November 2018 Issue

Winter Vegetables
By Sharon Palmer, RDN
Today's Dietitian
Vol. 20, No. 11, P. 20

Today's Dietitian shines a spotlight on five of the top winter veggies that clients can easily include in their diets this season.

When earthy tomatoes, plump zucchinis, and sweet bell peppers are in season at the farmers' market, it's easy to pump up the volume of fresh produce in one's diet. But, once those last warm rays of summer diminish, many vegetable offerings follow suit. Instead of recommending that your clients purchase fresh produce out of season—shipped from thousands of miles away or grown in heated greenhouses—suggest they switch to seasonal varieties. It's a more healthful, sustainable message. Winter vegetables include those that are harvested late in the season and endure well for a period of time, as well as cool-weather, hardy vegetables that may be grown in more temperate climates during winter. Many of these vegetables were those that once filled root cellars of our ancestors, providing a source of nutrients to sustain people over the long winter. Winter vegetables include root vegetables, such as potatoes, turnips, parsnips, carrots, and beets; allium vegetables, such as onions, garlic, and shallots; cruciferous vegetables, such as cabbage, Brussels sprouts, broccoli, and cauliflower; hardy greens, including kale, spinach, and chard; and winter squash and pumpkins.

Today's Dietitian chooses five top winter vegetables—Brussels sprouts, cabbage, parsnips, pumpkins, and winter squash—to focus on this month, asking dietitians to share their best tips on how to encourage clients to embrace these nutrient-rich vegetables this season.

Brussels Sprouts
Part of the cruciferous vegetable family, these petite cabbages grow along a stalk about three feet tall. There are many unusual varieties of Brussels sprouts, including purple, which you may grow in your garden or spy in a farmers' market. A 1/2-cup cooked serving of these tiny vegetables is packed with vitamin A (12% DV), vitamin C (81% DV), and vitamin K (137% DV), in addition to glucosinolate compounds, which are linked with anti-inflammatory effects and potential cancer prevention.1

"One serving of Brussels sprouts has all the vitamin K you need for the day, which helps lower inflammation and supports bone growth and the cardiovascular system," says Megan Casper, MS, RDN, dietitian and owner of Nourished Bite Nutrition, based in New York City. Casper advises her clients not to overcook Brussels sprouts, as they will lose some of their nutritional value and start to smell like rotten eggs. "Drizzle with oil, cut an 'X' into the core, and roast or try quickly steaming until tender," Casper adds.

"I'm obsessed with Brussels sprouts, because they have a mildly bitter flavor and are packed with cancer-fighting sulfurous compounds. I love them shredded into salad and enjoyed raw or halved and roasted until caramelized and crispy," says Abbey Sharp, RD, Toronto-based blogger at Abbey's Kitchen.

Though roasting is one of the most popular ways to enjoy this vegetable, they also can be included in stir-fries, grilled vegetable skewers, puréed in cream soups, and served as a side dish with a flavorful sauce.

Cabbage
Another member of the cruciferous vegetable family, cabbage—with hundreds of varieties grown around the world—show up as a key feature in many food cultures, ranging from Asia to Europe to Central America. Can you imagine Mexican street tacos without a generous topping of crunchy white cabbage, German cuisine without sauerkraut (fermented cabbage), and Chinese stir-fry without its foundation of cabbage?

Cabbage is packed with a variety of phytochemicals, such as glucosinolates, with antioxidant and anti-inflammatory activities. In particular, red cabbage may have more benefits, thanks to the presence of anthocyanins. A 1/2-cup serving of cooked red cabbage contains an impressive cache of vitamin K (45% DV), vitamin C (43% DV), and vitamin B6 (8% DV). In addition to cancer protection,1 cabbage intake may be linked with heart health, thanks to reductions in cholesterol levels and an increase in blood antioxidant levels.2

"Cabbage is high in sulfur-containing compounds, which helps protect against cardiovascular disease, diabetes, and many types of cancer," Casper says. She suggests that cabbage becomes sweeter when it's harvested in cooler weather, and that it's one of the most budget-friendly vegetable buys. "Encourage your patients to try it steamed, sautéed, or chopped into a salad," Casper adds.

Additional ways to encourage cabbage intake is to include fermented cabbage (sauerkraut) in casseroles, sandwiches, or as a side dish; shredded cabbage added to a slaw, sandwich, wrap, or taco; Thai- or Chinese-style stir-fries with cabbage served with brown rice; cabbage casseroles, such as stuffed cabbage or slow-cooker cabbage; and in classic soups and stews.

Parsnips
One of the lesser-known root vegetables, parsnips deserve more recognition during the winter vegetable season. Originating from the East Mediterranean, these vegetables have a long traditional use in Europe, where potatoes usurped their prominence when the Spanish explorers introduced them from the New World. Pale yellow or creamy colored, parsnips store well in root cellars and pack a nutritious kick into diets. One-half cup of cooked parsnips contains folate (11% DV) and vitamin C (17% DV), as well as fiber and phytochemicals with anti-inflammatory and antioxidant properties.

According to Toby Amidor, MS, RD, CDN, a Wall Street Journal best-selling cookbook author, during the first frost this winter vegetable converts its starch to sugar, giving it a sweet and nutty flavor. "Parsnips are also high in vitamin C and [are] a source of folate and vitamin K. Although you typically see parsnips eaten cooked, you can also eat them raw by grating or cutting them into matchsticks and adding to salads or as part of a crudité," Amidor says. She suggests using parsnips in creamy winter soups, as they provide a slight sweet flavor and natural thickening ability; roasting or baking them; puréeing them into a mash; or using them in place of potatoes and carrots in any recipe.

Sarah Koszyk, MA, RDN, author of 365 Snacks for Every Day of the Year, also enjoys recommending parsnips in the winter season. She notes, "They are so versatile to cook with and have less starch than a potato."

Pumpkins
While most of your clients might think pumpkin is relegated to pumpkin spice lattes, jack-o'-lanterns, and pumpkin pie, this winter vegetable has an important history in food traditions around the globe. Originating in North America, pumpkins are a cultivar of the squash plant and have been used in many cultures, including Caribbean, South American, and Asian, where pumpkin is enjoyed in soups, stews, stir-fries, and dumplings.

Pumpkins are potent with nutrients: a 1/2-cup cooked serving contains vitamin C (10% DV), vitamin E (5% DV), and a rich supply of beta-carotene, which is converted into vitamin A (141% DV). It's also a source of fiber and minerals. Studies have found that beta-carotene-rich foods are linked with lower mortality.3 

"Pumpkin is an excellent winter vegetable because it's readily available year-round," says Catherine Brown, CDM/CFPP, a chef, culinary nutritionist, and organic grower based in New Hampshire. "I keep it in cans on hand at all times. It's easy to use, and a nutrition powerhouse, with vitamins A, C, E, riboflavin, potassium, copper, and manganese." Brown suggests clients try purchasing whole pie pumpkins, roasting wedges, and serving them as a side dish, or puréeing pumpkin into a silky-smooth pumpkin soup. She says clients also can add canned pumpkin to hot whole grain cereal, chia pudding, or smoothies.

One quick way to encourage people to use pumpkins this winter is to start with those they use to decorate their porches and mantles during the fall season. Simply split them in half, remove the seeds (save them for roasting), and bake them as you would other winter squashes. The cooked flesh can be used in soups, stews, muffins, bars, cereals, smoothies, hummus, and more.

Winter Squash
An array of winter squash (from the Cucurbitaceae family) awaits discovery during the cool weather months, including acorn, buttercup, butternut, delicata, hubbard, and spaghetti squash. The hard outer shell means winter squash can be stored for long periods of time; once split open, they reveal vibrant yellow-orange flesh, a calling card for their rich carotenoid compounds linked with health benefits and disease protection.3 Depending on the variety, these vegetables contain varying amounts of vitamins A, B2, B6, C, and K; fiber; and minerals.

Winter squash can be traced back to Mexico. They're an important part of the agricultural traditions of the Native Americans dating back at least 1,000 years, in which maize, squash, and beans—known as "the three sisters"—were planted together, forming the backbone of the traditional diet.

"My favorite vegetable in the winter season is squash, rich in vitamin A, fiber, and folate," says Katie Pfeffer-Scanlan, MS, RD, LDN, a clinical dietitian and blogger at One Hungry Bunny. "There are so many beautiful varieties and versatile uses in cooking. Whether it's roasted, sautéed, or mashed, they make an excellent main and side dish."

Judy Barbe, RD, author of Your 6-Week Guide to LiveBest: Simple Solutions for Fresh Food & Well-Being, suggests, "Roasted winter squash, such as butternut, hubbard, kabocha, and acorn, can be served as a side dish, then tossed into tomorrow's salad, stirred into pasta with a spoonful of ricotta, or puréed for soup. Cooked squash also freezes well."

Elizabeth Shaw, MS, RDN, CLT, CPT, of ShawSimpleSwaps.com, coauthor of Fertility Foods Cookbook: 100+ Recipes to Nourish Your Body, says that acorn squash has become one of her favorite winter vegetables to recommend. "During winter months, when people are notorious for popping vitamin C pills, I enjoy educating on the 'food first' philosophy and including more whole foods in their diet."

Liz Weiss, MS, RDN, host of the Liz's Healthy Table podcast and blog, says, "I encourage people to include more vegetables in their diets, and spaghetti squash makes that recommendation easy. This nourishing winter vegetable is versatile, mild in flavor, and fun to eat. Once cooked, I shred it into spaghettilike strands and then top it with all sorts of nourishing ingredients, including beans, sautéed bell peppers, and avocado; pasta sauce, grated Parmesan, and meat-free crumbles; and steamed broccoli and shredded low-fat cheddar cheese."

Maggie Moon, MS, RDN, of the blog MIND Diet Meals, likes to showcase winter squash in a Korean dish called hobakjuk, which refers to zucchini or winter squash porridge, but most commonly refers to a porridge that celebrates the sweet winter squash called danhobak (also known as kabocha squash). See a recipe for the latter dish and others that celebrate the bounty of winter vegetables on the following pages.

— Sharon Palmer, RDN, The Plant-Powered Dietitian, is a blogger, author of Plant-Powered for Life, and nutrition editor of Today's Dietitian.

References
1. Royston KJ, Tollefsbol TO. The epigenetic impact of cruciferous vegetables on cancer prevention. Curr Pharmacol Rep. 2015;1(1):46-51.

2. Bacchetti T, Tullii D, Masciangelo S, et al. Effect of black and red cabbage on plasma carotenoid levels, lipid profile and oxidized low density lipoprotein. J Funct Foods. 2014;8:128-137.

3. Zhao LG, Zhang QL, Zheng JL, et al. Dietary, circulating beta-carotene and risk of all-cause mortality: a meta-analysis from prospective studies. Sci Rep. 2016;6:26983.