Separating nutrition facts from fiction

Q. Is there any truth to the statement that artificial sweeteners trigger the production of insulin, just as sugar does? Also, is there truth to the raw-foods movement's claim that cooking kills the natural enzymes in foods (including vegetables), and that this poisons our bodies? I hope you've seen and evaluated good research recently on these items. Many thanks.

J.C., San Diego, Calif.

A. You ask about "truth," but we have to accept that science is only as good as the data from the latest study or series of studies. Next, we need to realize that an assessment of what is true may depend upon the particular lens through which one views and interprets the available data.

Different people can look at the same data and come up with different assessments. Some people seek out and accept information that supports their preconceived opinions. This goes on in politics and the arts every day, but it can also occur in the sciences. With this as prologue, let's move on to your questions.

There is no evidence that artificial sweeteners trigger the production (or release) of insulin in humans. Next, raw foods contain enzymes that play a part in the metabolism of the plant while it is alive, and this includes the creation of the seed. Inside a viable seed, enzymes play a role in nourishing the growth of a new plant. Heat can destroy these plant enzymes, but these enzymes are there for the plant, not us; we make our own enzymes to digest the foods we eat.

Our digestive process tends to destroy enzymes, which are usually protein in nature, treating them like any other protein we might eat. Cooking can make certain foods easier to digest, and it can makes certain plant nutrients more bioavailable for our bodies.

Appropriate cooking will "kill" anything that is alive in a food, but eating food prepared in this manner does not poison the body. Overcooking, or excess heat, can destroy much of the nutritive value of a food, and it can, if taken to an extreme, create mutagenic and carcinogenic substances, but that is not what we are talking about here. There is nothing wrong with eating fresh, wholesome plant foods that have not been cooked, but do it because you like the taste, not because you fear that cooking creates poisons.

Q. I have a friend that is lactose intolerant. I was wondering if her allergy to milk means that she should not have butter.

M.A., Marrysville, Calif.

A. Lactose intolerance is not the same as an allergy to milk. An intolerance occurs when the body does not produce sufficient enzymes to digest a naturally occurring carbohydrate (lactose) that is present in many milk products.

When a lactose intolerant person consumes more lactose than their body can handle, they can experience symptoms such as stomach ache, bloating, gas or diarrhea. These individuals usually have no problem with butter as it contains little, if any lactose.

A milk allergy 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 eats products that contain milk protein, they can, depending on their level of sensitivity, experience symptoms ranging from sneezing to a life-threatening drop in blood pressure.

Butter will contain a small amount of protein and it, along with all other dairy products, should be considered off limits to an individual with a milk allergy.