Krill are small crustaceans similar to shrimp, and they are a major food source for whales, penguins, seals, and fish. Krill oil is typically extracted from a species of Antarctic krill, and it is sold as a dietary supplement, mostly in capsule form.
Like fish oil, krill oil is a highly concentrated source of omega-3 fatty acids. The oil contains other fatty acids derived from phospholipids, and it is a good source of astaxanthin, a type of carotenoid.
Patients have used krill oil to help with conditions such as high blood pressure, premenstrual syndrome, osteoarthritis, and depression.
While more research is needed on the potential benefits of using this oil as a treatment for certain medical conditions, patients interested in taking this supplement can consult their physician about whether krill oil might be useful for their individual health needs.
When taking a krill oil capsule, the capsule must be swallowed whole; puncturing the capsule is not recommended. Patients who are pregnant may need to avoid krill oil during their pregnancy due to its mercury content.
In addition, individuals having surgery will need to stop taking these supplements at least two weeks before their operation. Krill oil should not be taken by patients who are using blood thinners.
Health Benefits of Krill Oil
Some of the major health benefits of krill oil are outlined below.
1. Reduces Inflammation
Infection and injury can both trigger inflammation, the process by which the body attempts to fight damage and heal itself.
While this response is healthy in the short term, long-term (chronic) inflammation is a major risk factor for diseases such as cardiovascular disease, diabetes, cancer, and metabolic syndrome.
Research suggests krill oil supplements may be helpful to patients experiencing this type of inflammation. In fact, the unique makeup of krill oil could enable it to be more easily absorbed by the body as compared to fish oil.
In a laboratory study conducted in test tubes, scientists found krill oil successfully reduced the production of inflammatory substances by intestinal cells after they were introduced to harmful bacteria.
Research in humans has shown similar results. A study of ninety subjects who all had chronic inflammation concluded the daily use of a three hundred-milligram krill oil supplement reduced levels of a single inflammatory marker by as much as thirty percent over one month.
A smaller investigation of twenty-five patients with high cholesterol found taking one thousand milligrams of krill oil provided a greater reduction in a specific inflammatory marker than a two thousand-milligram supplement of purified omega-3 fatty acids did.
2. Lowering Triglycerides and Improving Cholesterol
Lowering triglycerides and improving cholesterol are two of the potential benefits of krill oil that have undergone the most research. Studies show krill oil raises high-density lipoprotein cholesterol (the healthy kind), an effect not seen with purified omega-3 supplements.
In comparison to olive oil, research suggests krill oil significantly boosts the function of the blood vessels, and it also provides a more marked improvement in insulin resistance scores.
A small study published in 2013 investigated the impact of krill powder supplements on cholesterol reduction and overall metabolic health in eleven male subjects who were either overweight or obese.
After twelve weeks, the men in the treatment group reduced their triglyceride levels by 22.5 percent, and there was a 20.6 percent reduction in triglycerides after twenty-four weeks.
In a larger study that was published in 2014, scientists examined three hundred male and female patients who had high or borderline high triglyceride levels. The patients were given varying dosages of krill oil supplements, and a control group received olive oil as a placebo.
After the study, individuals who received krill oil supplements had a 10.2 percent reduction in their triglyceride levels after twelve weeks of treatment, and they experienced no increase in low-density lipoprotein cholesterol (the ‘bad’ kind).
3. May Reduce Joint Pain
Krill oil supplements may reduce joint pain and other symptoms associated with osteoarthritis. Animal studies conducted on mice have reported krill oil reduces swelling and the number of inflammatory cells in the joints, and it also improves arthritis scores.
Trials in humans have shown similar results. One study of fifty adult patients who had mild knee pain, the supplements significantly reduced pain while standing after just thirty days of use.
In addition, the study authors observed an increase in the treatment group’s range of motion, and subjects reported less pain during sleep.
In a Canadian study of patients with either osteoarthritis or rheumatoid arthritis, daily use of a three hundred-milligram krill oil supplement was shown to reduce patient-reported pain scores by 28.9 percent after seven days.
Stiffness in the joints was reduced by 20.3 percent, and functional impairment decreased by 22.8 percent over the same period.
4. Protects Against Free Radical Damage
Krill oil contains several potent antioxidants that can protect against free radical damage. Free radicals are byproducts of various processes that occur within the body. If free radicals build up to unhealthy levels, oxidative stress occurs.
Oxidative stress is associated with chronic diseases such as cardiovascular disease and metabolic syndrome, and antioxidant intake can help restore the proper balance of free radicals and other substances in the body.
The astaxanthin contained in krill oil is particularly beneficial in reducing oxidative stress in the body. Preliminary research shows this compound could have the ability to cross the blood-brain barrier, enabling it to protect the central nervous system and the brain from damage caused by free radicals.
Since oxidation occurs when the body produces inflammation in response to an infection or injury, the anti-inflammatory properties of krill oil also help indirectly protect against free radical damage.
Potential signs of oxidative stress include fatigue, muscle and joint pain, headaches, sensitivity to noise, and memory issues. Patients concerned they may be experiencing oxidative stress should consider seeing a physician for an evaluation.
5. May Lessen Risk of Stroke
Strokes occur when the blood flow to the brain is reduced or stopped completely. Strokes are more common in individuals who have high cholesterol, heart disease, diabetes, or high blood pressure.
Scientists recently discovered high levels of C-reactive protein, an inflammatory marker, are strongly associated with an increased risk of stroke.
In fact, some studies show a four hundred percent increase in stroke risk among patients with the highest levels of C-reactive protein.
A study conducted in 2007 found taking three hundred milligrams of krill oil each day reduces C-reactive protein levels by 19.3 percent after seven days, and levels are decreased by 30.9 percent after thirty days. Patients should discuss their individual stroke risk with their doctor.