Chestnuts, low in fat and high in vitamin C, are more similar to fruits than true nuts. They have a spiny husk and a dark brown shell, both of which must be removed before eating.
Chestnuts have been a food source for thousands of years. They can be eaten raw, roasted, ground into flour, or mixed into pastries. They grow on trees in the genus Castanea, and many species in this group can live for an impressive 500 years or more.
There are four main species of chestnut tree: the Chinese chestnut, the Japanese chestnut, the European chestnut, and the American chestnut. The trees are native to many places around the world, but once had a much smaller growing area before people began to transplant them.
The American chestnut tree was once common across the eastern United States, but it was nearly wiped out by a fungal infestation in the early 1900s. The European chestnut, Castanea sativa, is the most common and provides the majority of chestnuts sold in grocery stores today.
Health Benefits
Chestnuts are rich in vitamin C, which makes them unique among nuts. In fact, half a cup of raw chestnuts gives you 35 to 45 percent of your daily intake of vitamin C.
Chestnuts lose some of their vitamin C if you boil or roast them, but still have anywhere from 15 to 20 percent of your daily intake for this healthy vitamin. To retain more vitamin C in chestnuts when cooking, you can roast them at lower temperatures or use a food dehydrator to dry them.
Chestnuts remain a good source of antioxidants, even after cooking. They’re rich in gallic acid and ellagic acid—two antioxidants that increase in concentration when cooked.
Chestnuts have these additional health benefits:
Support Heart Health
Antioxidants and minerals like magnesium and potassium help reduce your risk of cardiovascular issues, such as heart disease or stroke. Chestnuts are a good source of these nutrients and can help boost your heart health.
Improve Digestion
Chestnuts can also help improve your digestion. These nuts are a good source of fiber, which helps keep you regular and supports the growth of healthy bacteria in your gut. Chestnuts are also gluten-free, which makes them a healthy choice for people with celiac disease.
Control Blood Sugar
The fiber in chestnuts can also help balance your blood sugar. Eating high fiber foods ensures your body slowly absorbs starches. This helps avoid spikes in blood sugar, which can be dangerous for people with diabetes. Plus, chestnuts have a low glycemic index value of 54. Foods rated lower on the glycemic index won't cause major changes to your blood sugar levels when you eat them.
Nutrition
Chestnuts are lower in calories than many other types of nuts. They are a good source of amino acids, monounsaturated fatty acids, antioxidants, phenols, and vitamin C.
You'll also find a variety of vitamins and minerals in chestnuts, such as:
- Vitamin C
- Vitamin E
- Vitamin A
- Vitamin B complex
- Calcium
- Magnesium
- Zinc
- Iron
- Copper
- Manganese
Nutrients per Serving
One quarter-cup of raw chestnuts contains:
- Calories: 77
- Protein: 1 gram
- Fat: 1 gram
- Carbohydrates: 17 grams
- Fiber: 3 grams
- Sugar: 0 grams
- Cholesterol: 0 milligrams
- Sodium: 1 milligram
For comparison, one quarter-cup of roasted chestnuts contains:
- Calories: 88
- Protein: 1 gram
- Fat: 1 gram
- Carbohydrates: 19 grams
- Fiber: 2 grams
- Sugar: 4 grams
- Cholesterol: 0 milligrams
- Sodium: 1 milligram
Things to Watch Out For
Raw chestnuts are safe to eat for most people. However, they do contain tannic acid, which means they could cause stomach irritation, nausea, or liver damage if you have liver disease or experience a lot of kidney problems.
How to Prepare Chestnuts
Look for raw chestnuts in grocery stores from October to December, when they’re at their freshest and most nutritious. You can find them in many supermarkets, specialty grocers, and farmers markets. The majority of chestnuts sold in stores are European chestnuts grown in Italy, but some farmers in the United States grow them as well.
Since raw chestnuts are high in bitter tannins, you might prefer to roast them before eating. This increases their sugar content and adds a touch of sweetness.
Try some of the following ways to cook and eat chestnuts:
- Purée chestnuts in a blender and add to warm crepes or pancakes.
- Roast chestnuts and use them instead of croutons on a salad.
- Sprinkle chopped, roasted chestnuts on baked acorn or butternut squash.
- Make candied chestnuts—known in France as marron glacé.
- Bake a pound cake using chestnut flour.
