Researchers discovered that old pesticides called organochlorine chemicals, which are still found in the environment and in people’s bodies, may be lowering folate (a B vitamin) levels and raising homocysteine (a protein that can be harmful in high amounts). The good news? Taking folic acid supplements appears to reverse this problem. Scientists studied women before and after they started taking folic acid supplements, and found that the supplement protected them from the pesticide’s harmful effects. This research helps explain why some people exposed to these pesticides have health problems, and shows that getting enough folate might be especially important for people with pesticide exposure.

The Quick Take

  • What they studied: Whether old pesticides still in the environment can lower folate levels and raise homocysteine (a harmful protein), and whether taking folic acid supplements can prevent this problem.
  • Who participated: 186 women total: 103 women who weren’t taking folic acid supplements yet, and 83 women who were already taking folic acid supplements. The study also included rats exposed to DDT pesticide.
  • Key finding: Women without folic acid supplements who had higher pesticide exposure showed lower folate levels and higher homocysteine levels. However, women taking folic acid supplements did not show this problem, even with pesticide exposure.
  • What it means for you: If you live in an area with pesticide exposure or have been exposed to old pesticides, making sure you get enough folate (through food or supplements) may help protect your health. However, this is early research, and you should talk to your doctor before starting any supplements.

The Research Details

Scientists compared two groups of women: one group that hadn’t started taking folic acid supplements yet, and another group that was already taking them. They measured the levels of old pesticides in their blood, along with folate and homocysteine levels. They also did experiments with rats exposed to DDT (a common old pesticide) to confirm what they found in humans. The researchers used advanced statistical methods to look at how multiple pesticides together affected folate and homocysteine levels.

This type of study is called a cohort study, which means researchers followed groups of people and measured different things about their health. By comparing women with and without folic acid supplements, the scientists could see whether the supplements protected against the pesticide’s harmful effects.

The rat experiments were important because they allowed scientists to prove that the pesticide actually caused the folate and homocysteine changes, not just that they happened to occur together.

This research design is important because it shows cause-and-effect in the rat studies while also showing real-world patterns in humans. By studying women before and after they started supplements, researchers could see that the supplements actually prevented the problem, rather than just guessing. This type of evidence is stronger than just observing that pesticides and health problems happen together.

The study has several strengths: it included both human and animal studies, used advanced statistical methods to look at multiple pesticides at once, and showed that folic acid supplements actually prevented the problem. However, the human study was relatively small (186 women), and we don’t know details about other factors that might affect folate levels, like diet. The study was published in a respected scientific journal focused on environmental pollution.

What the Results Show

In women who weren’t taking folic acid supplements, higher levels of organochlorine pesticides were clearly linked to lower folate levels and higher homocysteine levels. The pesticides studied included DDT (a pesticide banned in many countries but still found in the environment), lindane, endosulfan, and several others. When researchers looked at all the pesticides together using advanced statistics, they found that the combination of pesticides had a strong effect on lowering folate and raising homocysteine.

The most important finding was that in women who were already taking folic acid supplements, these harmful connections disappeared. Even though these women had pesticide exposure, their folate levels stayed normal and their homocysteine didn’t increase. This suggests that folic acid supplements can protect against the pesticide’s harmful effects.

The rat experiments confirmed these findings. Rats exposed to DDT showed lower folate levels and higher homocysteine, just like the women without supplements. When researchers gave the rats folic acid supplements, the pesticide’s harmful effects were reduced.

Additional analysis showed that folate was responsible for about 13-27% of the pesticide’s effect on homocysteine, meaning that folate is one important way the pesticides cause harm, but not the only way.

The study found that folic acid supplements were associated with lower levels of multiple pesticides in the body, suggesting that the supplements may help the body get rid of these chemicals faster. This was true for at least 10 different pesticides studied. The researchers also found that the effect was strongest for certain pesticides like DDT and its breakdown products, suggesting that some pesticides may be more harmful to folate than others.

Previous research has shown that organochlorine pesticides are linked to birth defects and other health problems, but scientists weren’t sure exactly how they caused these problems. This study provides a new explanation: the pesticides lower folate levels, which then raises homocysteine. High homocysteine is known to increase the risk of birth defects and heart disease. This research also supports earlier findings that folate is important for protecting against environmental toxins.

The study has several limitations to keep in mind. The human study included only 186 women, which is a relatively small group. We don’t know details about the women’s diets, which can affect folate levels. The study was done at one point in time for most measurements, so we can’t be completely sure about cause-and-effect in the human study (though the rat studies help confirm this). We also don’t know how long the folic acid supplements need to be taken to prevent the pesticide’s harmful effects, or whether other B vitamins might help too. Finally, the study was done in one country, so results might be different in other populations.

The Bottom Line

If you have known exposure to organochlorine pesticides (through occupation, location, or other factors), talk to your doctor about whether you should take folic acid supplements. The evidence suggests that adequate folate intake may help protect against some of the harmful effects of pesticide exposure. However, this is early research, and more studies are needed before we can make strong recommendations. For the general population, the current recommendation to get enough folate through diet or supplements remains important for many reasons, including this potential protection against pesticides. Confidence level: Moderate - the findings are promising but based on a relatively small human study.

This research is most relevant to people who work with pesticides (farmers, pest control workers), people living in areas with high pesticide use, and women of childbearing age (since high homocysteine is linked to birth defects). It’s also important for people concerned about environmental toxin exposure. However, the findings don’t mean that everyone needs to take folic acid supplements - talk to your doctor about your individual situation. People who already eat folate-rich foods (leafy greens, legumes, fortified grains) and don’t have pesticide exposure may not need additional supplements.

Based on the study, folic acid supplements appear to work relatively quickly - the women taking supplements already showed protection. However, we don’t know the exact timeline for how long it takes for supplements to build up protection or how long protection lasts after stopping supplements. It may take weeks to months to see changes in homocysteine levels. If you start taking supplements, it’s reasonable to expect improvements within 2-3 months, but talk to your doctor about what to expect in your specific situation.

Want to Apply This Research?

  • Track daily folic acid intake (in micrograms) and any known pesticide exposures (occupational, location-based, or dietary). If possible, note any symptoms associated with high homocysteine like fatigue or cognitive changes. Users can set a goal of 400 micrograms of folic acid daily and track consistency.
  • Users can use the app to: (1) set daily reminders to take folic acid supplements if recommended by their doctor, (2) log folate-rich foods eaten (spinach, broccoli, lentils, fortified cereals), (3) track pesticide exposure situations and note any health changes, (4) record doctor visits and homocysteine test results to monitor progress over time.
  • Set up monthly check-ins to review folic acid supplement adherence and dietary folate intake. If the user has access to blood tests, track homocysteine levels every 3-6 months to see if supplementation is working. Create a long-term trend view showing folate intake and any health markers over 6-12 months. Alert users to discuss results with their doctor at regular intervals.

This research is preliminary and based on a relatively small human study combined with animal experiments. The findings suggest a potential link between pesticide exposure, folate depletion, and elevated homocysteine, but more research is needed before making clinical recommendations. This information should not be used to diagnose, treat, or prevent any disease. If you have concerns about pesticide exposure or homocysteine levels, please consult with your healthcare provider before starting any supplements. Folic acid supplements may interact with certain medications, so discuss with your doctor before beginning supplementation. Pregnant women or those planning pregnancy should especially consult their healthcare provider, as folate is critical during pregnancy and pesticide exposure may have additional risks.