In older persons and those with high BP (or hypertension), fish oil supplementation considerably decreased both systolic (upper reading of BP) and diastolic BP (lower reading of BP). A study has shown a greater fall in both systolic and diastolic BP in men with high BP at risk of heart disease, with fish oil consumption. The men included in the study were assigned to five high-fat (40% of daily energy) and two low-fat (30% of energy) groups. The five high-fat groups were assigned to take either six or 12 fish-oil capsules daily, fish or a combination of fish oil and fish, or placebo capsules. The two low-fat groups took either fish or placebo capsules. Omega-3 fatty acids from fish oils improve BP control and may reduce the long-term continuous rise in BP in patients who had hypertension and who underwent a heart transplant. The study also illustrated a favorable effect of omega-3 fatty acids on kidney function in these patients.