Q: I used to always see recommended amounts of nutrients listed as recommended daily amounts. Now sometimes I see dietary reference intakes. Are they the same thing?
A: Nutrient recommendations used to be primarily listed as recommended dietary allowances. Now you may see nutrient recommendations listed as dietary reference intakes that include several different systems for identifying nutrient levels that can be used to plan diets for healthy people. RDAs are one type of DRI. These are nutrient levels set by the National Academy of Sciences that current research says should meet the needs of almost everyone in a given age and gender group. For nutrients where data does not yet clearly identify amounts that can meet virtually everyone’s needs, a different type of DRI is used in order to make the uncertainty clear. Adequate intakes are our best estimate of nutrient amounts that meet everyone’s needs, but are based on less data and more judgment than RDAs. Other types of DRIs identify nutrient levels that could result in harmful effects if exceeded, almost always by supplements, and amounts that research suggests meet the needs for about half a given population group. For practical purposes, you can assume that when you see RDA, AI or DRI in consumer information they are all referring to current recommendations for nutrient consumption.
Q: Is it true that gum disease increases risk of heart disease? How could that be?
A: Research does not show a clear cause-and-effect relationship between gum disease and heart disease, but plenty of studies suggest a link. Scientists say that heart disease risk is related to much more than cholesterol and blood pressure. Inflammation and infection in one area of the body can promote inflammation and damage in blood vessels. Studies have found that otherwise healthy, lean people with gum disease have elevated signs of inflammation. So prompt treatment for gum disease and good dental hygiene to prevent it, may save more than your teeth. Taking care of your mouth seems likely to be another step, along with healthy eating, regular exercise, weight control and tobacco avoidance, that reduces inflammation and protects your overall health.
Q: Do all scalding hot foods and drinks increase cancer risk?
A: If you eat or drink multiple servings of scalding hot food or drink every day, this might increase your risk of esophageal cancer. The esophagus is the tube that carries food from the mouth to the stomach. Studies conducted in northern Iran, where people drink large amounts of very hot tea, show that people who drink their tea at extremely high temperatures are much more likely to develop esophageal cancer than those who drink tea at more moderate temperatures. According to the expert report from the American Institute for Cancer Research, which evaluated a wide range of dietary influences on cancer risk, 18 studies have investigated the impact of high-temperature foods and drinks. Most studies suggested some increase in risk of esophageal cancer. But in many cases it was hard to pinpoint how much of the increased risk might be linked with smoking or alcohol consumption. Repeated over time, extremely hot temperatures could damage tissue of the esophagus, which could become inflamed. Chronic inflammation in any area of the body can promote cancer development. This does not mean you need to switch to ice tea and coffee; simply allow your beverages to cool from “scalding” to “tolerable.”
Karen Collins is a registered dietician with The American Institute for Cancer Research that fosters research on the relationship of nutrition, physical activity and weight management to cancer risk.