When it comes to a nutritionally-supportive diet, we are often told that eating a variety of red, orange and green produce is the key to health. Many of us have even shunned white foods, believing that foods lacking in color are also lacking in nutrients – but do all white foods deserve a bad reputation? It is true that white, processed carbohydrates pale in comparison nutritionally (and literally) to fiber- and vitamin-rich whole grains, but it’s important to note that color is an indicator of some but not all phytochemicals (1). White vegetables like onions, garlic, cauliflower, turnips and white potatoes are an integral part of a healthy diet, and are rich in fiber, vitamin C and potassium – nutrients that are commonly under-consumed in the United States (1).
Onions and garlic
These superstars belong to the Allium family of vegetables, which have been valued for over 4,000 years due to their pungent flavors and health benefits. Studies have associated the consumption of onions and garlic with reduced risk for developing stomach, prostate and colorectal cancers. Alliums contain sulfur-based components, which add distinctive flavors to dishes, and are also thought to be responsible for their health benefits (2).
Humble cauliflower is making its way into all types of recipes these days – including pizza, rice and puree -and it’s no surprise why! Versatile, low calorie and nutrient-dense, cauliflower is an excellent source of vitamin C (a potent antioxidant) and fiber, which promotes satiety and gastrointestinal health. In addition, cauliflower contains bioactive compounds, called isthiocyanates and indole 3 carbinol, which have been linked to cancer prevention, and a reduced risk of cardiovascular diseases and thrombosis-related stroke, respectively (3, 4). Kohlrabi and white turnips are also among the list of white veggies that that contain these disease fighting compounds (5).
White potatoes are often prepared with ingredients (salt, oil, cheese, butter and sour cream) and cooking methods (peeled and fried) that discount their nutritional value. However, when prepared using health-supportive techniques, they are low in fat and are a significant source of vitamin C, potassium, magnesium and dietary fiber, especially if the skins are left intact (1). Cooked and cooled potatoes are a source of resistant starch, which provides similar benefits to fermentable fiber, like promoting the growth of “good” gut bacteria and playing a role in colon cancer prevention (6). The nutritional benefits don’t stop there – white potatoes actually provide protein of high biological value. Although the protein content is relatively low per gram compared to pasta, rice or corn flour, the biological value is between 90 and 100, making it higher than soybeans and legumes and comparable to that of an egg (the gold standard) at 100 (1).
Now that you know the nutritional potential of white veggies, pick some up on your next trip to the farmers market!
Weaver C, Marr ET. White Vegetables: A Forgotten Source of Nutrients: Purdue Roundtable Executive Summary. Adv Nutr. 2013; 4: 318S-326S
Nicastro H, Ross S, Milner K. Garlic and onions: Their cancer prevention properties. Cancer Prevention Research. January 13, 2015.
Wang X, Di Pasqua AJ, Govind S. Selective Depletion of Mutant p53 by Cancer Chemopreventive Isothiocyanates and Their Structure-Activity Relationships. J. Med. Chem. 2011; 54: 90
Park M, Rhee YH, Lee HJ, et al. Antiplatelet and Antithrombotic Activity of Indole 3 carbinol In Vitro and In Vivo. Phytother. Res. 2008; 22: 55-64.
Cartea ME, Francisco M, Soengas P, Velasco. Phenolic Compounds in Brassica Vegetables. Molecules. 2011; 16: 251-280.
Birt DF, Boylston T, Hendrich S, et al. Resistant Starch: Promise for Improving Human Health. Adv. Nutr. 2013; 4: 587-601.