Omega-3s are a popular category of dietary supplements, with strong scientific support and consumer awareness of their health benefits, reports David Hart, VP Marketing, Qualitas Health
On a retail level, omega-3 products account for almost $30 billion in sales, whereas the omega-3 ingredient market is just shy of $2 billion. One of the fastest growing segments of the omega-3 category in recent years has been krill oil. This has been driven by consumer preference for small, easy-to-swallow capsules that avoid 'fishy burps.'
The phospholipids present in krill oil provide these benefits. Plus, the omega-3 fatty acids in krill are more easily absorbed than those in fish oil because of their phospholipid-based structure.
A number of clinical studies have shown that krill oil has superior absorption compared with fish oils, both in acute blood plasma as well as red-blood-cell phospholipids. This means that a smaller capsule can deliver the same amount of health-promoting omega-3 to the bloodstream.
The unique molecular structure disperses easily in the gastric fluid, enhancing digestion. Krill oil also contains additional nutrients, most importantly, astaxanthin. Astaxanthin is a carotenoid that gives krill (and other seafood such as shrimp and salmon) its red colour, and is a potent antioxidant.
As krill oil has increased in popularity, questions have been raised about the sustainability of harvesting it. Krill oil comes from the frigid Southern Ocean near Antarctica, a very extreme and remote ecosystem. In this ecosystem, krill is at the bottom of the food chain: the source of food for whales, penguins, pelicans and other marine animals. An adult blue whale will eat more than 3500kg of krill per day!
However, Whole Foods Market, the leading natural and organic retailer in the United States, removed krill oil products from its shelves because of questions concerning its sustainability.
Now, there is a vegetarian, fully renewable and sustainable alternative to krill oil, sourced from microalgae. Marine animals, whether fish or krill, accumulate omega-3s in their diet. Microalgae are the original source of omega-3s in the marine ecosystem, as they create them using photosynthetic processes.
Qualitas is a leading pioneer in this field, and its Almega PL is an EPA-rich omega-3 oil sourced from microalgae. Almega PL is manufactured from marine algae that are grown on a farm in the desert of West Texas. This farm is powered by renewable energy and utilises unproductive desert land and brackish water.
Almega PL has a polar lipid structure (containing phospholipids and glycolipids) that gives it a similar bioavailability to krill oil. Polar lipid is a broader term describing similarly structured molecules such as phospholipids, glycolipids and sphingolipids: those with a hydrophilic head and a hydrophobic tail. Also, like krill, Almega PL contains additional nutrients, including omega-7 fatty acids, chlorophyll, phytosterols, tocopherols, zeaxanthin and beta-carotene.
Two published, peer-reviewed studies have done that compare the differences between Almega PL and krill oil regarding blood plasma and tissues absorption. A human study, published in Lipids in Health and Disease, showed equivalent absorption of total omega-3s into the bloodstream between krill and Almega PL. In a crossover study, 10 healthy adults were given approximately 1500mg of total omega-3s from either krill oil (1000mg of EPA and 500mg of DHA) or Almega PL (1500mg of EPA and no DHA) along with a high-fat breakfast.
Blood samples were taken at various intervals during 10 hours. Total omega-3 absorption into blood plasma was similar between Almega PL and krill oil, without a statistically significant difference (p=0.08).
However, when looking only at EPA, the plasma concentration of EPA was higher with algal oil than with krill oil at all time points. The maximum concentration of EPA was also higher with algal oil. Both the area under the concentration curve (AUC) and the incremental AUC (IAUC) for EPA were greater and statistically significant with Almega PL (p=0.006).
Even when taking into account the different dosages of EPA, this increase was disproportionally high for Almega PL (a 50% higher dosage of EPA gave a 100% higher increase). These results suggest that the combination of phospholipids and glycolipids in Almega PL may enable it to be a more effective carrier for EPA/omega-3s than the phospholipids in krill (Figure 1).
Figure 1: Plasma EPA absorption
Another peer-reviewed study, in an animal model, examined the uptake of omega-3s into different tissues, again comparing krill oil with Almega PL. Rats were fed approximately 7.3g of total omega-3s during a 7-day period and then the blood plasma, brain, liver, gonadal adipose tissue and retroperitoneal adipose tissue were analysed for omega-3 levels.
For most of the tissues, the uptake of total omega-3s was similar between Almega PL and krill oil. Levels of total omega-3s and EPA were statistically significantly higher in retroperitoneal adipose tissue in the Almega PL group when compared with the krill oil group (p<0.05 and p<0.01, respectively). Although the amounts of EPA provided were higher in the algal group, these results are important because when comparing equal doses of algal and krill oil, the former will lead to higher plasma and adipose levels. Adipose tissue may serve as a storage form of DHA and possibly EPA for delivery to the brain (Figure 2).
Figure 2: Distribution of EPA and DHA into tissues
These studies show that there are similar levels of krill oil and Almega PL absorption into the blood plasma and tissues despite differing compositions and polar lipid concentrations. Krill oil contains approximately 40% phospholipids, whereas Almega PL contains 15% polar lipids (minimum 8% glycolipids and minimum 5% phospholipids), and yet they have the same biological effect. These data point to the possibility that glycolipids could be a 'super carrier' for omega-3s. Currently, Almega PL is the only omega-3 ingredient that contains glycolipids.
To summarise, krill oil has been one of the fastest growing segments in the omega-3 category in recent years. Owing to its polar lipid structure, the omega-3s are better absorbed and digested — leading to better consumer acceptance with smaller capsules.
However, there have been questions raised concerning the sustainability of the krill biomass, particularly as demand for krill oil increases and competes with nature. There is a new source of omega-3 available, derived from a vegetarian, microalgal source: Almega PL. It is sustainably farm-grown and contains additional phytonutrients. Importantly, Almega PL has been shown in published studies to have similar bioavailability to krill oil — also allowing for potent doses to be delivered in small, easy-to-swallow capsules.