Researchers tested 84 instant coffee samples from China and found that most contained harmful substances called mycotoxins—invisible poisons that grow naturally on coffee beans. About 9 out of 10 samples had at least one type of toxin, with some containing multiple toxins at the same time. The most common toxin was found in 89% of samples, though usually in small amounts. Interestingly, toxins were more common in coffee from certain regions and in black coffee compared to flavored varieties. While the amounts detected were generally low, scientists say we need to keep watching coffee quality to make sure people stay safe.

The Quick Take

  • What they studied: Whether instant coffee sold in China contains poisonous substances that grow naturally on coffee beans, and how often multiple toxins appear together in the same product.
  • Who participated: 84 instant coffee samples purchased from stores in China, representing different brands, flavors, and regions.
  • Key finding: Nearly 9 out of 10 samples contained at least one type of natural toxin. The most common toxin (AFG2) was found in 89% of samples, though usually in very small amounts. About 92% of all samples had at least one of six different toxins tested.
  • What it means for you: If you drink instant coffee from China, you’re likely consuming small amounts of natural toxins, but the levels detected were generally low. However, people who drink coffee regularly may want to consider varying their sources or brands, and parents should be aware when giving coffee products to children.

The Research Details

Scientists collected 84 instant coffee samples from stores across different regions of China. They used advanced laboratory equipment called ultra-high performance liquid chromatography to detect and measure seven different types of natural poisons (mycotoxins) that can grow on coffee beans during farming and storage. These toxins form when certain molds contaminate the beans. The researchers measured exactly how much of each toxin was present in each sample and looked for patterns—like whether samples from certain regions had more toxins, or whether different toxins appeared together in the same product.

This research approach is important because it gives us a real picture of what’s actually in the coffee people buy and drink. Rather than just testing one toxin, the scientists looked for seven different ones and checked how they appear together. This matters because when multiple toxins are present at once, they might affect our health differently than a single toxin alone. Understanding regional differences also helps identify where quality control needs improvement.

This study used high-quality laboratory methods that are considered the gold standard for detecting these toxins. The researchers tested a reasonable number of samples (84) from different regions and brands. However, the study only looked at instant coffee from China, so results may not apply to coffee from other countries. The study is descriptive rather than experimental, meaning it shows what’s present but doesn’t prove that the toxin levels cause health problems in people who drink the coffee.

What the Results Show

The most striking finding was that 89% of instant coffee samples contained AFG2, a type of aflatoxin (a natural poison). However, the amounts were generally small—averaging 1.19 micrograms per kilogram, which is below safety limits set by many countries. The highest amount found was 13.60 micrograms per kilogram in a single sample. Other aflatoxins were also detected but in lower percentages: AFG1 appeared in some samples, followed by AFB1 and AFB2. Interestingly, two other toxins called HT-2 and T-2 were found in fewer samples (9.5% and 14% respectively), but when they did appear, they were sometimes at much higher levels—up to 125 micrograms per kilogram for HT-2. One toxin tested (OTA) was not found in any samples.

A very important finding was that most samples contained multiple toxins at the same time. About 52% of samples had just one toxin, but 15% had two toxins together, and some samples had as many as five or six different toxins present simultaneously. The four aflatoxins showed a strong pattern of appearing together (they were highly correlated), suggesting they come from the same source. Samples from mid-to-high latitude regions of China had higher toxin levels than samples from other areas. Black coffee samples also tended to have higher toxin concentrations than flavored coffee varieties.

This research adds to existing knowledge about mycotoxins in coffee worldwide. Previous studies have found similar toxins in coffee from other countries, but this is one of the first detailed studies looking at instant coffee specifically in China. The toxin levels found here are generally consistent with what other researchers have reported in coffee from different regions, though the specific patterns of which toxins appear together may be unique to Chinese coffee sources. The finding that regional differences matter aligns with previous research showing that climate and farming practices affect toxin levels.

This study only looked at instant coffee, not whole bean or ground coffee, so results don’t necessarily apply to other coffee types. All samples came from China, so we can’t say whether these findings apply to instant coffee from other countries. The study didn’t test whether the toxin levels actually cause health problems in people—it only measured what’s present. The study also didn’t investigate why some regions have more toxins than others or what specific farming or storage practices might reduce contamination. Additionally, we don’t know the exact brands or how long samples had been stored before testing.

The Bottom Line

Based on this research, there is moderate confidence that instant coffee from China may contain natural toxins, though usually in small amounts. For most adults who drink coffee occasionally, the risk appears low. However, for people who drink large amounts of instant coffee daily, or for children and pregnant women, it may be wise to limit consumption or vary coffee sources. This is not a reason to panic, but rather a reason to be aware and make informed choices. Regulatory agencies in China should continue monitoring coffee quality and may want to strengthen safety standards.

This research is most relevant to people who regularly drink instant coffee from China, particularly those who consume it daily. It’s especially important for parents of young children, pregnant women, and people with compromised immune systems, as they may be more sensitive to toxins. People with liver problems should also be aware, since some of these toxins affect the liver. If you occasionally drink instant coffee, the risk is likely very low. People who drink coffee from other countries may have different exposure levels.

The toxins detected in this study are already present in the coffee when you buy it—they don’t develop over time in your cup. If you switch to a different coffee brand or source, you would immediately be consuming different toxin levels. However, any health effects from long-term toxin exposure would develop slowly over months or years, not days or weeks. If you’re concerned, making changes now could reduce your long-term exposure.

Want to Apply This Research?

  • Track your instant coffee consumption by brand and region of origin. Log daily servings (e.g., ‘1 cup instant coffee, Chinese brand X’) and note any digestive symptoms or changes in how you feel. This personal data can help you identify patterns and make informed choices about which products to buy.
  • Consider rotating between different coffee brands and sources rather than drinking the same instant coffee every day. If you drink instant coffee regularly, try alternating with whole bean or ground coffee from different regions. For daily drinkers, reducing consumption from 3+ cups to 1-2 cups per day is a practical change that lowers overall toxin exposure.
  • Keep a simple log of coffee brands and types you purchase, noting the region of origin when available. Every 3 months, review your consumption patterns and consider whether you want to make changes. If you have health concerns, share this information with your doctor, especially if you consume instant coffee daily. Stay informed about any new safety guidelines from health authorities regarding instant coffee imports.

This research describes the presence of natural toxins in instant coffee samples but does not establish that consuming these products causes illness in humans. The toxin levels detected were generally below regulatory limits in many countries. This information is educational and should not replace professional medical advice. If you have specific health concerns about coffee consumption, particularly if you drink large quantities daily or have liver disease, consult with your healthcare provider. Pregnant women and young children should discuss coffee consumption with their doctor. This article is not a substitute for medical diagnosis or treatment.