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 healthcare, 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 both 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.

DEAR DR. BLONZ: A workout friend is a nutritionist, and she continues to tell me that the calcium from fat-free milk products is not absorbed into the body effectively. She insists that calcium needs to be consumed with a little fat in order to be absorbed. She says that my body is not absorbing any calcium from all the fat-free milk and yogurt products I consume. Is this true? Do I need to switch to low-fat milk products? -- N.N., Phoenix

DEAR N.N.: I question your "nutritionist" friend, and in my opinion, so should you. Switch to low-fat milk products only if you want. Calcium absorption will not be significantly affected by such a change. I challenge this individual to come up with any basis for these statements. Is there any chance she might have been referring to vitamin D, a nutrient typically added to milk? That is one that is more efficiently absorbed when fat is present.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: I use an extra-light olive oil for my cooking and salads. I have heard that the extra-light type may not have the same healthful benefits that fruity extra-virgin olive oil has. How do the two types of olive oil compare as far as their beneficial properties? -- M.T., Sun City, Arizona

DEAR M.T.: First, let’s look at how the various types are alike. Calorie content is similar in all olive oils. The composition of an olive’s fatty acids is approximately 77% monounsaturated, 9% polyunsaturated and 14% saturated. Extra-virgin olive oil will contain a higher concentration of phytochemicals than oils described as “light.”

Oils tend to be present as triglycerides: three fatty acids bound to glycerol. Fatty acids can begin to split off as olives age; measurements of their free-acidity are used as a gauge of olive quality. Premium olive oils often declare a maximum level of free-acidity on their labels.

The various grades of olive oil are distinguished by the order in which they emerge from specialized presses. The first pressing of the fruit provides the extra-virgin olive oil: the darkest, most flavorful and highest in quality. It also has the lowest free-acid level.

Next out is the virgin olive oil. It has less color, but still contains some of the olive’s fruitiness. The remaining oil is the standard, or “pure” olive oil, which has even less olive flavor. Some companies make a “light” (or “lite”) olive oil, which has little, if any, olive flavor, but is still quite functional. Many companies blend their oils to achieve a more standardized flavor. In Europe, you can even find pomace oil: a solvent extraction of the olive mash leftovers.

Understanding the idea of health benefits between the extra-virgin and the lighter types becomes apparent when you consider that the olive is the olive tree’s fruit. The oil is there to nurture the developing seed until it can begin to grow on its own. Rancid oil is less able to help the seed grow, and the olive has evolved to produce protective components. In the olive, we find some vitamin E and other antioxidant compounds known as polyphenols. These compounds help maintain the olive’s vitality while providing the distinct flavor characteristics detectable in premium oils.

Oil producers from around the Mediterranean, in addition to those in California, speak with understandable pride about the healthful attributes of their olive oil. They often tout that only the extra-virgin olive oil has the right stuff. Once you understand that it is the extra-virgin oil that contains the bulk of the beneficial phytochemicals, you can better appreciate the logic of their message.

Expect differences between, and within, brands of oils. Quality varies with the olive variety, the age of the tree, the geographical area, the method of cultivation, the weather and the length of the growing season. Some producers date the vintage of their oils, while others blend to achieve a consistent taste for their brand. We find the same types of differences with fruits and vegetables, as well as with products such as wine.

While tasting olive oils around the world, I noticed differences in pungency, buttery mouthfeel and peppery aftertaste -- each, no doubt, due to specific chemical compounds. Olives picked earlier in the harvest might have higher levels of certain constituents than those left until the end of the season.

Suffice it to say that sticking with extra-virgin will ensure that you are getting the best that an olive variety has to offer. When possible, taste several to find the type that meets your particular needs. For more, see b.link/bw-olive.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: I read your column about statins and cholesterol, and have a related question. I was recently advised (again) to avoid foods with cholesterol because I have too much in my blood, but many of the foods I love to eat contain cholesterol. Exactly how bad is cholesterol? What is the connection between the amount of it you eat and the amount in your blood? I have had discussions about this with my physician, but would like your advice. -- S.T., Greenville, South Carolina

DEAR S.T.: There are many factors in the connection between dietary cholesterol and that found in a blood test.

Cholesterol is a lipid substance, part of a large group that includes fats and oils. These have a unique ability to oxidize into troublesome compounds that increase disease risk, most notably cardiovascular disease. Some lipids are worse than others, but all seem to have this potential. Because our blood is a water-based medium, lipids must be transported around attached to proteins appropriately named “lipo proteins.”

A member of the sterol family of lipids, cholesterol is a large, complex compound with a build that looks like a piece of chicken wire. It was found initially in gallstones, the painful masses that sometimes form from bile inside the gall bladder. Accordingly, the name “cholesterol” is Greek for “the sterol found in hardened bile.” Cholesterol serves many functions in the body: It is needed to help the brain work properly, it keeps our skin watertight and it provides the basic building block for sex hormones and other essential substances.

The negative image of cholesterol comes from studies where elevated blood levels were found to be a predictor of disease. Examination of damaged arteries in those with cardiovascular disease tended to show a cholesterol-laden buildup. It was unclear whether cholesterol was directly responsible, but the weight of circumstantial evidence remains significant.

There is an important distinction between the cholesterol in our diet and the level in our blood. In the average individual consuming a balanced diet, the effect of dietary cholesterol on the blood level appears to be of secondary importance. Only about half the amount of cholesterol we eat gets absorbed. And if there were absolutely no cholesterol in our diet, the body would make all it needed on its own.

A healthful diet and lifestyle have always been key, but some of us must take special care due to a genetic predisposition to produce excessive amounts of cholesterol.

Greens, grains, fresh fruits and vegetables, nuts and seeds have the right stuff to help the body process dietary fats and cholesterol. You didn’t mention your exercise habits, but keep in mind that an active lifestyle keeps your muscles and systems demanding fats for energy, rather than having the bulk of dietary calories routinely headed for storage. It is also critical to avoid an excessive intake of sugars.

When we eat and live well, the importance of dietary cholesterol shrinks dramatically. You state that many of the foods you love to eat contain cholesterol. You also indicate that this is not the first time you have been counseled. If you want to keep your cherished foods on the plate, make that shift in your lifestyle and diet to include more foods and activities to keep your healthful rhythms intact.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.