DEAR DR. BLONZ: I am concerned about the dark circles under my eyes. They seem to run in my family, and I wonder if there are any vitamins, minerals or herbs I can take that might help. -- D.C., Tucson, Arizona

DEAR D.C.: Darkness under the eyes can be brought about by certain medical conditions, including allergies, dehydration, sleep difficulties and stress, and you should consult your physician if you have questions as to whether any of these might be involved.

Another common cause is the natural thinness of the skin under the eyes. The skin itself isn’t dark, but it is often thin enough to see the vascular bed underneath. This trait can indeed run in families, and its presence does not necessarily reflect any health problems. If one is fatigued, ill or under stress, the skin can become pale, and this would accentuate the darkness.

I am sorry to report that aside from using a normal, healthful diet and lifestyle to cope with life’s stresses, I am unaware of evidence showing that particular vitamins, minerals or herbs can help eliminate this problem.

DEAR DR. BLONZ: During my childhood, my grandmother from northern Italy made delicious candy from the seeds of peaches. Every fall, after we feasted on the fresh fruit, she took the seeds and fried them in butter, then added sugar till it all melted. It became the most delicious brittle candy. Now I have learned that there is poison in peach pits. Was the candy dangerous? We never got sick from it. -- L.D., Hillside, New Jersey

DEAR L.D.: It is fortunate that you did not get sick from that candy. Peach pits are not really the safest items to have in one’s diet. They, along with apricot kernels and apple seeds, are sources of a cyanide-containing compound known as amygdalin. Although a natural substance, cyanide is a very potent poison because it can effectively shut down metabolism. The body has a recovery mechanism, and as with most toxic materials, it’s the dose that determines the impact. The fact that you’re around to relate this story shows that the amount of cyanide in the peach pit brittle was insufficient to cause any obvious harm. But this is not a recipe I would pass down to future generations.

DEAR DR. BLONZ: I like to grind flax seeds and use them in my foods. I do not want them to go rancid, and was wondering if they need to be stored in the refrigerator or freezer. Also: Can fish oil capsules and other omega-3 supplements go rancid in the same way? -- E.A., San Diego

DEAR E.A.: You are correct in your approach to flax. The seed wall is designed to protect the oils within, but once the seeds have been ground, there needs to be some protection from oxidation. I would not recommend purchasing ground flax from a bulk bin, for example, where the grounds may have been sitting around for long periods of time.

If ground flax is in a well-sealed container, it should be OK at room temperature, but would do even better in the refrigerator. As regards fish oil, capsules are designed to protect their contents. If unbroken, they should be performing that function.

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 was surprised and disappointed at your recent comments about the progress of medical research. I’m just a layperson, but considering the number of major diseases that faced humans even 100 years ago, compared to today, medical science has made incredibly rapid progress. The development of antibiotics, for example, has cured too many diseases to list.

I’m really surprised at you. I experience atrial fibrillation and am alive because of heart medication and blood thinners, which will hopefully prevent a stroke, as my father had. Additionally, I’ll have surgery to implant a defibrillator to prevent sudden death from the condition.

Many cancers have been slowed or even “cured” through advances in therapies and surgeries. Medical advances are helping childhood diseases even before birth. At this point, we’ve cured so many diseases that the remaining ones are very complex, but medical science is finding innovative ways to tackle these by incorporating the body’s own immune system.

While it can be slow to get new drugs to market, this ensures that the drugs are safe -- and considering the tragedies of the past, when drugs have been rushed to market, this is a very good thing. Unfortunately, the progress of the past may be slowed or reversed by the current reluctance of parents to vaccinate their children. Even so, science continues to make incredible strides.

Dental health is frequently overlooked, but we’re learning that oral inflammation contributes to diseases of the whole body. The increasing number of medical specialties points to the rapid progress in medicine.

I believe you owe your readers and the entire medical profession an apology for your poorly thought-out response. -- S.R., Walnut Creek, California

DEAR S.R.: I appreciate your comments and the important perspectives they provide. There have indeed been amazing advances, but I had attempted to side with those suffering in the here-and-now from ailments such as autoimmune issues, Alzheimer’s and other dementias, ALS, Parkinson’s, unstoppable cancers and various forms of intractable pain from pathologies such as arthritis. All of these are instances where solutions remain beyond our grasp at the moment.

That questioner appeared to be writing from the standpoint of frustration within her circle of friends, and I did not want to respond in a palliative way by providing a glowing list of all science had accomplished to date.

Again, my regrets if this came across as a put-down to research; that was not the intention. As one focused on research and communication, I endeavor to keep chipping away at the unknowns, and I acknowledge and celebrate all that continues to be accomplished.

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 dispute between my wife and me. We buy organic peanut butter, and the oil rises to the top. I would prefer to mix the oil in with the rest of the peanut butter whenever we get a new jar. But my wife wants us to pour out the oil, saying that we don’t need the excess fat. What are your thoughts about this? -- S.S., via email

DEAR S.S.: Peanut butter is a healthful food, with or without its top oil. The oil rises to the top due to gravity, along with the fact that no substances were added to the product to help emulsify it -- that is, to keep it all together. The amount of oil reflects the fineness of the grind, and the temperature and length of time the jar has been sitting.

Regarding the fat content: While a significant portion of the calories in peanuts come from fat, most of them stay with the solids. Assuming you will be eating the same serving size either way, the calorie savings will be minimal. A 2-tablespoon serving of peanut butter with all its oil will contain about 188 calories, 16 grams of fat, 8 grams of protein and 3 grams of sugars. If you were to pour off 3 tablespoons of oil (about 45 grams), then take a 2-tablespoon serving of this less-oily nut butter, you would have about 183 calories, 15 grams of fat, 9 grams of protein, and 3 grams of sugars. So the differences will be slightly fewer calories, a bit less fat, and a bit more protein.

Of course, nut butters also contain other nutrients, all of which are affected when the oil is removed, however slightly. Looking specifically at vitamin E, the 2-tablespoon serving of “un-poured” peanut butter will contain 2.9 mg of vitamin E (about 15 percent of the recommended daily value), while the same serving of poured peanut butter will contain about 2.5 milligrams (roughly 13 percent of the daily value).

DEAR DR. BLONZ: Thanks for your response to a recent letter regarding frozen salmon. What length of time is reasonable to freeze other meats -- beef, pork or chicken -- assuming they are kept and thawed safely, as you described in your response? -- B.N., Walnut Creek, California

DEAR B.N.: If properly wrapped and kept in an airtight container at 0 degrees F (-18 degrees C), meats will be as safe to eat when thawed as when they were initially frozen. The flavor and texture quality, however, will deteriorate with time. The major risk is freezer burn, which attacks the edges and surface of meat first.

You will have an average of about three months of safe storage for frozen meats, but this will vary according to the cut, whether it was cooked before being frozen, and the efficiency of your freezer. Be sure to place a date on the package.

Check out more detailed information on frozen-food safety by visiting fsis.usda.gov and searching for “frozen food.”

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.