DEAR DR. BLONZ: Can eating carpaccio be considered safe? I know that it is made from raw meat or fish. The particular product I recently ate was veal dressed with salt, garlic and pepper, than quick-frozen at 0 degrees F and served very chilled. Is there any significant risk? -- N.C., New York

DEAR N.C.: Carpaccio is made from a number of raw meats or fish, and it is difficult to make any public health pronouncements when it comes to these raw foods. Not every serving is going to make you ill, but the risks are definitely there.

The villains are virulent microorganisms (bacteria, viruses and protozoan creatures) that contaminate food. Food is rarely sterile, so it's not unusual for fresh animal products to contain these microorganisms. The problem arises when a quantity of bad bugs sufficient to overwhelm the body's defenses manages to hitch a ride into your system because the food is served raw or undercooked. Carpaccio has no high-heat step to keep potentially dangerous microorganisms off your plate.

One cannot even say what percentage of servings can be considered safe. Some types may be more reliable than others, in that they are carefully selected, prepared rapidly and then immediately placed into an acid-based marinade to slow potential growth. But even with good practices, it is risky to say that any brand or restaurant offering will always be safe to consume.

In your particular case, if that meat had been contaminated before it was prepared, it does not matter how clean the dressing, freezing and serving operations might have been; there would still have been no intervening step to destroy the microorganisms that might be present. Salting, and use of garlic and pepper, helps to some degree. But again, it is not appropriate to generalize that this represents a solution and that all food prepared in this way would be safe.

It improves the comfort level when companies that sell such foods take specific steps to select, protect and monitor their products. This would involve routine screenings to check whether dangerous microorganisms might be present in any particular lot before the product reaches the consumer. If you insist on eating carpaccio, touch base with the supplier to see what steps are being taken with their particular product.

The best advice is to be wary when consuming high-risk foods. Exposure to food-borne infections can be life-threatening for small children, pregnant women, the elderly and those with weakened immune systems. It becomes less serious for those in good health, but even healthy individuals will have to balance the risks and decide for themselves.

Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 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 just read a book that says by blending fruit into a smoothie, you are not getting the benefits of the fruit's insoluble fiber because the blender completely destroys it. The book also says that not only am I not getting the fruit's full fiber benefit, but also the sugar from the fruit enters my bloodstream just as quickly as fruit juice. Is this true? Should I quit making smoothies? I get two of my daily fruit servings from my smoothie. Is there a better solution? -- K.S.D., via email

DEAR K.S.D.: I don't buy the argument that blending negates the benefits of the fiber in fruits (or vegetables or grains). The machine will most certainly reduce the size of fiber particles, but the fiber is still there. It is the unique way that the fiber molecules are bound together that's the key. Digestive enzymes help break down large compounds into ones small enough to pass through the absorptive surfaces in the intestines. Fiber is unique in that the human body doesn't have any enzymes to break it apart. We do, however, have the enzymes to effectively break down starch into its individual glucose units.

As a result, fiber gets to pass through the small intestine without being absorbed. The blender does indeed cut and shred, but there is no basis to fear that this process breaks down the molecular bonds that form the essence of the fiber.

Blending does effectively increase the viscosity (thickness) of the food as compared with a typical juice or with the product of a juicer, where the fruit's solids are not a part of the final output. Higher viscosity tends to slow the rate at which we eat, as well as the rate at which the stomach empties. Both these factors lead to less food being consumed before you feel full.

Eating fruits, vegetables and whole grains are the heart of what healthful eating is all about. One question associated with smoothies, which you mention, is whether consuming foods in this manner might cause the blood sugar level to rise more rapidly than eating the same foods in the whole, unblended state. The research is somewhat mixed on this matter, and considering the benefit of having these healthful foods in your diet, it makes sense to consider a few more specifics.

What, for example, are the ingredients in your smoothies? You say that you have been consuming fruits this way for a while. Is having smoothies as a regular part of your diet working for you? Do you have any health issues relating to blood sugar regulation? If so, then you should modify the components of your drink.

The great thing about the smoothie concept is the wide variety of wonderful sweet or savory recipes available, including the use of fruits, greens, grains, protein sources and spices (see tinyurl.com/kaduhn7). There are also plentiful recipes for those who want their smoothies strictly vegan (see tinyurl.com/lm4dk7y). As with any food, make it one part of a healthful "big picture." As always, eat slowly and enjoy.

Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 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: Should there be any concerns about eating baked potato peelings? I wash and prick holes in my potatoes, then put them in a sandwich bag with a little water and cook them in the microwave. The resulting peel is soft and I enjoy the taste, often seasoning it with garlic or onion, salt and pepper. -- S.T., Redding, Calif.

DEAR S.T.: The vitamins, minerals and fiber in a potato come primarily from the flesh. Although not a nutrition powerhouse, the peel does contain a small amount of iron and fiber, and it provides a good contrast to the smooth texture of the flesh. There's absolutely nothing unsafe about eating potato peels provided they are clean, free from sprouts and have no greenish discolorations.

The green aspect is particularly important as potatoes can produce solanine, a bitter-tasting toxin that affects the nervous system. Solanine is produced when the potato is exposed to sunlight or allowed to sprout. It is most concentrated in the sprout, but it's also present in potatoes having a greenish tint to the skin. The solanine itself isn't green, but when that color is present, it indicates that the sprouting process has begun. You can slow the production of solanine by storing your potatoes in a cool, dark place. Carefully cut away all sprouts and green portions before cooking. And discard any potatoes that taste bitter.

Regarding your plastic bag cooking technique, I trust you have already read the carton or checked with the manufacturer to verify that the product is safe for microwave use. All plastic bags are not the same, and a number of brands will melt in the microwave.

DEAR DR. BLONZ: Is it all right to combine fruits and vegetables together in blended drinks for breakfast, lunch or dinner? -- B.H., San Diego, Calif.

DEAR B.H.: Yes, but from a taste perspective, it helps to do some experimenting to see which combinations work best.

DEAR DR. BLONZ: How much fiber and fat is in an avocado? Also, what is the minimum amount of saturated fat that a person should have in his or her diet? -- R.M., Oakland, Calif.

DEAR R.M.: There are many avocado varieties on the market, each having different qualities of flavor and texture. There tend to be generic differences, however, between the varieties grown in California and Florida. Florida avocados tend to be larger in size, with less fat, protein and slightly more carbohydrates than a comparable serving of California avocado. A 100-gram (3.5-ounce) portion of a California avocado will contain 6.8 grams of fiber, and 167 calories from 2 grams of protein, 8.6 grams of carbohydrate and 2.1 grams of saturated fat, 9.8 grams of monounsaturated fat, and 1.8 grams of polyunsaturated fat.

That same 100-gram portion of a Florida avocado contains 5.6 grams of fiber and 120 calories from 2.2 grams of protein, 7.8 grams of carbohydrate and 2 grams of saturated fat, 5.5 grams of monounsaturated fat, and 1.7 grams of polyunsaturated fat.

As for your second question, the human body has no minimum requirement for saturated fat.

Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 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.