"I grew up eating wild purslane soup," says Rosemary Gladstar, founder of the California School of Herbal Studies in Forestville, California, and author of Herbal Healing for Women. "My grandmother made it for us as a kind of all-over tonic. She cooked the purslane with other plants, like amaranth and chickweed, then added some onions and garlic. It was powerful medicine."
Gladstar's Armenian grandmother may have relied on intuition and observation to feed her family, but science eventually backed her up: Purslane is now known to be especially rich in vitamins A, B, C, and iron. It's also among the best plant sources for omega-3 fatty acids, the essential fats that may reduce the risk of coronary heart disease and could increase the activity of white blood cells, which attack germs in the body. In general, purslane, which is not widely grown commercially in the United States, but can sometimes be found at Mexican produce stands or farmers' markets, acts as an immune-boosting supplement to any diet. Thanks to her grandmother, says Gladstone, 58, "I knew, even as a young girl, that plants could heal."
The truth is that long before researchers proved that certain plant foods contain the vitamins and phytonutrients that promote a healthy immune system, grandmothers (and other cooks) the world over figured out that some foods help bodies fight illness better than others. As a result, traditional foods and folk recipes often feature immune-boosting ingredients. Garlic, nature's best-known antibacterial food, shows up in soups from Spain to Thailand to Louisiana. Fermentation, which creates beneficial bacteria that support digestive health, is a technique that has brought about such foods as yogurt, miso, and sauerkraut (developed by the Chinese centuries before it was a German staple). My Russian grandmother favored borscht—a marriage of beets, cabbage, carrots, onions, and stock—so thick with brightly colored veggies that it could easily be called antioxidant soup.
And in my childhood home, the classic folk remedy, chicken soup—affectionately known as Jewish penicillin—was doled out at the first hint of a sniffle. Lo and behold, decades later a team of researchers at the University of Nebraska found that chicken soup may relieve the miseries of a cold—though not cure it. (It's interesting to note that the lead scientist conducted his initial research using a veggie-laden recipe handed down by none other than his wife's grandmother.) The study found that, whether it's homemade or canned, chicken soup helps inhibit the release of mucous. And the scientist jovially added that just knowing someone went to the trouble of cooking a pot of soup for you might make you feel better!
More and more, it seems, the scientists and the world's grandmothers are in agreement about the health-giving powers of certain foods. So to get ready for winter, I'm arming myself with research and anecdotes about healing soups filled with veggies, herbs, and spices that boost immune function. With two boys in germ-laden grade school and the first chilly days upon us, I can only do what any sensible grandmother would suggest: Make soup!
A Holy Trinity of Flavor
"When I don't feel well, I make a soup with ginger and garlic," says renowned cookbook author and whole-food champion Rebecca Wood. "Ginger increases circulation and cuts congestion. Garlic is antibacterial. You can also use kombu [an edible seaweed] in the stock and add other immune boosters like shiitake mushrooms and turmeric." Like Wood, I often add ginger and garlic—and turmeric, too—to my winter meals. I've dubbed this combo "the holy trinity" of immune-boosting ingredients and use it to spice up Indian dals and broths for Asian noodle soups.
"Current experiments suggest certain foods do have antibacterial properties and begin to validate what we know about traditional folk medicines in fighting infections," says Jeffrey Blumberg, Ph.D., a professor of nutrition at Tufts University. "You can actually do experiments that take extracts of garlic or curcumin [the substance in turmeric that gives it its yellow-orange color], put them in a cell culture, and see their antibacterial activities."
Perhaps more important than killing bacteria directly, some food constituents boost immune responses by increasing the activity of white blood cells. "This is as good, or even better," he says, "since an enhanced immune system is a much broader defense against disease."
What's more, he adds, "this knowledge stems from thousands of years of Ayurveda, traditional Chinese medicine, Native American medicine, and other traditional medicines. Using foods and spices for therapeutic uses isn't a trend; it's a global phenomenon."
Soup Is Good Food
To give your immune system a fighting chance against the colds and flus you'll be exposed to this season, be sure to eat plenty of foods rich in vitamins A, C, and E, including leafy greens, broccoli, carrots, sweet potatoes, tomatoes, legumes, and citrus fruits. Why these nutrients? Vitamin A is critical for supporting the lining of the lungs and gastrointestinal (GI) tract. Vitamins C and E maintain the healthy functioning of infection-fighting white blood cells, which are crucial to a strong immune system.
Minerals like selenium and zinc, commonly found in leafy greens, nuts, and seeds, are also important for immune system support. Seaweeds tend to be very high in mineral content. So do mushrooms, which also have probiotic qualities that help maintain the right balance between harmful and beneficial bacteria in the gut. The GI tract is host to many immune cells, so maintaining its health is essential to staying healthy yourself.
One simple and comforting way to enjoy these immune-boosting foods is to cook them up in a soup like the one Susun Weed, an herbalist and the author of the four-book Wise Woman Herbal series, calls Immune A-Go-Go Soup. Rich in vitamins and minerals, the soup is a funky mixture of onions, garlic, cabbage, seaweed, wild mushrooms, root vegetables (like beets, carrots, parsnips, or turnips) and tonic roots like dried Siberian ginseng and ginger, all simmered in water. Weed varies the ingredients every time she cooks up a pot—sometimes throwing in beet tops or a different root vegetable, for instance—and recommends it to cancer patients and others who need to fortify their immune response.
"The immune system needs lots of minerals to function well," Weed says, "and the typical American diet is low in minerals. I like using roots in my soup because they're mineral storehouses."
Weed also takes seriously the healing properties of even the most common herbs and often turns to mint, rosemary, thyme, oregano, basil, marjoram, or sage to dress up her soups. "I don't just season the soup with them," she says. "I add them by the handful." Volatile oils found in these herbs, like thymol in oregano, have antibacterial properties and are considered potent antioxidants.
One thing Weed, Wood, and many more of the world's healers have in common is the belief that soup truly is good food when you're looking to pamper a sick body or nourish a healthy one so that it can fight off disease. "Healing foods should be easy to digest," Wood explains. "Foods like soups and stews are easily converted to energy, which frees up the body to fight infection."
No Substitutes for
When it comes to strengthening the immune system, what you don't eat can be just as important as what you do. "Everything you eat builds your body," says Annemarie Colbin, who holds a Ph.D. in wholistic nutrition and is the author of Food and Healing. And you don't want a body built with refined sugars, white flour, and partially hydrogenated fats, Colbin says. Those foods are nutritionally empty, and when you are ill or need to build up immunity, you need food that is easy on the body and loaded with natural vitamins and minerals.
Colbin advises eating organic produce whenever possible, since the herbicides and pesticides that can be present in conventional produce can assault the immune system. If you have a less-than-optimal diet, taking vitamins might seem like an easy out. But experts say that it's better to stick with nutritious foods. "While there is an appropriate role for dietary supplements," Blumberg says, "remember they're called supplements, not substitutes. Natural whole foods have other things in them, including phytochemicals and flavonoids, which promote health and prevent disease."
Ginger Tea and Carrot Soup
After talking to several experts, I came to the most obvious conclusion: When we let our intuition guide us, we instinctively eat what we need when we need it. A case in point: One afternoon last winter, when a pair of colds—belonging to my twin boys, Matthew and Jack—dripped and snuffled into the house, Matthew asked me for a cup of tea with honey, and Jack asked for carrot soup.
So I made a light ginger tea, and carrot soup with onions and oregano. Matthew has never been told that ginger clears congestion or that honey has antibacterial properties. And Jack hadn't researched the healing properties of carrots (they're packed with vitamin A as well as C). But they both knew instinctively that these foods would help them feel better.
As Wood says, "If you're relatively healthy, you can trust your body to tell you what you need. I'm also pretty sure that cooking nutritious foods, and serving them with love—or at least some modicum of goodwill—plays some fundamental role in keeping my family healthy.
Learning about healing foods is not the domain of special people; it's knowledge that can be gleaned by anyone. All that's required is desire and genuine curiosity. "People are hungry for this tradition," Gladstar says, "because these foods represent the best of humanity. These foods bring health and beauty to people's lives, and they tie us to our ancestors."
So, next stop: my grandmother's borscht. I now know that beets are loaded with vitamins, antioxidants, and fiber, but to me, they are also soul satisfying.The astonishing, jewel-like magenta of the soup is nothing short of a miracle. I'll serve it as my grandma did, with a dollop of sour cream, which is loaded with calcium and active cultures good for the gut. Finally, I'll eat it with joy, knowing that 50 years ago, my grandmother ate the very same thing, because it was delicious and because she knew it was good for her—even though she'd never heard of phytochemicals.
Dayna Macy, a writer and musician who can be found at www.daynamacy.com, is the communications director of Yoga Journal.