DEAR DR. BLONZ: I have a question about fasting as a means to help release toxins from the body. I have used fasting in the past to help jump-start my weight loss, but I have also read that it helps with toxins. Is this true? -- S.H., Seattle

DEAR S.H.: Some connect the way they feel during a fast as an affirmation that their body is casting off toxins. This can be misleading, as the lack of food can cause sensations that might be mistaken for such an effect.

It is a bumpy road to assume that fasting facilitates healing through the removal of toxins. Detoxification is an ongoing process in our bodies. Our digestive system is designed to keep nasty stuff from gaining entry, while the liver and excretory systems work to neutralize and get rid of “undesirables” in the body. Stopping the intake of healthful foods can handicap detoxification by curtailing the raw materials that facilitate the process. With no food coming in, metabolic priorities get reshuffled.

Humans evolved amidst unreliable food sources; we made it through such stresses thanks to our ability to use stored energy in different ways, and thus keep our brains working and muscles fueled until we could find new food sources and increase our chances for survival.

Fat storage cells in our body (adipocytes) shrink in size during a fast, as their contents provide energy for the body. Some types of toxins accumulate in the fat cells because many problematic toxins are fat-soluble, and our fat storage is our largest depot to dilute these contaminants. The body slowly eliminates toxins during the normal cell turnover, as all cells are routinely taken apart and remade.

During a fast, the blood levels of some toxins can rise. Think of this as putting a dirty sponge in a pan of water, where the water is slowly but continually refreshed. Over time, the dirty sponge gets rinsed clean. Now, think of how squeezing a dirty sponge in the pan would have an immediate effect on the water.

If the body could easily eliminate stored toxins, they wouldn’t have built up in the first place. Now, also consider that with a fast, your body no longer has the fuel and other nutrients to keep things going. Heavy metals, for example, can only be slowly eliminated from the body, and they create a problem if the intake is greater than our ability to eliminate them. They must get stashed away to keep them from causing metabolic harm. During a fast, the reduction of body mass can release more of these into the system.

The other aspect of fasting you mention is the “jump-start” phenomenon, and this deserves consideration. Here, one can use the fast as a transition period to jettison past practices before shifting to a new lifestyle -- ideally a more physically, emotionally and spiritually healthful one. There is potential here, as the fast might serve as a productive time of contemplation to review the status quo and make new plans. It can be a powerful tool as it defines a distinct separation from what was and what is to be. But it should be approached cautiously, especially if there are ongoing health considerations and medications, so be sure to check with your health professional.

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: 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.