Why Macadamias, Pecans and Walnuts Should Be on Your Shopping List

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  • Because macadamia nuts and pecans have high fat and low protein and carb levels, they are superior choices, particularly if you eat a ketogenic diet
  • Walnuts, despite having a slightly higher protein and carb content, are also an excellent choice mainly because new research suggests eating them may reduce your risk of Type 2 diabetes
  • You may not realize most nuts labeled as roasted have actually been fried in vegetable oil, often at high temperatures, putting you at risk of exposure to acrylamide, a possible carcinogen
  • For best results, always buy organic, raw nuts and soak them for eight to 12 hours before eating them to break down the plant compounds that otherwise make them hard to digest; macadamias are an exception and do not require soaking
  • If you eat nuts often, you should be mindful of the protein content, especially since most Americans overeat protein, which can be hazardous to your health

By Dr. Mercola

While many consider nuts to be nothing more than a snack food, there are several healthy reasons you should considering eating certain nuts a little more often. Three tree nuts I highly recommend are macadamias, pecans and walnuts. Because macadamias and pecans have high fat and low protein and carb levels, they are superior choices, particularly if you eat a ketogenic diet.

Walnuts, while slightly less ideal than macadamia and pecans due to their higher protein and carb content, are also an excellent choice mainly because new research suggests eating them may reduce your risk of Type 2 diabetes. Before you add macadamias, pecans and walnuts to your shopping list, let’s take a closer look at the composition of each one and find out what makes them a healthy choice.

Why Macadamia Nuts Are Beneficial

Macadamias, which are among my personal favorite nuts, have the highest fat content and lowest protein and carbohydrate levels of any nut. If you eat a ketogenic diet, you probably already know macadamia nuts are a nutritional powerhouse. Macadamias are helpful to keto fans because they are loaded with healthy fat.

A 1-ounce serving — 28 grams (g) or about 10 to 12 nuts — contains 21 g of fat, 2 g of protein and 4 g of carbs. In addition, raw macadamia nuts contain high amounts of B vitamins, magnesium, manganese, phosphorus and potassium. Just one serving of macadamias provides 58 percent of your dietary requirement for manganese and 23 percent of the recommended daily value of vitamin B1.1

Moreover, about 60 percent of the fatty acid in macadamias is the monounsaturated fatty acid (MUFA) oleic acid. Olives are well-known for containing healthy amounts of oleic acid and macadamia nuts have about the same level of oleic acid found in olives. Below are more reasons to love macadamia nuts:2

Due to the rich stores of MUFAs found in them, similar to other tree nuts, macadamias offer cardioprotective properties. Macadamia nuts have been shown to optimize your total and low-density lipoprotein (LDL) cholesterol, apolipoprotein B (ApoB) and triglycerides.3

Macadamias contain flavonoids known to help prevent cell damage and protect your body from environmental toxins. Once ingested, these flavonoids are converted into antioxidants, which destroy free radicals and protect you from diseases such as cancer.

The high fat content of macadamia nuts can act as an appetite suppressant. This means a small handful of them will satisfy you longer than a calorie-comparable sugary snack.

As an excellent source of protein, raw macadamia nuts are also low in sodium with a satisfying crunch. They’re a healthier snack than processed salty snack foods.

A serving of 10 to 12 macadamia nuts contains 2.4 g of dietary fiber, which represents about 10 percent of your daily fiber requirement. As such, macadamia nuts promote healthy digestion and gut health.

Magnesium and phosphorus, as well as calcium, all of which are available in macadamias, are useful to support bone and teeth mineralization and the absorption and transportation of vital nutrients.

Compared to other tree nuts, macadamias boast the best omega-3 to omega-6 ratio and are therefore a healthier choice — especially if you are trying to avoid inflammation.

Why Pecans Are a Healthy Choice

Pecans, another of my favorite nuts, have the second highest fat content and second lowest protein and carb content among tree nuts. Along with macadamias, raw pecans can be a beneficial food source if you eat a ketogenic diet. A 1-ounce serving — 28 g or about 19 halves — contains 21 g of fat, 3 g of protein and 4 g or carbs. In addition, raw pecans contain good amounts of vitamin E and B vitamins, particularly thiamin (B1).

In terms of minerals, a 1-ounce serving provides 64 percent of your daily value for manganese, 17 percent of your copper needs and 9 percent of your daily needs for both magnesium and zinc.4 The nearly 3 g of fiber a serving that pecans provide help keep your digestive system well-regulated. Below are additional benefits to eating raw pecans:5

Pecans contain antioxidant power due to the presence of vitamin E and phytochemicals like lutein and zeaxanthin, which neutralize free radicals and protect your body from infections and diseases, including cancer.

Another phytochemical contributing to the antioxidant activity of pecans is ellagic acid, which helps prevent carcinogenic compounds from binding to your DNA and proliferating.

Pecans are packed with fatty acids like oleic acid, which is great for weight control.

The plant sterols in pecans offer cholesterol-optimizing properties.

The high amount of thiamin in pecans helps your cells convert carbs into energy and also supports your heart, muscle and nervous system functions.

The magnesium in pecans reduces the presence of C-reactive protein and interleukin-6 and protects against widespread inflammation within your body.

Why Walnuts Are Good for You

If you routinely eat nuts but overlook walnuts, you may be missing out. While they contain a little less fat and a little more protein than macadamias and pecans, walnuts are a healthy nut. A 1-ounce serving — 28 g or about 14 halves — contains 18 g of fat, 4 g of protein and 4 g of carbs. Walnuts also contain nearly 2 g of fiber, as well as vitamins B, C and E. In terms of minerals, a 1-ounce serving provides rich stores of magnesium, phosphorus and potassium. Furthermore, walnuts have the following impressive health benefits:6

A diet rich in walnuts and other nuts has been shown to play a role in supporting heart health,7,8 mainly due to the amino acid l-arginine.

Approximately 90 percent of the phenols — including flavonoids, phenolic acids and tannins — found in walnuts reside in its skin.

Eating a handful of walnuts daily is said to reduce blood pressure and lower your risk of cardiovascular disease. Walnuts have also been shown to slow tumor growth in animals.9,10

If you are a man eating a Western-style diet, studies suggest consuming higher levels of polyunsaturated fatty acids (PUFAs), which are found in walnuts, may increase your sperm quality.11

Consuming walnuts is thought to improve your brain function and cognition.12

Walnut intake has been shown to increase levels of three beneficial gut bacteria — Clostridium, Faecalibacterium and Roseburia — which produce a metabolic byproduct called butyrate that is believed to improve your colon health.13,14

“Walnuts have been called a ‘superfood’ because they are rich in omega-3 fatty acid, alpha-linolenic acid and fiber and they contain one of the highest concentrations of antioxidants,” states registered dietitian Lauri Byerley, research associate professor of physiology at Louisiana State University. “[A]n additional superfood benefit of walnuts may be their beneficial changes to your gut microbiota.”15

Consuming Walnuts May Lower Your Risk of Type 2 Diabetes

An epidemiological study published in the journal Diabetes/Metabolism Research and Reviews, involving 34,000 American adults, suggests consuming walnuts may slash your risk of developing Type 2 diabetes in half, as compared to people who do not eat nuts.16

The research, conducted at the University of California, Los Angeles (UCLA) in 2018, suggests eating 3 tablespoons, or 42.5 g, of walnuts per day is associated with a 47 percent lower prevalence of Type 2 diabetes. The data was extracted from the National Health and Nutrition Examination Survey (NHANES) and centered on adults aged 18 to 85 years.

Study participants were asked about their diets and assessed for diabetes using common laboratory measurements such as fasting plasma glucose and hemoglobin A1c.

"These findings provide more evidence for food-based guidance to help reduce the risk for diabetes," said Lenore Arab, nutritional epidemiologist and adjunct professor in UCLA’s School of Medicine. "The strong connection we see in this study between walnut consumers and the lower prevalence of Type 2 diabetes is additional justification for including walnuts in the diet."17

The walnut intake proposed to slash your diabetes risk by half is close to the recommended serving size of walnuts, which is 4 tablespoons (56.7 g). The data suggests the effect of walnut consumption on diabetes may be more potent among women than men. While this study sounds like really great news, especially if you love to eat nuts, it’s important to make note of two important limitations related to the research:18

  • Participants were asked about their dietary choices over the course of just one to two days, which may or may not represent their usual pattern of walnut consumption
  • Given the cross-sectional nature of the study, the findings do not prove eating walnuts directly causes you to be at less risk of diabetes

Although Nuts Are Healthy, Watch the Protein Content and Don’t Eat too Many

Most nuts, including macadamias, pecans and walnuts, should be eaten in moderation. While you may think the reason to moderate your consumption has to do with the high fat content, remember the kind of fat available in these nuts is the healthy type your body and brain need to thrive. The bigger concern I have about some nuts is their high protein content.

Because nuts are generally considered to be a snack food, you may not think to count the protein from them as part of your total daily intake. Even if you don’t eat nuts, most Americans consume three to five times more protein than they need. Eating too much protein can elevate your blood sugar, cause weight gain, stress your kidneys, leach bone minerals and stimulate cancer cells. For those reasons, it’s critical you keep track of how much protein you are eating and factor in protein from nuts.

If you develop a habit of eating nuts absent-mindedly by the handful, you can easily surpass your daily target for protein consumption. For optimal health, you’ll want to limit your protein intake to around 0.5 grams of protein per pound of lean body mass. For most people that comes out in the range of 40 to 70 grams a day. For example, a person weighing 160 pounds, with 128 pounds of lean body mass, should eat about 64 g of protein a day.

Why It's Important to Choose Organic Nuts

When choosing nuts, look for high-quality nuts that are certified organic and presented in raw form. Avoid roasted or pasteurized nuts, as well as nuts coated in sugar or covered in milk chocolate. Contrary to what you may think, only dry-roasted nuts are truly roasted. Most nuts labeled and sold as roasted are actually fried in vegetable oil. You can tell this because the ingredient label will identify the type of oil used for frying. This practice is ill-advised for a few reasons:

  1. Most vegetable oils are unhealthy and contain an overabundance of omega-6 fats. In addition, some vegetable oils used to fry nuts, such as canola oil, are genetically engineered (GE).
  2. Roasting raises the potential for the formation of a possible carcinogen called acrylamide, which results from a chemical reaction between sugars in certain foods and an amino acid called asparagine. Acrylamide, which is best known as the “browning” on chips and french fries, has the potential to form on certain nuts when they are fried or roasted at temperatures above 250 degrees F (121 degrees C) for long cooking times.19
  3. Vegetable oils heated to high temperatures can easily oxidize, promoting the formation of disease-causing free radicals. Nuts that oxidize can also become rancid and attract fungal mycotoxins. You can identify rancid nuts by a musty, stale or spoiled smell.
  4. Nuts roasted at high temperatures may contain lower amounts of antioxidants, vitamins and other nutrients. In addition, the healthy fats in some nuts may be damaged by high heat.

For Best Results, Buy Raw Nuts and Soak Them Before You Eat Them

Your healthiest option is to consume nuts raw. That said, it’s important to note how difficult it can be to find truly raw nuts in the U.S. For instance, pasteurized almonds sold in North America can still be labeled "raw" even though they've been blanched, steam processed or otherwise treated. While you may not be able to verify if nuts labeled raw are truly raw, seek out reputable sources and do the best you can. I also recommend you soak your nuts — for about eight to 12 hours — before you eat them to reduce their phytic acid content.

Phytic acid, found in the coatings of nuts (and seeds), is an "antinutrient" responsible for leeching vital nutrients from your body. By soaking nuts, you help rid them of phytic acid and also loosen up the enzyme coat, which can be removed from nuts like almonds. (Given their negligible amounts of enzyme inhibitors, macadamias and other white nuts do not need to be soaked.) As natural inhibitors, the enzyme coats help protect nuts as they develop and also prevent them from sprouting prematurely.

Although the coatings are beneficial to the nuts themselves, the antinutrients found in them may interfere with your body’s own digestive and metabolic enzymes, thereby making nuts harder to digest. When nuts are soaked, the germination process begins, allowing the enzyme inhibitors to be deactivated, making nuts much easier to digest. Given their superior nutrition, health benefits and convenience, I hope you will consider adding macadamias, pecans and walnuts to your shopping list this week.