World Macadamia Organisation (WMO) periodically commissions a review of key scientific research, United States (U S ) regulations, and nutritional analysis to support the creation and evolution of a nutritional and health narrative on the benefits of macadamias. This narrative aims to deliver a science-based, compelling, and ownable message on macadamia nutrition and health benefits. The scope includes creating consumer-friendly messaging that is easy to understand, based on sound science, and meets U S regulations Processors and handlers, brand owners, influencers, nutritionists, and the wider macadamia industry are encouraged to use these resources.
Method
The assessments were conducted by a United States-based team of external experts with backgrounds in nutrition, clinical studies, food science, regulatory, and food industry experience
The following multi-step approach was taken:
• Evaluate available scientific research on macadamias and related health research
• Nutritional comparison to other tree nuts and whole foods, based on 100g values and U S recommended serving size amounts
• Fatty acid profile breakdown, including ratios between monounsaturated and polyunsaturated fats
• Identification of potential claims and the ability to promote them based on U S regulatory requirements and limitations (e.g. nutrient content, structure/function claims)
• Categorisation of the research and analysis based on significance and priorities
• Broader recommendations on potential certified claims, health benefits, category opportunities, and consumer usage
• Deeper analysis of omega fatty acid ratios and substantiating work available to support the good fats narrative, including nutritional comparisons of other whole foods/oils
• Exploring additional supporting claims, such as heart health, inflammation, brain function, gut health, and blood glucose levels
• Expanded evaluation of research related to the use of macadamia oil in food processing and beauty products
• Final conclusions and recommendations
The reviews were conducted over a three-year period, incorporating science published recently and in preceding decades. This is the fourth edition, published July 2025, and replaces previous editions.
Executive summary
Macadamias have a nutritional profile that is aligned with the growing consumer trend of improving health through whole foods that have key benefits when consumed as part of an overall healthy diet Macadamias have a range of health benefits Scientific research has demonstrated that their nutritional benefits include improved cardiovascular health, reduced inflammation, improved glucose response, and a satiated feeling without weight gain. Overall, this report details the assessment of the health benefits of macadamia nuts, the importance of their nutrients, scientific reviews, and summarises an industry-aligned nutritional narrative to evolve consumer understanding over time.
Macadamia nuts contain a variety of good fats that support a healthy diet. They have the highest level of monounsaturated fats (MUFAs) of all nuts in the form of Omega-9 and Omega7. They also have polyunsaturated fats (PUFAs) in the form of Omega-3 and Omega-6, of which humans need both; however, in modern diets, we typically overconsume Omega-6 The ratio of 6:1 (Omega-6:Omega-3) found in macadamias is an excellent balance of the two The good fats in macadamias have benefits such as heart health, reduction of inflammation, improved cognitive function, and gut health. Macadamia nuts are low in carbohydrates and, combined with high levels of unsaturated fats, present an ideal snacking option for those aiming to maintain lower blood sugar levels. There is only a minimal spike in blood glucose levels following the consumption of macadamias
Further, consumers are increasingly seeking nutrient-dense ‘real foods’ – foods that are not highly processed. The good fats in macadamias, together with their vitamins, minerals, antioxidants, and phytonutrients, contribute to their nutrient density. Macadamias are uniquely rich in the mineral manganese, which is essential for skin development and resolving inflammation.
Macadamias offer a wide variety of uses and can be consumed raw, roasted, salted, or incorporated into products in many forms Popular options include snack bars and bites, granolas, dairy alternatives, food coatings and toppings, ice cream, confectionery, and chocolates.
Macadamia nut oil has multiple uses as an oil used in food preparation and formulated into health and beauty products. When used in cooking, it has a higher flash point, which reduces the speed of oxidation, making it a healthier option than many other cooking oils Its mild flavor complements many recipes and formulations. The fatty acid profile of macadamia oil is optimal and contributes similar nutritional benefits to eating whole nuts Its use in products targeted at improving skin has increased because it is lightweight, easy to absorb, and has potential antiaging benefits.
Macadamias meet evolving consumer trends, and our understanding of the nutritional and other health benefits continues to grow. Further scientific studies will further strengthen knowledge and acceptance.
This work has been undertaken for the United States and is in alignment with U S regulations. In other countries other claims or benefit areas may have more relevance or validity.
Scientific literature review
A review of over 120 available scientific research reports has been conducted. The studies included in this review examine both macadamias specifically, and the health effects of the nutrients contained in macadamias. The analysis identified studies that addressed potential claims, uses, and the unique role of the fatty acid profile in macadamia nuts
The studies include university, institutional, and government-supported research and are reviewed on an annual basis to ensure the industry continues to expand its understanding The latest findings are integrated into each new edition of this report.
Research on macadamias is growing, and more is needed to provide further substantiation of the phytochemical health properties and overall structure/function benefits. Advancing to more human clinical trials is a desired research goal, as it could provide more evidence of health benefits gained directly from eating macadamias.
The following Table 1 summarizes the most relevant and highest-quality studies They are categorized by the key findings, supporting nutritional benefits, potential claims, and a summary of key takeaways References are supported in Appendix 4, which is available as a separate document in Excel format. This appendix includes a complete list of studies reviewed during this work
Table 1
General nutrition benefits
Xing-Hao Tu, et al.
“A Comprehensive Study of Raw and Roasted Macadamia Nuts: Lipid Profile, Physiochemical, Nutritional, and Sensory Properties.” (1)
Boiling, Bradley, W. et al.
“Tree Nut Phytochemicals: composition, Antioxidant Capacity, Bioactivity, Impact Factors. A Systematic Review of Almonds, Brazils, Cashews, Hazelnuts, Macadamias, Pecans, Pine Nuts, Pistachios and Walnuts.” (2)
Ni Dongdong, et al.
“Exploring Relationships between Satiation, Perceived Satiety and Plant-based Snack Food Features.” (3)
Schwingshackl, L., and B. Strasser.
“High- MUFA Diets Reduce Fasting Glucose in P patients with Type 2 Diabetes.” (4)
Tim J.O’Hare and Hung Hong Trieu, et al
“Assessing Fatty Acid Profiles of Macadamia Nuts (various species)” (5)
Roasting improves taste sensation of macadamia nuts and does not diminish nutritional quality.
Macadamias are a source of plant sterols (which may lower cholesterol in the blood); as well as polyphenols and flavonoids (antioxidants)
Eating macadamia nuts had the greatest satiety over time, with lower initial satiation than other snack foods. We don’t feel as “full” but are not hungry for a longer time after eating macadamias.
Diets high in MUFA seem to reduce blood glucose levels in people with Type 2 Diabetes. More research is needed – an area to watch.
Tested fatty acid content of many macadamia lines. Potential exists to develop a reduced-saturated fat macadamia by combining characteristics found in different species through selective breeding.
Improved cardiovascular health markers
Griel, Amy E., et al.
“A Macadamia Nut-Rich Diet Reduces Total and LDL Cholesterol in Mildly Hypercholesterolemic Men and Women.” (6)
Maguire, L. S. et al.
“Fatty Acid Profile, Tocopherol, Squalene and Phytosterol Content of Walnuts, Almonds, Peanuts, Hazelnuts and the Macadamia Nut.” (7)
Hiroaka-Yamamoto, Junko, et al.
“Serum Lipid Effects of a Monounsaturated (Palmitoleic) Fatty Acid-Rich Diet Based on Macadamia Nuts in Healthy, Young Japanese Women.” (8)
Curb, J. D., et al. “Serum Lipid Effects of a HighMonounsaturated Fat Diet Based on Macadamia Nuts.” (9)
Nishi, S. K., Paz-Graniel, I., Ni, J., Valle-Hita, C., Khoury, N., Garcia-Gavilán, J. F., Babio, N, Salas-Salvadó, J. (2024).
“Effect of Nut Consumption on Blood Lipids: An updated Systematic Review and Meta-analysis of Randomized Controlled Trials.” (10)
Lutgarda Bozzetto, Anna Prinster, Giovanni Annuzzi, Lucia Costagliola, Anna Mangione, Alessandra Vitelli, Raffaella Mazzarella, Margaret Longobardo, Marcello Mancini, Carlo Vigorito, Gabriele Riccardi, Angela A. Rivellese; Liver Fat
Is Reduced by an Isoenergetic MUFA Diet in a Controlled Randomized Study in Type 2 Diabetic Patients. Diabetes Care 1 July 2012; 35 (7): 1429–1435. (11)
Replacing saturated fats with macadamia nuts reduces risk factors for cardiovascular disease; lowers total cholesterol and LDL in the blood.
Including macadamia nuts in a healthy diet resulted in lowered total cholesterol, LDL, and an increase in HDL.
The cholesterol-lowering effects of macadamia nuts were seen in healthy young women as well as older adults with elevated blood lipids.
Compared a macadamia nut-based diet (37% total fat) to a ‘typical’ American diet (37% total fat) and a ‘Step 1’ diet (30% total fat). Findings showed both the macadamia-based diet and Step 1 reduced TC, LDL-C, HDL-C concentrations. A diet with macadamias provided similar heart benefits to a low-fat diet.
A review of over 113 trials assessing effect of consuming nuts, including macadamias, with a median daily dose of 45.5g/day compared to a non-nut control group showed moderate reductions in total cholesterol, LDL ‘bad’ cholesterol, triglycerides and apolipoprotein B. Evidence supports current recommendations for consumption of nuts for cardiovascular risk reduction by favorably affecting the blood lipid profile in adults.
Substituting foods rich in MUFA for foods high in saturated fats (example: macadamias or macadamia butter for butter or bacon) benefits our health.
Monounsaturated fats (MUFAs) and inflammation
Sujatha Rajaram, et al.
“Macadamia Nut Consumption May Decrease Inflammation Markers” (12)
Patel, Alok, et al.
“Futuristic Food Fortification with a Balanced Ratio of Dietary Omega-3/Omega-6 Fatty Acids for the Prevention of Lifestyle Diseases.” (13)
Kalogeropoulos, Nick, et al.
“Unsaturated Fatty Acids Are Inversely Associated and N- 6/N-3 Ratios Are Positively Related to Inflammation and Coagulation
Markers in Plasma of Apparently Healthy Adults.” (14)
Gaetan Ravaut, et al. “Monounsaturated Fatty Acids in Obesity-Related Inflammation.”
International Journal of Molecular Sciences, vol. 22, no. 330, Dec. 2021, p. 330. (15)
Macadamia nut consumption appeared to reduce markers of inflammation in older people.
A more balanced ratio of Omega-6 to Omega-3 fats reduces inflammation and promotes health.
Both MUFA and PUFA intake were associated with lower inflammatory markers in the blood; a lower ratio of Omega-6 to Omega-3 fats was beneficial, but no ideal ratio was determined. The fatty acids studied mirror closely the fatty acids in macadamias.
Replacing saturated fatty acids, usually from animal sources, with unsaturated fatty acids reversed the detrimental effects of SFAs on cells.
MUFAs and cognitive/brain health
Prinelli, Rederica, et al.
“Specific Nutrient Patterns Are Associated with Higher Structural Brain Integrity in DementiaFree Older Adults.” (16)
Jiang, Yi-Wen, et al.
“Midlife Dietary Intakes of Monounsaturated Acids, n-6 Polyunsaturated Acids, and PlantBased Fats Are Inversely Associated with Risk of Cognitive Impairment in Older Singapore Chinese Adults.” (17)
Naqvi, Asghar Z., et al.
“Monounsaturated, Trans, and Saturated Fatty Acids and Cognitive Decline in Women.” (18)
Theodore, Lauren E., et al. “Nut Consumption for Cognitive Performance: A Systematic Review.” (19)
Omega-7 / palmitoleic acid - general
Sasagawa, Masa et al.
“Omega-7 Mixed Fatty Acid Supplementation Fails to Reduce Serum Inflammatory Biomarkers: A Placebo-Controlled, Double-Blind Randomized Crossover Trial.” (20)
Weir, N. L., et al.
“Circulating Omega-7 Fatty Acids Are Differentially Related to Metabolic Dysfunction and Incident Type 2 Diabetes: The Multi-Ethnic Study of Atherosclerosis (MESA).” (21)
Akio Nakamura, et al.
“Effects of Omega-7 Palmitoleic Acids on Skeletal Muscle Differentiation in a Hyperglycemic Condition.” (22)
A Mediterranean-style eating pattern including nuts was associated with better brain health and less dementia. This eating pattern also includes oleic acid-rich olive oil. Macadamias are rich in oleic acid.
An inverse association with cognitive impairment was found for plant-based fat intake. Substitution of total carbohydrate or saturated fat with MUFA and particularly PUFA was related to lower risk of cognitive impairment. Macadamias are rich in both MUFA and PUFA.
Greater MUFA intake was associated with less cognitive decline. Macadamias are rich in MUFA fatty acids.
Nut consumption in general was associated with better cognitive performance, although macadamias were not included in the study.
Supplemental Omega-7 palmitoleic acid was no better than a placebo at improving inflammation markers in the blood.
Palmitoleic acid positivity correlated with Type 2 Diabetes in some groups and was neutral in others. The more palmitoleic acid in the blood, the higher the risk of diabetes for some people.
Omega-7 fats may positively influence muscle growth in people with high blood sugar. This means it may help increase lean mass, however this research is in the very early stages.
“A review of biological functions, health benefits, and possible de novo biosynthetic pathway of palmitoleic acid in macadamia nuts” (23)
Domenico Tricò, Alessandro Mengozzi, Lorenzo
Nesti, Mensud Hatunic, Rafael Gabriel Sanchez, Thomas Konrad & Katarina Lalić, Nebojša M. Lalić & Andrea Mari & Andrea Natali & for the EGIR-RISC Study Group
“Circulating palmitoleic acid is an independent determinant of insulin sensitivity, beta cell function and glucose tolerance in non-diabetic individuals: a longitudinal analysis” (24)
Higher levels of palmitoleic acid in the blood were correlated with better insulin sensitivity; no cause/effect relationship has been shown to date but may support future studies to understand the function and benefits of palmitoleic acid in the body.
Investigated the role of palmitoleic acid in the blood in insulin sensitivity, insulin production, and blood glucose levels in humans
Those with higher levels of palmitoleic acid in the blood also had better insulin sensitivity, insulin production, and lower blood glucose levels. This study does not prove there is a relationship between them, just that they are both there.
“Protocol for a randomized placebo-controlled clinical trial using pure palmitoleic acid to ameliorate insulin resistance and lipogenesis in overweight and obese subjects with prediabetes” (25)
The study hypothesizes the ability to mimic the rescue mechanism of adipose tissue against obesity by supplementing high-dose POA exogenously, which will improve whole-body insulin sensitivity. Authors provide a protocol of testing pure palmitoleic acid, without any palmitic acid, and its effect on insulin resistance and diabetes. The results will be interesting for macadamias due to its high palmitoleic acid content. [final results pending]
Specific benefits – satiety and weight gain
Cesarettin Alasalvar and Bolling
“Review of nut phytochemicals, fat-soluble bioactives, antioxidant components and health effects” (26)
Julie L. Jones, et al., School of Public Health, Loma Linda University, Loma Linda, CA, USA
“Macadamia nut effects on cardiometabolic risk factors: a randomised trial’ (27)
O'Neil, Carol E et al. “Tree Nut consumption is associated with better adiposity measures and cardiovascular and metabolic syndrome health risk factors in U.S. Adults: NHANES 2005-2010.”
Confirms health benefits of nuts regarding satiety, lowered insulin resistance, heart health However, macadamias have the lowest amounts of studied nutrients.
Achieves satiety with no weight gain when consumed in moderation as part of a healthy diet.
Overall, nuts have been shown to provide a healthier blood glucose and insulin response, including macadamias.
Adding macadamia nuts to the diet did not result in weight gain; other results were not significant however the study was only 8 weeks long. “Macadamia nuts may be suggested as a nutrientdense food even among the overweight/obese population without fear of weight gain.”
People who regularly consume nuts have a reduced risk of overweight/obesity, hypertension, and cardiovascular disease.
nut oil
Xixiang Shuai, Taotao Dai, Mingshun Chen, Cheng-mei Liu, Roger Ruan, Yuhuan Liu, Jun Chen - “Characterization of lipid compositions, minor components and antioxidant capacities in macadamias (Macadamia integrifolia) oil from four major areas in China” (29)
Tafadzwa Kaseke, Olaniyi Amos Fawole, and Umezuruike Linus Opara
“Chemistry and Functionality of Cold-Pressed Macadamia Nut Oil” (30)
Compared nutrient profiles of oil from macadamia nuts grown in four areas of China
Each region was slightly different in the nutrient content of the oil, however all nuts provided good antioxidant and fatty acid content. Further supported the claim that macadamia nut oil provides healthy good fats and antioxidants.
Explored potential health benefits from cold pressed macadamia oil (CPMO)
CPMO has higher oxidative stability due to its high presence of MUFA's and natural antioxidants. Diets higher in oleic and palmitoleic acid may be seen as beneficial with more research.
CPMO contains bioactive constituents such as tocopherols, phytosterols and squalene which have antioxidant properties.
Beneficial fatty acid profile is maintained in the oil state. Higher oxidative stability due to high presence of MUFA's and natural antioxidants such as tocopherols, phytosterols, and squalene
Macadamia
Macadamia nut oil
Roberta Tardugno, Nicola Cicero, et al., “Exploring Lignans, a Class of Health Promoting Compounds, in a Variety of Edible Oils from Brazil” (31)
Xixiang Shuai, et al,
“Effect of different oleogelation mechanisms on physical properties and oxidative stability of macadamia oil-based oleogels and its application” (32)
Suvimol and Wantida Chaiyana, “Clinical Efficacy in Skin Hydration and Reducing Wrinkles of Nanoemulsions Containing Macadamia integrifolia Seed Oil” (33)
Yao Liu, et al,
“Effect of macadamia oil cake on blood lipid characteristics and intestinal microbiota in hyperlipidemic rat” (34) [animal study]
Macadamia nut milk
Victor Jonas da Rocha Esperança, Caroline Corrêa de Souza Coelho, Renata Tonon, Renata Torrezan, and Otniel Freitas-Silva “A review on plant-based tree nuts beverages: technological, sensory, nutritional, health and microbiological aspects” (35)
Winston J. Craig and Cecilia J. Brothers
“Nutritional Content of Non-Dairy Frozen Desserts” (36)
Measured the amounts of lignans in popular oils in Brazil, including Macadamia oil, as it had the most lignans of the nut oils tested and just behind olive and grapeseed oils. Lignans are anti-inflammatory molecules and generally macadamias are lignan-rich foods in the diet.
Macadamia oil may be a good substitute for cocoa butter for heat-resistant chocolates. This would have potential application to promote a healthier alternative to current chocolates and confections.
Both conventional emulsions of macadamia oil and nanoemulsions enhanced skin hydration and reduced skin wrinkles in human volunteers, while the nano-emulsion was outstanding in skin hydration enhancement. Macadamia oil may improve skin hydration and reduce wrinkles when applied to the skin.
A high-fat diet significantly damaged the intestinal microbiota of rats, and macadamia oil cake intake effectively reduced the negative effects of a high-fat diet on the intestinal microbiota of rats. May provide basis for research in humans and altering microbiome as a way to lower risk of heart disease.
High-pressure extraction seems to be the best method of turning nuts into nut milk. There are nutritional benefits to both nut milks and dairy milk, fortification can help bridge the nutritional gaps in nut milks (calcium, vitamin D, vitamin A).
This study compared nutritional profiles of many frozen non-dairy desserts, including those made from macadamia nut milk.
Using macadamia nut milk as the fatty/creamy component would improve the nutritional profile of a frozen dessert. The desserts made with coconut milk were prevalent, but high in saturated fat (an unhealthy fat). By using macadamia nut milk and adding protein and fiber from legumes, these desserts can be made healthier.
Manganese - general research
Sareen S Tropper, Jack L Smith, James L Groff –“Advanced Nutrition and Metabolism of Manganese” (37)
Manganese is necessary for many enzymes to work in: building collagen and connective tissue; protein metabolism; gluconeogenesis (making glucose when our blood sugar is low); antioxidant activity (both making antioxidants like glutathione and preventing free radical formation in our cells); cellular signaling (cells communicating); and calcium metabolism
Digestion and microbiome
Cândido, Flávia Galvão, et al. “Impact of Dietary Fat on Gut Microbiota and Low-Grade Systemic Inflammation: Mechanisms and Clinical Implications on Obesity.” International Journal of Food Sciences & Nutrition, vol. 69, no. 2, Mar. 2018, pp. 125–43. (38)
Inflammation physiology
Ahmed, A.U. An overview of inflammation: mechanism and consequences. Front. Biol. 6, 274–281 (2011). (39)
Nathan, Carl et al. Nonresolving Inflammation. Cell 140, Issue 6,871-882 (40)
Glycemic index
Foster-Powell, K et al. International Tables of Glycemic Index, The American Journal of Clinical Nutrition, Volume 62, Issue 4, October 1995, 871S-890S (41)
FDA
FDA Food Labelling – Claims. (i)
FDA Reference Amounts Customarily Consumed (RACC) (ii)
FDA Qualified Health Claim Petition for Macadamia Nuts and the Risk of Coronary Heart Disease (iii)
FDA Small Entity Compliance on Structure/Function Claims (iv)
Diets rich in MUFAs and PUFAs promote a healthier gut microbiome than those rich in SFAs.
This article explains the process of inflammation in the human body.
This article explains the process and consequences of chronic inflammation and its’ role in disease.
USDA Nutritional Food Database. (vi) FoodData Central (usda.gov)
The Glycemic Index Tables
Summary of scientific reviews
Based on the review of the studies, these are the following key takeaways:
• Macadamia nuts have the highest level of monounsaturated fats (MUFAs) of all nuts in the form of Omega-9 and Omega-7. (35)
• Macadamias are a source of polyunsaturated fatty acids (PUFAs) and provide a healthy ratio of Omega-6 to Omega-3 (6:1) (13, 35, Appendix 1)
• There is robust evidence supporting macadamia nuts in the area of cardiovascular health and healthy cholesterol levels in the blood There is mounting evidence that the healthy fats in macadamia nuts also contribute to a healthy inflammatory response, improved cognitive function, and potentially a healthier gastrointestinal tract. (2, 4, 6, 7, 8, 9, 10, 14, 17)
• Nut intake, including macadamias, results in a lower rise in blood glucose than many other snack foods. The low carbohydrate and high nutrient content of macadamia nuts contribute to this benefit. A preliminary study demonstrated higher levels of palmitoleic acid in the blood correlated with better insulin sensitivity. (4, 24, vi)
• Macadamias provide long-lasting satiety without bulk, which means that a snack of macadamias will keep you full for longer without negative effects. They do not cause a spike in blood sugar, like many other snacks such as pretzels, chips, or sweets. They do not cause a rise in inflammatory markers, unlike animal-based foods (meats, cheese) (3)
• The intake of macadamias does not result in weight gain when part of a healthy diet. There are several studies that support this message overall for most tree nuts and a specific study linked to macadamia nuts. (26, 27, 28)
• The research surrounding gastrointestinal health is more nuanced. However, the healthy fats provided by macadamia nuts do seem to provide a benefit when eaten in moderation. Macadamia nuts do not provide a lot of fiber, which typically seems to be the hallmark of improvements to gastrointestinal health in related studies. However, the reduction in inflammatory markers seen with the fat profile of macadamia nuts should extend to the gastrointestinal tract as that research becomes available. (38)
• The research on palmitoleic acid (Omega-7) is limited and does not seem to demonstrate specific benefits. However, there is no published research on eating it in the form of macadamia nuts. The overall health benefits seen with macadamia nut consumption include this fat, so it is within reason to extend the health benefits to it as well. With fats, it seems the combination and ratio of individual fatty acids have more of an impact than each individual fat itself.
• Palmitoleic acid is an area of emerging research, and while it will take time to get to human trials, research is moving forward quickly. The research has increased exponentially in the past three years and is focusing on the effects of palmitoleic acid on the gut microbiome and inflammation responses. (22)
• Macadamias are an excellent source of manganese at 50% Daily Value (DV), a trace mineral that is required by over one hundred enzymes in the body. These enzymes contribute to healthy blood sugar levels, collagen and connective tissue formation, antioxidant generation, preventing free-radical formation in the body, strong bones and teeth, and healthy cell communication. (34, vi)
• Macadamias are high in lignans, which are anti-inflammatory molecules that are correlated with lower rates of cardiovascular disease, hypertension, and even some cancers. Lignans are in the polyphenol class of antioxidants. Macadamia oil has the most lignans of the nut oils and is right behind olive and grapeseed oil. This is an area to watch as consumers become more educated about lignans and their health benefits. High amounts of lignans are one reason flaxseeds are considered extremely healthy. (31)
• Macadamia oil provides healthy good fats and antioxidants The MUFA and antioxidant (tocopherols, phytosterols, squalene) content of macadamias remain stable when the oil is cold-pressed, giving it high oxidative stability. (30)
• The healthy fat profile and creamy texture of macadamias make them ideal for nondairy frozen desserts, creamers, and nut butters. These are growing categories with increasing consumer demand. There is potential for growth for product development and consumer awareness of macadamias as a better plant-based food. (32, 36)
• Macadamia oil applied topically showed improvement in skin wrinkles and moisture due to its high content of monounsaturated fatty acids and natural antioxidants. Scientific research has noted that these antioxidants can reduce inflammation and oxidative stress of the skin. Further, the oil can penetrate the skin because the components are similar to the skin’s natural oils which serves to maintain moisture and nourish the skin. Macadamia oil is safe and approved for use in health and beauty cosmetic products. (33)
• Roasting macadamia nuts enhances flavor and does not negatively impact the nutrients they contain. This makes macadamia nuts a minimally processed whole food and a healthy snack that tastes great. (1)
• The fatty acid content of macadamias is consistent among published research studies, even among different varietals (29)
Nutritional composition and comparisons
Macadamia nuts, when compared to other tree nuts, are higher in total fat and lower in protein There is a risk that this could create a false perception that they are not healthy. Further analysis of the fatty acid profile shows macadamia nuts contribute the highest amount of monounsaturated fats per serving, which is a healthy fat. Table 2 compares the per serving of nuts or snacks, based on United States Food and Drug Administration (FDA) dietary guidelines, which is a 30g or ¼ cup of the product with macadamia nuts equivalency is 1oz, 28-30g, typically 10-12 kernels per serving (i, ii, vi)
Table 2 - See Appendix 2 for full analysis
Further analysis was conducted on how the monounsaturated fats in macadamia nuts compared to other types of perceived healthy products such as peanuts, seeds, oils, avocados, dark chocolate, and cheeses (Table 3). Macadamia nuts had one of the highest contents of monounsaturated fats per 100g serving, when compared to similar foods. (vi)
Table 3 – See Appendix 4 for full analysis MONOUNSATURATED
Good fats
The sources of monounsaturated and polyunsaturated fats are another important component of understanding the health benefits associated with certain foods. The main contributors of monounsaturated fats in macadamia nuts are palmitoleic acid (Omega-7) and oleic acid (Omega-9), which are known to reduce inflammation, improve heart function through lowered low-density lipoprotein (LDL) levels, and support overall wellness. (4, 7, 8)
Table 4 shows the complete fatty acid profile per serving of macadamia nuts with an emphasis between Omega-7 & 9 (MUFA) and Omega-3 & 6 (PUFA) (vi)
Table 4
MACADAMIA NUTS – FATTY ACID PROFILE
(linoleic acid)
PUFA 18:3 (alpha-linolenic acid)
(Omega-6)
(Omega-3)
PUFA 2:5 n-3 (EPA)
PUFA 22:5 n-3 (DPA)
PUFA 22:6 n-3 (DHA)
Further, macadamias have polyunsaturated fats, including both Omega-3 and Omega-6 Their ratio of Omega-6 to Omega-3 is 6:1, considered an ideal balance for optimal health (vi) In a typical Western diet, which is high fat and processed foods, we overeat Omega-6 with an estimated ratio of 15-20:1 (13) This imbalance can result in negative health consequences Macadamias are a good source of healthy fats, with key benefits that are supported by the “healthy ratio.”
• Humans need both Omega-3 and Omega-6 fats. However, we are consuming a ratio on average of 15-20 Omega-6 fats to every one Omega-3 fat. (13)
• We need to move closer to 2-5 Omega-6 fats to every 1 Omega-3 fat
• Consuming foods with a better ratio of omega fats gives our bodies the ability to start inflammation for healing, resolve it, and finish the inflammation so it doesn’t become chronic and supports overall heart health. (39, 40)
The following Table 5 compares the amount of polyunsaturated fats and ratio found in macadamia nuts compared to other tree nuts and select foods, further highlighting macadamia nuts as a differentiator with the ideal Omega-6 to Omega-3 ratio. (vi, 39)
Table 5 – Complete product list and analysis, see Appendix 1, 2 & 3.
Table 6 compares the amount of monounsaturated and polyunsaturated fats found in macadamia oils compared to other commonly used oils. Macadamia oil has the most monosaturated fats then other oils.
Table 6 – Commonly used oil comparisons
Vitamins and minerals
Macadamia nuts contain a variety of vitamins and minerals The levels of some of those result in the ability to make a nutrient content claim. The FDA defines nutritional content claims as:
• Excellent/rich source: 20% or more of Daily Value (%DV)
• Good source 10-19% of Daily Value (%DV)
Macadamia nuts are uniquely rich in manganese, which is essential to activate specific enzymes (such as prolinase) that help produce skin cells while reducing inflammation. (37, vi) Macadamia nuts also contain copper and thiamine, which contribute a good source of minerals and vitamins. Studies have shown that these nutrients support important body functions such as making energy, maintaining the nervous and immune systems, brain development, and preventing kidney and circulation disorders (37)
FDA does not allow unqualified structure/function claims of food products, but a brand can make a nutrient content claim For macadamia nuts this can be:
• Excellent source of manganese
• Excellent source of copper
• Excellent source of thiamine
Additional references as to why these vitamins and minerals are important for our body can be added to a label without compromising regulatory restrictions.
Appendix 2 provides a full vitamin and mineral breakdown of macadamias compared to other nuts.
Health benefit insights
Inflammation
Macadamia nuts are a good source of monounsaturated fats and provide a healthy ratio of Omega-6 to Omega-3 fats (13). Both are essential fats that have been shown through scientific research to contribute to a healthy inflammatory response. Inflammation is a complex reaction in the body in response to damage or invasion. An example would be if we scrape our arm, we experience inflammation in the form of swelling, redness, heat, and pain. When our arm heals, we experience the inflammation resolving itself and returning to normal. This resolution or finishing of the inflammatory process uses Omega-3 fats and getting enough of them in our diets is essential for maintaining healthy inflammation. (39, 40)
Omega-6 fats contribute to the increase of an inflammation response. When we eat too many Omega-6 fats in relation to Omega-3 fats, some of the inflammation in our body never resolves itself, which leads to chronic inflammation (40). This chronic inflammation contributes to cardiovascular disease, diabetes, Alzheimer’s disease, arthritis, and other chronic illnesses. For this reason, we look to consuming foods with a healthy ratio of Omega-6 to Omega-3 fats to improve our inflammatory response and keep us healthy (13). Small inflammatory responses occur inside our bodies all the time and resolving them while keeping our level of inflammation low is essential for good health. (39, 40)
Saturated fats, solid at room temperature and most common in animal products, cause an increase in inflammation, which is one reason they are implicated in the development of these same chronic illnesses. Replacing the saturated fats in dairy products and meat with the MUFA and PUFA fats found in macadamia nuts improves inflammation and may reduce our risk of developing these chronic illnesses. (15, 39, 40)
The vitamins in macadamias, specifically manganese, also work to ensure a healthy inflammatory response. Manganese is necessary for many enzymes involved in antioxidant production and healthy cell signalling, which are essential for resolving chronic inflammation. (34)
Unfortunately, research is too limited in the direct relationship of inflammation to macadamia nuts to make a formal claim, but evidence focused on unsaturated fats is robust and growing. For example, one study found that monounsaturated fats reduce the production of proinflammatory cell signalling molecules, which help resolve chronic inflammation and promote complete healing. (11, 13)
Digestive and brain health
MUFA and PUFA fats, like those found in macadamia nuts, may protect our brain and cognitive function while supporting a healthy gastrointestinal tract. Diets high in total fat and saturated fat are detrimental to our gut health because they do not promote a healthy microbiome and can cause some inflammation in the cells that line our GI tract. However, it does appear that eating a moderate amount of healthy fats in an overall healthy whole-food diet, including the consumption of macadamia nuts, is good for our digestive health. (38)
The monounsaturated fats so prevalent in macadamia nuts have been shown to help protect our brains from cognitive decline and reduce our risk of developing dementia. In one study, intake of nuts in general, including macadamias, was associated with better cognitive performance. More research will be forthcoming in this area, as it is a new and exciting segment of nutrition science (17, 18, 19)
Blood sugar/insulin levels
The nutrition content of macadamia nuts, high in healthy unsaturated fats and low in simple carbohydrates, promotes a minimal rise in blood glucose, or blood sugar, after eating them. While the fiber and protein content of macadamia nuts is modest, they do contribute to this healthy blood glucose response. The anti-inflammatory healthy fats, combined with low carbohydrate and protein levels, require lower levels of insulin to be released during digestion, leading to a healthier insulin response. (4)
The glycemic index (GI) of macadamia nuts is 10 on a scale of 1-100, which is extremely low (a GI of under 55 is considered low) (41) Foods low on the glycemic index reduce the blood sugar rise of any meal or snack they are part of. This means adding macadamias to a meal or snack will reduce the total glycemic load, providing improved blood glucose control.
There is preliminary evidence that adding nuts to a carbohydrate-rich meal or snack lowers the resulting post-prandial rise in blood glucose. This is encouraging, future research should verify these results. (4)
Further, macadamia nuts contain an abundance of manganese, which is an essential mineral that has been shown to help regulate blood glucose levels. (37, vi)
Putting this all together, macadamia nuts are a healthy food for those with diabetes as well as those who want to maintain lower blood glucose levels for their overall health.
Satiety and weight loss
Satiety is the feeling of fullness, or of being satisfied (satiated). This is an area of research gaining steam in the field of weight management. Nuts, including macadamia nuts, provide long-term satiety after eating them. This means that adding macadamia nuts to a meal or snack will keep someone full for a longer period than many other foods. (3)
One of the biggest misconceptions about macadamia nuts is that their high-calorie content will lead to weight gain. Several studies refute this myth with all nuts (including macadamias), and one study with macadamias specifically. Weight management is complex and difficult for most people and physicians. Macadamias can be an ally in the fight to lose weight rather than a hindrance. Macadamia nuts are rich, satisfying, and nutritious, which can lead to a reduced desire to eat another meal or snack within a few hours. While definitive research has not been completed in this area, the theory is that eating whole, natural, nutritious foods like macadamia nuts will lead to lower calorie consumption overall. (26, 27, 28)
The bottom line is that incorporating macadamia nuts into a healthy diet will not lead to weight gain and may even help with weight loss.
Claims
Communicating the overall benefits of macadamia nuts or other food products is limited in the United States to only those qualified health claims or authorized nutrient content.
Qualified health claims
FDA identifies certain claims as Qualified Health Claims (QHCs) that are supported by scientific evidence but do not meet the more rigorous “significant scientific agreement” standard required for an authorized health claim. To ensure that these claims are not misleading, they must be accompanied by a disclaimer or other qualifying language to accurately communicate to consumers the level of scientific evidence supporting the claim. (i, v)
FDA does allow marketing of macadamia nuts as “Heart Healthy” as a QHC with the following disclaimer that must appear on the packaging associated with the claim: (iii)
Heart healthy
Supportive but not conclusive research shows that eating 1.5 ounces per day of macadamia nuts, as part of a diet low in saturated fat and cholesterol and not resulting in increased intake of saturated fat or calories may reduce the risk of coronary heart disease. See nutrition information for fat [and calorie] content.
Recommendation for further scientific research, FDA positioning, and improving the positioning of the health and wellness benefits of macadamia nuts in the marketplace to consumers is important to strengthen consumer understanding and consumption.
Food manufacturers can petition the agency to consider exercising enforcement discretion for the use of additional qualified health claims. The FDA does not “approve” qualified health claim petitions. For a QHC petition with credible scientific evidence, the FDA issues a Letter of Enforcement Discretion, including specific claim language that reflects the level of supporting scientific evidence and details of all enforcement discretion factors under which the FDA will not object to the use of the QHC (iv)
Authorized nutrient claim
A nutrient content claim is a specific claim to the amount of a nutrient or vitamin/mineral present in a serving of the product and the amount it represents based on recommended daily intakes (RDIs). For macadamia nuts, the following can be made:
• Excellent source of manganese
• Excellent source of copper
• Excellent source of thiamine
There are no RDIs specific to monounsaturated and polyunsaturated fats, but they can be expressed as 'good fats’ with qualifiers on the benefits of consuming macadamia nuts as part of a healthy diet and lifestyle based on scientific research and knowledge. (i, iv, v)
Other certified claims
Other certified claims to consider strengthening consumer support are Kosher, Vegetarian, NonGMO Project Verified, Keto, Gluten-Free, Plant-Based, Sustainably Grown, and Fair Trade.
Nutritional narrative
Role of narrative
Macadamias have excellent nutritional credentials that are highly relevant to long-term food trends. There is an opportunity to build a stronger understanding of the composition of macadamias and related benefits with current and future consumers.
Consumers are inundated with nutritional messaging across various food categories. The most effective categories differentiate themselves using simple, believable, scientifically backed positioning that connects with consumer needs. They usually use only one to four core messages, which are repeated often.
The nutritional narrative for macadamias intends to inform consistent messaging around why macadamias are healthy. The narrative is at the convergence of consumer trends, science, and the attributes that are ownable by macadamias. Macadamia brand owners, processors, communicators, and the wider industry are encouraged to use the core narrative, as consistency and repetition are key to changing consumer behaviour.
Core narrative
The following summarises the key points supporting each area of the narrative. In addition, there are some online statements that are supported by sound science and could be used effectively in marketing materials (but not on packaging).
Good fats
Macadamia nuts contain a variety of good fats that support a healthy diet. They have the highest level of monounsaturated fats (MUFAs) of all nuts in the form of Omega-9 and Omega-7 (vi) Omega-9 is known to reduce inflammation, improve heart function through lowering of ‘bad cholesterol’ levels, and support overall wellness (8, 9, 10) Emerging research on the rarer Omega-7 shows correlations with lower blood sugar levels and healthier insulin responses (24). Macadamias have polyunsaturated fatty acids (PUFAs) in the form of Omega-3 and Omega-6 and humans need both, however we typically overconsume Omega-6. The ratio of 6:1 (Omega-6:Omega-3) found in macadamias is an excellent balance for optimal health. (13, 14, 39, 40, vi)
• Macadamia nuts can be included in a heart-healthy diet, due to cholesterol lowering effects. (6)
• Macadamia nuts can substitute for foods higher in saturated fats and increase satiety. A satisfying, portable snack that keeps you full between meals. (3, 27, 28)
• Macadamia nuts have the highest level of monounsaturated fats (MUFAs) of all nuts in the form of Omega-9 and Omega-7. (vi)
• Macadamia nuts are a source of polyunsaturated fatty acids (PUFAs) and provide a healthy ratio of Omega-6 to Omega-3 (6:1) (vi)
• We need good fats in our diet to remain healthy. Macadamia nuts provide healthy fats to meet these needs and promote our overall best health. (2, 6, 7)
• Macadamia nuts are high in healthy fats. (vi)
• Healthy boost of monounsaturated fats and less of the bad fats. (vi)
• Packed with monounsaturated fatty acids, making them a healthy source of fat. (vi, 8)
• Whole-food source of healthy fats. (vi)
• Macadamia nuts are great for heart health – fats matter now and into your future (2, 6, 8, 10)
• The healthy fat content of macadamias makes them an excellent option for nut butter, nut oil, non-dairy frozen desserts, and potential innovative uses. (32, 36)
• Macadamias have healthy fats similar to avocados, salmon, and extra virgin olive oil (vi)
• Macadamias have more Omega-3s than most fish. (vi)
Low in carbs
Macadamia nuts are low in carbohydrates, and combined with high levels of unsaturated fats, present an ideal snacking option for those aiming to maintain lower blood sugar levels. There is only a minimal spike in blood glucose levels post-consumption (41) Encouragingly, preliminary evidence suggests that incorporating macadamia nuts into a carbohydrate-rich meal or snack can lead to a reduced rise in blood glucose levels shortly after consumption, this is particularly relevant to consumers following a LCHF (low-carb, high-fat) diet or managing diabetes (4) Increased use of personal continuous glucose monitors has elevated the conversation around blood sugar management.
• Adding macadamias to a meal helps keep blood sugar stable. (4)
• Nut intake, including macadamias, causes a smaller rise in blood glucose and a healthier insulin response than other snacks. (4, 28)
• Higher levels of palmitoleic acid in the blood were correlated with better insulin sensitivity Macadamias contain a unique amount of this acid compared to other nuts (24, vi)
Nature’s real food
Consumers are increasingly seeking nutrient-dense ‘real foods’ which are not highly processed. The good fats in macadamias contribute to nutrient density together with vitamins, minerals, antioxidants, and phytonutrients (vi). Macadamias are uniquely rich in the mineral manganese, essential for skin cell development and resolving inflammation (37). Healthy fats also enable the absorption of fat-soluble vitamins. Macadamias are a direct-fromnature whole food that offers exceptional nutritional benefits relative to their calorie content. (vi)
• Macadamias are an excellent source of manganese. This nutrient is essential for healthy blood sugar levels, building collagen, antioxidant activity, preventing free radical formation inside our bodies, cell signalling, and healthy bones and teeth. (vi, 37)
• One serving of macadamia nuts also contains dietary fiber, protein, thiamine, and copper. (vi)
• Macadamia nut intake does not result in weight gain when consumed as part of a healthy diet. (27)
• Nut intake, including macadamias, causes a smaller rise in blood glucose and a healthier insulin response than other snacks. (4)
• Macadamia nuts are as healthy as all other nuts regarding cardiovascular health, lowered cholesterol, and low rises in blood sugar. (6, 29)
• Macadamias are a source of plant sterols (which may lower cholesterol in the blood) and polyphenols (antioxidants). (2, vi)
• Macadamia nuts have the fighting power of polyphenols and flavonoids (vi). Flavonoidrich foods are essentially superfoods.
• Roasting improves the taste and texture of macadamia nuts and does not diminish nutritional quality. Roasted macadamia nuts are just as nutritious as raw ones (1)
• The heavy metal content of macadamias is within safe limits, just like other nuts. Note: more research is needed, and it is likely not a good claim until further testing and understanding are evaluated.
• The overall fatty acid and antioxidant content of macadamias remained consistent even though some small differences occurred when they were grown in different regions. (29)
Inflammation
Inflammation is a significant health concern. It is a complex immune system reaction in the body in response to damage or invasion, and excess inflammation can cause chronic diseases. Too much added sugar contributes to inflammation, along with an excess of saturated fats found in meat and dairy (39, 40) Macadamia nuts help to reduce inflammation through the presence of good fats, a favorable ratio of Omega-3 and Omega6, along with vitamins, minerals, and phytonutrients. The consumption of macadamias may help address inflammation related issues, such as digestive, brain, and heart health. (14, 40)
• The fats in macadamia nuts may help fight inflammation and reduce cellular damage. (14)
• Increasing consumption of monounsaturated fats can benefit digestion and overall gut health. Macadamia nuts are an important source of monounsaturated fats because they offer the ideal ratio of Omega-6 to Omega-3. (38, vi)
• Increasing the consumption of monounsaturated fats and lowering saturated fats can help support our brain and cognitive function. (17)
• The fatty acid content of macadamia nuts, especially the oleic acid, showed antiinflammatory effects in cells. (38)
• Macadamia nuts have anti-inflammatory fats similar to those found in salmon and avocados. (vi)
Macadamia nut oil
Additional benefits of macadamia oil:
• Cold-pressing macadamia oil is a healthy method of oil extraction that maintains the nutrient benefits of macadamias in this form. (29)
• Macadamia nut oil has a high level of lignans, which are health-promoting antiinflammatory compounds that act somewhat like fiber. (31)
• Macadamia nut oil has a smoke point of 410°F(210°C), making it ideal for high-heat cooking methods like frying, sautéing, and baking Macadamia oil is a good replacement for less healthy oils. (vi)
This work has been undertaken for the United States and is in alignment with U S regulations. In other countries other claims or benefit areas may have more relevance or validity.
ii. FDA Reference Amounts Customarily Consumed (RACC) https://www.fda.gov/media/102587/download
iii. FDA Qualified Health Claim Petition for Macadamia Nuts and the Risk of Coronary Heart Disease https://www.fda.gov/food/cfsan-constituent-updates/fda-completes-review-qualifiedhealth-claim-petition-macadamia-nuts-and-risk-coronary-heart-disease
iv. FDA Small Entity Compliance on Structure/Function Claims https://www.fda.gov/regulatory-information/search-fda-guidance-documents/smallentity-compliance-guide-structurefunction-claims
v. Food Labelling: Nutrient Content Claims
Nutrient Content Claims | FDA
vi. USDA Nutritional Food Database FoodData Central (usda.gov)
1. Fats comparison of various foods/oils, per 100g
2. Macadamia nuts and tree nuts nutritional values, serving size 1oz (28.35g)
3. Monounsaturated fats and polyunsaturated fats
4. 2023 revised scientific studies summary (separate document upon request)
5. Nutritional summary
6. Consumer claims and statements
Appendix 1 – Fat comparison of various foods/oils, per 100g
NUTRITIONAL ANALYSIS based on USDA Food Data Central Database and FDA RDIs
