Nutrition factoids at the farmers market

some factoids with your veggies?

some factoids with your veggies?

Customer: “So what do I do with kale?  Do I just eat it raw?”

Farmer 1: “You can use it in stir fry.  Or in soup.  It’s really easy to cook.”

Farmer 2: “Cooking destroys all the enzymes and vitamins.”

The customer is now confused.  We all should be.  If in fact cooking destroys all the vitamins and supposed enzymes (more on that later), why do we eat any cooked food?  How does anyone survive on cooked food?  Isn’t it all nutritionally worthless pulp?

If in fact cooking destroyed all the vitamins, why does the USDA food database for 1 cup of cooked kale says this:

vitamin C      53 mg
vitamin B1     0.7 mg
vitamin B2     0.9 mg
vitamin B6     0.18 mg
vitamin A     17700 IU

By the way, that’s enough vitamin A to cover your daily requirement in just one cup of cooked kale.

The USDA arrived at those numbers by laboriously analyzing each food in a laboratory for all possible nutrients.  The numbers aren’t just made up, like the factoids some people dish out as nutrition advice.

So no, cooking doesn’t destroy all the vitamins.  In fact, in some instances, cooking makes nutrients more available by breaking down cell walls so your digestive enzymes can process the food more completely.

Which brings us to the topic of enzymes.  Enzymes are proteins.  They come in multiple shapes and sizes, and they have very specific tasks to perform in metabolism.  Sometimes an enzyme will have just one job: attach one specific molecule to another, or take another molecule and split it at a specific location.  Your body is full of enzymes.  Plants and other animals also have enzymes doing specific tasks.  When you eat a food, you are likely eating some of those enzymes.

Keep in mind: enzymes are proteins.  And when you eat protein it is digested, whether it’s an enzyme or a muscle fiber from beef or chicken, or a protein in milk or an egg.  Your digestion doesn’t care.  All proteins are broken apart into amino acids.  The process starts in the stomach and continues in the intestines.  Whether or not cooking destroys enzymes (or other proteins in that food) doesn’t matter to you.  You have your own specific digestive enzymes.

There’s another problem with the “cooking destroys enzymes” myth.  Enzymes are proteins, so if cooking is destroying them, it’s likely destroying all the other proteins in the food.  Which doesn’t happen, unless you happen to burn your steak into a blackened crisp on the grill.  Then we can safely say that method of cooking destroyed the proteins; in fact it destroyed the food.

By the way, that cup of cooked kale has 2-1/2 grams of protein.  Not bad for a vegetable with only 36 calories.

Farmers’ markets are great.  You can find local vegetables, in season, so they’re at the peak of flavor and freshness.  The farmers who grow the produce and raise the chickens and cows work hard.  But nutrition experts they are not.  Fortunately, most of the vendors refrain from making silly statements about nutrition.  If they do, ask to see their nutrition credentials.  And yes, cooked kale is still packed with nutrients.


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