What is the appropriate storage of flaxseed?
Confusion surrounds the appropriate use of flaxseed, as it can be purchased in a variety of forms: whole, ground, milled, crushed, and oil. All forms of flaxseed can have health benefits, but some forms may allow for better absorption of the healthy lignans, which you also may hear referred to as "phytoestrogens."
Crushing or milling the flaxseed before eating it can increase the absorption of the lignans from 28% to 43%. Eating the whole flaxseed does not allow for the same absorption of the alpha-linolenic acid, a type of omega-3 fatty acids, as flax oil or the ground flax. It is important to note that significant gastrointestinal side effects may occur when consuming the whole flax or the flax oil.
Flax oil is pure fat, which means it will add significant calories to your diet if you use it. Flax oil cannot withstand typical stovetop cooking temperatures, so use this product only for "room-temperature" foods, such as in salad dressings or uncooked sauces and dips.
One option for using flaxseed is by incorporating it into baked goods. The flaxseed-derived secoisolariciresinol diglucoside (SDG), an anti-oxidant nutrient, is not broken down or damaged by normal baking temperatures. It retains its beneficial properties in baked goods and is stable under normal storage conditions. Flaxseed can be baked into cereal-like products and kept on shelves while still maintaining health benefits, as well.
The original question and answer were generously donated by Diana Dyer, MS, RD a cancer survivor, registered dietitian, organic garlic farmer, and the author of "A Dietitian's Cancer Story: Information & Inspiration for Recovery & Healing from a 3-time Cancer Survivor.
Question and Answer updated by Amy DiCioccio, RD, CSO, CD-N, on behalf of the ON DPG
- Kuijsten, et al. The relative bioavailability of enterolignans in humans is enhanced by milling and crushing of flaxseed. J Nutr. 2005;135(12):2812-2816.
- Austria JA, et al. Bioavailability of alpha-linolenic acid in subjects after ingestion of three different forms of flaxseed. J Am Coll Nutr. 2008;27(2):214-221.
- Malcolmson LJ, Przybylski R, Daun JK. Storage stability of milled flaxseed. Journal of the American Oil Chemist's Society. 2000;77(3):235-238.
- Hyvarinen HK, et al. Effect of processing and storage on the stability of flaxseed lignan added to bakery products. J Agri Food Chem. 2006;54(1):48-53.
Updated: June 2013