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The original page can be found on-line at http://www.pioneerthinking.com/nutritionwise.html

Weekly column for the week of: March 3, 2009

Nutrition Wise

by Karen Collins, MS, RD, CDN

For American Institute for Cancer Research

Q:Some sources refer to Yerba Maté as a risk factor for cancer but others say it is very healthful. What’s up?

A: Yerba Maté, from the plant of the same name, is popular in parts of South America, where it is consumed through a metal straw as a scalding hot beverage. It’s spreading rapidly in the United States and Europe either as a tea or as an ingredient in foods and dietary supplements. Yerba Maté (also simply called maté) is high in antioxidant compounds called polyphenols. In laboratory studies, maté has protected DNA exposed to damaging chemicals and enhanced DNA repair. However, analysis also shows that both the leaves and hot or cold infusions made from them contain high levels of apparently cancer-causing compounds called PAHs. Population studies have linked maté to increased incidence of cancers of the mouth and throat. But it’s not clear how much of the link seen is related to alcohol and smoking. In a review of the research, the 2007 AICR report identifies the primary concern of maté as a probable link to increased risk of esophageal cancer. But the report attributes this risk mainly to damage from the scalding hot temperatures at which it is traditionally consumed; such heat can lead to inflammation and leave cells vulnerable to cancer development. We need further research before we will know whether maté served at safer temperatures increases, decreases or does not change risk of cancer.

Q:How much weight will I lose if I switch all my sweets and snack foods to low fat or sugar-free versions?

A: I’d reconsider relying on this as a strategy for weight loss. These products aren’t necessarily any lower in calories because producers may add other ingredients to make up for the change in taste or texture when they take out fat or sugar. Believing that they are “diet foods” could even set you up for trouble. Studies suggest that when we think a food is healthier or less fattening, we tend to eat larger amounts. The harder, but healthier and more long-lasting change is to eat less processed sweets and snack foods. Try replacing one or two daily servings of processed snacks with fruit, raw veggies, a small handful of nuts or some other nutrient-supplying food.

Q: What’s the difference between kefir and yogurt?

A: Both are cultured dairy products, but whereas yogurt’s cultures are all bacteria, kefir (pronounced kef-EAR) is produced with more different bacteria cultures plus yeast. Both are good sources of protein and calcium. Yogurt tends to be about 20 calories per serving higher than kefir with comparable fat and sugar levels. But the biggest difference in calorie content is not between these two products, but between products made from whole, low fat or nonfat milk. Both yogurt and kefir also take major calorie jumps from “plain” to “fruit” versions, which usually contain added sugar too (unless an artificial sweetener is used). You may hear claims that kefir is a potent anti-cancer weapon that can slow growth of cancer cells and boost levels of immune cells that defend against cancer. But that’s based on preliminary research and has not been confirmed in humans. Both products offer the benefits of probiotic cultures that may promote digestive health. Both make a great base for smoothies and cold fruit soups or a topping for cereal or fruit. Choose whichever has the taste and texture you like, keeping a watch on sugar and saturated fat content. Nutrition Wise Archives 2009 The American Institute for Cancer Research (AICR) is the cancer charity that fosters research on the relationship of nutrition, physical activity and weight management to cancer risk, interprets the scientific literature and educates the public about the results. It has contributed more than $86 million for innovative research conducted at universities, hospitals and research centers across the country. AICR has published two landmark reports that interpret the accumulated research in the field, and is committed to a process of continuous review. AICR also provides a wide range of educational programs to help millions of Americans learn to make dietary changes for lower cancer risk. Its award-winning New American Plate program is presented in brochures, seminars and on its website, www.aicr.org. AICR is a member of the World Cancer Research Fund International.