Which Leafy Greens Have the Most Iron? A Guide to Top Sources

November 4, 2025 •

4 min read

While spinach is a popular choice, several other leafy greens contain comparable or even higher levels of iron, such as amaranth leaves. To determine which leafy greens have the most iron, one must consider both iron quantity and factors affecting absorption.

Quick Summary

This guide reveals the best leafy green sources of iron, comparing their nutritional value and discussing the critical role of absorption enhancers like Vitamin C. It provides a detailed comparison table and practical tips for maximizing iron intake from plant-based foods.

Key Points

Spinach is a great source, but not the only one: While high in iron, its absorption is impacted by oxalates, making it less bioavailable than some believe.
Amaranth leaves are a top contender: Containing significant iron levels and fewer oxalates than spinach, amaranth leaves offer a compelling alternative for increasing plant-based iron.
Pair greens with Vitamin C: Boosting non-heme iron absorption is crucial and easily achieved by adding vitamin C-rich foods like citrus or bell peppers to your meals.
Cooking methods matter: Cooking can break down cell walls and reduce oxalate content, improving iron bioavailability from leafy greens.
Diversify your greens: A mix of spinach, amaranth, Swiss chard, and beet greens ensures a broad intake of nutrients and a balanced approach to iron consumption.
Use an iron skillet: Incorporate cooking with a cast-iron pan to naturally infuse more iron into your leafy greens and other foods.

The Non-Heme Iron Challenge

Iron from plant-based sources, known as non-heme iron, is typically not as bioavailable or easily absorbed by the body as heme iron found in animal products. However, this does not mean plant-based diets are deficient in iron. The amount of non-heme iron that your body absorbs can be significantly influenced by other compounds in food, such as inhibitors like oxalates and phytates, and enhancers like vitamin C. Cooking processes can also influence bioavailability, often making the iron more accessible. Understanding these factors is key to getting the most iron from your greens.

Amaranth Leaves

Often referred to as 'Chinese spinach,' amaranth leaves are a powerful source of iron and other nutrients, including calcium and potassium. While reported iron content can vary based on the method of preparation, they generally provide a high concentration, with some cooked varieties offering around 2.3mg per 100g, and others reporting even higher values after specific cooking methods. Unlike spinach, amaranth leaves contain lower levels of oxalates, which can improve the overall absorption of its non-heme iron.

Spinach

Spinach is arguably the most famous iron-rich leafy green, largely due to its high raw iron content. A 100g serving of cooked spinach contains approximately 3.6mg of iron. However, spinach is also high in oxalic acid, a compound that can bind to minerals like iron and inhibit their absorption. This is why combining spinach with a source of vitamin C is so important to maximize the health benefits. While cooking can reduce the level of oxalates, it is still a factor to consider when consuming spinach as an iron source.

Swiss Chard

Another excellent choice is Swiss chard, which offers a good amount of iron along with other essential nutrients, including vitamins A and K. A 100g serving of cooked Swiss chard provides around 2.3mg of iron, a figure comparable to cooked amaranth leaves. Swiss chard has a lower oxalate content than spinach, which is a key advantage for iron absorption. It is also a versatile green that can be added to soups, stir-fries, and salads.

Beet Greens

Beet greens, the leafy tops of beetroots, are another often-overlooked nutrient powerhouse. They contain significant levels of iron and vitamin C, making them a dual-purpose vegetable for boosting iron intake. The naturally high vitamin C content means the iron present is more readily absorbed by the body. They are also rich in antioxidants and fiber.

Maximizing Iron Absorption from Leafy Greens

Because leafy greens contain non-heme iron, simply eating them is not enough. Strategic meal planning can significantly increase the amount of iron your body absorbs. Here are some effective strategies:

Pair with Vitamin C: Consuming vitamin C-rich foods with your leafy greens is one of the most effective ways to boost non-heme iron absorption. A squeeze of lemon juice on a spinach salad or adding bell peppers to a Swiss chard stir-fry can significantly enhance uptake.
Cook with Allium Vegetables: Ingredients like garlic and onions can also improve iron absorption. Adding these to your cooked greens not only enhances flavor but also helps your body utilize the minerals more efficiently.
Use an Iron Skillet: Cooking your greens in a cast-iron pan can help transfer some of the pan's iron content into the food, providing a passive and simple way to increase intake.
Avoid Inhibitors: Tannins in coffee and tea can inhibit iron absorption, so it's best to consume these beverages at least an hour or two away from iron-rich meals. Similarly, large doses of calcium supplements can interfere with iron, so consider spacing out their intake.

Leafy Green Iron Comparison

This table provides a quick overview comparing the iron content and key absorption factors for some of the best leafy green sources.


Leafy Green	Iron (mg per 100g cooked)*	Oxalate Content	Key Absorption Notes
Amaranth Leaves	~2.3mg	Low	Lower oxalate levels than spinach may lead to better absorption.
Spinach	~3.6mg	High	Best paired with vitamin C sources to counteract oxalates.
Swiss Chard	~2.3mg	Moderate	Lower oxalate content than spinach; excellent with vitamin C.
Kale	~1.0mg	Low	Lower oxalate levels and good vitamin C content make for decent absorption.
Beet Greens	Variable	Moderate	Naturally high in vitamin C, which aids absorption.

*Note: Iron content can vary significantly based on cooking method and preparation.

A Diversified Approach to Iron

While individual iron numbers are useful, a diversified diet remains the most effective strategy. Focusing on a variety of leafy greens ensures you get a broader spectrum of nutrients. Incorporating amaranth leaves, Swiss chard, and beet greens alongside spinach can provide a more balanced intake of minerals, as each offers unique benefits and absorption profiles. The key is to be mindful of how you prepare and pair your foods, taking simple steps to enhance absorption.

Conclusion

While the search for a single, definitive "winner" is complicated by factors like non-heme bioavailability and absorption inhibitors, amaranth leaves and spinach often lead the list in terms of sheer iron content. However, greens like Swiss chard, kale, and beet greens provide fantastic complementary sources. The best strategy is not to rely on just one green but to build a varied diet rich in leafy greens, pairing them with vitamin C sources and implementing optimal cooking practices. By understanding how to maximize absorption, you can ensure your body is effectively utilizing the iron from all your nutritious, plant-based meals.

For more information on daily iron requirements and dietary sources, visit The Nutrition Source from Harvard T.H. Chan School of Public Health.

Frequently Asked Questions

Yes, cooking leafy greens like spinach and amaranth can slightly decrease their iron content due to leaching. However, cooking also breaks down cell walls and may reduce levels of oxalates, potentially increasing the bioavailability and absorption of the remaining iron.

To significantly boost absorption, pair leafy greens with foods high in vitamin C, like bell peppers or lemon juice. Cooking with allium vegetables (garlic, onions) and using a cast-iron pan can also help.

Leafy greens contain non-heme iron, while meat contains heme iron. Heme iron is more readily absorbed by the body, whereas non-heme iron absorption is more tightly regulated and can be inhibited by other compounds in plants, such as oxalates and phytates.

Cooked spinach is one of the highest sources of iron among common leafy greens, providing approximately 3.6mg per 100g. However, the presence of oxalates affects its absorption. Amaranth leaves also contain substantial iron with fewer oxalates.

Yes, it is recommended to avoid drinking coffee or tea around the time you consume iron-rich foods. The tannins in these beverages can inhibit iron absorption, so it's best to wait at least an hour or two after your meal.

Yes, it is possible to get sufficient iron from a vegetarian or vegan diet rich in leafy greens and other plant sources. However, it requires a balanced diet and conscious effort to maximize absorption, primarily by pairing iron-rich plants with vitamin C.

Yes, other plant-based sources of non-heme iron include lentils, beans, tofu, pumpkin seeds, and potatoes. Eating a variety of these foods along with leafy greens provides a comprehensive approach to meeting your iron needs.