Krill oil research
When selecting nutritional supplements we all strive to use the most effective products available. But what should we base that determination on?
One option is to ask others about their personal experiences. This is commonly referred to as anecdotal evidence. Another source of data can be found in the scientific literature. Here we’re trusting that researchers are performing well designed and impartial research in a more controlled manner.
Since these types of studies typically involve larger groups of people, the results may apply to broad segments of the population. But there’s another very prevalent manner of learning about dietary supplements and that is information provided by the manufacturers themselves.
My contention is that we ought to examine all three sources of input. Ask questions of your colleagues, family and friends. Read the product literature provided by nutraceutical companies and pose any inquires that you might have.
Finally, investigate whether modern science has produced any evidence to back up the other two sources. I’ll apply this model to examine an area of debate that’s currently active in the natural health community: Is krill oil superior to fish oil?
Background information on Krill Oil
Krill oil is a supplemental source of powerful antioxidants, omega-3 fatty acids and phosholipids derived from tiny crustaceans harvested largely in the Southern Ocean waters of the Antarctic.
A superior form of omega 3
Krill oil proponents claim that it is essentially a superior form of omega-3s. Krill contains a rather unique reddish antioxidant called astaxanthin, and they’re also rich in phospholipids, which help emulsify fatty acids and enhance their absorption and retention.
Reduction of fat in the body
A new study presented in the Journal of Nutrition appears to support this point of view. Research conducted in a group of overweight rats found that krill oil provoked a 42% decrease in fat (triglyceride) build-up in the hearts of the test rats. Fish oil only lead to a marginal decline in cardio-lipids of 2%.
When the authors of the study examined the livers of these animals, they discovered a 60% reduction in fat in their livers, as opposed to 38% in the livers of rats fed fish oil.
The normalization of fat content in the heart and liver indicate potential benefits to overall heart function and an improvement in insulin sensitivity, which can be impaired in cases of fatty liver disease. In addition, the krill oil test subjects exhibited positive changes associated with a reduced “inflammatory response”.
A study from 2008 demonstrated anti-cancer and heart benefits in relation to krill oil (KO) supplementation. In that trial, rats who were fed Krill Oil showed weight loss and a drop in LDL “bad” cholesterol, total cholesterol and triglyceride levels. The scientists also tested krill oil in an in-vitro model of colon cancer. The scientists concluded that, “Treatment of colon cancer cells with KO also resulted in time-dependent inhibition of cell growth”.
Krill Oil research into a variety of medical conditions
Krill oil has also been evaluated in other health conditions as well. The results of those studies have all been positive and, in a roundabout way, can be applied to what we currently know about heart disease.
Heart disease / arthritis: In 2007, a paper was published in the Journal of the American College of Nutrition. 90 participants with heart disease and/or arthritis (osteo or rheumatoid) with elevated CRP (C-reactive protein) levels were provided with KO or a placebo for a 30 day period. CRP is a measure of inflammation in the body. By the 7th day of treatment with KO (300 mg daily), there was a 19% drop in CRP levels. The placebo group exhibited a 16% increase in CRP. By the 30th day of treatment, there was a 31% reduction in CRP in the krill oil group and a 32% rise in CRP in the placebo group. In the arthritic patients, there were significant improvements in pain and stiffness scores, and a trend towards “reduced functional impairment”.
(PMS) Premenstrual syndrome: A 2003 study on 70 women with PMS and dysmenorrhea (painful menstruation) found that those taking KO for a total of 90 days demonstrated reduced discomfort, pain and emotional symptoms relating to PMS.
This experiment compared equal dosages of KO vs. fish oil - 2 grams daily for the first 30 days and then 2 grams daily for 8 days prior to menstruation and during the first 2 days of the menstrual cycle.
Cancer / cardiovascular disease: Chronic inflammation is now believed to be a contributing factor in many cancers and cardiovascular disease.
The fact that KO appears to reduce inflammatory markers and symptoms may provide a clue to part of its cardioprotective effect. A human trial from 2004 is perhaps the strongest piece of evidence that supports the krill/heart health link. That study produced a profoundly positive shift in cardiovascular risk factors in a group of 120 volunteers.
Blood sugar levels / cholesterol: A starting KO dosage of 500 mg daily reduced blood sugar levels, LDL, total cholesterol and triglycerides, and raised the beneficial HDL cholesterol in the participants. The men and women who were given fish oil didn’t fare nearly as well.
Summary of the krill oil health benefits
Krill oil seems to be an extremely promising antioxidant/omega-3 supplement.
Substantial evidence suggests that the astaxanthin content of krill largely contributes to its net effect. Astaxanthin is the same carotenoid that gives wild salmon its pink hue. But there may also be something to the phospholipid content of this crustacean. That’s the only explanation I’ve found as to why a lower dosage of KO could produce equal or greater effects than higher dosages of fish oil.
