Onion significantly decreased the levels of total cholesterol within each group ; however , these changes were stronger in the high-onion group ( weighted mean differences -LSB- WMD -RSB- : -@ -LSB- @ % confidence interval -LSB- CI -RSB- : -@ , -@ -RSB- ; P = @ ) than in the low-onion group ( WMD : -@ -LSB- @ % CI : -@ , -@ -RSB- ; P = @ ) .