Effect of long-term omega-3 supplementation and a lifestyle multidomain intervention on intrinsic capacity among community-dwelling older adults: Secondary analysis of a randomized, placebo-controlled trial (MAPT study).

OBJECTIVES

To investigate the effect of omega-3 (ω-3) polyunsaturated fatty acid supplementation and a multidomain intervention (MI) (physical activity counselling, cognitive training and nutritional advice) among community-dwelling older adults on levels of intrinsic capacity (IC), a construct recently proposed by the World Health Organization.

STUDY DESIGN

Secondary analysis from the factorial-design 3-year Multidomain Alzheimer Preventive Trial (MAPT) with 1445 subjects (64.2 % female, mean age 75.3 years, SD = 4.4) randomized to one group of MI plus ω-3 (800 mg docosahexaenoic acid and 225 mg eicosapentaenoic acid/day); MI plus placebo; ω-3 supplementation alone; or placebo alone. Data collection was held between 2008 and 2014.

MAIN OUTCOME MEASURES

IC domains were examined with the Geriatric Depression Scale (psychological); Short Physical Performance Battery (mobility); Z-score combining four tests (cognitive function); and handgrip strength (vitality). All domains were combined into a composite IC Z-score.

RESULTS

After 3 years, IC Z-score decreased among all groups when time was considered continuous (MI plus ω-3: -0.16, 95 %CI: -0.22 to -0.10; MI alone: -0.13, 95 %CI: -0.19 to -0.07; ω-3 alone: -0.19, 95 %CI: -0.25 to -0.10; placebo: -0.20, 95 %CI: -0.26 to -0.14; all p < 0.0001). There were no significant differences between groups. In a sensitivity analysis with categorical time, significant within-group declines were first identified at 24 months for all groups.

CONCLUSIONS

This trial designed to improve cognitive function was unable to find effects of the intervention on the composite IC Z-score. Further investigations are needed, especially trials providing stronger interventions (such as exercise training and a controlled diet) and also embracing the sensorial domain of IC.