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.

DEAR DR. BLONZ: Two weeks ago, I found out I was seven weeks pregnant with my second child. I typically have irregular periods and I had no idea that I was pregnant. I had been drinking wine periodically with dinner, but I am now concerned that this might have affected my unborn child. Aside from this, I have a good diet and take good care of myself. Several women have told me that they had a glass of wine every day or so during their pregnancies, and that nothing happened to their babies. Another friend heard from her doctor that a glass of wine once in a while during her pregnancy wouldn't do any harm. But then I read the horror stories. How could anyone know what is safe or unsafe given this conflicting information? Please do what you can to clarify. -- D.D., Berkeley, Calif.

DEAR D.D.: First, let me offer my congratulations on your pregnancy. The question of whether your wine consumption might have had (or will have) an effect on your developing child is difficult to answer with any degree of certainty. We simply don't know. Research and statistical tables are available that reveal associations between the level of alcohol consumption and subsequent problems for the developing child. In most cases, the connection gets made between risk and the habitual amount of alcohol consumed.

You are not the first woman to find out that she was pregnant while engaging in a healthful lifestyle that might have included a moderate consumption of wine. It is not an uncommon circumstance, so don't let it consume you with guilt. There are many studies with gobs of statistics in the scientific literature. Abusive or binge drinking has been associated with problems, but a low-to-moderate intake (not daily, or less than an average of one drink per day with a meal) does not appear to be associated with any harm to the health of the child or mother. Having the alcohol with food is important.

Indeed, in a systemic review of available evidence in the January 2007 issue of BJOG, the International Journal of Obstetrics and Gynaecology, it was reported that there was no convincing evidence of adverse effects from low-to-moderate levels of alcohol intake. This being said, however, it must be emphasized that any excess of alcohol is definitely dangerous, and that alcohol is not essential for the health of your child. Of all the times in life, pregnancy is not one to take risks, however small. I recommend that you talk about these issues with your OB/GYN, and until you have had that conversation, consider tapering off your consumption of wine, if you haven't stopped already. It is always best to err on the side of safety.

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.