Health Benefits Of Spinach

Introduction

Spinach (Spinacia oleracea) is a leafy green vegetable native to Central and Western Asia. It belongs to the Chenopodiaceae family, along with beetroot, chard, and quinoa. Spinach is a
versatile vegetable that can easily be added to a range of dishes, either cooked or raw. Spinach is often referred to as a ‘superfood’ as it provides several health benefits. Not only is it a good source of multiple vitamins, it is also high in antioxidants and has a range of properties that can prevent many diseases.

This article will explore the many health benefits of spinach and provide you with different ways you can include it in your diet.

Health benefits of spinach

Eye health

The dark green colour of spinach is a result of its high levels of chlorophyll and carotenoids, such as beta-carotene, lutein, and zeaxanthin. These phytonutrients are important for healthy eyesight and improving vision. Multiple studies have found that lutein and zeaxanthin are linked with a reduced risk of age-related macular degeneration (AMD) and cataracts, which are major causes of blindness.¹

Heart health

Spinach is a rich source of nitrates. In fact, it is one of the highest dietary sources of nitrate to date. Nitrates are compounds that help improve blood flow and pressure by relaxing the blood vessels, promoting dilation, and decreasing arterial stiffness. This reduction in blood pressure reduces the risk of many heart-related diseases, such as heart disease and stroke.²

A study involving 27 people found that consuming spinach was effective at lowering blood pressure.² Spinach is also an excellent source of vitamin K, which has heart health-promoting properties. This is because vitamin K plays a role in the production of proteins that help prevent calcification and hardening of the heart arteries which are contributors to heart disease.

Protective properties

Spinach is also a  source of antioxidants, compounds that protect the body by fighting oxidative stress caused by free radicals. This, in turn, protects the body against chronic diseases such as cancer, heart disease, and diabetes.

Many different substances, including vitamin C, vitamin E, and beta-carotene, can act as antioxidants. Most of these substances are naturally occurring and present in food, such as spinach. One study found that increased consumption of fresh vegetables that are high in antioxidants reduces the risk of diseases caused by oxidative stress.³

Anti-cancer properties

Spinach has a high content of protective compounds called polyphenols. Studies suggest that, like other antioxidants, polyphenols protect the body against cancer. Animal studies found that adding spinach to your diet can reduce the risk of colon cancer.⁴

In addition, spinach contains a high content of carotenoids such as lutein and zeaxanthin, which the body converts into vitamin A. Population studies have found that high levels of carotenoids in the diet or blood may be linked with a lower risk of breast cancer. The same study found that people with high levels of vitamin C in their blood had a lower overall risk of cancer.

Infection and inflammation

Spinach is one of the most popular anti-inflammatory vegetables as it is a great source of vitamin E, B vitamins, and other anti-inflammatory compounds. Vitamin E is a powerful antioxidant that neutralises free radicals and, therefore, suppresses cytokine production. In both human and animal studies, high doses of vitamin E were found to promote anti-inflammatory effects by decreasing C-reactive protein (CRP) and inhibiting the release of pro-inflammatory cytokines. One study found that vitamin E significantly reduced colonic inflammation and reduced the number of adenomas in mice.⁵

Bone health

Spinach is a good source of vitamin K as well as calcium, magnesium, and phosphorus. These are nutrients that are essential for bone health. Vitamin K plays a role in the production of proteins such as osteocalcin, which is needed to prevent the weakening of bones. Some studies show that a high intake of vitamin K is linked with a lower incidence of hip fractures and low bone density. One study suggested that assigned females at birth (AFAB) who get at least 110 mcg of vitamin K a day are 30% less likely to fracture or break a hip compared to women who get less than that. They found that eating a serving of a leafy green vegetable a day cut the risk of hip fracture in half compared to eating one serving a week.

Nutritional content of spinach

An 80g serving of raw spinach contains:

• 20kcal/82KJ
• 1.3g of carbohydrates
• 2.2g of protein
• 2.2g of fibre
• 0.6g of fat
• 136mg of calcium
• 91mcg of folate
• 1.68mg of iron
• 21mg of vitamin C

Fibre

Dark, leafy green vegetables are a rich source of insoluble fibre. Dietary fibre consists of two types of fibre:

• Soluble fibre – A fibre that dissolves in water so it can be digested by the body. It helps lower blood glucose and cholesterol levels. It is found in food such as oats, beans, apples, nuts, citrus fruits, and barley.
• Insoluble fibre – helps the movement of food through your digestive system and increases stool bulk. It is found in food such as whole grains, vegetables, wheat bran, beans, and nuts.

Spinach is a good source of insoluble fibre, and therefore, it supports the digestive system and can prevent constipation.

Vitamin K

Vitamin K is an essential vitamin for blood clotting and keeping your bones healthy. Vitamin K also plays a role in heart health.

Vitamin E

Vitamin E is a fat-soluble vitamin that acts as an antioxidant. It is also involved in maintaining healthy skin and eyes, enhancing immune function, and preventing clots from forming in blood vessels. Vitamin E is found in a variety of foods, such as plant oils, nuts, seeds, red bell pepper, spinach, and mango. 

Vitamin C

Vitamin C, or ascorbic acid, has many important functions. These include wound healing, protecting the cells and keeping them healthy, but also maintaining healthy skin, bones, cartilage, and blood vessels. Vitamin C is also a powerful antioxidant that can protect the body against many diseases.

Vitamin A

Spinach contains a high content of carotenoids, which the body converts into vitamin A. Vitamin A has several important functions, such as supporting the immune system and eye health as well as keeping the skin and the lining of some parts of the body healthy.

Iron

Eating spinach is an excellent source of iron. Iron is an essential mineral found in such proteins as haemoglobin, an oxygen-binding protein in red blood cells. Red blood cells carry oxygen around the body and are essential for our health. Iron is also important for a fully functioning immune system. An iron deficiency, known as anaemia, can be detrimental to your health as it can cause many health problems.

Calcium

Calcium is a mineral important for bone and teeth health, regulation of muscle contractions (including your heartbeat), and helping blood to clot normally. Lack of calcium can be detrimental and can lead to rickets in children and osteomalacia or osteoporosis later in life. 

Folate

Spinach leaves are also a good source of folate. Folate is the natural form of vitamin B9 and is found in many foods. It plays a role in normal cellular function and tissue growth and is vital for pregnant women.

Plant compounds

Spinach also contains several plant compounds:

• Lutein – a naturally occurring carotenoid that supports eye health
• Zeaxanthin – a fat-soluble antioxidant compound and one of the most common carotenoids. Like lutein, it also improves eye health
• Nitrates – chemical compounds that help improve heart health
• Kaempferol – an antioxidant that can reduce your risk of cancer and other chronic diseases
• Quercetin – an antioxidant that can prevent infection and inflammation

Ways to include spinach in our diet

Spinach can be easily added to our diet in many different ways. For example:

• Add into a smoothie or make spinach juice
• Include in your omelet
• Add into sandwiches or wraps
• Eat it on pizza
• Bake it into muffins
• Blend it into hummus
• Swap lettuce with spinach
• Add it to a rice or pasta dish, e.g. chicken and spinach alfredo bake

Side effects and recommended consumption

The recommended amount of spinach is around 80g per day.

Spinach is considered safe to consume for most people. However, spinach contains a high amount of oxalates, so it may not be safe for people with kidney stones. Therefore, people who suffer from kidney stones or people with a history of kidney stones should limit their consumption of spinach.

In addition, people on blood-thinning medication should be cautious of their vitamin K intake. This is because vitamin K plays a role in blood clotting and may interfere with any blood-thinning medication. If you are on blood-thinning medications, it is best to consult your GP before you consume large amounts of spinach.

Summary

In summary, spinach is a leafy green vegetable that has tremendous health benefits. It is a good source of vitamin C, vitamin K, vitamin A, calcium, nitrates, iron, and folate. The high content of carotenoids in spinach, including lutein and zeaxanthin, play a role in eye health and are linked with reduced risk of age-related macular degeneration (AMD) and cataracts, major causes of blindness. In addition, spinach is a rich source of nitrates, which can improve heart health by reducing blood pressure and lowering the risk of heart disease and stroke. Moreover, spinach has many protective properties, as the antioxidants found in spinach reduce the risk of many chronic diseases, including cancer, cardiovascular disease, and diabetes.

Spinach can easily be added to many dishes and is safe for most people to consume. However, its high content of oxalates may not be safe for people who suffer from kidney stones. The vitamin K content of spinach also plays a role in blood clotting and, as a result, may interfere with blood-thinning medication.