Ingesting flaxseed that has surpassed its expiration date carries potential risks. As a high-fat seed, flaxseed is susceptible to rancidity. Rancidity occurs when the fats within the seed undergo oxidation, leading to the development of unpleasant flavors and odors. Consumption of rancid flaxseed may result in gastrointestinal distress, including nausea, stomach upset, or diarrhea. While generally not life-threatening, it is advisable to avoid consuming seeds exhibiting signs of spoilage to prevent discomfort. The extent of the symptoms depends on the amount consumed and individual sensitivity.
Proper storage of flaxseed is crucial to extend its shelf life and minimize the likelihood of rancidity. Storing seeds in airtight containers in a cool, dark, and dry location helps to preserve their quality. Ground flaxseed, due to its increased surface area, deteriorates more quickly than whole seeds. Therefore, grinding seeds just before use is often recommended. The presence of antioxidants, such as Vitamin E, in flaxseed may offer some protection against oxidation, however, this protection diminishes over time.