The “intervention group” and “control group”
The intervention group added half a cup of walnuts to their usual daily diet while the control group did not.
After two years, the participants’ cholesterol levels were tested and the size and concentration of lipoproteins were analysed by nuclear magnetic resonance spectroscopy.
Firstly, participants in the walnut group had an average of 4.3mg/dL lower LDL cholesterol levels than the control group.
As for total cholesterol levels, the intervention group had, on average, 8.5mg/dL lower levels.