Fish oil is one of the most widely consumed dietary supplements globally, primarily valued for its high content of Omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These polyunsaturated fats support various aspects of health, including cardiovascular and cognitive function. Despite its popularity, a common and unpleasant side effect discourages many consumers from taking it: the regurgitation of a fishy taste, often referred to as “fish oil burps.” This issue led to the development of “burp-less” fish oil, a modified product designed to deliver the beneficial Omega-3s without the lingering aftertaste.
Why Standard Fish Oil Causes Reflux
The fishy aftertaste results from the oil being released in the stomach. When the softgel capsule dissolves, the oil, being less dense than the water-based stomach contents, floats on top of the gastric fluid. As the stomach contracts to digest food, this layer of oil can be easily forced back up the esophagus, causing the characteristic fishy burp.
The freshness of the oil is a significant factor contributing to the unpleasant taste. Omega-3 fatty acids are highly susceptible to oxidation, accelerated by exposure to light, heat, or air. When the oil becomes rancid, it breaks down into volatile, foul-smelling compounds responsible for the strong, decaying-fish odor and taste. Rancidity often indicates a poor-quality product and increases the likelihood of experiencing reflux.
The high fat content of the supplement can cause the lower esophageal sphincter (LES), the muscle separating the stomach from the esophagus, to relax. This relaxation allows stomach acid and floating oil to escape back up the digestive tract. This results in the burning sensation of acid reflux alongside the fishy flavor.
Methods Used to Create Burp Less Supplements
Manufacturers employ several methods to prevent the oil from being released in the stomach, the primary source of reflux. The most common technique is the application of an enteric coating to the softgel capsule. This specialized coating remains intact in the acidic environment of the stomach, dissolving only once it reaches the alkaline conditions of the small intestine. By bypassing the stomach entirely, the oil cannot float on the gastric contents and cause burping.
Increasing the concentration of EPA and DHA within each capsule is another strategy. Fish oil concentrates allow for a smaller pill size, meaning less total oil is consumed per dose, which reduces the potential for reflux. Highly concentrated oils are available in the re-esterified triglyceride (rTG) or ethyl ester (EE) forms. These forms are subjected to advanced purification processes, such as molecular distillation, which removes impurities and volatile compounds contributing to the fishy odor.
Some supplements include added flavorings, such as lemon or orange oil, to mask the fishy taste. While these aromatic compounds make the initial experience more palatable, they do not prevent the physical reflux of the oil from the stomach. Flavoring addresses the sensory issue but does not solve the underlying mechanical problem of the oil floating in the stomach.
Evaluating Quality and Effectiveness
Choosing a burp-less fish oil does not automatically guarantee a high-quality supplement, so consumers should look for independent verification. Third-party testing programs, such as the International Fish Oil Standards (IFOS), provide accountability. IFOS certification verifies the product’s potency, ensuring the EPA and DHA content matches the label, and checks for contaminants like heavy metals, polychlorinated biphenyls (PCBs), and dioxins.
The IFOS program also tests for stability and oxidation levels, which directly relates to the burping issue, as fresh oil is less likely to cause a fishy aftertaste. A low oxidation value indicates a fresh product. Consumers should also consider the molecular form of the omega-3s, which affects both absorption and stability.
Omega-3s naturally occur in the triglyceride (TG) form, which is absorbed more efficiently by the body than the synthetic ethyl ester (EE) form. While both forms can be made into a burp-less product, the TG form is generally more stable and less prone to oxidation than the EE form. This stability acts as a safeguard against rancidity. If burping persists even with an enteric-coated product, it may signal that the oil inside is already rancid or the overall quality is poor.