DEAR DR. BLONZ: My daughter is sensitive to gluten, so I was wondering if glutamate will cause similar trouble. I cannot find anything helpful. One label, on a can of chicken broth, says: "Small amount of glutamate occurs naturally in yeast extract." Is this a likely problem? -- A.M.H., via email

DEAR A.M.H.: I am not aware of any connection between being sensitive to gluten and being sensitive to glutamate. These are completely different substances. Gluten is a unique mix of proteins found in the wheat family of grains, while glutamate is an amino acid found in all complete proteins -- in foods and in our bodies.

Yeast is a living organism that contains protein, so it is not surprising that it will contain some glutamate, along with other amino acids. However, yeast does not contain gluten. In short, sensitivity to gluten does not translate to sensitivity to glutamate.

DEAR DR. BLONZ: I put flax meal in my morning smoothies and sometimes on sandwiches and cereal. After opening a new package, should it be frozen or refrigerated? Would I be better off grinding my own from flaxseeds? Also: Is organic or gold flax any better than conventional? I consume about two tablespoons of it daily; is that too much? -- S.S., via email

DEAR S.S.: Flaxseeds should be stored in a cool place away from any direct sun or heat. Once ground, rely on refrigerated storage in a well-sealed container. Some already-ground flaxmeal is sold refrigerated, but if properly sealed (with little, if any, air, or with a controlled atmosphere in the package), the risk of oxidation is limited.

As regards grinding at home: As long as it's properly packaged and stored, there is no "better off" either way, so the choice would be yours. Always check for freshness dating on the package. I don't favor purchases from a room-temperature bulk bin.

Flax should have a mild, nutty flavor and aroma, so give it a sensory check when the package is first opened. This can provide a baseline for repeat assessments after the ground flax has been around for a while. If you detect "off" odors or flavors, that's a sign that it's time to toss it out (or put it in your compost bin). I also favor organic, not necessarily because of significant evidence that the organic flaxseeds are more healthful, but because I feel we need to encourage (with our purchases) this method of agriculture when possible. It benefits the land, and those who work in agriculture.

Ground flaxseed can add a flavor dimension and nutritional quality to other foods. There is no daily requirement for flax, so the amount you consume is up to you. Depending on the brand, a two-tablespoon serving of ground flaxseed will provide in the range of 3-4 grams of protein, 4 grams of carbohydrates, 6-8 grams of fat and 4-6 grams of dietary fiber.

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 read that the minute a jar or bottle of cooking oil -- such as safflower, canola, peanut or olive -- is opened, oxygen enters and the oil starts to go rancid. Will refrigeration stop this? I know that people won't die from using unrefrigerated oils, but are there negative consequences, healthwise? I read the label on a bottle of canola oil and it said nothing about needing to be refrigerated. And what about fish oil in capsules? -- J.S., Phoenix

DEAR J.S.: Any oil can go rancid if stored in the wrong way. Rancidity occurs when the oil reacts with oxygen. Aside from having an odor and giving foods an "off" taste, the consumption of oxidized oil does represent a health risk.

With refined oils, there is only minimal risk in leaving oils at room temperature, provided you follow some simple guidelines. Oils should be stored out of the sunlight and away from any source of heat. Since air, and therefore oxygen, gets in whenever the container is opened, keep the container sealed when not in use. This doesn't mean you need to get frantic and cap the container instantly, but it does make sense to close it when you are done, especially if it takes you months to get through the entire container. If you buy more oil than you tend to use in a few months, consider splitting the large size into smaller portions and refrigerating the unused bottles until needed.

Whenever an oil is stored in the refrigerator, keep it well-sealed to prevent it from picking up any undesirable refrigerator odors. Some oils may become cloudy when refrigerated, but this disappears when they return to room temperature, and is not a reflection on the oil's wholesomeness.

It is an oil's points of unsaturation, the double bonds in its fatty acids, which are most vulnerable to attack from oxygen. This means that the greater the degree of unsaturation, the greater the tendency to oxidize. As produced in nature, oils are blends of fatty acids with varying degrees of unsaturation, but we tend to classify them by their predominant type. Monounsaturates, such as olive oil, mostly contain one double bond. Polyunsaturates, such as soy, corn and safflower, have two. These types are more stable, but they should also be well-sealed and stored away from sun and heat. With flaxseed oil, over half the fats contain three double bonds, so it should be chilled.

Fish oils have four or five double bonds, so they are among the most susceptible to oxidation, and should always be refrigerated when in bottles. As dietary supplements, however, fish oil tends to be dispensed in air-tight capsules, which can be kept at (cool) room temperature.

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 am hoping you will weigh in on a discussion regarding eating habits in our house. My concerns relate to my husband's reliance on nutrition bars. The brand he favors contains protein, along with a bunch of vitamins and minerals. Just about every work day, he will have one for breakfast and another for lunch, sometimes with a piece of fruit such as a banana or an apple. Dinners are more normal: We have a variety of dishes, most balanced and healthful, some less so. We often have meat, poultry or fish for dinner.

We are in our mid-40s. My husband takes supplements and works out about three times a week, though his favorite snacks are cookies and chips. He is not overweight and has no health problems.

His reasoning is that the nutrition bars are a reasonable option since he doesn't have the time or energy to make breakfast or bring "real" food to work, and he does not have time to go out to eat. They are also a way to control his overindulgence tendencies during the day so he can give in to his cravings at night. My argument is that he needs more variety, and also he could be harming his colon because of the lack of roughage. There could also be other deficiencies I don't know about. Would you please enlighten us? I have my husband's best interests at heart. -- I.P., Berkeley, California

DEAR I.P.: No question that your husband is doing many good things with his active lifestyle. Nutrition bars have a place, but they are not a balanced, whole meal to be relied on day after day. Those bars are made with recipes designed to accomplish a specific flavor and texture -- and, ultimately, a certain marketing goal. Whole foods, by contrast, provide a working symphony of healthful compounds, honed through millennia of trial-and-error "rough drafts." Everything works together with health and survival as the goal.

We continue to research which components, in what quantity, are best for us in given situations. At present, the whole-food model provided by nature is associated with the best health outcomes for us. Granted, we are not plants, but it seems foolhardy to grab a processed food from column A and another from column B and think we've got it covered. We may feel fine doing so, but chronic disease sneaks up on us like a thief in the night.

A more thoughtful approach is to rely on real, whole foods as the core of the diet. There are many healthful, flavorful alternatives to a daily reliance on nutrition bars, but they require some advance preparation. Suggestions include cereals with fresh fruit for breakfast; lunchtime can include salads or sandwiches with whole-grain breads, sprouts, greens and a rotating menu of stuff in between. Then there is plain yogurt, nuts, seeds, dried fruit and cut-up veggies.

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.