Nuts may just be some of nature's perfect foods. Rich in vitamins and minerals, low in carbohydrates, and high in fiber, protein, and polyunsaturated fats, nuts—eaten in moderation—are an undeniably healthy addition to any diet. Let's take a look at some of the different types of nuts and how they promote better health.
Almonds are the edible seeds of the almond tree and, among all nuts, have the highest calcium content. Native to the Middle East, almonds are low in carbs, but high in fiber, vitamin E, and magnesium; and rich in healthy fats, antioxidants, and vitamins. The health benefits almonds offer include reduced cholesterol, and reduced risks of both heart disease and diabetes.
In patients with diabetes, who are often magnesium deficient, almonds—with their high magnesium content—can help correct this deficiency, which in turn helps lower blood sugar levels and improve insulin function. This was true even in healthy adults. Correcting magnesium deficiency can also bring about significant blood pressure reductions.
Antioxidants also abound in these wonderful nuts, and are found primarily in their brown skin. Researchers have found that eating almonds with a main meal can reduce some of the markers of oxidative damage, as well as decrease postprandial glycemia and insulinemia.
Almonds also contain a lot of phosphorus, which helps maintain bone strength and prevents conditions such as osteoporosis. Finally, these wonderous nuts can also lower LDL cholesterol levels, and thereby reduce the risks of heart disease.
Cashews come from the cashew tree, a tropical evergreen native to northeastern Brazil. These nuts contain high levels of iron, magnesium, zinc, copper, phosphorus, and manganese. They are a good source of monounsaturated fatty acids that can reduce triglyceride levels and promote healthy levels of HDL cholesterol. Like olive oil, cashews contain oleic acid, an unsaturated fat. Rich in copper, cashews can also help prevent cancer, promote good heart health, strong bones, and healthy skin.
Walnuts are produced by any tree of the Juglans genus. They are not considered true botanical nuts because, technically, they are the seeds of a drupe, or stone fruit. Nevertheless, walnuts are high in omega-3 fatty acids, antioxidants, and phytosterols. Phytosterols are structurally similar to cholesterol, and compete with it for absorption.
In a recent analysis of data from the National Health and Nutrition Examination Survey (NHANES), researchers found that eating walnuts was associated with a lower prevalence and frequency of the symptoms of depression. Compared with people who didn't consume nuts, those who ate walnuts had a 26% lower depression score (other nuts reduced these scores by 8% as well).
The fatty-acid profile of walnuts is different than that of other tree nuts because it contains primarily polyunsaturated fats, including a significant amount of omega-3 alpha-linolenic acid—more than any other nut. Walnuts promote good heart health and can reduce depression and the risk of age-related diseases, including Alzheimer's disease.
Brazil nuts come from Brazil nut trees, which are native to the Guianas, Venezuela, Brazil, eastern Colombia, eastern Peru, and eastern Bolivia. These nuts have an almost creamy taste, and are rich in selenium, a mineral that plays a role as an antioxidant and can even help with other bodily functions. Better kidney health, better immune and thyroid function, and increased blood flow and sperm motility are all benefits of selenium.
Macadamia nuts are native to Australia. With a rich, buttery flavor, these nuts provide high levels of flavonoids, which are converted into antioxidants that can help fight the cellular damage caused by oxidative stress. Like almonds, macadamia nuts help fight inflammation and improve heart health.
Pecans come from pecan trees, a type of hickory tree native to northern Mexico and the southern United States. Of all the nuts, pecans are possibly the sweetest, and are loaded with manganese, which not only supports bone health but may help ease the symptoms of premenstrual syndrome (PMS). Manganese can reduce mood swings and cramps, and does this best when taken with calcium.
Like most nuts, pecans also contain polyphenols, which act like antioxidants. Another pecan-plus: they contain beta-sitosterol, which can help with enlarged prostates.
Hazelnuts are the nuts of the hazel tree, which are widespread throughout North America, Europe, and Asia. These nuts, also called filberts, have been shown to increase levels of serum vitamin E, which plays a vital role in maintaining healthy skin, hair, and nails, and can also protect against cognitive decline. Hazelnuts are rich in unsaturated fats, high in magnesium, calcium, and vitamins B and E. Thus, they promote good heart health, may reduce the risk of cancer, and help with muscle, skin, bone, joint, and digestive health.
Hazelnuts also contain thiamine, crucial to both nerve function and cognitive function. Finally, hazelnuts contain folate, which can help prenatal spine and brain development.
Fun fact: Peanuts are not nuts, but legumes. They are harvested from the peanut plant, which flowers above the ground, with the peanuts growing below it. Native to tropical South America, peanuts are similar in taste and nutritional profile to tree nuts, and are usually served in similar ways to walnuts and almonds in Western cuisine. Compared with nuts, peanuts contain a higher amount of folate, which is vital to proper brain development. Because of this, increased folate intake can help reduce the risk of birth defects. Peanuts can also boost memory, as well as decrease depression and the risk of heart disease.