DEAR DR. BLONZ: We would appreciate some information regarding the subject of naturally appearing arsenic. I have heard reports on the radio and elsewhere regarding natural arsenic in fruit juices. Could you please give some perspective and guidance on this issue as it affects children? -- P.M., via email

DEAR P.M.: The adage “the dose makes the poison” definitely applies, but with children, it’s a dose in relation to a smaller body in the process of growth. A cup of juice is the liquid extract of several pieces of fruit. For example, a child will not typically consume four apples at a sitting, but an 8-ounce glass of apple juice typically contains the fluids extracted from three to five medium apples. The whole fruit contains pulp, fiber and skin, but juice does not come with all the good stuff in the whole fruit. Added concerns are the sweetness and attraction of a sweet liquid that gets consumed like water, not to mention the potential negative impact on developing teeth. Children also have a smaller body size, which makes the concentrations higher; a greater risk in growing bodies. Bottom line, more of any heavy metal contaminant, such as arsenic, will be taken in with a volume of fruit juice than a similar volume consumed as whole fruit. I would monitor the sites of juice manufacturers you are considering to see if they are taking steps to reduce the arsenic levels in their products. You can push this forward by writing to them to express your concerns. More on arsenic in apple juice at b.link/arsenic48.

DEAR DR. BLONZ: I am doing the best I can with a big change in diet and activity but want to know what controls how much cholesterol the body manufactures. How can it manufacture more cholesterol than it gets in food? -- S.T., Charlotte, North Carolina

DEAR S.T.: Even if there were no cholesterol in your diet, your body would need to continue making it. This is because cholesterol is an essential structural element in every cell of the body. In addition, cholesterol is a raw material for a number of hormones, including estrogen and testosterone. Most of the cholesterol in the body is manufactured in the liver. When cholesterol is present in the foods we eat, the liver is programmed to make less. There are also genetic conditions in which the body makes way more cholesterol than it needs, but these tend to be rare. More common is the condition in which the body is forced to cope with an unbalanced diet that's light on the plant-based component, such as whole grains, fresh fruits and vegetables, but heavy on the rest. More on that debit side are stress-filled, unhealthful lifestyles with poor sleep habits. All these negatives contribute to blood cholesterol levels that are inconsistent with an interest in health.

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 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.