1. Thirteen normo-cholesterolaemic male students consumed one 450 g can of baked beans (Phaseolus vulgaris) in tomato sauce, daily, for 14 d as part of their normal diet. After a 14 d washout period, eleven of the students went on to consume one 440 g can of spaghetti in tomato sauce, daily, for 14 d.
2. Fasting blood samples were taken frequently for measurement of plasma cholesterol, high-density lipoprotein (HDL)-cholesterol, triacylglycerols, glucose, insulin and C-peptide. Diet diaries (3 d) were completed by the subjects during each period.
3. Consumption of beans and spaghetti led to a significant reduction in the amount of fat eaten daily (P < 0.05). Bean consumption also resulted in significant increases in protein, fibre and sugar intakes (P < 0.02, P < 0.001 and P < 0.05 respectively).
4. During the bean-eating period the mean total plasma cholesterol level of the students fell significantly from 5.1 to 4.5 mmol/l (P < 0.02). No reduction in plasma cholesterol occurred during the spaghetti-eating period.
5. HDL-cholesterol levels fell significantly during both periods (P < 0.001), but HDL:total cholesterol ratio was significantly reduced only during the spaghetti-eating period (P < 0.001). Neither beans nor spaghetti affected triacylglycerol, insulin or C-peptide levels.
6. The benefits of a legume-rich diet are discussed.