What Is Annatto and How Is It Used?
Annatto is a natural food coloring and flavoring derived from the reddish seeds of the achiote tree (Bixa orellana), native to tropical regions of the Americas. The vibrant yellow-to-orange color is due to its high concentration of carotenoid pigments, primarily bixin (oil-soluble) and norbixin (water-soluble). Annatto is a staple ingredient in many cuisines and is a common additive in a wide range of processed foods to provide or enhance color.
Common food products containing annatto include:
- Cheddar, Colby, and other orange-colored cheeses
- Butter and margarine
- Processed snack foods
- Breakfast cereals
- Baked goods
- Smoked fish
- Sausages and other processed meats
The Carcinogenicity Question: What the Science Says
The potential for annatto extract to cause cancer has been thoroughly investigated through numerous studies and evaluated by regulatory agencies. The overwhelming consensus is that annatto is not carcinogenic in the amounts typically consumed in food.
Absence of Carcinogenic Effects
Several key studies have explicitly examined annatto's potential for causing cancer:
- Medium-Term Bioassays in Rats: A 2004 study published in Food and Chemical Toxicology found no evidence that dietary annatto was genotoxic or carcinogenic in a medium-term bioassay on rat liver. The study, conducted at a dietary level of 1000 ppm (containing approximately 5% bixin), concluded that annatto showed no hepatocarcinogenic effect.
- Genotoxicity Studies: Multiple genotoxicity and mutagenicity assays have been conducted on annatto and its main components, bixin and norbixin. The weight of evidence from these assays supports a conclusion that they are negative for mutagenic activity. One animal study noted an increased frequency of micronucleated cells at extremely high concentrations (10,670 ppm) when administered with a known mutagen, but stated annatto alone was not mutagenic.
- Long-Term Animal Studies: Longer-term studies on experimental animals have also been conducted. For instance, a 1959 study on rats and mice, while lacking some specific details, reported no increase in tumor incidence in animals treated with high doses of annatto for extended periods. More recent, detailed studies further solidify the safety conclusion.
Potential Anti-Cancer Properties (In Vitro)
Ironically, some test-tube and animal studies have explored the anticancer properties of annatto's components, specifically bixin and norbixin. These lab-based findings suggest that annatto constituents may possess potential therapeutic qualities, such as suppressing the growth of certain cancer cells.
- A study on prostate cancer cells showed that annatto tocotrienol could suppress cell growth.
- Other research indicated that bixin could induce cytotoxicity in various solid tumor cell lines.
It is crucial to emphasize that these are preliminary findings from lab and animal studies and do not equate to annatto being a cancer cure or preventative agent in humans through regular dietary intake.
Annatto Safety: A Comparison with Other Dyes
Annatto is often viewed as a safer, natural alternative to synthetic food dyes. However, it is not without its own considerations, particularly regarding allergic reactions.
| Feature | Annatto (Natural) | Common Synthetic Dyes (e.g., Tartrazine, Allura Red) |
|---|---|---|
| Source | Seeds of the achiote tree (Bixa orellana). | Synthetically produced from petroleum-based sources. |
| Carcinogenicity | No carcinogenic effect found in extensive animal studies when used in food amounts. | Some have historical concerns, but are generally deemed safe by regulatory bodies after testing. Early research sometimes flagged synthetic dyes as more reactive in allergy tests, but annatto may be more allergenic for some. |
| Key Concerns | Rare allergic reactions (hives, swelling, IBS flare-ups), blood sugar interactions. | Allergic reactions (annatto allergies may be more common than for some synthetics), hyperactivity concerns in children for some dyes. |
| Regulatory Status | Exempt from FDA certification as a colorant; has acceptable daily intake (ADI) levels set by EFSA. | Requires FDA certification for each batch. Strict regulations on purity and usage. |
Key Regulatory Perspectives
- U.S. Food and Drug Administration (FDA): The FDA considers annatto extract and annatto to be safe color additives that are exempt from certification for their intended uses.
- European Food Safety Authority (EFSA): The EFSA has reviewed annatto extracts multiple times. Based on genotoxicity studies, they concluded that annatto does not raise a concern for genotoxicity and have established acceptable daily intake (ADI) levels for its color compounds, bixin and norbixin. In cases where exposure levels for norbixin for toddlers were shown to exceed the ADI, EFSA concluded the level of exposure was not a health concern due to uncertainties and likely overestimation.
Potential Side Effects and Interactions
While annatto is overwhelmingly safe for most people, some potential issues are worth noting:
- Allergic Reactions: Although uncommon, allergic reactions to annatto appear to be more frequent than to some synthetic food dyes. Symptoms can include hives, swelling, and stomach pain.
- IBS Flare-ups: In some rare cases, annatto has been linked to triggering symptoms of irritable bowel syndrome (IBS), such as abdominal pain, bloating, and diarrhea.
- Drug Interactions: Annatto can potentially interact with certain medications, particularly antidiabetes drugs, by affecting blood sugar levels. It may also interfere with medications broken down by the liver.
Conclusion
Based on decades of toxicological research and extensive review by major international food safety authorities, the answer to the question "Is annatto extract a carcinogen?" is no. When consumed in the typical amounts found in foods, annatto is considered safe for the vast majority of the population. While preliminary lab studies have shown potential anticancer properties of annatto's components, these are not relevant to its safety as a food additive. Consumers should be aware of the rare possibility of allergic reactions or interactions with certain medications, but for most, annatto remains a safe, natural, and widely used food colorant.
For more information on the toxicology of annatto extracts, a comprehensive review can be found on the Inchem website.
