Sunflower seeds are popular in trail mix, multi-grain bread, and nutrition bars, as well as for snacking straight from the bag.
They’re rich in healthy fats, beneficial plant compounds, and several vitamins and minerals.
These nutrients may play a role in reducing your risk of common health problems, including heart disease and type 2 diabetes.
Here’s everything you need to know about sunflower seeds, including their nutrition, benefits, and how to eat them.
What are sunflower seeds?
Sunflower seeds are technically the fruits of the sunflower plant (Helianthus annuus).
The seeds are harvested from the plant’s large flower heads, which can measure more than 12 inches (30.5 cm) in diameter. A single sunflower head may contain up to 2,000 seeds.
There are two main types of sunflower crops. One type is grown for the seeds you eat, while the other — which is the majority farmed — is grown for the oil.
The sunflower seeds you eat are encased in inedible black-and-white striped shells, also called hulls. Those used for extracting sunflower oil have solid black shells.
Sunflower seeds have a mild, nutty flavor and a firm but tender texture. They’re often roasted to enhance the flavor, though you can also buy them raw.
Summary: Sunflower seeds come from the large flower heads of the sunflower plant. The edible variety has a mild, nutty flavor.
Nutritional value of sunflower seeds
Sunflowers pack many nutrients into a tiny seed.
The main nutrients in 1 ounce (30 grams or 1/4 cup) of shelled, dry-roasted sunflower seeds are:
- Calories: 163
- Fat: 14 grams
- Protein: 5.5 grams
- Carbs: 6.5 grams
- Fiber: 3 grams
- Vitamin E: 37% of your daily need
- Niacin: 10% of your daily need
- Vitamin B6: 11% of your daily need
- Folate: 17% of your daily need
- Pantothenic acid: 20% of your daily need
- Iron: 6% of your daily need
- Magnesium: 9% of your daily need
- Zinc: 10% of your daily need
- Copper: 26% of your daily need
- Manganese: 30% of your daily need
- Selenium: 32% of your daily need
Health benefits of sunflower seeds
Sunflower seeds may help lower blood pressure, cholesterol, and blood sugar as they contain vitamin E, magnesium, protein, linoleic fatty acids, and several plant compounds.
Furthermore, studies link sunflower seeds to multiple other health benefits.
While short-term inflammation is a natural immune response, chronic inflammation is a risk factor for many chronic diseases.
For example, increased blood levels of the inflammatory marker C-reactive protein is linked to an increased risk of heart disease and type 2 diabetes.
In a study in more than 6,000 adults, those who reported eating sunflower seeds and other seeds at least five times a week had 32% lower levels of C-reactive protein compared to people who ate no seeds.
Though this type of study cannot prove cause and effect, it is known that vitamin E — which is abundant in sunflower seeds — helps lower C-reactive protein levels.
Flavonoids and other plant compounds in sunflower seeds also help reduce inflammation.
High blood pressure is a major risk factor for heart disease, which can lead to heart attack or stroke.
A compound in sunflower seeds blocks an enzyme that causes blood vessels to constrict. As a result, it may help your blood vessels relax, lowering your blood pressure. The magnesium in sunflower seeds helps reduce blood pressure levels as well.
Additionally, sunflower seeds are rich in unsaturated fatty acids, especially linoleic acid. Your body uses linoleic acid to make a hormone-like compound that relaxes blood vessels, promoting lower blood pressure. This fatty acid also helps lower cholesterol.
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In a 3-week study, women with type 2 diabetes who ate 1 ounce (30 grams) of sunflower seeds daily as part of a balanced diet experienced a 5% drop in systolic blood pressure (the top number of a reading).
Participants also noted a 9% and 12% decrease in “bad” LDL cholesterol and triglycerides, respectively.
Furthermore, in a review of 13 studies, people with the highest linoleic acid intake had a 15% lower risk of heart disease events, such as heart attack, and a 21% lower risk of dying of heart disease, compared to those with the lowest intake.
The effects of sunflower seeds on blood sugar and type 2 diabetes have been tested in a few studies and seem promising, but more research is needed.
Studies suggest that people who eat 1 ounce (30 grams) of sunflower seeds daily as part of a healthy diet may reduce fasting blood sugar by about 10% within six months, compared to a healthy diet alone.
The blood-sugar-lowering effect of sunflower seeds may partially be due to the plant compound chlorogenic acid.
Studies also suggest that adding sunflower seeds to foods like bread may help decrease carbs’ effect on your blood sugar. The seeds’ protein and fat slow the rate at which your stomach empties, allowing a more gradual release of sugar from carbs.
Summary: Sunflower seeds contain nutrients and plant compounds that help reduce your risk of inflammation, heart disease and type 2 diabetes.
Potential downsides of sunflower seeds
While sunflower seeds are healthy, they have several potential downsides.
Calories and sodium
Though rich in nutrients, sunflower seeds are relatively high in calories.
Eating the seeds in the shell is a simple way to slow your eating pace and calorie intake while snacking, as it takes time to crack open and spit out each shell.
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However, if you’re watching your salt intake, keep in mind that the shells — which people commonly suck on before cracking them open — are often coated with more than 2,500 mg of sodium — 108% of the RDI — per 1/4 cup (30 grams).
Sodium content may not be apparent if the label only provides nutrition information for the edible portion — the kernels inside the shells. Some brands sell reduced-sodium versions.
Another reason to eat sunflower seeds in moderation is their cadmium content. This heavy metal can harm your kidneys if you’re exposed to high amounts over a long period.
Sunflowers tend to take up cadmium from the soil and deposit it in their seeds, so they contain somewhat higher amounts than most other foods.
The WHO advises a weekly limit of 490 micrograms (mcg) of cadmium for a 154-pound (70-kg) adult.
When people ate 9 ounces (255 grams) of sunflower seeds per week for one year, their average estimated cadmium intake increased from 65 mcg to 175 mcg per week. That said, this amount didn’t raise their blood levels of cadmium or damage their kidneys.
Therefore, you shouldn’t worry about eating reasonable amounts of sunflower seeds, such as 1 ounce (30 grams) per day — but you shouldn’t eat a bagful in a day.
Sprouting is an increasingly popular method of preparing seeds.
Occasionally, seeds are contaminated with harmful bacteria, such as Salmonella, which can thrive in the warm, moist conditions of sprouting.
This is of special concern in raw sprouted sunflower seeds, which may not have been heated above 118℉ (48℃).
Drying sunflower seeds at higher temperatures helps destroy harmful bacteria. One study found that drying partially sprouted sunflower seeds at temperatures of 122℉ (50℃) and above significantly reduced Salmonella presence.
If bacterial contamination is discovered in certain products, they may be recalled — as has happened with raw sprouted sunflower seeds. Never eat recalled products.
Eating a large number of sunflower seeds at once has occasionally resulted in fecal impaction — or stool blockages — in both children and adults.
Eating sunflower seeds in the shell may increase your odds of fecal impaction, as you may unintentionally eat shell fragments, which your body cannot digest.
An impaction may leave you unable to have a bowel movement. Your doctor may need to remove the blockage while you’re under general anesthesia.
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Besides being constipated due to the fecal impaction, you may leak liquid stool around the blockage and have abdominal pain and nausea, among other symptoms.
Though allergies to sunflower seeds are relatively uncommon, some cases have been reported. Reactions may include asthma, mouth swelling, itching of the mouth, hay fever, skin rashes, lesions, vomiting, and anaphylaxis.
The allergens are various proteins in the seeds. Sunflower seed butter — roasted, ground seeds — can be just as allergenic as whole seeds.
Refined sunflower oil is far less likely to contain enough of the allergenic proteins, but in rare cases, highly sensitive people have had reactions to trace amounts in the oil.
Sunflower seed allergies are more common in people exposed to sunflower plants or seeds as part of their jobs, such as sunflower farmers and bird breeders.
In your home, feeding pet birds sunflower seeds can release these allergens into the air, which you inhale. Young children may become sensitized to sunflower seeds by exposure to the proteins through damaged skin.
In addition to food allergies, some people have developed allergies to touching sunflower seeds, such as when making yeast bread with sunflower seeds, resulting in reactions such as itchy, inflamed hands.
Summary: Measure sunflower seed portions to avoid excessive calorie intake and potentially high exposure to cadmium. Though uncommon, bacterial contamination of sprouted seeds, sunflower seed allergies, and intestinal blockages may occur.
Tips for eating
Sunflower seeds are sold either in the shell or as shelled kernels.
Those still in the shell are commonly eaten by cracking them with your teeth, then spitting out the shell — which shouldn’t be eaten. These seeds are a particularly popular snack at baseball games and other outdoor sports games.
Shelled sunflower seeds are more versatile. Here are various ways you can eat them:
- Add to trail mix.
- Stir into homemade granola bars.
- Sprinkle on a leafy green salad.
- Stir into hot or cold cereal.
- Sprinkle over fruit or yogurt parfaits.
- Add to stir-fries.
- Stir into tuna or chicken salad.
- Sprinkle over sautéed vegetables.
- Add to veggie burgers.
- Use in place of pine nuts in pesto.
- Top casseroles.
- Grind the seeds and use them as a coating for fish.
- Add to baked goods, such as bread and muffins.
- Dip an apple or banana in sunflower seed butter.
Sunflower seeds may turn blue-green when baked. This is due to a harmless chemical reaction between the seeds’ chlorogenic acid and baking soda — but you can reduce the amount of baking soda to minimize this reaction.
Lastly, sunflower seeds are prone to becoming rancid due to their high-fat content. Store them in an airtight container in your refrigerator or freezer to protect against rancidity.
Summary: Unshelled sunflower seeds are a popular snack, while shelled varieties can be eaten by a handful or added to any number of foods, such as trail mix, salads, and baked goods.
Sunflower seeds make for a nutty, crunchy snack and tasty addition to countless dishes.
They pack various nutrients and plant compounds that may help fight inflammation, heart disease, and type 2 diabetes.
Still, they’re calorie-dense and may lead to unwanted side effects if you eat too many.