DEAR DR. BLONZ: Six months ago, I moved into a wonderful apartment that included some furnishings. The kitchen table appears to be constructed from an old painted door. It is beautiful and solid, but what concerns me is that that I noticed a powder on the surface when I moved in. I keep the table clean and have always used a tablecloth, but one of my friends told me that there could be lead in the old paint, and that this could be dangerous -- pointing out that the tablecloth and my cleaning would not provide any real protection.

I need more information about this risk, and about how best to determine whether there is any lead on this door. There are no children in the apartment, but I do have a dog and want to be certain that neither the dog nor I am in danger. -- J.S. Anderson, South Carolina

DEAR J.S.: You are right to be concerned about lead. This potentially toxic substance can enter the body in a number of ways, the most common being the consumption of substances containing lead, or the inhalation of lead in dust. Lead poisoning in children, for example, is often related to the consumption of leaded paint chips that peel off walls and other surfaces, or by putting toys that contain lead dust in their mouths. (This could also be an issue with dog toys, in your case.) For adults, leaded water pipes are a common source of lead poisoning. Others include cooking in, or eating on, pottery that is rich in lead; consuming food or liquids that have been stored in leaded containers; and working in industries that use lead compounds.

For you, a prudent first step is to determine whether there is any lead on the door, or elsewhere in the apartment. There are products to help with this, many available at your local hardware store, or online. I have used the LeadCheck swabs made by 3M, but there are other brands, and any can provide the information you need. Most involve a color indicator that reacts to the presence of lead, changing to a specific color if lead ions are present. The tests are simple and straightforward, and will let you know instantly if your painted table -- or any surface or object -- presents a risk.

There are blood tests to determine if the body has been exposed to excessive lead. Speak with a physician for a precise evaluation. The body can rid itself of lead, albeit slowly. The first step is to identify and stop the exposure.

The symptoms of lead poisoning in adults can include anemia, fatigue, depression, high blood pressure, heart failure, abdominal pain, gout, kidney failure, wrist or foot weakness or reproductive problems. In children, lead poisoning symptoms include anemia, fatigue, decreased appetite, digestive problems, sleeplessness, learning problems and lowered I.Q.

The Environmental Protection Agency has information on a variety of issues relating to lead: epa.gov/lead.

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 friend is lactose-intolerant, and I was wondering if her allergy to milk means that she should not have butter. -- S.T., Orlando, Florida

DEAR S.T.: An intolerance to lactose, a carbohydrate found in milk and milk products, is not the same as an allergy. A lactose intolerance typically occurs when the body does not produce sufficient amounts of the lactase enzyme needed to break apart the naturally occurring lactose as a prelude to absorption in the small intestine.

When a lactose-intolerant individual consumes more lactose than their body can digest, the lactose passes through the small intestine, into the large intestine. This is where the problems occur, including stomachaches, bloating, gas or diarrhea.

The human body can produce lactase during infancy, but then loses some or all of this ability at about age 5. People’s levels of lactase production-ability vary, and therefore, so do levels of lactose intolerance. Some with this condition have no problems with a half-glass of milk, or with cheese, but if they were to have an entire glass of milk -- especially on an empty stomach -- the symptoms would arise. Some are intolerant to the point that any level of intake causes problems. Lactose-intolerant individuals usually have no problem with butter as it contains little, if any, lactose.

A milk allergy, by contrast, occurs when there is a specific sensitivity to milk protein. This condition is one that should be confirmed through testing by an allergist. When an individual with a milk allergy gets a product that contains milk protein, they can -- depending on their level of sensitivity -- experience symptoms including sneezing, runny nose, asthma, rashes, nausea, diarrhea, swelling and headache, or even a life-threatening drop in blood pressure. These are reactions caused by the immune system reacting to a substance in the body. As butter contains a small amount of milk protein, it should be considered off-limits to an individual with a milk allergy, along with all other dairy products. Read more on milk allergies from the Food Allergy Research and Education site: b.link/milk75.

DEAR DR. BLONZ: Is there a health difference between steel-cut oatmeal and longer-cooking oatmeal? Does the preparation make a health difference, too? I prepare mine the smooth way by putting both oatmeal and water in at the same time, and then cooking. -- O.M., Healdsburg, California

DEAR O.M.: There is no health or nutrition composition difference between steel-cut and traditional long-cooking oatmeal. The same goes for quick-cook oats, which are nothing more than oat flakes pressed to be thinner to facilitate water penetration and reduce cooking time. The main difference is the cut of the oats and the speed in which they cook. One half-cup (40 grams) of the dry oats in any of those cuts will contains about 3 grams of fat, 5 grams of protein, 27 grams of carbohydrate, 4 grams of fiber, and no sodium. Your method of preparation is fine.

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: Is there truth to the “raw foods” movement’s claim that cooking kills the natural living enzymes in foods, including vegetables, and that this creates poisons in our bodies? -- R.V., Berkeley, California

DEAR R.V.: The concept of “living enzymes” is misleading, in that enzymes are not living substances. Rather, they are a type of protein in living cells that speeds up chemical reactions, helping to change other things without being changed themselves.

In our bodies, enzymes not only work on digesting food, but they are involved in most aspects of our metabolism, which can be thought of as the processes associated with life. Enzymes have unique characteristics that determine how and when they become active. For example, if our blood sugar (glucose) is normal, one set of enzymes becomes active to process incoming nutrients. But if blood sugar is elevated, another set of enzymes gets the call. It is a remarkable system, all designed to ensure that things get handled in the most appropriate way for a given situation.

Like us, plants contain enzymes that play a part in their metabolisms. Inside plant seeds, enzymes can remain inactive for years, springing into action when conditions favor a need for their participation in the chemical reactions involved with the development of the new plant. Heat can indeed destroy plant (or any) enzymes, but it is important to appreciate that plant enzymes are there for the plant -- not for us.

A normal, healthy body makes its own enzymes as needed to digest the foods we eat. One of the initial stages of the human digestive process subjects foods to the acid environment in the stomach, which breaks down enzymes, treating them like other proteins that might be in the foods we just swallowed.

The heat of cooking helps make certain foods easier to digest, and it can make certain plant nutrients more bioavailable for our bodies. The idea of cooking being inherently negative because it “kills” anything alive in food is a bogus spin. Eating cooked food does not “poison” our body. Overcooking, the use of excess heat, can destroy some of the nutritive value of food -- and it can, if taken to an extreme, create mutagenic and carcinogenic substances. But that is not what we are talking about here.

By all means, we should enjoy eating fresh, raw, wholesome plant foods as part of a varied, healthful diet. But we should do so because we like the flavors and textures of the foods -- not because we fear that cooking creates poisons.

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.