kidney health with a healthcare provider, especially if living in or frequently consuming food from areas with known mold contamination. Track any new symptoms related to kidney function and note dietary changes made to reduce exposure.

This research is preliminary and represents the first study of its kind examining ochratoxin A exposure and kidney health in Lebanese teenagers. The findings show only weak associations and low-level kidney stress markers that don’t indicate actual kidney disease. This information should not be used for self-diagnosis or to replace professional medical advice. If you have concerns about kidney health or toxin exposure, consult with a qualified healthcare provider. Pregnant women, children, and people with existing kidney problems should be especially cautious and seek medical guidance before making dietary changes based on this research. More research is needed to confirm these findings and determine their clinical significance.