Wednesday, April 15, 2009

The Power Of Super Foods

These 10 top nutritional performers can transform your diet -- and possibly your life.

It's come to this again: A New Year and a wincingly honest appraisal in front of the mirror. And even if the scale doesn't show it, January can make the excesses of the last few weeks -- OK, months -- feel like armies of fat globules occupying your body.

What's the get-healthy, get-thin new you to do, especially now that low-carb is over?

Don't despair. This year's version of New Year's salvation lies in the concept of "superfoods" -- the current darlings of healthy-eating bestsellerdom. It's eating lots of blueberries and avocado, spinach and, yes, dark chocolate, although not necessarily on the same plate.

The premise is that certain foods are nutritional powerhouses, and should be piled into grocery carts and lunch boxes. Blueberries bubble with cancer-fighting, heart-healthy antioxidants, avocados ooze with the same good fats that olive oil has, and spinach, well, spinach has it all, as Popeye always knew.

Current superstars are tea and dark chocolate, both brimming with antioxidants. (As soon as coffee makes the list, it will be nirvana.)

The claims about these foods made by food marketing professionals and in popular books like "SuperFoods Rx," by San Diego opthamologist Steven Pratt (William Morrow 2004, 336 pages, $24.95) tend to create the impression that "superfoods" are the nutritional equivalent of the fountain of youth and will save you from cancer, heart disease, diabetes and every other scourge of good health.

That's probably not true.

But that doesn't mean superfoods should be dismissed.

The fact is, there's every reason to eat them.

Good nutrition

The antioxidants in blueberries are good for you. Avocado's monounsaturated fats are healthier than, say, the saturated fats in butter. A little bit of dark chocolate does contain micronutrients that help lower blood pressure and do other good things for the heart.

It's called nutrition, a concept dietitians have been trying to sell for years. Now, suddenly, it's trendy.

Food companies find the superfoods concept irresistible for advertising. But that doesn't mean that Dole, the fruit and vegetable giant, was wrong when it called Brussels sprouts a superfood in a holiday publicity pitch to food writers. The sulfurous brassicas do contain lots of vitamin C and some other useful phytonutrients, and they're very good for you.

Pratt, and co-writer Kathy Matthews, have probably done the most to popularize the concept. Pratt noticed the connection between good nutrition and health when patients suffering age-related macular degeneration improved when they started eating more nutritious foods.

Their "SuperFoods Rx," with 300,000 copies in print, spotlighted "14 foods that will change your life," and made the case for each as an ingredient that "can help you extend your lifespan." The book summarizes research studies on the beneficial effects of various foods, pulling together the good news from the torrent of conflicting reports about nutrition that flood the media.

For example, tomatoes, especially processed or cooked ones, have tons of cancer-fighting lycopene. Turkey breast is an exceptionally lean source of protein; it has much less saturated fat than chicken. And drinking tea -- green or black -- delivers a potent dose of antioxidants.

This month, the authors are coming out with a follow-up called "SuperFoods HealthStyle," which updates research on the first 14, and adds another dozen or so.

New to the list are apples (for fiber), kiwis (for vitamin C), and the avocado and dark chocolate previously mentioned.

A lot of this is common sense, or at least not exactly news. But here's the thing: Even though people know what's good for them, they don't always know how to work these foods into three meals a day.

Pumpkin, for instance, shows up around the holidays, usually as pie, but then disappears for the rest of the year -- depriving you of its fiber, potassium and most of all its carotenoids, the antioxidants prevalent in orange and dark-green foods.

To offer some fun and delicious approaches to using 10 "superfoods," The Chronicle's Roving Feast columnist Marlena Spieler has devised the accompanying recipes.

Think 'whole'

The thing to remember, as both Pratt and nutritionists like the Bay Area's Jo Ann Hattner emphasize, is that superfoods are really just a way to think about adding whole foods to your diet. Most of them are fruits and vegetables; oats, a whole grain, are also on the list.

All of the superfoods would fit neatly into the federal government's prescription for healthy eating -- if they're eaten in appropriate amounts.

One ounce of dark chocolate may be good for you, but more is not merrier -- at least nutritionally. Chocolate -- and likewise olive oil -- has so many calories, you really should eat only a little at a time.

The other thing is, the superfoods list means people are likely to be eating lots of blueberries while ignoring all their berry friends, like raspberries and boysenberries, as well as other red fruits like cherries. But that would be a mistake.

The other berries may not have quite as many anthocyanins (antioxidants) as blueberries, but they have some and are likely to contain other micronutrients whose value simply hasn't yet been studied as much yet.

More to come

"When you look at the list of superfoods, it's the ones that have had the most research," says Hattner, a San Francisco registered dietitian who teaches nutrition at the Stanford School of Medicine.

"There are so many foods that there are benefits for but we haven't studied it."

Many food-specific studies are paid for by a crop board or commodity group, she points out, adding, "the poor celery stalk hasn't had it yet.

"You don't want to eat just blueberries because you may miss out on other nutrients in other fruits that you need as well," Hattner says. And Pratt covers the point in his books, listing "sidekicks" to each superfood that should be consumed to round out the diet.

Whole foods will always be better than trying to get the same nutrients through supplements, Hattner says. Foods deliver many nutrients, not just the ones science has pinpointed.

And the nutrients are delivered in combinations that may give them more power than any one alone -- a concept known as synergy.

For example, Hattner says, current research shows that consuming vitamin E and lycopene together -- avocados with tomatoes, say -- enhances their antioxidant effects. The oligosaccharides in onions also boost tomatoes' lycopene.

That's likely to be the next nutrition frontier, according to Hattner, who says, "I think the future of food would be combinations of foods."
Glossary of terms

The language of superfoods can be confusing, because many of the terms for nutrients overlap. Here is a basic glossary:

Antioxidants. An umbrella name for many substances that retard the body's normal process of oxidation, meaning a reaction to oxygen that releases "free radicals" that damage cells and break the body down. Digestion releases free radicals from food. Antioxidants help prevent this and also are thought to destroy free radicals and slow oxidation, reducing allergies, heart disease, cancer and aging effects. Dozens of antioxidant nutrients have been identified so far, and there are likely many more. Many vitamins have antioxidant effects, including A (which is a carotene), C and E.

Flavonoids.These are the best-known antioxidants -- think tea and dark chocolate -- among a group called polyphenols. You also see the word flavonol, which is a subgroup of flavonoids. Relatives are anthocyanins (which give blueberries their fame).

Carotenoids. These are the pigments that protect dark green, yellow, orange and red fruits and vegetables from sun damage -- and they work as antioxidants in humans, too. Beta-carotene is the best known -- it's also called vitamin A. Other famous carotenoids -- there are dozens -- are lycopene and lutein.

Vitamins. Nutrients considered essential to health; a shortage of vitamins can create health problems.

Phytonutrients. Plant-derived compounds that are believed to improve your health, but aren't essential to your health. This includes many antioxidants.

What's so super about ... ?

Apples. According to "SuperFoods Lifestyle" author Dr. Steven Pratt, different varieties of apples have different phytonutrients, but they all have tons of antioxidants, including flavonoids and other polyphenols, and fiber.

Avocados. Avocados have the same thing going for them that olive oil does: healthy monounsaturated fatty acids. These are the "good fats," and they appear to lower LDL (bad) cholesterol levels, and raise HDL (good) cholesterol levels. Fiber, potassium, magnesium, folate and antioxidants up the ante. And Pratt cites research showing that avocado helps the body absorb more nutrients from other foods -- the tomato in the same salad, for instance.

Beans. They haven't gotten the same media buzz as blueberries, but some beans have even more health-promoting antioxidants. They also have as much cholesterol-lowering fiber as oats, and lots of lean protein. All of that is good for your heart. They also are rich in B vitamins and potassium. This category includes both dried and green beans.

Blueberries. Frozen do the trick as well as fresh, and they're easier to find in winter. For such tiny fruits, they deliver a huge wallop of antioxidants of many kinds, including anthocyanins and other polyphenols, and carotenoids. They also have fiber, folic acid and vitamins C and E. And they taste good with very few calories.

Dark chocolate. The magic word here is flavonoids, the same kinds of antioxidants that make tea so potent a health brew. Research shows flavonoids have a role in helping lower blood pressure and in keeping your arteries from clogging -- both good news for your heart. Only dark chocolate does the trick, not milk or white. And the more cocoa solids the better -- look for the percentage on the label.

Kiwis. Vitamin C, vitamin C, vitamin C -- kiwis are loaded in this antioxidant, which also makes oranges a superfood. Kiwis rival bananas in potassium, pound for pound. And flavonoid antioxidants abound in the skin, which is edible but best if you rub the fuzzy stuff off first.

Oats. Kings o' fiber, oats also deliver protein, potassium, magnesium and other minerals, and phytonutrients, including antioxidants. Their cholesterol-lowering powers are well known, and all that fiber is also believed to help stabilize blood sugar. Oats' combination of nutrients appears to have more healthy effects than if each nutrient were consumed separately -- which seems to be true of all whole grains. And, they're inexpensive.

Spinach. What doesn't spinach have? It's loaded with lutein (great for eyes) and many other carotenoids, which are healthful antioxidants; plus other antioxidants like coenzyme Q, in serious doses; plus several B vitamins plus C and E; plus iron and other minerals; plus betaine, a vitamin-like nutrient research suggests is good for your heart. And with almost no calories, you can eat as much as you want. Also good for similar reasons: kale, chard and other dark leafy greens.

Walnuts. All nuts have been rehabbed as good-for-you foods, for their healthy fats and micronutrients. A few go a long way, though, as they are calorie bombs. Walnuts' main claim to stardom are their omega-3 fatty acids, which fight heart disease. Other goodies: plant sterols, which lower cholesterol, and lots of antioxidants.

Yogurt. Nutritionist Jo Ann Hattner says if she could pick only two superfoods, they would be yogurt and tea, because their health-giving attributes have been known for centuries. Yogurt's claim to fame is live cultures, also called probiotics or beneficial bacteria. They are what turns milk into yogurt (but some commercial yogurts are heated to kill the cultures after they do their work, so be sure to read the label). In your gut, they fight bad bacteria, aid digestion, help metabolize food and generally tune your system up. Yogurt also is a good source of calcium and protein.

--------------------------------
Carol Ness at cness@sfchronicle.com.
--------------------------------

No comments: