By now, you've probably heard how a raw-foods diet can soothe digestive woes, boost vitality, and even prevent disease. Based on the premise that heating foods above 114 degrees destroys essential enzymes and nutrients, "living food" plans focus on organic raw and dried fruits, fresh vegetables, herbs, nuts, and seeds; beans and grains; and unrefined plant oils. Excluded are animal products, refined sugars, and processed foods. Far from being a fad, "there's nothing new about [it]," says Renee Loux Underkoffler, author of Living Cuisine (Avery, 2004). "It's a re-emergence of a very old and traditional way of eating that focuses on food in its whole, natural state."

But don't sell your wok on eBay just yet. Some health experts caution that a totally raw-foods regimen may not suit everyone. Check out both sides of the debate below.

Nutrients
Pro raw>> Raw foods may retain more nutrients than cooked. Aside from sun-drying or dehydrating, "when you cook food you destroy up to 80 percent of the vitamins and minerals," claims Gabriel Cousens, MD, author of Rainbow Green Live-Food Cuisine (North Atlantic, 2003). "You lose more than 90 percent of a food's B12, half of the protein, and 100 percent of enzymes and phytonutrients."

This matters, because raw nutrients appear to exert a strong protective effect against disease. In one study, people who ate more raw vegetables demonstrated a lower risk of stomach cancer (Medicina (Kaunas), 2005, vol. 41, no. 9); in another, eating raw foods showed a stronger cancer-protective effect than eating cooked foods (Cancer Epidemiology, Biomarkers, and Prevention, 2004, vol. 13, no. 9). Raw diets also lower total cholesterol and triglyceride levels, both indicators of heart health (Journal of Nutrition, 2005, vol. 135, no. 10).

Raw-foods diets may lack sufficient vitamin B12, primarily available through animal-based foods. you go raw, take a high-quality B12 supplement.

Pro cooked>> "Some nutrients are not as bioavailable until they are cooked," says Shari Lieberman, PhD, CNS, author of The Real Vitamin and Mineral Book (Avery, 2003). The vitamin C in cabbage, for example, is better absorbed after cooking; same for cancer-preventive lycopene, abundant in tomatoes, beta-carotene in carrots, and nutrients found in grains (Critical Reviews in Biotechnology, 2001, vol. 21, no. 1). And raw-foods diets may lack sufficient vitamin B12, primarily available through animal-based foods.

If you go raw, Cousens recommends taking a high-quality B12 supplement.

Digestibility
Pro raw>> Raw foods may be easier to digest. Proponents claim that the enzymes preserved in raw foods help your digestive system to do its job. "Raw foods make a quick exit from the body," says Natalia Rose, author of The Raw Food Detox Diet (Regan, 2005). "This means they're not going to stick around in the body and cause constipation, compromising organs and depleting energy. They are processed so efficiently that the body takes the nutrients it needs and passes the rest through."

Pro cooked>> "Cooking enhances the digestibility of some foods," especially tough, fibrous vegetables, says Lieberman. And certain foods, such as beans, should be cooked for the body to access their nutritional benefit.

Gentle cooking methods to preserve nutrients
>> Lightly steam vegetables or bake on low heat.
>> Slice, shred, or grate dense, starchy vegetables, such as potatoes, to minimize cooking time.
>> Use a low-temperature slow-cooker for soups and stews.
>> Presoak and pressure-cook beans and grains.
>> Instead of roasting nuts and seeds, raw-food adherents soak them in water to activate sprouting and improve digestibility. Use twice as much water as the volume of nuts or seeds; soak 8 to 12 hours.

—L.T.

Detox
Pro raw>> Eating raw foods can help eliminate toxins. A typical American diet that includes animal products, processed foods, and conventionally grown produce contains potentially harmful pesticides, hormones, antibiotics, preservatives, and trans fats. And some cooking methods, such as grilling, can create carcinogens. An all-natural, raw-foods diet, because it's rich in water and promotes digestion, helps rid the body of existing toxins and avoids creating others, Cousens says.

Pro cooked>> Whole, organic foods—raw or cooked—decrease exposure to the most common food toxins. If you're already big on plant foods, you're getting a lot of water to help flush out your system. "You can eat cooked foods and still eliminate most toxins," says Lieberman. "And remember, vitamins are involved in the detoxification process, and some of them, like vitamin C, are released from foods and better absorbed with light cooking."

Convenience
Pro raw>> Cooking with raw foods can be simpler. "Once you get into the flow of raw-food preparation, you'll spend less time in the kitchen," says herbalist Brigitte Mars, author of Rawsome! (Basic Health, 2004). "Cleanup is much easier; dirty dishes go into the dishwasher after a simple rinse—no more baked-on grease requiring soaking and scrubbing."

Pro cooked>> Unless you're fairly committed to the lifestyle, it can be tricky to follow long term. "You can't always access raw, organic foods," says Pamela Peeke, MD, author of Body for Life for Women (Rodale, 2005). "Also, many people get bored or feel deprived; most of us want a good stew in the winter. If I have a lot of time to plan, shop, and cook, it's a great diet; but most people don't live like that." According to Peeke, it's better to focus on a whole-foods diet with plenty of fruits and vegetables, beans, whole grains, nuts and seeds, and healthy fats, and eat raw foods whenever it's practical or appealing.

Food and nutrition writer Lisa Turner makes raw almond-butter cookies laced with green foods powder for her three-year-old, who actually eats them.