Here's which nuts boost your health the most

Experts say that certain nuts offer surprising advantages—including a lower risk of cancer, better cognitive function, and even a longer life.

While most people know that nuts contain vitamins and minerals, you may not realize just how many health benefits are associated with the salty snack.

Some of the advantages that can come from eating nuts include reduced cancer risk, stronger bones, and, because they keep blood sugar levels in check, a lower risk of getting diabetes. One study shows that eating just an ounce of nuts daily comes with a staggering 21 percent decline in cardiovascular disease risk.

Perhaps most surprising of all, considering their high-calorie content, nuts eaten in moderation don't promote weight gain—a contradiction of common dietary guidelines from the 1990s.

In fact, "diets that include regular intake of nuts are actually related to weight loss," says Deirdre Tobias, an obesity and nutritional epidemiologist at Harvard Medical School. That’s because the fat, fiber, and protein in nuts help with feelings of fullness, curb hunger pangs, and aid in gut health. Additionally, it’s been found that there are at least 20 percent fewer calories than expected in nuts such as almonds and walnuts because some of those calories are excreted in stool.

(Beans are also nutrient-dense. Here's how they stack up nutritionally.)

The list of nut-consumption benefits further extends to lower blood pressure, improved cognitive function, reduced cholesterol levels, and even living longer. "If you are looking to improve the quality of your diet, I highly recommend eating more nuts," says Katherine Zeratsky, a registered dietician nutritionist at Mayo Clinic.

At the same time, not all nuts provide equal benefits—and no nut should be consumed excessively. "Even though the calories may be less than the amount on the package, a small handful of nuts is still loaded with calories," says Jill Weisenberger, a Virginia-based registered dietician and author of “Prediabetes: A Complete Guide.”

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Here are some of the top nuts to include in your diet—plus a few of the unique benefits that each provides.

Almonds rank near the top of just about every nutritional scientist's list when it comes to nuts that offer great health advantages. For one, Tobias says they contain more fiber than any other nut—a whopping 17.9 grams in a single cup. Fiber can lower your risk of cancer and type 2 diabetes and aid in weight control.

(How your fiber intake affects your colon cancer risk.)

Almonds are also rich in vitamin E, "which promotes skin health, a strong immune system, and supports vascular function," says Amy Goodson, a nutritionist and registered dietitian based in Dallas. And a cup of almonds contains 386 milligrams of magnesium, "which is critical for muscle function," she adds.

Studies show that almonds also help lower LDL or “bad” cholesterol levels because their skins are rich in polyphenol antioxidants—which can help prevent cholesterol oxidation. "Almonds also contain lots of calcium and phosphorus, which have been linked to improved bone health," says Jen Messer, a registered dietitian and president of the New Hampshire Academy of Nutrition and Dietetics.

Pistachios are another excellent tree nut because they contain lots of potassium—1,250 milligrams in a single cup—which helps with brain function and muscle control. This is especially useful because "potassium is a nutrient that's low in many people's diets," says Zeratsky.

Pistachios are also rich sources of lutein and zeaxanthin, which "protect our eyes from light damage and our brains from cognitive decline," says Weisenberger. And pistachios are considered a complete protein, "since they have been found to contain all nine essential amino acids," says Messer.

(Some vitamins and minerals simply work better when eaten together.)

The nut is a great source of vitamins B6 and B1 (thiamine) as well, says Kristina Cooke, a registered dietitian with the Academy of Nutrition and Dietetics. These are useful in boosting immune health, preventing the blood disorder anemia, and reducing nausea during pregnancy.

"Pistachios also have one of the lowest calorie counts among nuts, making them great for snacking," says Goodson.

Brazil nuts are unique because they contain the highest amount of selenium per ounce than any other food source. Selenium is a nutrient that helps with healthy thyroid function and boosts white blood cells—cells that improve the body's ability to fight off illness and infection.

But eating too many can be a problem as the tolerable upper limit for selenium is only about 400 micrograms, and each nut contains about 95 micrograms. "It's probably best to limit consumption of Brazil nuts to no more than three a day," suggests Messer.

Brazil nuts are also associated with lower LDL cholesterol levels and are an especially good source of prebiotic fiber. "This helps them support brain function and promote gut health," says Kate Donelan, a registered dietician with Stanford Health Care. And they contain lots of iron—an essential mineral that supports growth and development and is vital in transporting the protein hemoglobin from the lungs to the rest of the body.

Though technically a legume, peanuts are often treated as nuts in culinary terms, “because they have a nutrient profile that’s similar to tree nuts," says Goodson.

Being in the same family as beans offers some advantages over nuts though because, like beans, peanuts are especially high in protein and folate—higher than any nuts, says Zeratsky. Protein is essential for muscle growth and tissue repair, and folate is critical for healthy fetal development in pregnant mothers.

(How much protein do you actually need? Consider these factors.)

Tobias says that peanuts also contain more niacin than any nut—a whopping 17 milligrams in a single cup. Niacin is a B vitamin that supports your nervous and digestive systems and has been associated with reduced arthritis pain. Goodson says their higher-fiber content means peanuts can also reduce your risk of developing gallstones.

What's more, one ounce of peanuts contains 2.2 milligrams of vitamin E—15 percent of the recommended daily intake. This "antioxidant nutrient," Weisenberger notes, can help prevent blood clotting and can protect cells from damage caused by free radicals.

The last nut on this list might be the best one for you. "Because they boost both brain health and heart health, walnuts are a nutritional powerhouse," says Messer.

Although most nuts have similar compositions of healthy fats and plenty of vitamins and minerals, "walnuts are noteworthy because they also provide a bonus of omega-3 fatty acids," says Walter Willett, a professor of epidemiology and nutrition at Harvard T. H. Chan School of Public Health.

Omega-3s offer numerous health benefits including boosting one's mood, reducing symptoms associated with ADHD, and improving eye, skin, and joint health. Omega-3s are also associated with lower triglycerides, reduced inflammation, and improved blood pressure—making them critical for lowering heart disease risk.

"Walnuts also have a phenolic compound called ellagic acid that could help protect against colon cancer," adds Weisenberger. And Tobias says they have the highest amounts of polyunsaturated fatty acids of any other nut—which can improve cognitive deficits and provide more energy.

Eating these nuts can also support a healthy microbiome "by promoting beneficial gut bacteria," adds Goodson. And their high levels of the hormone melatonin mean walnuts are also able to "slow the aging process and promote a restful sleep," says Cooke.

As great as each nut is individually, a broader range or collective benefits might come from opting for mixed nut assortments. "Eating a variety of nuts,” says Donelan, “can be a simple yet powerful way to protect your heart, improve your brain function, and lower your risk of chronic diseases.”