The macadamia nut is a rich, buttery tree nut native to the rainforests of eastern Australia. It has the highest fat content of any edible nut, with about 75% of its calories coming from fat, the vast majority of which is the heart-healthy monounsaturated type. Prized for its creamy texture and mild, sweet flavor, it’s now grown commercially across tropical and subtropical regions worldwide.
Where Macadamia Nuts Come From
Macadamia trees are part of the Proteaceae family and originated in the rainforests of northeastern New South Wales and southeastern Queensland, Australia. Of the four recognized species, only two produce edible nuts: Macadamia integrifolia and Macadamia tetraphylla. These two species crossbreed freely, and most commercial orchards today grow hybrids and cultivars bred for larger kernels and higher yields.
Though the tree is Australian, Hawaii became the first place to grow macadamias at commercial scale in the early 20th century. Today, South Africa is the world’s leading producer and exporter. In 2024, South Africa accounted for 42% of global in-shell exports and 47% of shelled exports, followed by Australia (24% in-shell), Kenya (15%), and Zimbabwe (8%). The United States, mostly Hawaii, contributed just 3% of in-shell exports.
Nutrition in a One-Ounce Serving
A one-ounce serving (about 10 to 12 nuts) contains roughly 200 calories, 22 grams of total fat, 2 grams of protein, and 2 grams of fiber. That fat content sounds high, but the composition is what matters: 82% of the fat in macadamia nuts is monounsaturated, with very little polyunsaturated fat and 12 to 18% saturated fat. No other edible nut comes close to that monounsaturated ratio.
Beyond the macronutrients, macadamias are a standout source of manganese, delivering 51% of the daily value in a single ounce. Manganese supports bone health and helps your body process carbohydrates and cholesterol. They also supply a solid dose of thiamine (vitamin B1), with 0.34 milligrams per ounce, which plays a central role in converting food into energy.
What Makes the Fat Profile Unusual
Macadamia nuts contain an uncommon fatty acid called palmitoleic acid, sometimes labeled omega-7. Most edible nuts and oilseeds contain less than 6% of this fat. Macadamias contain 15 to 22%, making them one of the richest dietary sources available. Palmitoleic acid has drawn attention for its potential to improve insulin sensitivity and reduce the risk of type 2 diabetes, though research is still building on how much you’d need to eat for a meaningful effect.
Effects on Cholesterol and Heart Health
The high monounsaturated fat content translates into measurable cardiovascular benefits. In a clinical trial, men with high cholesterol who ate 40 to 90 grams of macadamia nuts daily (roughly 1.5 to 3 ounces) for four weeks saw their total cholesterol drop by 3% and their LDL (“bad”) cholesterol drop by 5.3%. Their HDL (“good”) cholesterol rose by 7.9%. These improvements happened despite the overall diet being high in fat, reinforcing that the type of fat matters more than the amount.
This pattern is consistent with what researchers see in studies of other monounsaturated-fat-rich foods like olive oil and avocados. The practical takeaway: replacing snacks high in saturated fat or refined carbohydrates with a handful of macadamias can shift your cholesterol numbers in a favorable direction.
How They’re Harvested and Processed
Macadamia nuts have an exceptionally hard shell, one of the toughest of any commercial nut. The process from tree to table involves several steps that explain why these nuts tend to cost more than almonds or cashews.
After the nuts fall from the tree (they’re typically not picked), the outer green husk is removed immediately. The nuts then air-dry in their shells for two to three weeks, spread no more than two layers deep with good air circulation. This loosens the kernel from the inner shell. A final drying step at controlled low temperatures, starting around 100°F and gradually increasing to 140°F over a couple of days, brings the moisture content down enough for long-term storage and that signature crisp, buttery snap when you bite into one.
Cracking the shell itself requires specialized equipment. The shells are so dense that a standard nutcracker won’t do the job, which is why macadamias are almost always sold pre-shelled.
Common Uses in Cooking
Raw macadamias have a mild, slightly sweet, creamy flavor that works in both savory and sweet dishes. They’re a staple in white chocolate macadamia cookies, but they also blend into dairy-free milk, pesto, and crusts for fish. Roasting deepens their flavor and adds crunch. Macadamia oil, pressed from the nut, has a high smoke point and a clean, neutral taste that makes it useful for sautéing and salad dressings.
Because of their high fat content and relatively low protein, macadamias also blend into an especially smooth nut butter without needing added oils.
Toxic to Dogs
Macadamia nuts are one of the few foods that are perfectly safe for humans but genuinely toxic to dogs. The exact compound responsible hasn’t been identified, but the effects are well documented. Dogs that eat macadamias can develop weakness (particularly in the hind legs), vomiting, tremors, fever, and difficulty standing. In experimental studies, dogs given 20 grams per kilogram of body weight developed these symptoms within 12 hours, with rectal temperatures reaching 104.9°F.
The average toxic dose reported across veterinary cases was about 11.7 grams per kilogram. For a 30-pound dog, that’s roughly 5 to 6 ounces of nuts. Most dogs recover within 24 to 48 hours without lasting damage, but the symptoms can be alarming. If your dog gets into a bag of macadamias, contact your vet or an animal poison control line.