DEAR DR. BLONZ: I am looking for general advice: I am 70 years old, in good health and hope to stay that way. I do my best to get five or six fruits and vegetables each day and a lot of cereals/grains. I also take a multivitamin that contains between 100 percent and 200 percent of my recommended nutrients. I am at the top end of the normal bracket for cholesterol, so I am very careful with fats. Most of the vegetables I eat, and a lot of the fruits, are raw. Is that good, bad or does it matter? -- J.W., Phoenix

DEAR J.W.: What you are doing sounds great! Having your vegetables raw is neither good, bad nor indifferent; having them at all is what's most important. The way they are prepared is a matter of taste. If you are going to take a supplement, it is best to take it with a meal. The choice of the meal is up to you, but it should contain fat, protein and carbohydrates. As regards your cholesterol, what you are doing with your diet sounds good to me. The one item you haven't mentioned is physical activity, and I would try to stay as active as possible. If you have not previously been active, you should touch base with your doctor before you start.

DEAR DR. BLONZ: I want to know about the no-calorie sweetener called Splenda. What is it? Have studies shown that it is safe for long-term use? -- B.B., Chicago

DEAR B.B.: Splenda is the brand name for the compound known as sucralose, which is a modified form of sucrose, or table sugar. Sucralose is approximately 600 times as sweet as sucrose. It's not absorbed to any appreciable degree, and that means no carbohydrate grams as well as no calories. It does not contribute to tooth decay. It does contain a small amount of a carbohydrate as a bulking agent in packing, but it is less than one gram per serving -- not enough to provoke the release of insulin by the pancreas. The sweetener has been in use in Europe and in Canada since 1991, but only approved for use in the U.S. since 1998.

Sucralose is made through a multi-step process that substitutes chlorides in three places along the sucrose molecule. These tightly bound chlorides change the character of the molecule to the point that it is not recognized as a carbohydrate. Sucralose gets the green light for cooking because, unlike other artificial sweeteners, it does not lose its sweetness when heated.

As for your second question: Is sucralose safe? Safety studies to date reveal no cause for concern. A review in the October 2009 edition of the journal Regulatory Toxicology and Pharmacology has affirmed this fact. As an artificial sweetener, this one looks like a winner, but our history with novel food additives would dictate that it pays to be prudent with this or any artificial sweetener.

Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 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 wife and I really liked your recent column that answered a question on protein. We are vegetarians. You mentioned that vegetarians "can easily meet their daily protein requirements by combining different foods so that sufficient amounts of essential amino acids are consumed during the day." Our question is: What are those food combinations? Please help us with some examples of vegetarian foods that form a complete protein when eaten together. -- P.G., Freemont, Calif.

DEAR P.G.: From a vegetarian perspective, the concept of a protein requirement can be misleading. It's not the complete protein the body needs as much as the amino acids the proteins are made from. When we eat protein foods such as meat, poultry or fish, the human digestive process breaks down the "complete" protein to its individual amino acid parts. This is an essential prelude to absorption.

Once inside, the body can custom-make its own protein according to what is needed at the moment. Need more muscle? Time to make a few new red blood cells? Have to replace some organ tissue? Whatever is on the body's build/replace/repair menu, the on-site construction team goes to work by grabbing essential amino acids out of bodily fluids to assemble the desired protein substance. The message here is that we have to eat in a way that ensures our body has all the amino acids available. We are able to manufacture most amino acids from scratch, but the essential amino acids (EAAs) are those we have to get from the foods we eat.

Vegetarians can easily meet their daily protein requirement by combining different foods so that sufficient amounts of all the EAAs are present during the day. There are three basic types of vegetable protein: whole grains, such as rice, corn, oats and barley; legumes, such as beans and lentils; and nuts and seeds, such as almonds, sunflower seeds and sesame seeds. By combining foods from different groups, you end up supplying the EAAs the body requires, the same as if you had eaten a complete protein. For example, bean protein, from the legume group, has most of the EAAs, but comes up short with tryptophan and methionine. Nuts, grains and seeds are relatively short in lysine and isoleucine, but they have higher levels of the EAAs that legumes lack. By having foods from both groups during the day, you can satisfy your protein requirement.

Factors that often drive people towards vegetarianism include health, the environment, cost, religion and animal welfare. Health statistics for vegetarians include lower rates of heart disease, obesity, obesity-related diabetes, colon cancer, lung cancer, breast cancer, hypertension, osteoporosis, kidney stones, gallstones and diverticular disease. Though some of these gains can be attributed to a healthier lifestyle that's frequently adopted with new eating habits, the data are certainly impressive.

As regards cost, I recommend reading an article in the October 2009 issue of the Agricultural and Resource Economics Review (available online in pdf format here: tinyurl.com/cxfq6ms). Vegetarianism does not have to be thought of as an all-or-nothing proposition. Having one or more vegetarian days during the week can get you thinking more about what you eat and effectively expand the selection of healthful foods on your table. 

Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 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: What controls the body's ability to make cholesterol, and how much is made? Can we manufacture much more cholesterol than we take in with our food? -- E.D., Palo Alto, Calif.

DEAR E.D.: Even in people without a dietary source, such as strict vegetarians or vegans, the body makes all the cholesterol it needs. This is because cholesterol is an essential structural element in every cell of the body. In addition, cholesterol is a raw material for a number of hormones, including estrogen and testosterone. Many cells in the body can make cholesterol, but much of it gets made in the liver.

There are feedback mechanisms to stop cholesterol production when there is enough; ideally, when cholesterol is absorbed from the foods we eat, the liver and the body's cells will make less. There are a number of genetic conditions in which the body is misprogrammed to make more than it needs. They are referred to as familial hypercholesterolemias, and there is an informative page explaining these rare conditions at the National Institutes of Health (tinyurl.com/ld48). However, a more common condition is an unbalanced diet: too much fat and sugar and not enough grains, fiber, fresh fruits and vegetables. This can contribute to elevated blood cholesterol levels with especially high levels of the LDL (low-density lipoprotein) cholesterol associated with chronic disease. When there is stress, smoking, excess alcohol and lack of physical activity, things can get even worse.

DEAR DR. BLONZ: I filled out an online health questionnaire, which told me I had a "sluggish liver." Three of the items I had checked were cellulite, a hard time losing weight and frequent pains in the hips. The site recommended a particular dietary supplement that, of course, they were selling, which made me quite suspicious. What is known about sluggish liver? -- B.N., Janesville, Wisc.

DEAR B.N.: I have seen the term "sluggish liver" used to explain everything from hemorrhoids to headaches, but the entire concept of the "sluggish liver" has no real medical meaning. The liver is a very complex organ, perhaps the hardest working and most diverse organ in our body. Its responsibilities include: making blood and various blood proteins; detoxifying chemicals, including alcohol and all matter of drugs and contaminants, whether they are eaten, injected, absorbed through the skin or present in the air we breathe; manufacturing and storing glycogen, a form of stored glucose (blood sugar); manufacturing fats whenever the body has more dietary energy (calories) than needed at the moment; facilitating the burning of fats when there is insufficient energy; producing bile, a substance needed to digest fats; storing iron and other vitamins and minerals; and making many of the factors that help clot the blood.

The implication of such an impressive list is that there are serious consequences if the liver is not functioning up to par. But what does it mean if it is "sluggish"? It is just too vague a term. Using it is like telling a new doctor that you don't feel well and then expecting a complete diagnosis and treatment plan.

There might be nothing wrong with your liver, but if there was, it would not be something you could uncover through an online questionnaire. A health professional can take a careful history, do a physical examination and order any appropriate laboratory tests. For more background, see the NIH page on liver diseases is at: tinyurl.com/4p8kcv.

Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 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.