Healthy Eating: Mirror image foods

Some foods look alike on the outside, but are they the same on the inside? Find out how these fruits and vegetables match up on this round of food fights.

By KATHRYN RUBIN
Spinach (photo credit: Courtesy)
Spinach
(photo credit: Courtesy)
Do you ever get mixed up between a zucchini and a cucumber? Have you ever wondered if there is a difference between a peach and a nectarine? And what about spinach and kale? Find out how they compare as these fruits and vegetables square off in the following food fights:
Spinach vs. Kale
Both dark leafy green vegetables, spinach and kale each provide an extensive list of healthy nutrients, earning them both a top spot amongst the heath food “must haves." While including these two veggies in one’s diet is extremely beneficial – as both deliver an ample supply of vitamins, minerals and diseases fighting antioxidants - if push came to shove, and you had to choose, which one is healthier?
First up: Spinach. The symbol of the popular comic hero Popeye the Sailor Man, spinach is low in calories (only seven calories per cup), rich in fiber, as well as loaded with many vital nutrients, including vitamins A, C and K, manganese, magnesium, iron, folate and even calcium.  Moreover, like other green vegetables spinach is rich in lutein and zeaxanthin - two antioxidants that are needed to maintain proper eye health and to protect the eyes from cataracts and age-related macular degeneration. 
This dark green veggie is also abundant in certain flavonoids that have been shown to slow the division of stomach and skin cancer cells, while other studies have shown that eating spinach may provide significant protection against prostate cancer. So while Popeye may be a fictional character, the ability of spinach to make this cartoon character big, strong and of course healthy is very real. 
But how does kale stack up? While it may not be as famous as spinach, kale should not be easily dismissed – in fact, when it comes to the nutritional content of these two vegetables, kale marches all over its more celebrated rival. A nutritional all star, one cup of chopped kale (approx. 67grams) provides 134 percent of one’s daily-required intake of Vitamin C, a whopping 684% of one’s daily recommended intake of vitamin K – an essential vitamin needed for proper blood clotting and maintaining the strength and density of bones - as well as 206% of one’s daily-recommended intake of beta-carotene, a pre-cursor to Vitamin A that also boosts the immune system as well as acts a potent anti-oxidant.
So how does this compare to Popeye’s spinach? Gram for gram, kale contains about four times as much Vitamin C, approximately twice as much Vitamin K and A and three times more of the anti-oxidants lutein and zeaxanthin. Moreover, researchers have now identified over 45 different flavonoids inside kale, giving this dark leafy green some extraordinary anti-oxidant and anti-inflammatory powers to fight oxidative stress and chronic inflammation. In fact, kale is so rich in disease fighting nutrients that its risk-lowering benefits for cancer have recently been increased to include at least five different types of cancer: bladder, breast, colon, ovary, and prostate. Finally, like spinach, one cup of kale provides approximately 10% of one’s daily recommended intake of omega 3, an essential fatty acid that is needed for proper brain function as well as helping to regulate the body’s inflammatory process amongst many other important roles. 
So who is the winner in this leafy green food showdown? While spinach certainly packs a health food punch, Popeye would not have suffered if he had swapped his daily spinach for a cup (or two) of kale.
Peaches vs. Nectarines
With a pinkish yellow or whitish flesh and a delicate aroma, the only apparent difference between a peach and a nectarine is the texture of their skin – a peach is coated in velvety fuzz while nectarines are silky smooth. But are their differences more than just skin deep? A peach (175grams) and a nectarine (156grams) both contain around 70 calories, 2.6 grams of fiber and both offer approximately 10% of one’s daily recommended intake of Vitamin A and potassium – an essential mineral needed to maintain a proper electrolyte balance and acid base balance. Peaches contain slightly more Vitamin C, a vitamin that is needed for normal growth and development, to help repair tissues throughout the body. However, aside from this difference, it appears that peaches and nectarines are nearly identical. This is probably due to the fact while peaches and nectarines are regarded commercially as different fruits, nectarines actually belong to the same species as the peach!
Cucumber vs. Zucchini
Cucumbers and zucchinis may have the same long cylindrical shape, a similar pale and seedy flesh and of course a nearly identical dark green skin, but how do their nutritional contents match up?  Unlike peaches and nectarines whose similar outward appearance mirrors their nearly identical nutritional content, the similarities between cucumbers and zucchini do not extend much beyond their outward appearance. 
While both green vegetables are extremely low in calories, zucchini, also referred to as summer squash, is higher in fiber (offering 1.1grams per 100 grams as compared to cucumber’s 0.5grams). Moreover, while cucumbers contain slight amounts of Vitamin C, 100 grams of zucchini offers an impressive 28% of one’s daily-recommended intake of this essential vitamin.
Moreover, zucchini contains more potassium, manganese, beta-carotene, and more of the B-complex vitamins, including Vitamin B6, riboflavin (Vitamin B2) and folate - a vitamin that has been shown to decrease blood homocysteine levels, which if left too high may contribute to an increased risk of cardiovascular disease.
Sounds like zucchini is winning by a landslide, right? A cucumber is 95% water, and therefore is lower in most vitamins and minerals than other vegetables, including the zucchini; nonetheless a serving of cucumber (100 grams) still provides an impressive 21% of one’s daily-recommended intake of Vitamin K – squashing the zucchini in this mini round. But all in all, while zucchini may not be “as cool as a cucumber” it certainly does offer more impressive health benefits.