DEAR DR. BLONZ: I recently had heart bypass surgery after blockages were found in my coronary arteries. I am looking for my own brand of a healthy lifestyle to make sure that this is my last visit to an operating table. One natural component is diet, and I have read all these handouts and websites about fats. I have read that the oils in certain cold-water fish are beneficial. One of my favorite foods has become sardines because they are easily available in the supermarket. I looked at the label of the brand I buy, and I have determined that I have been having 11 grams total fat, 2 grams saturated fat and 131 milligrams cholesterol. Given my history, should I discontinue eating sardines? -- M.M., Tulsa, Oklahoma

DEAR M.M.: There is no need to stop eating sardines if you enjoy them. The totals you cite are for a 3.5-ounce tin. According to my nutrient database, aside from its 11 grams of fat, one tin of sardines also contains about 23 grams of protein and 350 milligrams of calcium, along with other nutrients. Sardines have a moderate fat content, and they do contain the heart-healthy fats EPA and DHA, collectively known as the omega-3s. The key to a healthy diet, however, is variety and moderation. You could be eating a variety of fish, not only sardines, but the emphasis should be that your meals include whole foods, such as fruits, vegetables and fiber-rich grains. Combine this with the non-food essential element -- a daily serving of physical activity -- and you'll be on the road to the healthy lifestyle you seek. I don’t know how recently you went through your bypass, so proceed with caution, taking into account the advisories of your physician. Consider also enlisting the guidance of a trainer with expertise in this area as you weave this important aspect of healthful living into your daily life.

DEAR DR. BLONZ: This is to help settle an office argument. Does the extra virgin vs. virgin grade of an olive oil reflect the fatty-acid proportion as well as other health values? -- F.S., Tucson, Arizona

DEAR F.S.: A couple of things to consider here. First, the main fatty acid in all types of olive oil is oleic acid, which is a monounsaturated fatty acid. The grade of an olive oil reflects the level of “acidity,” which indicates the level of free fatty acids, those not attached to a triglyceride in the oil. Higher grades of olive oil have only a small amount of free fat. Extra-virgin olive oil must have no more than 0.8 percent acidity. Virgin olive oil can have no more than 2 percent acidity. This means that, as a general rule, all grades of olive oil will have comparable proportions of monounsaturated, saturated and polyunsaturated fatty acids. When considering potential health attributes, I favor the extra-virgin olive oil (EVOO). This is the first oil out during the pressing of the olives. EVOO has higher levels of the olive’s protective assets, the main one being the plant polyphenols that are there to protect the olive and its seed. Research evidence suggests that these substances can be beneficial for us as well (see b.link/olive30).

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 don’t like overcooked vegetables like broccoli and cauliflower, so I choose to have them raw or cut up in a salad. I tend to stay away from the stems, but wanted to know: How much of these plants should be eaten to provide health benefits? -- T.S., Milwaukee, Wisconsin

DEAR T.S.: The budding broccoli and cauliflower florets at the top of the plant contain the most vitamins, minerals and phytochemicals. This makes sense, as this is the part of these plants that, if allowed to grow, develops into the flowers and seeds for the next generation. Plants have evolved to have significant nutritive and defensive assets in the parts involved with seed development, to help assure the success of the next generation.

As you work your way toward the stem, you transition to parts that are more structural (i.e., dietary fiber) than anything else. From the standpoint of healthful eating, this should be viewed as an additional asset rather than a negative. Dietary fiber is an essential part of healthful eating, and the average fiber intake in the U.S. is about 15 grams a day, which is half the recommended level from the foods we eat. The risk for chronic diseases, such as diabetes, obesity, heart disease, constipation and colon cancer tend to be inversely related to the level of dietary fiber in our diet. We continue to learn about the impact of the microbiome, the population of bacteria that live in our colon, on our health. A healthful, high-fiber diet is also associated with beneficial effects on our gut microbiome, which can also benefit our immune system. I encourage you to give those stems a second chance.

Let’s accept that most people in this country need more dietary fiber. If there are no health issues to the contrary, the goal should be to get fiber from foods, not supplements. But, eating the uncooked stems of cruciferous vegetables such as broccoli and cauliflower might pose a bit of a challenge. Consider steaming them a bit. Other possibilities are to grate the broccoli and cauliflower stems and create a vegetable slaw, or cut them into thin slices and have them sit in a marinade to pick up flavors. For more on dietary fiber, check out b.link/fiber57 and b.link/fiber93.

DEAR DR. BLONZ: Are California wines as good for the heart as French wines? -- S.C., Lafayette, Louisiana

DEAR S.C.: To my knowledge there's been no study that has performed a head-to-head comparison. But research studies on the benefits of wine have come from both sides of the Atlantic. I'd think it safe to assume that the wine made from grapes in both areas would have comparable effects. An important point not to lose here is the fact that diet and lifestyle carry more weight in determining one's state of health than any possible contribution alcohol might make.

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 have been interested in taking niacin for my cholesterol but am concerned that it might be harmful. I get some pretty bad rashes when I take it, like an allergic reaction, but I can’t imagine that I might be allergic to a vitamin. Is this normal and safe? -- H.C., Berkeley, California

DEAR H.C.: Doubtful that you are allergic to niacin, which is indeed an essential nutrient. The daily value for niacin for adults and children (aged four or older) is 16 milligrams per day. What you are probably experiencing is appropriately referred to as a "niacin flush." This is nothing more than a dilation of the small blood vessels near the skin that can occur when a high dose of niacin is taken, usually about 10 times the daily value. It varies from individual to individual, and some can experience a “flush” at much lower doses. You can avoid the flush effect by lowering your intake of niacin, taking it in divided doses, or opting for an extended-release form. There are flush-free forms of niacin, such as nicotinamide or inositol hexanicotinate, but the evidence does not support these as having the same cholesterol-lowering effect. Niacin (also known as vitamin B3, or the related compounds nicotinic acid and nicotinamide) is required for normal cell metabolism and energy release from carbohydrates. Niacin also plays a role in the synthesis of hormones and DNA. Food sources include organ meats, poultry, seafood, nuts, green vegetables and legumes. For more on niacin and its use regarding cholesterol, check b.link/medlineplus54.

DEAR DR. BLONZ: I recently got lightheaded and blacked out. I have no idea why. Could it be from dehydration? Not enough salt? The reason I was not that concerned is that I am in good shape and I bike and run. I have had problems with heat exhaustion in the past. Just curious what you might think it was. I had been getting dizzy when I got up from sitting earlier in the day after a hefty workout. I got up and stood for a minute, and next thing I knew, I was on the floor. Not a big deal, I think I was out for only a few seconds. Any thoughts? -- W.R., via email

DEAR W.R.: I am not a physician, and I have no real handle on other health issues in your life; my advice is that such episodes need to be checked out by your physician. There can be risks in delay, so why take a chance? That said, there can be many explanations for an unexpected loss of consciousness. You have mentioned a few. It could have been a freak intersection of factors that ended up leading to a rapid drop in blood pressure (vasovagal episode). Staying hydrated is important, and if you tend to perspire heavily, it is reasonable to replenish fluids and lost electrolytes when exercising. Anemia is also a possibility. I encourage you to find out what is involved with your situation now, with the help of your doctor.

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.