Hazelnuts in their shells, with and without their skin

Ivar Leidus · CC BY-SA 4.0

Hazelnuts

A handful of hazelnuts per day slightly lowers LDL and total cholesterol and improves diet quality, without causing weight gain; no effect on triglycerides, inflammation or blood sugar in diabetics.

Benefits

• Slightly lowers LDL: −0.150 mmol/L in a meta-analysis of 3 randomised trials, out of 9 studies and 425 participants in total; total cholesterol also tends to decrease.
• In 48 people with slightly high cholesterol, 30 g per day for 4 weeks lowered total cholesterol, LDL and apolipoprotein B, and increased HDL and vitamin E, whether the hazelnuts were whole, slivered or ground.
• With 18 to 20% of calories from hazelnuts for 4 weeks, in 21 people with high cholesterol: −7.8% total cholesterol, −6.17% LDL, −7.3% triglycerides and +6.07% HDL, with improved arterial dilation.
• In 32 healthy seniors, about 57 g per day for 16 weeks: −6.0% LDL, −3.4% fasting blood glucose and slightly more blood magnesium (+2.1%).
• Improves diet quality: 42 g per day as a snack for 12 weeks provided more vitamin E and monounsaturated fats, and fewer saturated fats, than chocolate or crisps.
• Does not cause weight gain: 30 or 60 g per day for 12 weeks did not change the body composition of 107 overweight individuals, and a review of 22 studies finds no adverse effect on weight.