Food for Thought: Lactose intolerance is not a type of milk allergy

Is lactose intolerance a type of milk allergy?ANSWER - No. Lactose intolerance is the result of a shortage of the enzyme needed to split lactose, or milk sugar, into its two component sugars, glucose and galactose. This process must occur in order for the sugars to be absorbed. If the amount of the enzyme, called lactase, is insufficient, individuals may face a variety of symptoms, among them abdominal pain and bloating. When the sugar gets to the large intestine, bacteria use it as food and, in the process, produce gas.

In contrast, milk allergy is related to an intolerance to protein. It can make its appearance during adolescence or even later, but most often it crops up in very young infants, usually between one and four months old. Those who suffer from milk allergy may experience gastrointestinal symptoms such as vomiting, diarrhea and abdominal pain. Some also develop hives and upper-respiratory problems. Fortunately, as the immune system and the gastrointestinal tract mature, the problem often disappears, commonly by the time the child is one year old.

QUESTION - What is gum acacia? I keep seeing it on food-ingredient lists and would like to know what I am eating and why it is used.

ANSWER - Gum acacia, also called gum arabic, is actually a gum produced by acacia trees in response to injury. Of the several hundred species of gum acacia trees, only a few, growing in the semi-arid desert of north central Africa, are used commercially for gum production. The tree is intentionally provoked to ooze the gum, which is allowed to dry in place, then collected and put through a series of processing steps.

Commercially, gum acacia has several properties that make it useful in the food industry. About half of it is used in producing confections, where it helps retard crystallization and promotes emulsification of other ingredients. It's particularly helpful in encapsulating flavors used in food production.

Encapsulation is the coating of flavor compounds. The reason it's so important is that flavor compounds are volatile and can readily evaporate from food during storage. Encapsulating can also protect flavors from undesirable interactions in foods as they sit on the shelf.

The technique may also be used to keep different flavors from mixing with one another during food production, and can shield flavors from the effects of exposure to light or oxygen. Most recently, it has been used to control the release of flavors during processing.

As you can see, gum acacia travels a long way from the peaceful trees of the African desert to the complex chemistry of a food-processing plant.

QUESTION - I know it's recommended that we get no more than 30 percent of calories from fat, but how are we supposed to know if we're meeting that goal?

ANSWER - Where there's a will, there's a way, albeit with a little work. Step one is to get yourself a copy of one of the many paperbacks available containing information about fat and calories. Next, keep track of all the foods you eat, recording as accurately as possible both types and amounts for several days. Be sure to add in the fat you use in cooking and at the table (for instance, when you butter your toast). Whenever possible, rely on the information given on food labels, which should make the exercise a bit easier.

Then, to fill in the gaps not provided by labels, turn to the food tables in your paperback and record the grams of fat and the calories for each food. Add up the totals. Now, multiply the grams of fat by 9 (the number of calories in one gram of fat) and divide by the total number of calories you consumed. This gives you the percentage of calories from fat.

If you find that over 30 percent of the calories in your diet come from fat, study your calculation sheets to see where you can cut back on fat to bring the figures into line. In doing so, remember to take particular care to trim away calories provided by saturated fats, found in largest amounts in whole-milk dairy products and meats.

On the other hand, if your research shows you are already consuming no more than 30 percent of your calories from fat, give yourself a pat on the back. If not, at least you have a better idea of where you stand and you can begin to work on reaching your goal.

QUESTION - What are the origins of the restaurant?

ANSWER - The word dates back to the 16th century. But at that time, it meant not a place to sit down and be served but a food that "restores." Specifically, it referred to a rich, highly seasoned soup that could restore one's strength. Gradually the term evolved to mean an establishment selling foods with restorative powers.

Records indicate that the first restaurant was opened by a Frenchman named Boulanger, who sold bouillon described by him as "a restorative fit for the gods." Two others followed the next year, billed as "houses of health." And in 1782, over 200 years ago, what we'd describe as a restaurant in the modern sense opened in Paris. It was in the Grand Taverne de Londres that the novel concept of listing dishes on a menu and serving diners at fixed hours at small individual tables was introduced.

But the French Revolution gave real impetus to the development of restaurants. Guilds were abolished. The cooks and servants whose employers had fled their Paris estates created the necessary labor pool. And the arrival of people from other parts of France provided another essential ingredient, customers.

1990, Washington Post Writers Group