Breast cancer survivors who eat a healthy dose of omega-3 fats may get some extra energy from it, a new study suggests.
Fatigue can linger years after cancer therapy ends. There's evidence that good sleep habits and regular exercise can help, but there's still a need for other options, researchers say.
Exactly what causes cancer survivors' long-term fatigue is unclear, according to Dr Rachel Ballard-Barbash of the US National Cancer Institute, senior author on the new study.
But there's evidence that chronic inflammation in the body may play a role, she said.
Lower odds of fatigue
Research suggests that omega-3 fats, thought to lessen inflammation, are especially effective if they replace some of the omega-6 fatty acids that make up a large share of the typical American diet.
For their study, Dr Ballard-Barbash and her colleagues looked at the relationship between omega-3 intake and fatigue among 633 breast cancer survivors.
Overall, 42% of the women were considered "fatigued" three years after their diagnosis. And the problem was more common in those with higher C-reactive protein levels.
On the other hand, women who got more omega-3 in their diets had lower odds of fatigue, particularly if they used fish oil pills.
Too early for those with cancer related fatigue
Of women who got the most omega-3 relative to omega-6, at least partly from fish oil supplements, about 23% were considered fatigued.
That compared with 49% of women who did not use supplements and had the lowest omega-3 intake relative to omega-6, the study team reported online in the Journal of Clinical Oncology.
When the researchers accounted for factors like the women's age, race and weight, higher omega-3 intake was still linked to lower odds of fatigue. Dr Ballard-Barbash said it's too early, however, for people with cancer-related fatigue to invest in fish oil pills.
Add fish to diet
"I wouldn't recommend that women start taking supplements," she said, but adding some fish to their diets might be wise.
"Consuming fish a couple times a week – particularly fatty fish – is already recommended to the general public, for overall health," Dr Ballard-Barbash noted. So that's something that breast cancer survivors with fatigue can do for themselves, she said.
She also recommended that women who are not physically active already look into taking up an exercise routine.
As for fish oil, "a next step," Dr Ballard-Barbash said, "could be for randomized clinical trials to test whether increasing amounts of omega-3, either dietary or supplements, could lead to a decrease in inflammation, and a decrease in fatigue."
(Amy Norton, Reuters Health, March 2012)
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