Published in the journal Clinical Nutrition, the team found as little as four grams of Aker BioMarine’s Superba krill oil daily for six months could have benefits on skeletal muscle’s role and mass in this age range.
“As humans age, we experience a slow deterioration of our muscle mass and function,” says Line Johnsen, VP Science & Regulatory Affairs at Aker BioMarine.
“Previous research has indicted that EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) supplementation can positively impact muscle protein synthesis, muscle volume and strength.
“This new study also suggests that choline in krill oil may have additional beneficial effects for skeletal muscle metabolism and health,” Johnsen adds.
“This study strengthens the hypothesis that daily supplementation of krill oil for an extended period can improve knee thigh muscle strength, grip strength and muscle thickness in healthy, older adults.”
The enrolment process
The team from the University of Glasgow’s Institute of Cardiovascular and Medical Sciences (ICAMS) began enrolling 102 men and women aged over 65 years, with a BMI less than 35kg/m2.
These subjects participated in less than one hour per week of structured self-reported exercise.
Participants were randomised to either control or krill oil supplements (4g/day) for 6 months in this double blind randomised controlled trial.
At baseline, six weeks and six months, knee extensor maximal torque was measured as the primary outcome of the study.
Secondary outcomes measured included grip strength, vastus lateralis muscle thickness, short performance physical battery test, body fat, muscle mass, glucose and insulin levels amongst others.
The study found an increase in thigh muscle strength (9.3%), grip strength (10.9%) and thigh muscle thickness (3.5%), relative to control group.
There was also an increase in red blood cell fatty acid profile for EPA 214%, DHA 36% and the omega-3 index 61%, relative to control group.
Further findings extended to an increase in M-Wave by 17% (relative to the control group), which shows the excitability of muscle membranes.
“This is yet another a strong indication that the omega-3 fatty acids EPA and DHA are important nutrients for adults as we age,” said Dr Stuart Gray, Senior Lecturer at the University of Glasgow’s ICAMS,
“We are keen to investigate this further, particularly whether this could be a useful treatment for those who already have muscle weakness.”
Previous studies have used fish oils as the source of long-chain n-3 polyunsaturated fatty acids (LCn-3 PUFA). However, Antarctic krill is also a rich source of these fatty acids.
Fish oil supplements contain most of their LCn-3 PUFA in either triacylglycerol or ethyl ester form, while krill oil has more than 40% of its LCn-3 PUFAs in phospholipid form.
On top of this, krill oil contains choline and astaxanthin which may also be important for muscle health.
In previous supplementation studies, similar increases in plasma eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels were seen with krill- and fish oil, despite lower doses of EPA and DHA in the krill oil supplements.
Furthermore, greater increases in the omega-3 index were seen with krill oil supplementation, compared to fish oil supplementation, when EPA and DHA in the supplements were matched.
Source: Clinical Nutrition
Published online: DOI: 10.1016/j.clnu.2022.04.007
“The effect of krill oil supplementation on skeletal muscle function and size in older adults: A randomised controlled trial.”
Authors: Saleh AA. Alkhedhairi et al.