Three omega-3 fatty acids play a crucial role in human physiology.
Alpha-linolenic acid (α-linolenic acid – ALA) comes from plant sources, and other two – eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) – come from animal sources.
Omega-3 fatty acids are essential nutrients that our body cannot produce. The only way to get them is diet. Fish, marine animals, plants, and nut oils are the primary dietary sources of omega-3 fatty acids.
It has been shown in many studies that vegans and vegetarians have significantly lower levels of omega-3 fatty acids (EPA and DHA) than meat eaters.
Vegans who are not supplementing have no intake of essential omega-3 EPA and DHA from their diet
Research shows that omega-3 fatty acids reduce inflammation and may help lower risk of heart disease, cancer, and arthritis. Omega-3 fatty acids are highly concentrated in the brain and appear to be important for cognitive (brain memory and performance) and behavioral function. Infants who do not get enough omega-3 fatty acids from their mothers during pregnancy are at risk for developing vision and nerve problems. Symptoms of omega-3 fatty acid deficiency include fatigue, poor memory, dry skin, heart problems, mood swings or depression, and poor circulation.
The health benefits of omega-3 fatty acids are mostly linked to EPA and DHA.
Omega-3 fatty acids are used differently in our body:
- EPA and DHA of animal origin are “ready-made” and can be utilized immediately.
- ALA of plant origin has to be converted in the body to EPA and DHA but the conversion rate is very low.
It remains an ongoing debate in the nutrition community: fish and sea vegetable sources of EPA and DHA versus vegetarian sources of ALA.
Omega-3 / omega-6 ratio
Moreover, it is important to have the proper ratio of omega-3 and omega-6 (another essential fatty acid) in the diet. Omega-3 fatty acids help reduce inflammation, and most omega-6 fatty acids tend to promote inflammation. All plant oils – corn, sunflower, canola, olive oil and others are extremely rich in omega-6. And we use oils too much on a daily basis. The typical for industrial countries diet contains 10 to 30 times more omega-6 fatty acids than omega-3 fatty acids. It can completely destroy the omega-6 / omega-3 balance worsening inflammation over time and raising the risk of different health problems.
Foods with lowest Omega-6 to Omega-3 ratios:
- flaxseed oil – 1:4 – 2.5g/teaspoon
- chia seeds – 1:3 – 5g/oz
- canola oil – 2:1 – 1.3g/tablespoon
Flax seeds are probably the most well-known source of omega-3 for vegans that are rich in fiber as well. They also make a dandy egg substitute for vegan baking. Chia seeds provide a healthy dose of omega-3 as well as calcium, and hemp seeds are loaded with protein and omega-3. Other seeds like sunflower and pumpkin have omega-3, but they have it in unfavorable ratios.
Do not prepare food with oils high in omega-6 such as corn, soy, safflower, sunflower, most vegetable oil blends (typically labeled “vegetable oil”) and sesame oil. Instead, use low omega-6 oils like olive, avocado, peanut, or canola. Only cook canola under low heat and for short periods.
Many studies have shown that people who follow the Mediterranean diet rich in omega-3 fatty acids, including whole grains, fresh fruits and vegetables, fish, olive oil, garlic, and moderate wine consumption, have a healthier balance between omega-3 and omega-6 fatty acids.
Lacto-ovo vegetarians can get very small amounts of dietary EPA and DHA
How much omega-3 do we need daily?
To date, there is no “official amount” of daily intake of omega-3s.
In general, most of health authorities recommend a minimum of 250-500mg combined EPA and DHA each day for healthy adults.
It may look like if you make sure to eat healthy fats with your meals, it is very easy to get your daily dose of Omega 3: simply eat about 9 walnut halves every day and you are done. No way!
The problem is not with Omega 3 daily intake; the problem is with DHA and EPA!
The traditional way that vegetarians were encouraged to raise EPA and DHA levels was by increasing Alpha-linolenic acid (ALA) and decreasing linoleic acid (LA), which is found in abundance in plant oils.
Traditional remedy for vegans: take more alpha-linoleic acid (ALA) and reduce linoleic acid (LA)
The body can convert ALA into eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA); however the conversion rate is very low. Moreover, the enzymes that do this conversion can be saturated with omega-6s if there is a lot in the diet; while saturated, they are not able to do this meaning that the conversion is completely blocked.
So, aside from algae, there are virtually no vegan sources of DHA or EPA. To get enough DHA and EPA, vegans must rely on their bodies’ natural ability to make it from ALA.
- http://articles.mercola.com/omega-3.aspx (Your Practical Guide to Omega-3 Benefits and Supplementation)