It’s no secret that I believe eating nutritious foods is one of the best ways to protect your health. But when the buzz about certain foods doesn’t give both sides of the story, then it’s time for me to weigh in with the facts. We’ve always known that whole, nutritious food functions as medicine. But advertisers have now gotten in on the action by co-opting the term “superfood” for one-sided campaigns to sell grocery items-and not in a way that’s always healthful! While there’s certainly plenty of truth to the health benefits conferred by superfoods, it’s only fair that any downsides of these highly touted foods get equal airtime. Some not-so-super facts about four enormously popular superfoods…
- Kale. This slightly bitter, leafy green is rich in vitamin K, folic acid and calcium. It also contains indole-3-carbinol, a compound thought to lower cancer risk. All that sounds great. But there can be some problems if certain people consume too much kale. If you take a blood thinner, such as warfarin (Coumadin), all that vitamin K will interact with the drug. Kale also contains oxalates that may contribute to kidney stones, and raw kale can act as a goitrogen, meaning it reduces thyroid function. Additionally, when eaten raw, kale can cause intestinal gas and bloating in some people.
Bottom line on kale: If you are on a blood thinner or have had oxalate-type kidney stones, avoid kale. If you have hypothyroidism (low thyroid function), don’t consume concentrated, juiced kale. Cooking kale deactivates some of its goitrogenic properties, so it’s OK to enjoy a couple of servings per week. For everyone else, it’s safe and healthy to eat kale once a day.
- Goji berry. Goji is believed to improve physical stamina, promote sleep and help confer a longer life. The downside? Well, goji isn’t all that unique from a nutritional standpoint-in fact, it’s similar to many red-colored fruits and berries. Goji is rich in vitamins, particularly beta-carotene and vitamin C, and it’s a good source of calcium. However, there have recently been reports of pesticide-laden goji being imported from Asia. That’s why you must read labels and inquire about sources when you purchase goji. To play it safe, avoid goji from Asia-it may contain pesticides. Buy organic goji from the US or grow it yourself. Enjoy goji as you would raspberries or blackberries.
- Chia seeds. Rich in fiber, antioxidants and calcium, chia seeds (like flaxseeds) have a mild, nutty flavor. They are a good plant source of omega-3s and make a nice addition to oatmeal, baked goods and protein-rich snack bars. The problem with chia seeds? Some promoters sell chia seeds as a weight-loss aid, but this has not been proved.(For more on chia seeds’ real health benefits-and a delicious dessert recipe using them-see page 15.)
- Quinoa. Gluten-free and high in protein, quinoa is often called the superfood of grains. However, quinoa contains saponins, foamy, bitter chemical compounds that can create indigestion in some people. Food manufacturers know this and often prewash quinoa before processing it to be sold to consumers. Even so, some saponins slip through. So if you like quinoa but it gives you indigestion, be sure to rinse it thoroughly before cooking.
Source: Jamison Starbuck, ND, is a naturopathic physician in family practice and a guest lecturer at the University of Montana, both in Missoula. She is past president of the American Association of Naturopathic Physicians and a contributing editor to The Alternative Advisor: The Complete Guide to Natural Therapies and Alternative Treatments (Time Life).