Omega-3 sources: Krill oil or fish oil vs algae oil
Krill oil and fish oil both are rich sources of omega-3s, especially DHA and EPA, which are essential for human health – so essential in fact that the Food and Drug Administration is likely to establish minimum daily requirements for them in the near future.
Krill are the tiny crustaceans harvested in the Antarctic both for feeding fish in aquaculture, and for their oil for use in dietary supplements for humans. Fish oil is harvested from a variety of species, especially menhaden, a very oily, coldwater fish that has limited market value as a food fish.
There are other vegetarian sources of omega-3s, as well, including algae, hemp and chia seed. We’ll compare the attributes of krill oil vs fish oil vs algae later in this article.
Krill oil vs fish oil – phospholipids & astaxanthin
Krill oil contains phospholipids, fish oil does not. The phospholipids found in krill oil are the very ones from which our bodies’ cell walls are made. Because of this, phospholipids are rapidly and easily absorbed into our bodies. Fatty acids (EPA & DHA) bound to the phospholipids are fed into a complex signaling cascade known as the eicosanoid system, which regulates a huge array of the body's functions.
Krill oil contains astaxanthin, a powerful antioxidant. Fish oil does not. Antioxidants enter your blood and scavenge for DNA-damaging free radicals. Free radicals are formed when a molecule in your cells loses an electron. This can be triggered by the presence of environmental factors such as pollution, radiation, herbicides or smoking (among many other agents). Free-radical activity can even be triggered by consumption of excessive calories, such as those found in simple sugars.
Free radicals are unstable and they try to steal their needed electron from another compound – a method used to gain stability. The compound from which the electron is stolen sometimes becomes another free radical, which can begin a chain reaction that will damage living cells, something that accumulates with age.
If you're a vegetarian, obtaining omega-3s from vegetarian sources such as algae oil, hemp oil, chia and flaxseed oil is obviously the way to go. However, research is clear that the human body more fully converts the marine oils to EPA and DHA.
Many of the fats we ingest from foods, vegetable oils, fish and fish oil are in the form of triglycerides. Tri means “three,” and triglycerides have three fatty acids bound to a simple backbone. Triglycerides are an important source of energy for our bodies, containing twice much energy as carbohydrates or proteins. However, triglycerides cannot freely pass through cell membranes. Special enzymes on the walls of blood vessels called lipoprotein lipases must break down triglycerides into free fatty acids and glycerol. And high levels of triglycerides in the body are linked to atherosclerosis (vascular disease), heart disease, and stroke.
While there is some excellent information about sources of omega-3 fatty acids on the Internet (especially doing a krill oil vs fish oil comparison), a great many of the sites and blogs are focused on selling a specific brand of product, and they often spread misinformation. This makes it tough for us regular folks who are looking for all the promised benefits of taking omega-3 supplements to determine what to spend our money on. So let's try to simplify the comparisons between krill oil vs fish oil.
How do they compare: krill oil vs fish oil vs algae oil?
The following chart may shed some light on the subject. Without endorsing any particular form of omega-3 supplements, let’s illustrate some simple comparisons between several of the forms in which omega-3s come – fish oil vs algae oil vs krill oil.
SOURCE COMPARISON: Krill oil or fish oil or algae oil
You are likely to read that a typical fish oil capsule contains more DHA and EPA than a capsule of krill oil. This is true, but you are less likely to hear that the EPA and DHA in krill oil are bonded to phospholipids, which have unique attributes in human biology. Several studies are now underway to examine the potential bioavailability benefits (ability of the body to absorb a nutrient) of phospholipid-based omega-3 fatty acids.
As yet, the body of scientific research on krill oil is much smaller than that on fish oil, and studies pitting krill oil vs fish oil are very few. But you can read the summaries of several such krill oil studies here, here and here. What we do know is that because human cell walls are identical in composition to the phospholipids in krill oil, the omega-3s can pass freely into the cell.
The lead researcher in a 2011 study on the effect of omega-3s (krill oil vs fish oil omega-3s) on mice genes found that "... omega-3 fatty acid in phospholipid form, which is abundant in krill oil, is more bioactive than the corresponding triglyceride form of the omega-3 fatty acids [found in fish oil]. This research builds upon the body of evidence supporting the theory that phospholipid-bound EPA & DHA is utilized more effectively."
We would add that the astxanthin component in krill oil may be contributing to the observed effect.