Ethoxyquin (E324) is a controversial synthetic antioxidant commonly found in animal feed and pet food. It helps preserve shelf life and keeps certain foods, like apples and pears, from browning.
It's controversial in that the Federal Food and Drug Administration (FDA) has stated ethoxyquin cannot be added to human food; however, limited amounts of the antioxidant are allowed in animal feed. As such, manufacturers commonly use ethoxyquin in fish feed, such as salmon or krill.
These farmed fish are then processed for food or omega-3 fish oil supplements, which can expose humans to the preservative. Given the overwhelming benefits of omega-3 supplements, it's essential to understand the importance of choosing ethoxyquin-free options.
Ethoxyquin was originally developed in the 1950s as a synthetic preservative in the rubber industry to help keep the rubber from cracking during manufacturing. It was then used as a preservative in dry and canned pet food to maintain freshness and keep fats from breaking down.
Synthetic preservatives—including ethoxyquin, BHT, and BHA—have been used for decades to preserve the freshness, flavor, color, and lifespan of animal feeds, pharmaceuticals, and cosmetics.
When it was first released, one of the largest ethoxyquin producers in the United States performed a series of tests and studies that showed the antioxidant to be a safe preservative in food. However, new studies in the 1980s revealed harmful effects in animals and those occupationally exposed to the substance. Scientists found ethoxyquin could be linked to liver damage and other side effects.
In the 1990s, the FDA began to receive complaints from dog owners about ethoxyquin in dog food and adverse effects it was causing, including:
After studies confirmed ethoxyquin could harm pets, the FDA asked pet food manufacturers to voluntarily lower the maximum use of ethoxyquin in dog foods from 150 ppm to 75 ppm.
Today, ethoxyquin is still used in animal feed to protect against lipid peroxidation, a process that causes stored food to spoil quickly. Most food manufacturers need to use natural or synthetic antioxidants to slow down this process and preserve the freshness of their products.
Many natural antioxidants such as tocopherols, vitamin C, and flavonoids can preserve foods for short periods of time, but they won't hold up for long-term storage.
This antioxidant is currently used to preserve color in spices like paprika or ground chili and prevent brown spots in fruits like pears and apples. Outside of this minimal use, it generally cannot be used in other foods made for human consumption, according to the FDA.
Animal feeds, however, have higher limits on their use of the preservative. Although ethoxyquin is not permitted for preserving human food, humans can still be exposed through farmed fish, poultry, and eggs.
Studies have found that Atlantic salmon, halibut, and rainbow trout contain high ethoxyquin residues in their tissues. The antioxidant binds to fish muscle and is thereby consumed by humans through food or omega-3 supplements.
The researchers estimated that consumer exposure to ethoxyquin from a single portion (300 grams) of skinned fillets of farmed fish could account for 15% of the antioxidant's recommended daily intake.
Ethoxyquin's safety has been under scrutiny for many years. The jury is divided on whether or not it is harmful to humans and animals. Some research shows synthetic antioxidants can cause tumors, while others have reported ethoxyquin to have anticarcinogenic properties in low concentrations.
Regardless, the FDA currently limits how much ethoxyquin can be used in animal feeds:
Ethoxyquin is currently an approved food additive for animal feed, but it does require specific labeling and disclosures. According to the FDA, a product containing the antioxidant needs to disclose the product as "Ethoxyquin, a preservative," or "Ethoxyquin added to retard the oxidative destruction of carotene, xanthophylls, and vitamins A and E."
Still, labels are not required for all products, and it is really up to the fishmeal suppliers and manufacturers of marine products to regulate the addition of the preservative to their products. Consuming a diet of wild-caught fish can also help prevent contact with farmed fish that have been fed preserved animal feed.
If you're looking for safe omega-3s, Physician's Choice Krill Oil is a safe option completely free of ethoxyquin. Our manufacturer, Aker BioMarine, does not use ethoxyquin to produce krill oil. The krill meal used for oil extraction is sustainably harvested in the Antarctic Ocean and does not contain any additives.
Additionally, the Antarctic krill is processed into krill meal by cooking and drying on-board Norwegian-registered factory vessels and is intended for human consumption. There is no need to add ethoxyquin to the supplement as krill oil naturally contains astaxanthin, which naturally protects it from oxidation and offers it a long shelf life without the need for additional preservatives.
Ethoxyquin is a controversial antioxidant whose benefits and risks have been debated for many years. Some countries have placed more strict restrictions on the addition of this preservative to animal feeds, while others are less regulated.
Regardless, research shows that this antioxidant can bind to fish and animal products, therefore exposing humans to the preservative. While it is not clear whether or not the amount of ethoxyquin in these products is harmful to humans, adverse risks have been linked to high consumption of this additive.
When purchasing fish or omega-3 supplements, keep an eye out for farm-raised fish, which may have been fed a diet containing ethoxyquin. Choosing wild-caught fish and clean supplements from trusted suppliers are a safer bet to avoid this synthetic preservative.
Regina Rayan - Contributing Writer, Physician's Choice