How we rate
“Strong” = several concordant meta-analyses or systematic reviews. “Moderate” = one synthesis, or several controlled trials. “Limited” = early trials only. The rating is about the quality of the studies, not about how useful the supplement is.
Macadamia nuts
In small trials, macadamia nuts slightly lower cholesterol when they replace saturated fats; simply added to the diet, the effect is no longer significant.
Benefits
- Cholesterol: in 25 adults with slightly elevated cholesterol, 42.5 g per day for 5 weeks brought total cholesterol down from 5.45 to 4.94 mmol/L and LDL from 3.44 to 3.14 mmol/L.
- In 17 men with high cholesterol, 40 to 90 g per day for 4 weeks: total cholesterol −3.0%, LDL −5.3% and HDL +7.9%.
- Over 30 days in 30 volunteers, a macadamia-based diet brought total cholesterol down from 5.20 to 4.95 mmol/L, as much as a low-fat diet.
- In young Japanese female students, 3 weeks of a macadamia-based diet lowered total cholesterol, LDL, weight, and BMI.
- In a small 4-week trial, an inflammation marker (LTB4) and an oxidative stress marker (8-isoprostane) decreased in 17 men with high cholesterol.
Precautions
Limitations: added for 8 weeks to the diet of 35 obese adults, they did not significantly change cholesterol (−2.1%), weight, or blood glucose. The macadamia-based diet did not perform better than a low-fat diet on cholesterol. Triglycerides did not budge in two trials. Only six small trials, from 17 to 35 people and from 3 to 8 weeks, and no meta-analysis.
Recommended dosage
42.5 g per day, or 40 to 90 g per day depending on needs (approximately 15% of calories), for 3 to 8 weeks in the trials.
How to take it
- Who it is for: the trials involve adults with high cholesterol, healthy volunteers, and obese adults at cardiometabolic risk.
- As a replacement, not in addition: cholesterol decreased when the nuts replaced saturated fats; simply added to the usual diet, the decrease was not significant.
- Dose: 42.5 g per day in one trial, 40 to 90 g per day (approximately 15% of calories) in another.
- Duration: from 3 to 8 weeks; no trial lasts longer.
- Composition: macadamia nuts contain 75% fat, of which 80% is monounsaturated fat.
Did you know?
A macadamia nut-based diet, as high in fat as a "typical American" diet (37% of calories from fat), lowered cholesterol as much as a low-fat diet.
What the studies say
This study examined the effects of daily macadamia nut consumption in overweight or obese adults for 8 weeks. It showed that macadamia nuts do not lead to weight gain or fat mass gain under normal living conditions. Non-significant reductions in total cholesterol (-2.1%) and LDL cholesterol (-4%) were observed, with more pronounced effects in overweight individuals.
Jones JL, Sabaté J, Heskey C, Oda K, Miles F, Rajaram S. — Journal of nutritional science (2023) — View the source study
For information only: not a substitute for medical advice. Dietary supplements are not a replacement for a varied, balanced diet. Learn more