Authors: Registered Dietitians
(HealthCastle.com) “I’m Popeye the Sailor Man”….the star of the famous cartoon made spinach a food well recognized for its powerhouse nutrition. All it took was a can of spinach for Popeye to gain the strength to take on the world. It’s no wonder Popeye always received superhuman strength after eating spinach; it’s packed with nutrition. While eating spinach will not produce instant magical effects, it is exceptionally rich in nutrients such as beta-carotene, lutein, quercetin (a phytochemical with antioxidant properties), folate, vitamin K, magnesium, manganese and an excellent source of calcium and potassium and fresh spinach has only 13 calories per 2 cups.
Raw spinach is a healthy addition to salads or it can be used as the main green for a salad, but to get the full benefit from this leafy green, eat it cooked at least some of the time. Cooking spinach makes the antioxidant carotenoids easier for the body to absorb much in the same way that lycopene is better absorbed from cooked tomato products. Cooking also makes the calcium and magnesium more available for absorption.
There are three basic types of spinach:
Savoy: has a crinkly, curly leaf with a dark green colour; it is the type sold fresh in bunches at most markets. Fresh and crisp, it’s particularly good in salads.
Flat or smooth-leaf: has unwrinkled, spade-shaped leaves that are easier to clean than savoy; this is the type generally used for canned and frozen spinach as well as soups, baby foods, and other processed foods.
Semi-savoy: increasing in popularity, they have slightly crinkled leaves. These offer some of the texture of savoy but are not as difficult to clean, they are used for both fresh market and processed foods.
How to choose: Fresh spinach is sold both loose and in bags. Loose spinach is easier to evaluate for quality. Select small spinach leaves with good green colour and a crisp, springy texture; avoid wilted, crushed, or bruised leaves, and those with yellow spots or insect damage. Smaller leaves and thinner stems are tenderer; spinach with coarse, thick stems indicates overgrown spinach, which may be leathery and bitter. Fresh spinach should smell sweet, never sour or musty.
How to store: Store unclean in an open plastic bag in your crisper. Spinach is fairly perishable (it will only keep about a week) so plan to and do eat it soon after purchase. If it gets a little soggy, wash it in cold water and put it in your freezer for a minute to perk it up. Don't forget about it, though, but if you do, you have frozen spinach which can be cooked easily enough.
A word on lutein. Lutein (pronounced LOO-teen) is one of the yellow and orange pigments found in dark green leafy vegetables such as spinach, kale, collards and bok choy plus various fruits and corn. In vegetables like spinach and broccoli, the yellow colour is masked by a high level of chlorophyll. Egg yolks are also sources of lutein as are mangoes, watermelon, cooked carrots, winter squash, cooked tomato products.
Why is lutein important in our diet? Simply put, lutein is an antioxidant that appears to quench or reduce harmful free radicals in various parts of the body. Free radicals can play a role in a variety of chronic diseases. Lutein is highly concentrated in the macula, a small area of the retina responsible for central vision, and high visual acuity. The macular pigment (MP) is the yellow pigment within the macula that protects this tissue from the damaging photo-oxidative effects of blue light, and is comprised entirely of lutein and its related compound, zeaxanthin.
Of the 600 or so carotenoids (plant pigments that give plants their colour) present in nature, only a handful are present in our bloodstream. Of those, nature has chosen only lutein and zeaxanthin to be present in the macula. By increasing the macular pigment density, lutein helps to filter the damaging blue light (think of lutein as internal sunglasses) and it also helps to quench any free radicals that are produced. Studies using lutein supplements have also shown improvements in slowing existing macular degeneration, but food offers much more in the way of nutrients.
In population studies, those who eat more dark green vegetables, and therefore lutein (confirmed by measuring the macular pigment), tend to have lower rates of macular degeneration. These facts alone suggest that lutein plays a critical role in eye health and while further studies are required to confirm that lutein can prevent macular damage, eating more vegetables will help to ensure that you are getting all the possible benefits that they confer. Lutein is also showing promise in the fight against heart disease. Lutein helps to protect LDL cholesterol from oxidation, an important first step in plaque formation.
To increase your intake of lutein, include some of these foods every week
- Turnip greens
- Collard greens
- Swiss chard
- Brussels sprouts
- Green Peas
- Winter squash
- Cooked tomato products
- Dark green lettuces