One of the reasons I welcome cold weather is that it signals the arrival of harvest season – when our markets are brimming with a bounty of seasonal vegetables. It’s the perfect time to break out of your cooking habits and incorporate new vegetables in your kitchen. Enjoy the hearty, fresh vegtables that are making their seasonal appearance.
Aside from their complex, earthy flavors, Brussels sprouts, pumpkin, pumpkin seeds, sweet potatoes, turnips, and winter squash supply important micronutrients and phytochemicals – that’s why they’ve each earned a place on my list of 100 Best Foods for Health and Longevity. Let’s take a look at what makes them so special.
It’s no coincidence that, in both looks and flavor, Brussels sprouts resemble tiny green cabbages. Both are members of the cruciferous family of vegetables, which are known for having anti-cancer benefits. Cruciferous vegetables contain glucosinolates, which are converted to protective phytochemicals, isothiocyanates (ITCs) or indole-3-carbinol, after the vegetables are chopped or chewed.1,2 Higher intake of cruciferous vegetables is linked to a reduced risk of several cancers.3-7
As with other cruciferous relatives, the phytochemicals in Brussels have cancer-preventive effects. For example, Brussels sprouts may protect DNA from damage due to carcinogens and oxidants. A study of people who consumed about 10 ounces of Brussels sprouts daily showed improved stability of DNA in their white blood cells.8
Did you know? While Brussels sprouts were named after the capital city of Belgium, it is believed that a forerunner of this tiny green vegetable was grown in ancient Rome as well.
Cruciferous vegetables and human cancer risk: epidemiologic evidence and mechanistic basis.
Cruciferous vegetables intake and the risk of colorectal cancer: a meta-analysis of observational studies.
Cruciferous vegetables intake is inversely associated with risk of breast cancer: a meta-analysis.
Consumption of Brussels sprouts protects peripheral human lymphocytes against 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and oxidative DNA-damage: results of a controlled human intervention trial.
Butternut, buttercup, acorn, kabocha, pumpkin, delicata, hubbard, spaghetti squash and more are available from late fall through the winter, and have a subtly sweet taste despite their low glycemic load.9
The yellow to orange colors of these vegetables are an indicator of their especially rich supply of carotenoids, alpha-carotene, beta-carotene and beta-cryptoxanthin in particular. These carotenoids provide us with vitamin A and are powerful antioxidants, offering protection against aging and chronic diseases by preventing oxidative damage. In the skin, carotenoids counteract UV-induced oxidative stress, and have been shown to prevent or repair DNA damage to the skin caused by the sun.10, 11 Carotenoids are also key nutrients for eye health and good vision. Higher beta-carotene intake is associated with a lower risk of macular degeneration.12 In addition, high blood levels of circulating carotenoids have been linked to longer life.13
Did you know? Pumpkin pie spice – that seasonal favorite with a devoted fan base – doesn’t actually contain any pumpkin. It’s a blend of cinnamon, ginger, nutmeg, allspice, and/or cloves that complements the flavor of pumpkin in desserts and smoothies.
The role of phytonutrients in skin health.
Dietary intake of antioxidants and risk of age-related macular degeneration.
Low-serum carotenoid concentrations and carotenoid interactions predict mortality in US adults: the Third National Health and Nutrition Examination Survey.
Pumpkin seeds provide minerals, including iron, magnesium, zinc, copper, and manganese. Pumpkin seeds are the richest plant source of zinc, making them an especially helpful food for vegetarians and vegans, since zinc is more absorbable from animal foods than from plant foods. Zinc has many functions in the body and is essential for the proper functioning of many different types of immune cells.14-18
Did you know? Pepitas – the green pumpkin seeds without shells you’ll often find in the bulk bin of your supermarket – come from come from a variety of pumpkin whose seeds don’t have shells. When you cut open your own pumpkins or other squash, you’ll find seeds with edible white shells.
From the orange-fleshed garnet and jewel varieties, to the magenta-skinned Japanese sweet potatoes and the purple-fleshed Okinawan sweet potato, the colors represent the flavonoids and other phytochemicals in the sweet potato.19
Like winter squash, orange-fleshed sweet potatoes are rich in beta-carotene, an important antioxidant nutrient and precursor to vitamin A. Sweet potatoes are also rich in fiber and vitamin C, an essential antioxidant nutrient.
Did you know? Sweet potatoes are native to Central and South America, and are one of the oldest vegetables known to man, dating back 2500-1850 B.C.
Like Brussels sprouts, turnips are members of the cruciferous vegetable family, known for their cancer-preventive properties. The turnip root is a low-calorie starchy vegetable rich in vitamin C and fiber, while the greens are rich in carotenoids, folate, and vitamin K.
Did you know? In Ireland and Scotland, people carved faces into turnips, beets and potatoes to create Jack-o-Lanterns. When immigrants brought this practice to America, they discovered that pumpkins made the ideal vehicle for the scary faces.
1 head cauliflower, cut into florets
2 large turnips or 1 rutabaga, peeled and cut into quarters
12 ounces frozen artichoke hearts, thawed
2 tablespoons nutritional yeast
2 teaspoons garlic powder
1 teaspoon black pepper or to taste
sauteed onions, parsley or other herbs for garnish
Steam the cauliflower until it is fork tender.
Boil the turnips for 30 minutes or until soft.
Place the cooked cauliflower, turnips and artichokes in a food processor or high-powered blender along with nutritional yeast, garlic powder and black pepper and blend until very smooth. Serve hot.
Royston KJ, Tollefsbol TO. The Epigenetic Impact of Cruciferous Vegetables on Cancer Prevention. Curr Pharmacol Rep 2015, 1:46-51.
Higdon J, Delage B, Williams D, Dashwood R. Cruciferous vegetables and human cancer risk: epidemiologic evidence and mechanistic basis. Pharmacological Research 2007, 55:224-236.
Zhang Z, Bergan R, Shannon J, et al. The Role of Cruciferous Vegetables and Isothiocyanates for Lung Cancer Prevention: Current Status, Challenges, and Future Research Directions. Mol Nutr Food Res 2018, 62:e1700936.
Hu J, Hu Y, Hu Y, Zheng S. Intake of cruciferous vegetables is associated with reduced risk of ovarian cancer: a meta-analysis. Asia Pac J Clin Nutr 2015, 24:101-109.
Wu QJ, Yang Y, Vogtmann E, et al. Cruciferous vegetables intake and the risk of colorectal cancer: a meta-analysis of observational studies. Ann Oncol 2013, 24:1079-1087.
Wu QJ, Yang Y, Wang J, et al. Cruciferous vegetable consumption and gastric cancer risk: a meta-analysis of epidemiological studies. Cancer Sci 2013, 104:1067-1073.
Liu X, Lv K. Cruciferous vegetables intake is inversely associated with risk of breast cancer: a meta-analysis. Breast 2013, 22:309-313.
Hoelzl C, Glatt H, Meinl W, et al. Consumption of Brussels sprouts protects peripheral human lymphocytes against 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and oxidative DNA-damage: results of a controlled human intervention trial. Mol Nutr Food Res 2008, 52:330-341.
Atkinson FS, Foster-Powell K, Brand-Miller JC. International tables of glycemic index and glycemic load values: 2008. Diabetes Care 2008, 31:2281-2283.
Evans JA, Johnson EJ. The role of phytonutrients in skin health. Nutrients 2010, 2:903-928.
Stahl W, Sies H. beta-Carotene and other carotenoids in protection from sunlight. American Journal of Clinical Nutrition 2012.
van Leeuwen R, Boekhoorn S, Vingerling JR, et al. Dietary intake of antioxidants and risk of age-related macular degeneration. JAMA 2005, 294:3101-3107.
Shardell MD, Alley DE, Hicks GE, et al. Low-serum carotenoid concentrations and carotenoid interactions predict mortality in US adults: the Third National Health and Nutrition Examination Survey. Nutr Res 2011, 31:178-189.
King JC. Zinc: an essential but elusive nutrient. Am J Clin Nutr 2011, 94:679S-684S.
Prasad AS. Zinc in human health: effect of zinc on immune cells. Molecular Medicine 2008, 14:353-357.
Barnett JB, Hamer DH, Meydani SN. Low zinc status: a new risk factor for pneumonia in the elderly? Nutr Rev 2010, 68:30-37.
Office of Dietary Supplements, National Institutes of Health. Dietary Supplement Fact Sheet: Zinc. [http://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/]
Mocchegiani E, Romeo J, Malavolta M, et al. Zinc: dietary intake and impact of supplementation on immune function in elderly. Age (Dordr) 2013, 35:839-860.
Wang A, Li R, Ren L, et al. A comparative metabolomics study of flavonoids in sweet potato with different flesh colors (Ipomoea batatas (L.) Lam). Food Chem 2018, 260:124-134.