At least two factors determine the nutrition level of the produce – the fruits and vegetables – we eat: the source and the preparation method. In the November 2000 column on Farmers’ Markets we saw that the freshness hierarchy among sources is generally your own garden first, then the local farmers’ market, then frozen, then supermarkets, then canned. Many nutrients oxidize rapidly after produce is disconnected from its umbilicus to the earth, and cooking and preservation methods can further affect its nutrition for better or worse. Once we have those fresh, green goobers in our hot little hands, it’s up to us to prepare and serve them to best insure the best nutrition from our produce … and to decide whether the benefits of the “best” way are worth the effort.
The increasing tendency with produce is towards raw, crunchy and still wiggling. While that’s unsettling -- probably downright dangerous -- with pork chops, it’s easy with raw apples or bananas, even broccoli. After all, produce provides the best nutrition when it’s raw – LIVE -- doesn’t it?
Yes … and no. There are advantages to both raw and cooked, and they vary across the produce spectrum. Let’s dig into the garden and examine the advantages of both. Is raw a fad, or do the best fruit and vegetable nutrition really come from eating produce still “warm from the vine”, and raw to boot? Maybe the latter … if you like eating boots, have four stomachs, and moo.
OK, that was a joke. While many methods of cooking our produce preserve – sometimes even improve -- its nutrition, many types of produce are tasty and quite digestible raw, even for us humans. The people, cookbooks, restaurants, books, Californians, etc. which advocate eating produce still squealing on the plate offer several arguments for their side. They say cooking:
- Breaks down vitamins, thousands of micronutrients, and fiber, into useless, inert mush.
- Leaches many vitamins and other nutrients into the cooking water, which is then discarded.
- Breaks down enzymes nature put in the food to help us digest and assimilate it.
- Transforms some food components to carcinogens.
- Transforms healthy oils to harmful oils.
The anti-milk, anti-aspartame (Equal), and anti-carbohydrate purists list pages of frightening reasons to support their phobias, but many of their objections are based on reactionary, unsupported, sometimes distorted, claims. The raw produce advocates, however, are on to something. Their basic claims listed above are generally true, and should be considered in our diets. But who’s going to eat yams or corn raw? They enhance our nutritional profile, so cooking them beats not eating them, and candied yams are better than many desserts in every way. It can transform some vegetables from lumber only a beaver could endure to beneficial gastronomic pleasures your favorite meat’n’taters lumberjack will enjoy.
True, heat breaks down many vitamins, up to 30% in some cases. Boiling leaches another 10-20% of the vitamins, 5-15% of the minerals, and some of the fiber into the water. Phytochemicals, enzymes, and other important micronutrients only a microbiologist could love suffer the same fate, as the raw produce lobby correctly points out.
OK … and their point? Those effects are essentially inconsequential as long as we eat a wide variety of produce in a variety of ways. We don’t need every micronutrient every day, and the enzymes spared by eating our produce “live” quickly die a horrible death anyway the minute they hit our stomach acid.
A moment of silence for the departed enzymes.
Cooking, however, starts the digestive process by breaking down cell walls, often facilitating nutrient assimilation more than the poor, deceased enzymes would have. We may lose 30% of the vital carotenoids – important antioxidants in some entire classes of vegetables – to heat and water, but their bioavailability triples with cooking. Do the math: 100% minus 30% or 40% = 60 or 70%, times 3 … we essentially double the amount of antioxidants we absorb from those veggies by cooking them. Fresh home-grown tomatoes taste marvelous, but there’s nothing like long-simmered tomato sauce to free up their natural, cancer-inhibiting lycopene. We aren’t cows by nature, and become Californians by choice or (tragic) accident, but Mother Nature gave us fire, pizza dough, and tomato sauce by design.
Nuking, steaming, or stir-frying veggies with just a little water or oil (olive or canola, please) cuts nutrition losses to <15%, and enhances flavor and appeal for all but the most Californicated live-veggie enthusiasts. The vegetables many of us grew up eating – long-dead plants stewed to tasteless, mushy, oblivion by overzealous cooks – would turn anyone off vegetables, and leaches out many nutrients. But cooking them only until hot and lightly tenderized retains the nutrition and the chewy texture, and enhances the flavor. Adding herbs, spices, and healthy sauces further entices that Iowa corn-fed beefeater in the house to expand his culinary interests while shrinking his waistline and extending his lifespan.
A friend’s pot roast and green beans are tough to tell apart. They have similar textures, their primary remaining flavor is salt after a day in or on the stove, and the juices, containing half of the nutrition and most of the natural flavor, are put on the dog’s food. (Her husband died at 40 but the dog hit 45.) At least in the deep South they gave the cooking juice a name – pot liquor, pronounced pot likker – and serve it with the food. That’s one reason southern food TASTES so great, and it usually improves its nutrition. Doing this with the juice from canned vegetables salvages much of their nutrition and flavor, too.
Next time the kid in your family -- whether he is in grade school or a midlife crisis -- refuses to eat that big bowl of fresh spinach, steam or nuke the whole bowlful for a moment into a more compact form, put it in a corner of the big baby’s plate, and tell him to eat the dang thing and shut up. He won’t know those few tender, moist forkfuls were the whole bowl if you don’t tell him, and the walnuts, raisins, dash of bacon, and honey mustard dressing in the lightly cooked version will draw him in and put a smile on his face. Condensing vegetables in this way helps the medicine go down, and enhancing them with seasonings creates food that even your favorite carnivore will enjoy … probably for an extra decade or two.
Not that there’s anything wrong with raw, as Seinfeld might say. It expands our options, makes for more convenient and more enticing snacks than cooking up some greens and pot likker, and dips far more easily in fondue than do pureed carrots or stewed tomatoes. The raw crunch appeals to many people, and provides a broader range of nutrients. Those who promote increasing our veggie consumption warn us to do so slowly, especially if it’s raw, to avoid gas due to the sudden change. Let me ask you veggie-phobes, though: how likely are you to increase your daily veggie consumption overnight from one baked potato to the recommended five to nine servings of green and yellow and red produce? I just thought I’d mention the warning in case you decide tonight that properly prepared Brussels sprouts (under seven minutes, or pay the price) are better than prime rib and ice cream.
Raw does have the advantage of not producing the carcinogens that baking and frying at high temperatures can generate from veggies and grains. Even cereal and toast may be guilty, but frogfries (a little contribution to the boycott) and potato chips are more likely suspects. Anyone who deep fat fries their food needn’t be concerned about freshness anyway, because the raw/cooked/fresh/frozen dilemma fades into insignificance as soon as the food hits the hot grease. Grilling it much more healthy, but only if we discard the burned edges and don’t subject the veggies to too much carcinogenic meat drippings smoke.
In essence, the biggest factor in our produce nutrition is variety in sources, colors, and preparation. Achieve that, and the details will take care of themselves. A great side benefit of all this delicious, healthy food is that we can eat all the produce we want and still manage our weight.
Thanks for being good sports, Californians. But watch out; those bean sprouts can harbor many biological and chemical hazards.