Why to head for the greens!

I’ve been exploring various sources of calcium and seeing how they stack up against one another. In general, cheese, with its low water content, does well in the Most Calcium per Gram category, especially Parmesan cheese. Leafy greens do rather well with Most Calcium per Calorie – collard greens and Chinese cabbages are winners here.

So why pick leafy greens over dairy products? Besides side-stepping the protein issue, leafy greens have so much going for them that I’m ashamed that I don’t eat them at every meal. Let’s compare a cup of plain low-fat yogurt with a cup of cooked collard greens on a smattering of nutrients: fiber, fat-soluble vitamins, and a few minerals.

Plain low-fat yogurt vs.Cooked collard greens

	Yogurt	Collard Greens
Fiber:	0g	5g
Vitamin A:	125 IU	15416 IU
Vitamin D:	n/a	n/a
Vitamin E:	0.1 mg	1.7 mg
Vitamin K:	0.5 mcg	836 mcg
Calcium:	448 mg	266 mg
Iron:	0.2 mg	2.2 mg
Magnesium:	41.7 mg	38.0 mg
Phosphorus:	353 mg	57.0 mg
Potassium:	573 mg	220 mg
Sodium:	171 mg	30 mg

Collard greens clearly have the upper hand when it comes to fiber and fat-soluble vitamins (water-soluble vitamins – C and the Bs – are more of a mixed bag), but yogurt comes rushing back in the mineral department, with the exception of iron.

But more sodium is not necessarily better, despite what Cargill might tell you, and too much phosphorus in conjunction with too little calcium is bad news for your bones.

Two more points I’d like to bring out. First, yogurt has 32 mg of omega-3 fatty acids and 76 mg of omega-6 (~1:2.4 ratio) compared to collard greens’ 177 mg and 133 mg, respectively. That’s a 1.3:1 ration, which is great! The more omega-3’s, the better, especially when they outnumber omega-6’s.

Second, a cup of collard greens has a third of the calories of a cup yogurt, so you could eat three times as much and get the upper hand on the minerals! I would recommend, however, adding between a quarter of a teaspoon to a teaspoon of olive oil or butter per cup of greens. Doing so would add up to 40 more calories, but also increase absorption of fat-soluble vitamins, satiety, and deliciousness.

I could go on about phytonutrients and the Brassica family, but I believe I hear the greens of a farmers’ market calling my name.

Photo by Mark Farnham