Often relegated to the post-Halloween garbage bin, pumpkin seeds, also known as pepitas, have enjoyed a minor resurgence in popularity in recent years, and for good reason. They still, however, remain a fringe food that is all-too-easily forgotten among the almonds, walnuts, hemp, and chia seeds of the world.
Pumpkins are the fruit of Cucurbita plants and are a member of the Cucurbitaceae, or gourd, family, which also includes melons and squash. An unusually large fruit, pumpkins are usually between 9 and 18 pounds but in extremes can grow up to 75 pounds. Common to North America and Europe, pumpkin is often eaten as a side dish (which itself is very nutritious). The pumpkin’s seeds have a cream-coloured hull, with the olive green seeds found inside. Slightly larger and flatter than sesame seeds, pumpkin seeds are mild tasting and easier to chew than many nuts.
Pumpkin seeds can be eaten raw or roasted, in the shell or hulled. You can add pumpkin seeds to salads or trail mixes (they pair particularly well with dried cranberries and ginger), and they can be sprinkled on baked goods, including breads and muffins. Pumpkin seed oil can be used as a salad dressing, though its low smoke point means it is not typically recommended for cooking or frying. Since they don’t need to be refrigerated, pumpkin seeds are great for travelling and can be transported in school bags and left in desk drawers for a week or two, where they make a great choice for an afternoon snack.
Perhaps the most significant of pumpkin seeds’ claims to fame centres on their iron content: A 1-ounce (28 gram) serving of pumpkin seed kernels (the softer part of the seed found inside the tougher shell) provides about 23% of our daily iron needs, making them, along with pulses, some of the richest non-meat sources of iron available. Pumpkin seeds are also a good source of protein, providing 9 grams per ounce, which is more than you’ll find in an egg or a glass of milk, although it does not contain all the essential amino acids that serve as the building blocks of protein, making pumpkin seeds a lower-quality protein source than animal foods.
Pumpkin seeds are also one of the best food sources of magnesium, the often underappreciated mineral that plays a role in blood pressure control, bone health, and muscle function. Magnesium’s muscle-relaxing effects may help with constipation as well as ease the restless, achy legs that are common in athletes and older adults, especially those taking statin (cholesterol) drugs. Higher magnesium intakes have also been associated with a lower risk of both stroke and colorectal cancer. Unfortunately, many North Americans do not meet their daily requirements (320 mg per day for women, 420 mg per day for men), in large part since magnesium-rich foods, such as fish, nuts, seeds, and green leafy vegetables, are not always the most popular foods. Since a 1-ounce serving of pumpkin seeds provides an impressive 151 mg of magnesium, equivalent to 36% of an adult male’s needs, they make an easy choice to help meet the requirements of this important yet under consumed nutrient.
Like all nuts and seeds, pumpkin seeds are relatively high in calories, so portion control is important: That same 1-ounce serving packs 146 calories, and if you were to enjoy a full 1-cup serving, you would put away more than 1,100 calories’ worth of energy, more than a half-day’s worth for most adults!
Like soybeans, pumpkin seeds contain phytoestrogens, compounds that mimic estrogen in the human body. As a result, there is a question as to whether or not pumpkin seeds can influence the risk of certain hormone-dependent cancers, especially breast cancer. Although the research on pumpkin seeds in humans is limited, a 2012 study on nearly 3,000 post-menopausal German women, published in the journal Nutrition and Cancer, found that regular consumption of soybeans, sunflower seeds, and pumpkin seeds was associated with a reduced risk of breast cancer versus controls. There are also suggestions that pumpkin seed oil may have heart health benefits.
As for the high iron content of pumpkin seeds, since they are a plant food, it is possible that only a limited amount of the iron is actually available for use by the body, yet since iron-deficiency anemia is an enormously burdensome health-care issue, especially in the developing world, there is great interest in finding foods that are cost effective and can have a significant effect on iron status. To test the effect of pumpkin seeds on iron, Iranian researchers conducted a small study, providing a daily serving of an iron-rich cereal (providing 7.1 mg of iron per day), along with 30 grams of pumpkin seeds (providing 4.0 mg of iron per day), to eight healthy females of reproductive age (the age of the women is significant, as iron losses from menstrual periods are a major contributor to iron deficiency). After four weeks, the women’s iron status improved significantly, but since the researchers did not test the two iron sources separately, it’s unknown just how much of the effect was from the cereal and how much was from the pumpkin seeds.
The Bottom Line
Pumpkin seeds are a quiet nutritional gem that packs a healthy punch: Rich in some often-evasive nutrients, including iron and magnesium, they are also a vegetarian protein source, making them a good choice for the environment. Since they are a seed, pumpkin seeds are usually welcome in nut-free environments, making them a good alternative when almonds, walnuts, pistachios, and peanuts are forbidden. Although only time and research will tell whether eating pumpkin seeds can help prevent certain conditions, including anemia, for now, they stand as a nutritious and easy choice for home or on the road.