Omega-3 fatty acids are important fats that provide numerous health benefits. Our body can make most of the types of fats it needs from other fats or raw materials. However, omega-3 fatty acids cannot be made in our body & must be taken from diet. Hence, these are called essential fatty acids.
Not all omega-3 fatty acids are equal. Among the 11 types, the 3 most important types are ALA, EPA, and DHA.
ALA is a plant based omega-3 fatty acid, while EPA and DHA are found in animal foods & algae.
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What are omega-3 fatty acids?
Omega-3 fatty acids are a type of polyunsaturated fat. They’re named essential fatty acids because they’re essential for health but cannot be made by our body.
Thus, they are essential to be taken from diet.
These fats are not used as an energy source in our body. They play major roles in many body processes like inflammation, heart health & brain function.
Omega-3 deficiency is associated with low IQ, depression, heart disease, arthritis, cancer & many other health issues.
Alpha-linolenic acid (ALA), the Plant Based Omega-3 Fatty Acid
ALA is the most common omega-3 fatty acid in our diet. It’s found in plant foods & is an essential precursor to EPA or DHA.
However, the conversion process is inefficient in humans. Only a small amount of ALA is converted into EPA & even less into DHA..
When ALA is not converted to EPA or DHA, it is stored as fat or used as energy like other fats.
Some studies link a diet rich in ALA to a reduced risk of heart disease, while others show an increased risk of prostate cancer.
This increase in prostate cancer risk was not found to be associated with the other two omega-3 types, EPA and DHA & they in fact seem to protect against this cancer.
ALA is found in many plant foods, including kale, spinach, soybeans, walnuts & many seeds like chia, flax & hemp. It also occurs in some animal fats.
Some seed oils, such as flaxseed & rapeseed (canola) oil, are also good sources of ALA.
Eicosapentaenoic acid (EPA)
Our body uses EPA to produce signaling molecules called eicosanoids, which play various physiological roles & reduce inflammation.
Chronic, low-level inflammation is known to be the root cause of a number of diseases.
Research studies indicate that fish oil, which is high in both EPA & DHA, may reduce symptoms of depression. Some studies suggest that EPA is superior to DHA in this regard.
One study in menopausal women noted that EPA reduced the incidences of hot flashes.
Both EPA & DHA are mostly found in seafood, including fatty fish & algae.
EPA concentration is highest in herring, salmon, eel, shrimp & sturgeon. Grass-fed animal products, like dairy & meats, also contain some EPA.
Docosahexaenoic acid (DHA)
DHA is an important structural component of skin & the retina of eyes.
DHA fortified baby formula leads to improved vision in infants.
It is vital for brain development & function in childhood, as well as for brain function later on.
DHA deficiency in childhood is associated with problems later on, such as learning disabilities, ADHD & aggressive hostility.
A low level of DHA in later life is also associated with impaired brain function & the onset of Alzheimer’s disease.
DHA may show positive effects on some conditions like arthritis, high blood pressure, type 2 diabetes & some cancers.
It can boost heart health by reducing blood triglycerides and LDL.
DHA is found in high amounts in seafood like fatty fish & algae. Grass-fed animal products also provide some DHA.
ALA to EPA & DHA Conversion
ALA, the most common omega-3 fatty acid, is an essential fatty acid that is converted into EPA and DHA.
However, this conversion process is very inefficient in humans. On an average, only 1-10% of ALA is converted to EPA & only 0.5-5% to DHA.
Furthermore, the conversion rate depends on efficient levels of other nutrients like copper, calcium, magnesium, zinc, iron & vitamins B6 & B7.
In addition, some omega-6 fatty acids compete for the same enzymes needed for the omega-3 fatty acid conversion process. If there is high amount of omega-6 in the diet, it can reduce the conversion of ALA to EPA and DHA. This can be a very common case because our modern diets are obsessed with omega-6.
Omega-3 fatty acids (ALA,EPA & DHA) offer numerous health benefits & protect from inflammation & associated diseases and provide healthy brain function.