DEAR DR. BLONZ: I have been using olive oil as much as possible in cooking and salads. Much of the time, and always in baking, I use the "extra light" olive oil from a warehouse store. Recently, I have heard suggestions that the extra light may not have the same healthful fats and other benefits that fruity extra virgin olive oil has. How do the health properties of these two types of olive oil compare? -- O.O., Chicago

DEAR O.O.: The fats in all types of olive oil are comparable, containing approximately 77% monounsaturated, 9% polyunsaturated and 14% saturated fatty acids. The calorie content is also comparable. Extra-virgin olive oil, however, tends to have a greater concentration of healthful phytochemicals and more health attributes than lighter oils.

The phytochemical benefits become apparent when you consider that the olive is the fruit of the olive tree, and the oil is there to nurture the developing seed until it can begin to grow on its own and sprout leaves to gather needed energy from the sun. It would reduce the seed's growth ability if the oil it needed for energy had turned rancid.

Because oils are prone to breakdown, mostly through oxidation, successful plants have evolved to produce protective phytochemical compounds that include different antioxidants. We find some vitamin E and other important antioxidant compounds, known as polyphenols, in the olive. These compounds help maintain the vitality of the olive oil, and many have distinct flavor characteristics that can be detected in premium oils.

If you want the fats provided by the olive and are less interested in its flavorful polyphenols, then the "extra light" version is worth consideration. (For more on olive oils, see b.link/qwngx9ee.)

DEAR DR. BLONZ: I buy raw almonds and roast them at home, baking them in a toaster oven at 250 degrees for about half an hour. I often add spices for unique flavors. After serving them at a party, one of my friends asked whether roasting the almonds causes the oil in the nuts to become saturated fat. I have also heard that heating almonds diminishes their nutritional value, specifically vitamin B. Is this true? Are raw almonds preferable for their nutrition and health value? -- M.C., San Diego

DEAR M.C.: Dry-roasting in a toaster oven is not associated with any meaningful decrease in almonds' nutrient value. The same can be said for oil-roasting, although the oil adds a bit more fat content. Using either method and roasting correctly, the oils in the nuts do not become more saturated.

In terms of nutritional value, any high-heat process can destroy some thiamin (vitamin B1), but the other nutrients, especially the minerals, are relatively unharmed. I consider nuts and seeds to be healthful foods. The choice between raw and roasted almonds, nuts or seeds is simply personal preference. In all cases, be sure to store them properly. (For more information on correct nut storage, see b.link/2xb9aq7.)

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: Please explain the difference between fats, oils, serum lipids, cholesterol and triglycerides. My main question is about a close friend with high blood cholesterol who is now on a statin, which brought down their lipid profile into the normal range: Is there any reason, except for weight gain, why they should not eat high-fat, high-cholesterol foods? -- M.K., Chicago

DEAR M.K.: We can discuss these components and the general impact of diet, but discussions about health issues relating to blood lipids and medications should be with your physician.

"Lipids" is an umbrella term for a group of chemicals, including fats and oils (both made of fatty acids), waxes and steroids. Each type of lipid has a particular chemical structure that distinguishes it from the others. Although the terms "fats" and "oils" tend to be used interchangeably, the difference is that the former are solid, while the latter are liquid at room temperature. All lipids share one characteristic: They cannot dissolve in water, but will dissolve in organic solvents, such as mineral spirits or cleaning fluids. Triglycerides are also lipids; they're the form in which fats and oils are packaged in the body. (For more on dietary fats, see b.link/s2fd25z.)

Cholesterol, a type of steroid, is a waxy, fatlike substance with a complex structure resembling a honeycomb. It is an essential structural element in every body cell. Unlike fats and oils, the body does not use cholesterol for energy; it is a raw material used to make hormones, including estrogen and testosterone.

However, whether due to a genetic predisposition, poor diet and lifestyle or some other factor, cholesterol can become elevated. Taking a cholesterol-lowering drug, such as a statin, provides a means to help correct that element of imbalance in the body. (Read more about statins at b.link/8wsa7ak.) If you're prescribed such medication, by all means, use it.

Medications to control an elevated blood cholesterol level should not be considered a "license to eat" and live in an unhealthful manner. It is not correct to assume that a pharmaceutically lowered cholesterol level fixes the problem -- medication can help, but it does not absolve us of the responsibility to treat our bodies with care.

The takeaway, and the message for your friend, is to consider it a worthy goal to adopt diet and lifestyle changes that might help reduce the need for such medications.

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: Please help settle a family debate. It is my impression that when vegetables are boiled with no lid on the pot, some nutrients leave with the steam. My son says that all the nutrients stay in the cooking water. -- J.A., Hayward, California

DEAR J.A.: Your son is much closer to accuracy, but there is one nutrient that does, indeed, exit with the steam: water! The steam/water itself is a nutrient, which means you and your son both have some claim to correctness.

The cooking process can cause a breakdown of some vitamins, but these are not lost with the steam. For an article on how cooking affects nutrients, see b.link/xrz7zcd.

DEAR DR. BLONZ: This is a follow-up to your recent column on repelling mosquitoes. When we went camping years ago, we learned that Avon Skin So Soft Bath Oil worked well to repel mosquitoes. We liked using it rather than applying insect repellents that contained other chemicals. This could be a good option for young children. -- G.F., San Ramon, California

DEAR G.F.: After my piece on how a particular dietary supplement was ineffective against mosquitoes, I received several notes about Avon Skin So Soft Bath Oil. I recall when the rumors emerged, years ago, that this product could repel mosquitoes; it became a go-to product for many summers and was difficult to find.

Studies were undertaken to verify its efficacy, using a sample population to assess the oil's benefits. The studies failed to find a significant difference in the performance of the oil and a placebo substance. There are various possible explanations for this: 1. The product is indeed ineffective as a mosquito repellent; 2. The placebo selected was equally effective, so there was no difference between the two; or 3. There were other characteristics -- whether genetic, cosmetic or something else -- that were unequally distributed between the groups and these impacted the results.

The bottom line is that the mosquito-repellent effect has not been confirmed. To Avon's credit, the company has never promoted this as a feature of the bath oil product. Consumer Reports has also discussed the issue: see b.link/sajmfx2.

All of that being said, some people may experience good results when using this product to repel mosquitoes, and there is no reason to stop if you are having success.

We do not yet fully understand the individual and combined factors that entice or repel mosquitoes. Any of these can play a role in our odor, and therefore our attractiveness to bugs: what we have recently eaten; the detergent or fabric softener used on our garments; the moisturizers, sunscreens or deodorants on our skin; when we last bathed or exercised; even our stress levels.

It is a wildcard; better to rely on our individual observations of what works for us.

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.