Omega-3 fatty acids present in fish and soy oil increase a measure of heart-healthiness called heart rate variability in older people. Consuming a supplement of fish or soy oil daily might reduce the risk of irregular heart rhythm or sudden cardiac death. Researchers from the Emory University School of Medicine in Atlanta, followed 52 people who were 60 years or older. They were randomly assigned to take one of the oil supplements, given as 1-gram capsules twice daily for 6 months. The heart rate variability of the participants was measured every other day. Fish oil supplementation increased the average total variability from 3.26 units prior to supplementation to 3.54 afterwards. Soy oil increased the measure from 3.16 to 3.28. The study group showed improvements in heart function in 2 weeks. Some participants reported discomfort with the supplements. Belching was reported by 41 per cent in the fish oil group and 16 per cent in the soy oil group. Corresponding rates for nausea were 12.5 per cent and 8 per cent. The researchers therefore recommend omega-3 fatty acids supplements derived from either soy oil or fish oil in conjunction with other factors known to increase heart rate variability such as exercise, weight loss, stress reduction, and restoration of normal sleep to improve heart health.
Chest,
April 2005