Dear Dr. Blonz: What do you see in the future for health and nutrition in the U.S., given that with all our resources, we do not rate among the top 20 healthiest nations on Earth? — S.T., Chicago

Dear S.T.: According to the Bloomberg Healthiest Countries index, the U.S. is rated No. 35 in the world (Spain is No. 1). These ratings are based on life expectancy, environmental factors and risk factors such as smoking. There are many complexity levels here, including lifestyle issues, access to health care and economic factors that can limit choice. Regarding nutrition, I believe such disappointing ratings will continue as long as we remain subject to influence by advertising forces. These have a proven ability to entice the populace toward value-added, less-healthful convenience fare rather than the routine consumption of a balanced, plant-based, whole foods diet as an anchor.

Dear Dr. Blonz: What is carrageenan? It’s an ingredient in the yogurt and salad dressing I use. My neighbor said it’s seaweed. Is this true, and if so, is it safe? — R.T., San Jose, California

Dear R.T.: Carrageenan, named after the southern Ireland town of Carragheen, where sea algae cultivation began, belongs to a group of food additives called vegetable gums. These include agar, locust bean gum, tragacanth, xanthan gum and pectin. These gums don’t contribute vitamins or minerals. Still, they act as binding and thickening agents to add texture and a “slippery feel” in the mouth to a growing variety of foods such as yogurt, salad dressings, sauces, jellies, puddings, sherbets and ice cream. Although they’re built like a carbohydrate, our bodies cannot digest or absorb these gums, so, to a degree, they end up acting like dietary fiber.