✓ Evidence Based

Spinach: Facts, Nutrition, Benefits, and More

Spinach is a popular leafy green vegetable eaten all over the world.

Did you know spinach contains a large amount of a variety of vitamins, minerals, and antioxidants all great for your health?

Consuming spinach on a regular basis may help to improve heart health, reduce the risk of cancer, and improve brain and eye health.

Not only is spinach high in a ton of nutrients, but it is also a great food to add to salads, smoothies, cooked vegetables, soups, and other dishes.

Keep reading to find out all you need to know about spinach.

History & Facts

Spinach (Spinacia oleracea L) is a dark green leafy vegetable that is part of the Amaranthaceae family. The Amaranthaceae family includes other vegetables like beets and chard and has been believed to originate in Persia. The earliest written records of spinach were from China in 647 A.D with it being named the herb of Persia during that time (1).

Spinach is cultivated all around the world, and since 1970 production of spinach has increased by 418.7%. China is the largest producer of spinach and amounts to 90% of the world’s spinach production. The second largest producer of spinach is the United States. Other major producers of spinach include Japan, Turkey, Indonesia, and France (1).

Classifications

There are 3 different classifications of spinach: smooth-leaf, savoy, and semi-savoy. Smooth-leaf spinach is the most common type of spinach used in salads or smoothies. Semi-savoy and savoy are more often used for cooking in dishes such as casseroles, soups, and steamed (1).

Among the classifications of spinach, there are approximately 82 different varieties of spinach that exist, all unique to each other. Some of the most popular varieties of spinach include Amsterdam Giant, Bloomsdale, Hollandia, Juliana, Old Dominion, and Del Monte. Hybrid species of spinach are the most popular type of spinach grown today (1).

Nutrition Facts

Spinach is a great addition to the diet because of its high nutrient content. The nutrient content may differ based on the variety and type of spinach.

Macronutrients

Per 100g (about 3.5 ounces) of spinach, some of the highlighted nutrition facts include (2):

  • Calories: 28 kcal: Spinach is nutrient-dense, meaning it is lower in calories and high in nutrients. You may feel satiated more quickly when eating spinach because of this.
  • Protein: 2.91 grams
  • Carbohydrate: 2.64 grams
  • Dietary fiber: 1.6 grams: This is 8.8% of a person’s recommended dietary allowance (RDA) on a 2,000-kcal diet, meaning spinach is high in fiber. Consuming an adequate amount of fiber is an important part of maintaining digestive health (5).

Vitamins and minerals

In just one serving (100 grams) of spinach, there are a plethora of vitamins and minerals:

  • Calcium (Ca): 67 milligrams (mg)
  • Iron (Fe): 1.05 milligrams (mg)
  • Magnesium (Mg): 93 milligrams (mg)
  • Phosphorous (P): 41 grams (g)
  • Potassium (K): 460 milligrams (mg)
  • Vitamin C: 30.3 milligrams (mg)
  • Folate: 113 micrograms (mcg)
  • Vitamin A: 306 micrograms (mcg)
  • Beta carotene: 3670 micrograms (mcg)

Having 1 serving of spinach (100 grams) is enough to consume 604% of the RDA for vitamin K, 188% of the RDA for folate, and 47% of the RDA for vitamin C (4).

Along with these nutrients, spinach is high in beta-carotene. It contains 3670 mcg per 100-gram serving, which has been shown to have health benefits including provitamin A and antioxidant properties (4). Eating foods like spinach that are high in beta-carotene is associated with lowering the incidence of cancer, and cardiovascular disease. Furthermore, it is associated with decreasing age-related macular degeneration, and cataract formation (4).

Compared to other vegetables like broccoli, cabbage, and lettuce, spinach contains an even higher amount of minerals like potassium, iron, and magnesium (1).

Benefits of spinach

Spinach is beneficial for health because of its amazing nutrient profile. Let’s have a look at some of the several health benefits of Spinach.

Spinach is High in Antioxidants

Spinach contains a high number of antioxidants that play various roles in the body. One of their main functions is to protect against free radicals that damage cells in the human body (6).

Additionally, spinach contains phenols which are a type of antioxidant. Phenols function as antimicrobial, antiviral, and anti-fungal agents in the body. Studies have measured spinach and found it contains 40% more phenols than cabbage and 70% more phenols than lettuce (1).

Other antioxidant studies on spinach found that it decreases DNA damage and the amount of reactive oxygen species (ROS). ROS are unstable cells in the body that can have negative effects like causing cell death (1).

Spinach May improve heart health

Cardiovascular disease is the leading cause of death in the United States (13). High levels of LDL cholesterol, triglycerides, cholesterol, and high blood pressure are all contributors and risk factors for heart disease (13).

As mentioned above, spinach contains a large amount of the antioxidants lutein and zeaxanthin. These compounds have been shown to play a role in preventing heart disease.  In addition, spinach contains a high number of phytoestrogens. These have been associated with having beneficial effects on cardiovascular disease (14).

Eating Spinach May Improve Eye Health

Spinach contains a high amount of lutein, much more than other vegetables. Lutein is a type of carotenoid that has been found to help decrease the risk of age-related macular degeneration and cataracts (1).

Additionally, spinach contains zeaxanthin, another type of carotenoid. It is part of the main pigments found in the yellow spot of the retina in the eye and contributes to improving visual acuity and protecting the macula of the eye7. Zeaxanthin has been shown to be an essential component for eye health. Studies have shown zeaxanthin plays a role in preventing age-related macular degeneration and cataracts, similar to lutein (7).

It may prevent cancer

Diets rich in vegetables, in particular dark green vegetables, are associated with a reduced risk for many cancers, esophageal, colon, and breast cancers in particular (1). A study done in North America and Europe observed that consuming one serving of spinach (73 grams) per week decreased the risk of colon cancer by 11% (1).

Due to its high amount of vitamin A, spinach has been associated with decreasing the risk of cancer, more specifically breast cancer (1, 12).

One study showed an inverse relationship between the consumption of carotene-rich dark green vegetables (like spinach) and the risk of incidence of human cancer. So, the more spinach you eat, the lower your risk is for getting cancer (4).

Potential risks

Although spinach is high in key nutrients, vitamins, and antioxidants, there are things to keep in mind when consuming it on a regular basis.

Some of the potential risks of regularly consuming spinach include:

It may have an effect on certain health conditions

  • It may cause low blood sugar: Spinach has the potential to lower blood sugar (10) due to it naturally containing a high amount of fiber. People with diabetes should monitor blood sugar levels if consuming spinach on a regular basis.
  • It may lead to kidney stone formation: Having a high amount of oxalate in the blood is a risk factor for kidney stones (11). Consuming a large number of foods with oxalate may increase the risk of kidney stones. Spinach has naturally high oxalate content, therefore increasing the risk of kidney stones (11). Cooking methods may alter the amount of oxalate content in foods.

Drug Interactions

  • Warfarin: Warfarin is an anticoagulation medication, commonly taken for the prevention of blood clots. Spinach contains a large amount of vitamin K. Vitamin K is most commonly known for helping to make proteins that are necessary for blood clotting (8). By consuming spinach, it may decrease the effect of warfarin (9). Be sure to talk to your doctor. 

Ways To Eat

Spinach can be enjoyed in a variety of ways. It has a mild taste that does not overpower the flavor of other foods so it can be added to a variety of different foods. Keep in mind that the method of preparation for spinach can alter the nutrient content (1) and, as always, be sure to properly wash and rinse your spinach before consuming it.

  • Cooking spinach: Popular cooking methods for spinach include sautéing, steaming, and boiling. Spinach will cook down or look like it shrank due to its high-water content. This is because as the spinach is cooking, the water evaporates. For instance, if you take a big handful of spinach, it will shrink down to about ¼ of that size or less when cooked. Different ideas for consuming cooked spinach could include adding it into soups, stir-fry, omelets, or preparing it as a side dish on its own.
  • Raw spinach: If you want to try spinach raw, it is a great vegetable to enjoy without cooking. It is a great additive to smoothies without having the spinach flavor overpower other smoothie ingredients. It can be added as a topping to snacks like toast, pizza, and sandwiches. Moreover, it can be a great swap for lettuce in salads or mixed in addition to your favorite salad ingredients.

Frequently Asked Questions

Does all spinach contain the same amount of nutrients?

No. Depending on the variety of spinach, and the preparation method (cooking, consuming raw, etc.), the nutrient composition can fluctuate (1).

Some studies have found that spinach grown in the summer versus the winter had a higher amount of folate and vitamin E. Spinach grown in the Fall (October and November) contained higher levels of nitrogen, potassium, calcium, magnesium, copper, zinc, and manganese in their leaves than spinach grown in winter (December– February) (1). Another study found that spinach grown organically contained 31% more vitamin C than conventionally grown spinach (1).

Boiling and steaming fresh spinach was found to decrease the amount of folate by 3-47% and vitamin C by 34-75% (1).

How should I store spinach?

Spinach is best kept in the refrigerator prior to consuming it. Some tips that may be helpful for keeping it fresh include putting it in a plastic container or resealable bag. Adding a paper towel and laying it on top of the spinach can help prolong its freshness and absorb extra water. The shelf life for keeping spinach in the refrigerator is about two weeks.

Conclusion

Spinach is a delicious vegetable that is packed with tons of vitamins and nutrients including vitamin K, folate, and vitamin C in addition to antioxidants. Not only is it high in fiber content which can aid in digestion, but it also has additional health benefits. This dark leafy green is part of an overall healthy and balanced diet and can be easily added to a variety of foods you are likely already eating like soups, omelets, and smoothies.

There are a ton of health benefits that spinach may play a role in improving, some of them including eye and heart health. Additionally, it may play a role in preventing cancer and improving other health conditions, but more research and evidence are needed to confirm. It is important to note that eating spinach on a regular basis may be a potential risk for people with certain health conditions like diabetes and kidney stones.

Don’t forget to add spinach to your next grocery list to start eating more of it today!