When you hear the word “omega-3s,” what’s the first thing that pops into mind? For many dietitians, it’s probably fish. But how do you help clients and patients get enough omega-3s if they don’t eat fish? What if they don’t eat any animal-based foods?
Whether you’re in private practice, do outpatient counseling, or work in a hospital, school, or foodservice operation, you’re bound to come across clients and patients who are vegan, excluding all animal products from their diets, including meat, fish, dairy, eggs, and honey. So how can you help them get their omega-3s?
What Are Omega-3s?
First, let’s have a refresher on omega-3 essential fatty acids. They’re polyunsaturated fatty acids, and their nomenclature means the first double bond occurs three carbons in from the omega (methyl) tail of the fatty acid. Omega-3s differ in length and number of double bonds.
While there are several types of omega-3 fatty acids, those most common in discussions about human nutrition are ALA, EPA, and DHA.
ALA stands for alpha-linolenic acid, an 18-carbon omega-3 with three double bonds. ALA can be found in plant foods including flaxseeds, chia seeds, hemp seeds, and walnuts. It’s technically the only omega-3 humans must consume, as it can be converted to longer-chain omega-3s, though this is an inefficient process.
EPA stands for eicosapentaenoic acid, a 20-carbon omega-3 with five double bonds. EPA can be found in oily fish, krill, and algae.
DHA stands for docosahexaenoic acid, a 22-carbon omega-3 with six double bonds. Like EPA, DHA can be found in oily fish, krill, and algae.
Why Are Omega-3s Important?
Omega-3s are incorporated into the phospholipid membrane of cells and impact the structure, function, and activity of cells. They’re found in high concentrations in the eyes and the brain; this is especially true of DHA, which is important for functionality of the retinas and development and functionality of the brain throughout all life stages.
A 1982 case study of a 6-year-old girl receiving total parenteral nutrition for five months without linolenic acid experienced vision issues and neuropathy. When ALA was added to the parenteral nutrition regimen, her neurological symptoms disappeared. From this, researchers concluded that ALA was an essential nutrient, required at 0.54% of total daily energy intake.
How Much Omega-3s Do People Need?
The Institute of Medicine has established Adequate Intakes, or AIs, for ALA of 1.1 g per day for women 14 and older, and 1.6 g per day for males 14 and older. During pregnancy and lactation, 1.4 g and 1.3 g per day are required, respectively.
The adult AI is specifically for ALA. There’s no AI for EPA or DHA, except in the first year of life, where the AI of 0.5 g per day is for total omega-3s. This is because ALA is a precursor to EPA and DHA, and the human body can facilitate this conversion.
Delta-6-desaturase, or FADS2, is an enzyme needed for these conversions and is considered the rate-limiting enzyme of the pathway. This is because FADS2 has another important role: It’s involved in converting shorter-chain omega-6 fatty acids (eg, linoleic acid, or LA) to longer-chain omega-6 fatty acids (eg, arachidonic acid). In other words, FADS2 is a very busy enzyme, and, when it’s crowded with LA, it’s unable to convert as much ALA.
Because of this, researchers have suggested that as long as a prudent ratio of omega-3 to omega-6 fat intake is maintained (1:4), vegans should easily be able to convert ALA to EPA and DHA. However, evidence to support that hypothesis is extremely limited—not to mention it’s quite labor-intensive for an individual to mind their ratio of omega-3 to omega-6 intake throughout the day.
Should Vegans Take an EPA/DHA Supplement?
The question is: Is ALA intake alone sufficient to produce enough EPA and DHA? We don’t know. As with many nutrition-related quandaries, we need more research.
Research on vegans specifically is especially limited. The few studies we have show that vegetarians and vegans tend to have lower blood levels of EPA and DHA compared with meat-eaters, but researchers aren’t sure whether that has any negative impact. More importantly, we don’t know whether the DHA levels in vegans’ eyes and brains is lower than those of meat eaters.
We do know that vegans tend to have lower heart disease risk than meat-eaters. The American Heart Association recommends adults eat two servings of fish, especially fatty fish, per week to reap the heart-healthy benefits of EPA and DHA. Since vegans have a lower risk of heart disease than nonvegans, it’s questionable whether exogenous EPA and DHA is required for good heart health.
The Academy of Nutrition and Dietetics’ 2016 position paper on vegetarian diets states, “Evidence suggests that [omega]-3 needs of healthy individuals can be met with ALA alone, and that endogenous synthesis of EPA and DHA from ALA is sufficient to keep levels stable over many years.” However, experts in vegan nutrition recommend an extra 2 g ALA or 200 to 300 mg supplemental vegan DHA per day to help vegans meet their DHA needs.
What Should I Tell Vegan Clients and Patients?
It’s important that vegans at the very least meet the AI for ALA. Dietitians can counsel vegan clients and patients on how to incorporate ALA-rich foods into meals and snacks throughout the day. Because many ALA-rich foods are seeds and oils, this makes for easy additions to foods, such as adding to smoothies, stirring into oatmeal, sprinkling over toast, or drizzling on a salad. The following is the ALA content in common foods:
1 tsp flaxseed oil = 2.42 g
1/4 cup walnuts = 2.27 g
1 T chia seeds = 1.82 g
1 T ground flaxseed = 1.6 g
1 T hemp seeds = 0.87 g
1 tsp canola oil = 0.41 g
1 tsp soybean oil = 0.31 g
Because research is limited on exactly how much ALA vegans need, dietitians should educate vegan clients and patients on the option of taking a vegan DHA supplement. Taking a DHA supplement daily or a few times per week can offer insurance and peace of mind, with little to no side effects. Vegan nutrition experts say that taking a supplement that contains EPA in addition to DHA is unnecessary if vegans are meeting the AI for ALA.
Vegan DHA supplements contain algae oil. Algae is the source of DHA in the ocean—fish get their DHA from eating krill and algae. There are several supplement brands that make vegan DHA supplements in nongelatin capsules.
If unsure about making dietary recommendations for vegan clients and patients, dietitians should refer to those who specialize in vegan nutrition.
— Taylor Wolfram, MS, RDN, LDN, is a private practice dietitian, health writer, and consultant based in Chicago. Her specialties include intuitive eating, vegan nutrition, research, and communications.