Apples are one of the most popular fruits in the U.S. and are known for their numerous health benefits, including improving digestion and protecting against chronic illnesses like diabetes and heart disease.

Apples, especially with the skin on, are a rich source of fiber, polyphenols, and other nutrients that support heart health.

Several studies have linked apples to a lower risk of heart disease. One review found that eating about one small apple daily is associated with a decreased risk of heart disease and risk factors such as high cholesterol and high blood pressure.

In addition, daily apple consumption was associated with a 27% lower risk of dying from a stroke and a 25% lower risk of dying from heart disease.

Apples are a good source of pectin, a soluble fiber that can improve digestion. As a soluble fiber, pectin absorbs water in the digestive tract, creating larger, softer stools that are easier to pass.

Pectin is also recognized as a prebiotic that encourages the growth and activity of beneficial bacteria in the gut.

Apples are high in water and fiber yet low in calories, which can support weight management by keeping you full and reducing your daily calorie intake.

One study linked a higher intake of fiber-rich fruits and vegetables to weight loss. Participants who frequently ate apples lost an average of 1.24 pounds over four years.

Another review found that apple intake significantly decreased body mass index (BMI). However, no significant differences in body weight were found.

Research suggests that people who eat two servings of whole fruits, such as apples, per day have a 36% lower risk of type 2 diabetes than people who consume less than half a serving.

One review found that apples and pears were associated with a significant 18% reduction in the risk of type 2 diabetes. Researchers found that even one serving per week can reduce the risk by 3%.

One potential reason for this may be the concentration of flavonoids, including quercetin, in apples, which may help lower blood sugar and improve insulin sensitivity. The soluble fiber in apples may also prevent diabetes by slowing down the absorption of carbohydrates, preventing blood sugar spikes.

Apples are rich in antioxidants, which may decrease cancer risk by neutralizing cancer-causing free radicals. In addition, research suggests that the phytochemicals in apples can help slow down the growth of cancer cells and prevent them from multiplying.

The fiber found in apples may also help protect against colorectal cancer. Recent findings from the American Institute for Cancer Research suggest that for every 10-gram increase in dietary fiber, there’s a 7% decrease in the risk of colorectal cancer.

Several observational studies suggest that apples may help decrease the risk of:

• Breast cancer
• Lung cancer
• Prostate cancer
• Certain cancers of the digestive tract

However, more human studies are needed to confirm the anti-cancer effects of apples. Note that there is no single food that will prevent cancer.

The antioxidants in fruits and vegetables may benefit cognitive function, especially in older adults.

Studies have shown that quercetin in apples may help protect neurons in the brain from oxidative damage and prevent Alzheimer’s disease. However, human studies are needed to establish a clear relationship.

One medium raw apple—with the skin on—provides the following nutrients:

• Calories: 95 calories
• Protein: 0.5 g
• Carbohydrates: 25 g
• Sugar: 19 g
• Fiber: 4.4 g
• Vitamin C: 9% of the Daily Value (DV)
• Water: 86%

Apples are relatively high in vitamin C, an antioxidant that helps the immune system work properly to fight off disease. Vitamin C helps improve iron absorption from plant foods and is required for collagen production.

The fruit is also high in phytochemicals, including quercetin, catechin, chlorogenic acid, and epicatechin, all of which have strong antioxidant properties.

Since apples contain carbohydrates, people with diabetes should stick with one small apple—equal to around 15 carbs—per meal or snack. Consider balancing it with a healthy protein or fat by pairing it with a handful of nuts, nut butter, or cheese.

Apples are unlikely to cause any serious side effects when consumed in moderation. However, after eating apples, some people experience bloating, gas, and digestive issues.

This is because apples are high in fiber and contain the FODMAPs fructose and sorbitol, which are sugars that some people can’t tolerate.

People with an apple allergy should avoid apples and foods containing apples that could trigger symptoms. Studies show that 70% of people with birch pollen allergy develop pollen-related food allergies, especially to apples. This is due to the similarity between apple proteins and birch pollen.

Lastly, while a few apple seeds are unlikely to cause harm, consuming too many can be dangerous. This is because chewed or crushed apple seeds release a highly toxic compound called cyanide.