Hormone replacement therapy (HRT) can increase levels of beneficial fatty acids in postmenopausal women. In a study, women taking HRT had higher levels of docosahexaenoic acid and eicosapentaenoic acid in their blood after 12 months compared to those not on HRT. These fatty acids are known to have antiatherosclerotic effects, which means they can help prevent the buildup of plaque in arteries. This suggests that HRT may have a positive impact on heart health by increasing these fatty acids in the body.