There are several possible reasons why omega-3 levels in the body may be low:Inadequate dietary intake: Omega-3 fatty acids are primarily obtained through the diet. If someone has a diet that is low in foods rich in omega-3s, such as fatty fish, their omega-3 levels may be low.Imbalance in omega-3 to omega-6 ratio: Omega-6 fatty acids are also essential fatty acids, but they are more commonly found in the Western diet due to the high consumption of vegetable oils and processed foods. An imbalance between omega-3 and omega-6 intake can affect the body’s ability to maintain optimal omega-3 levels.Limited conversion of ALA to EPA and DHA: Alpha-linolenic acid (ALA) is a type of omega-3 fatty acid found in plant sources like flaxseeds, chia seeds, and walnuts. However, the conversion of ALA to the more biologically active forms, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in the body is limited. Therefore, relying solely on plant-based omega-3 sources may result in lower omega-3 levels.Health conditions and medications: Certain health conditions and medications can affect omega-3 metabolism and absorption. For example, gastrointestinal disorders, liver diseases, or medications that interfere with fat absorption or metabolism may impact omega-3 levels.Genetics: Some individuals may have genetic variations that affect their ability to metabolize or utilize omega-3 fatty acids efficiently. This can contribute to lower omega-3 levels even with a sufficient dietary intake.
The conversion of alpha-linolenic acid (ALA), which is found in plant-based sources like flaxseeds, chia seeds, and walnuts, to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in humans is relatively limited.On average, the conversion efficiency of ALA to EPA and DHA in humans is estimated to be less than 5%. However, it's important to note that this conversion can vary among individuals and may be influenced by genetics, sex, age, and overall dietary composition.In contrast, chickens have a higher conversion efficiency of ALA to EPA and DHA than humans. While the exact percentage can vary, chickens are considered more efficient converters of ALA into these long-chain omega-3 fatty acids.Many supermarkets now sell eggs with higher levels of EPA and DHA due to what chickens are fed.Therefore, if the goal is to increase EPA and DHA levels, it is generally recommended to obtain these fatty acids directly from marine sources such as fatty fish (e.g., salmon, mackerel, sardines) or through the consumption of fish oil or algae-based supplements, which are rich in EPA and DHA.
The time it takes for omega-3 levels to increase in red blood cells can vary depending on several factors. Here are a few reasons why it may take time:Metabolism and turnover rate: Red blood cells have a lifespan of approximately 120 days. As old cells die off and new cells are formed, it takes time for the new cells to accumulate omega-3 fatty acids and reflect the changes in dietary intake.Dietary intake and absorption: The rate at which omega-3 fatty acids are absorbed from the diet and transported to the red blood cells can vary. It depends on factors such as the type of omega-3 fatty acids consumed (EPA, DHA, ALA), the source (marine-based or plant-based), and individual variations in metabolism and absorption.Tissue distribution: Omega-3 fatty acids are distributed throughout the body, and reaching different tissues and organs takes time, including red blood cells. The distribution rate can vary among individuals and may be influenced by overall health, metabolism, and genetic factors.Compliance and duration of supplementation: If omega-3 supplementation is used to increase levels, it's essential to consistently take the supplements as recommended. Achieving significant increases in omega-3 levels may require several weeks or months of regular supplementation.It's worth noting that the omega-3 index, which reflects the percentage of EPA and DHA in red blood cell membranes, is considered a long-term indicator of omega-3 status rather than a short-term measure. It may take time for dietary changes or supplementation to lead to measurable changes in the omega-3 index.
Harris WS, von Schacky C. The Omega-3 Index: A New Risk Factor for Death from Coronary Heart Disease? Prev Med. 2004;39(1):212-220.Harris WS, Sands SA, Windsor SL, et al. Omega-3 Fatty Acids in Cardioprotection: Opportunities and Challenges. Curr Treat Options Cardiovasc Med. 2008;10(5):330-340.Block RC, Harris WS, Reid KJ, Sands SA, Spertus JA. EPA and DHA in Blood Cell Membranes from Acute Coronary Syndrome Patients and Controls. Atherosclerosis. 2008;197(2):821-828.Nelson JR, Harris WS. Clinical and Experimental Evidence for a Cardiovascular Benefit of Marine Lipid-Derived Omega-3 Fatty Acids. Mar Drugs. 2019;17(6):307.Albert CM, Campos H, Stampfer MJ, et al. Blood Levels of Long-Chain n-3 Fatty Acids and the Risk of Sudden Death. N Engl J Med. 2002;346(15):1113-1118.Del Gobbo LC, Imamura F, Aslibekyan S, et al. Omega-3 Polyunsaturated Fatty Acid Biomarkers and Coronary Heart Disease: Pooling Project of 19 Cohort Studies. JAMA Intern Med. 2016;176(8):1155-1166.