Q: How do seltzer, “vitamin water,” and mineral water compare to plain water?
A: Judith C. Thalheimer, RD, LDN, executive editor of Tufts Health & Nutrition Letter, answers:
“The short answer to your question is this: it doesn’t matter which type of water you drink, as long as it doesn’t have added sugars or sodium.
“Plain water is always a good choice (straight from the tap or filtered). For variety, or as a soft drink substitute, try flavored (unsweetened) seltzer or sparkling water. (The idea that seltzer is less hydrating than plain water has been debunked.) Be aware that tonic water contains added sodium, a mineral most Americans should cut back on.
“Water fortified with vitamins is advertised as having nutritional benefits, but take a close look at the Nutrition Facts label. Many of these ‘healthy’ drinks come with a very unhealthy dose of added sugars. Plus, if you get your nutrients from foods like vegetables, fruits, and seafood instead of fortified beverages, you get the added benefit of a wider array of vitamins, minerals, and phytochemicals along with fiber or protein. Extras doses of vitamins don’t provide extra benefits.
“Mineral water naturally contains minerals—like calcium and magnesium—that leach from the rocks at its underground source. Although some have a higher concentration of minerals than plain water, the amounts are unlikely to make a difference to one’s overall health. Mineral water, therefore, is a perfectly good choice for hydration, but not significantly healthier than (less expensive) plain water.
“Unsweetened coffee and tea (hot or cold) are also good beverage choices, as are low-fat or fat-free milk and plain soy or pea-based milks.
“How much fluid you need depends on many factors, including your size, age, and activity level, as well as the temperature and altitude at your location. The popular (but unscientific) advice to aim for eight eight-ounce cups of fluid a day (from food, water, and other beverages) is a helpful benchmark, but, in general, listen to your thirst and drink extra if you are sweating.”
José M. Ordovás, PhD, is senior scientist and leader of the Precision Nutrition & Healthy Aging directive at the Human Nutrition Research Center on Aging and professor of nutrition and genetics at the Friedman School of Nutrition Science and Policy. His research focuses on the genetic and epigenetic factors that predispose individuals to heart disease and obesity as well as the interaction of these genetic factors with the environment and behavioral factors to promote healthy aging.