Nuts are an antioxidant powerhouse.

Antioxidants help control free radicals, which are unstable molecules produced as a normal part of metabolism. Free radical production increases in response to heavy sun exposure, stress, pollution and other causes.

Although free radicals can play a beneficial role in immune response, having too many can lead to cell damage. When your level of free radicals is too high, your body is said to be in a state of oxidative stress, which increases disease risk (3).

The antioxidants in plant foods, including the polyphenols found in nuts, can combat oxidative stress by neutralizing free radicals so they can’t harm your cells.

The ORAC is a test that measures a food’s capacity to fight free radicals. One study found that the ORAC of walnuts was greater than that of fish (4).

Research has shown that the antioxidants in walnuts and almonds can protect the delicate fats in your cells from being damaged by oxidation (5, 6, 7).

In one study, 13 people consumed walnuts, almonds or a control meal on three separate occasions. Both nut meals led to higher polyphenol levels and significantly less oxidative damage compared to the control meal (7).

Another study found that two to eight hours after consuming whole pecans, participants experienced a 26–33% drop in their levels of oxidized LDL cholesterol, a major risk factor for heart disease (8).

However, studies in older people and individuals with metabolic syndrome found that walnuts and cashews didn’t have a big impact on antioxidant capacity, although some other markers did improve (9, 10).

3. Nuts Can Help You Lose Weight

Although they’re considered a high-calorie food, research suggests that nuts may actually help you lose weight.

One large study called the PREDIMED study assessed the effects of the Mediterranean diet.

Analysis of data from a subgroup of the study found that those assigned to eat nuts lost an average of 2 inches (5 cm) from their waists, which is significantly more than those assigned to eat olive oil (11).

Almonds have consistently been shown to promote weight loss rather than weight gain in controlled studies. One study found that pistachios may also be helpful for weight loss (12, 13, 14).

In one study of overweight women, those who consumed almonds lost nearly three times as much weight and experienced a significantly greater decrease in waist size compared to the control group (15).

What’s more, even though the calorie counts listed for nuts are quite high, studies have shown that your body doesn’t absorb all of them. This is because a portion of fat stays trapped within the nut’s fibrous wall during digestion (16, 17, 18).

For instance, the nutrition facts on a package of almonds may indicate that a 1-oz (28-gram) serving has 160–170 calories, but your body only absorbs about 129 of those calories (19).

Similarly, recent studies have found that your body absorbs about 21% fewer calories from walnuts and 5% fewer calories from pistachios than had previously been reported (20, 21).

4. Nuts Can Lower Cholesterol and Triglycerides

Nuts have impressive effects on cholesterol and triglyceride levels.

Pistachios have been shown to lower triglycerides in obese people and diabetics. In one 12-week study, obese people who ate pistachios had triglycerides that were nearly 33% lower than the control group (14, 22).

The cholesterol-lowering power of nuts is believed to be due in part to their high content of monounsaturated and polyunsaturated fatty acids.

Almonds and hazelnuts appear to reduce total cholesterol and LDL cholesterol while increasing HDL (“good”) cholesterol levels. One study found that ground, sliced or whole hazelnuts had similar beneficial effects on cholesterol (23, 24, 25, 26).

Another study found that consuming a 1-oz (30-gram) mixture of walnuts, peanuts and pine nuts per day for six weeks significantly lowered all types of cholesterol except HDL in a group of women with metabolic syndrome (27, 28).

Several studies have shown that macadamia nuts lower cholesterol levels. In one, a moderate-fat diet including macadamia nuts reduced cholesterol just as much as a lower-fat diet (29, 30, 31, 32).

5. Nuts Are Beneficial for Type 2 Diabetes and Metabolic Syndrome

Type 2 diabetes is a common disease that affects hundreds of millions of people.

Having a condition called metabolic syndrome is strongly associated with type 2 diabetes.

Interestingly, nuts may be one of the best foods for people with metabolic syndrome and type 2 diabetes.

First off, they are low in carbs and don’t raise blood sugar levels much. Substituting nuts for higher-carb foods should lead to reduced blood sugar levels.

Studies suggest that eating nuts may also lower oxidative stress, blood pressure and other health markers in people with diabetes and metabolic syndrome (33, 34, 35, 36, 37).

In a 12-week controlled study, people with metabolic syndrome who ate 25 grams of pistachios twice per day experienced a 9% decrease in fasting blood sugar, on average (37).

In addition, compared to the control group, the pistachio group had greater reductions in blood pressure and C-reactive protein (CRP), a marker of inflammation linked to heart disease.

However, the evidence is mixed and not all studies have found a benefit from eating nuts in people with metabolic syndrome (38).

6. Nuts Can Help Reduce Inflammation

Nuts have strong anti-inflammatory properties.

Inflammation is your body’s way of defending itself from injury, as well as bacteria and other potentially harmful pathogens.

However, chronic (long-term) inflammation can cause damage to organs and increase disease risk. Research suggests that eating nuts may reduce inflammation and promote healthy aging (39).

In the large PREDIMED Mediterranean diet study, the participants whose diets were supplemented with nuts experienced a 35% decrease in CRP and a 90% decrease in another marker of inflammation called interleukin 6 (IL-6) (40).

Specific nuts have been found to fight inflammation in healthy people and those with serious diseases. These include pistachios, Brazil nuts, walnuts and almonds (25, 37, 41, 42, 43, 44).

However, one study of almond consumption in healthy adults found that, although a few inflammatory markers decreased, overall there wasn’t much difference between the almond group and the control group (45).

Fiber provides many health benefits.

Although your body can’t digest fiber, the bacteria that live in your colon can.

Many types of fiber function as prebiotics or “food” for your healthy gut bacteria.

Your gut bacteria then ferment the fiber and turn it into beneficial short-chain fatty acids(SCFAs).

These SCFAs have powerful benefits, including improving gut health and reducing your risk of diabetes and obesity (46, 47, 48).

In addition, fiber helps you feel full and reduces the number of calories you absorb from meals. One study suggests that increasing fiber intake from 18 to 36 grams daily might result in up to 130 fewer calories being absorbed (49, 50).

Here are the nuts with the highest fiber content per 1-oz (28-gram) serving:

• Almonds: 3.5 grams
• Pistachios: 2.9 grams
• Hazelnuts: 2.9 grams
• Pecans: 2.9 grams
• Peanuts: 2.6 grams
• Macadamias: 2.4 grams
• Brazil nuts: 2.1 grams

8. Nuts Can Reduce Your Risk of Heart Attack and Stroke

Nuts are extremely good for your heart.

Several studies suggest that nuts help lower heart disease and stroke risk because of their benefits for cholesterol levels, LDL particle size, artery function and inflammation (11, 51, 52, 53, 54, 55, 56, 57).

Studies have found that small, dense LDL particles may increase heart disease risk more than larger LDL particles (58, 59).

The PREDIMED study found that the group who consumed nuts had a significant decline in small LDL particles and an increase in large LDL particles. What’s more, their HDL (“good”) cholesterol levels increased (11).

In another study, people with normal or high cholesterol were randomly assigned to consume either olive oil or nuts with a high-fat meal.

People in the nut group had better artery function and lower fasting triglycerides than the olive oil group, regardless of their initial cholesterol levels (51).

Nuts Are Delicious, Versatile and Widely Available

Nuts are undeniably tasty and satisfying.

They can be enjoyed whole, as nut butters or chopped up and sprinkled on food.

It’s actually quite easy to make your own homemade nut butter using whichever combination of nuts you like.

Nuts can be purchased in grocery stores or online. They are available in a wide variety of options, including salted or unsalted, seasoned or plain, raw or roasted.

In general, it’s healthiest to eat nuts raw or toast them in the oven at a temperature below 350°F (175°C). Dry-roasted nuts are the next-best option, but try to avoid nuts roasted in vegetable and seed oils.

Nuts can be kept at room temperature, which makes them ideal for on-the-go snacks and traveling. However, if you’re going to be storing them for long then a refrigerator or freezer will keep them fresher.

At the end of the day, nuts are a highly nutritious and super tasty food that can fit into almost everyone’s diet.

Eating nuts on a regular basis is a very enjoyable way to improve your health.