Effects of regular consumption of different forms of almonds and hazelnuts on acceptance and blood lipids.

Purpose: Regular nut consumption is inversely associated with cardiovascular disease risk. No study has compared the effects of regular consumption of different types and forms of nuts on acceptance, which is a crucial determinant of long-term compliance to consume nuts regularly.

Methods: This study examined the effects of different types and forms of raw, unpeeled nuts on acceptance and the effects of nut consumption on blood lipids through a randomised crossover study with six dietary phases: 30 g/day of ground, sliced, or whole almonds or hazelnuts for 5 days each (n = 74). Acceptance ('desire' and 'liking') for nuts was measured daily using visual analogue scales. Blood lipids were measured at baseline and week 6.

Results: Acceptance was stable over all conditions, but there were differences between nut forms (ground < sliced < whole, P < 0.001 for both 'desire' and 'liking') with some nut type-nut form interactions. Compared with baseline, week 6 HDL-C was higher (0.06 mmol/L, 95% CI 0.02-0.10, P = 0.002) while LDL-C and total-C:HDL-C ratio were lower (0.15 mmol/L, 95% CI 0.06-0.25, P = 0.002 and 0.25, 95% CI 0.07-0.43, P = 0.006).

Conclusions: In conclusion, acceptance was stable for all combinations but was highest for whole nuts. Six weeks of nut consumption improved blood lipids.