DEAR DR. BLONZ: My hair is thin and subject to frequent breakage. Someone suggested that taking Norwegian kelp will help. Will this remedy my symptoms and stimulate hair growth? What other natural products would you suggest? By the way, I’m African American, if that makes a difference. -- S.T., Tulsa, Oklahoma

DEAR S.T.: Kelp, a vegetable that grows in the sea, is primarily known for its iodine content. But it also contains lesser amounts of potassium, calcium, magnesium, sodium, folate, vitamin A, vitamin K and several other nutrients. An ounce of kelp provides 100% of the recommended daily intake of iodine (150 micrograms), but not much more than 5% of the daily requirement of other nutrients.

Iodine is an essential mineral that plays a role in the manufacture of the thyroid hormones, the substances that help regulate the body’s metabolism. There may be some logic to your friend’s recommendation, because dry, coarse and breaking hair, and hair loss, are among the host of symptoms of inadequate thyroid hormone (hypothyroidism). However, that does not mean that adding kelp can represent a solution in your particular case. Today, it is rare for anyone eating a varied diet to suffer from an iodine deficiency.

Iodine is plentiful in the ocean, but it is not well-distributed on land. Foods with natural iodine are limited to seafoods, crops grown in coastal areas, and dairy or meat foods from animals that have grazed on feed containing iodine. Starting in 1924, iodine was added to table salt in the U.S.

One’s genetic background, certain health conditions and medications can all have a range of influences on how hair looks and behaves. The quality of your diet is also a player. I would take a look at what you have been eating and aim for a good mix of fruits, greens and grains, as these provide the essential vitamins and minerals. Eggs provide many nutrients used in hair growth, and I would also suggest regular intakes of seafood and other sources of essential fatty acids. These are all regulars of healthful eating.

But keep in mind that regardless of what one eats, hair will always be affected by the products and treatments we use. A knowledgeable aesthetician or hairstylist might be able to recommend products well-suited to your particular situation.

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: Can you please explain a bit about the controversy with taking vitamin A as beta carotene, namely that it might contribute to lung cancer in smokers? -- R.T., Phoenix

DEAR R.T.: Cancer can be thought of as stemming from a “mistake” in a cell’s DNA, the inherited genetic blueprint that tells a cell what to do. Substances that alter genes fall into two categories: Mutagens cause genetic changes that may or may not lead to cancer; carcinogens alter genes in ways known to cause cancer.

Tobacco is a very powerful carcinogen, and inhaled smoke comes in direct contact with sensitive lung tissues. Normally the lungs secrete mucus to entrap dust and other inhaled particles. The healthy lung then works to shuttle the mucus out of the lungs through a series of cilia, or hairs. Tobacco smoke introduces that carcinogen while at the same time causing a breakdown in the self-cleaning system. The mucus then tends to collect in the lungs, resulting in a hacking “smokers’ cough,” since coughing is another way the lungs attempt to eject unwanted substances.

Lung cancers are often present years, or even decades, before the signs emerge. Early symptoms of lung cancer include coughing, weight loss and decreased appetite, but these get disregarded as expected effects of smoking. The fact that fewer than 1 out of 10 lung cancer patients survive for five years once diagnosed is a testimony to the virulence of the disease once it develops.

Now, about beta carotene. It is an antioxidant, but it’s not all-powerful. It works as a member of the team of nutrients in our diet, and that “team” concept is critical. Many studies have found that the risk of lung cancer is lower in those who have higher levels of beta carotene naturally present from the foods they eat.

Concerns about the connection between beta carotene and lung cancer came initially from a 1994 study in The New England Journal of Medicine. That study was conducted in Finland, using males between 50 and 69 years of age. All were smokers, having an average of 20.4 cigarettes a day. These individuals smoked for an average of 35.9 years before the start of the study, so many of them may have already had the disease brewing before the study began. The paper reported a higher incidence of lung cancer in those who took beta carotene supplements for six years.

It should be noted that beta carotene taken as a supplement has never shown any ability to remove cancer once it’s already set up shop -- especially a cancer as virulent as lung cancer.

A well-nourished body needs a daily supply of all nutrients, ideally from foods, as opposed to supplements. Antioxidants should be included in the mix, as well as the beneficial substances found in plants. While nutrients do different things, they work together to produce the powerful synergy we need. You cannot rely on supplements and feel you’ve got the bases covered.

Good nutrition helps protect us, but it cannot make us invincible. Long-term exposures to cancer risk factors, such as tobacco, are going to take their toll, regardless of what foods we eat or supplements we take.

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’ve been taking 1 to 3 grams of RNA/DNA nucleic acid supplements per day for the last 30 years. I’m almost 70, but most people think I’m 50. -- H.W.

DEAR H.W.: It has been 40 years since the publication of “Dr. Frank’s No-Aging Diet” by Benjamin Frank. This book is considered to be the popular starting point of the dubious concept that dietary nucleic acids can slow aging and assist with degenerative diseases. I used the word “dubious” because there has been no reliable evidence in the scientific literature to support such a notion.

Stepping back a bit, the principle nucleic acids in our genetic material are DNA (deoxyribonucleic acid), which is found mainly in the nucleus of our cells, and RNA (ribonucleic acid), which can be found throughout the cells. Both DNA and RNA are large, complex biochemical compounds that contain particular sequences of substances known as purine and pyrimidine bases. Similar to how sentences in Morse code are made up of dots and dashes, the arrangement of the bases in the nucleic acids contain a message, which, in this case, is the genetic blueprint of how we are made.

Frank promoted in his book that increasing one’s dietary intake of nucleic acids, from either foods or supplements, could “de-age” the body and slow ailments connected with getting older.

It would be great, if it were that simple.

At the time, the concept was characterized by promoters as a “revolution in the making,” but there are problems with the logic. First, everyone’s nucleic acids are unique. Most nucleic acid supplements come from yeast, and it is a bit of a stretch to think that they would have the claimed effects for us. Another problem is that when consumed, the nucleic acids will be broken down by the digestive system. Finally, individuals at risk for gout should be aware that taking nucleic acids will increase their dietary intake of uric acid. All this said, these dietary supplements are still available in stores.

The most telling fact is that in the 40 years since the book was published, there has been no evidence in the scientific literature to support claims of youth promotion from nucleic acid supplements.

One reliable benefit from RNA and DNA supplements? Profits for their marketers.

DEAR DR. BLONZ: I eat the whole apple -- seeds, stem and all. Is this bad? -- J.G.

DEAR J.G.: How many entire apples are we talking about? The skin and flesh are good food, and no problem. There would be no problem with eating a washed stem, although I don’t see the attraction.

One thing to be aware of are the seeds, which for any plant are the keys to the next generation and, in essence, the survival of the species. Plants have evolved to produce chemical defenses in seeds to help them survive and develop. The seeds of apples contain amygdalin, a compound that degrades into hydrogen cyanide: a deadly toxin in high doses.

Swallowing apple seeds intact should not represent a problem, as their tough seed coats will allow them to pass through your system. Nor should crunching a few seeds by accident send you to the ER; as with most toxic substances, it’s the dose that makes the poison. A danger zone for a 150-pound individual, for example, would take the contents of over 200 apple seeds. Check out the article at b.link/seeds35 for more details.

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.