Fish oil can more than double the benefit of exercise in older women – potentially helping reduce falls.
Aberdeen University scientists believe the findings could be a breakthrough in efforts to keep an ageing population on its feet.
Their study – conducted with academic colleagues from Glasgow – measured the results of regular resistance training for 18 weeks.
As expected, all those taking part saw their muscle size, function and quality improve as a result.
But among female participants, those taking Omega 3 supplements at the same time enjoyed a significantly bigger benefit.
Increased muscle function led to their strength improving by more than a third – 34% – compared with 16% for other women taking a placebo.
It was a particularly important finding as women tend to cross the “disability threshold” where functional abilities are lost 10 years earlier – making them more vulnerable to falls.
It remains unclear why men did not get the same boost.
The results are published today in The American Journal of Clinical Nutrition.
Dr Stuart Gray, who completed much of the research in Aberdeen before moving to Glasgow University, said: “These findings provide important information for nutritional guidelines in older people where policy makers may want to consider recommendations for fish oil supplements to be consumed by older women.
“Why men do not see the same benefit as women is important to understand and the underlying mechanisms need to be studied.”
Researchers noted that it was muscle quality rather than size which was improved.
The main purpose of skeletal muscle is carrying out daily tasks, such as rising from a chair or getting on a bus – often referred to as functional abilities.
Both size and function progressively decrease as a normal part of healthy ageing.
This can result in a reduction in quality of life, increased risk of falls and a loss of independence.
Dr Gray added: “With the percentage of people aged over 65 predicted to rise from 17%, of the total population in 2010 to 23% in 2035, it is crucial to develop effective treatments for the age-related loss of muscle function.”