DEAR DR. BLONZ: What are your thoughts about liver as a food? We used to eat it every now and then, but stopped with the rise in concerns about cholesterol and food safety. There have been some changes in the demonic view of dietary cholesterol, so is it OK to indulge as long as it comes from a healthy source? -- H.S., Walnut Creek, California
DEAR H.S.: The liver is a rich source of many vitamins and minerals (see tinyurl.com/k3ju22s). It is also a major processing and detoxifying organ of the body. You could think of it as a transportation hub, with absorbed nutrients heading there to be processed and packaged so that they will be in the correct form when they reach their eventual destination. Many medications and foreign substances also end up in the liver, where they get broken down or inactivated in preparation for elimination from the body.
It is a remarkably resilient organ, with a healthy liver even having the power to regenerate itself. It has an undeserved reputation as the body's toxic waste dump, and while it does serve as a clearinghouse for unneeded or unwanted substances, the liver does not hold on to its products -- it works to ship them out. If, however, there is an ongoing exposure to a dangerous compound, it is likely that the liver will be in the midst of the battle to re-establish health.
For those in good health with an otherwise healthful diet, an occasional serving of liver should not be a problem. A healthful option is to opt for grass-fed organic beef, and pastured organic poultry. Another alternative is to seek out a provider with a stated philosophy of raising animals without hormones or feed additives. You can often find such providers at farmers' markets and natural food stores.
DEAR DR. BLONZ: Do you consider meats to be the best source of dietary iron? What are some other options? -- V.H., El Cerrito, California
DEAR V.H.: Red meats are definitely a prime source, mainly because the iron is in a highly bioavailable (easy to absorb) form. This being said, there are many non-meat sources as well, including apricots, oysters, spinach, legumes and raisins. Periodic use of cast-iron pans is another way to add iron to the diet. When acidic foods, such as spaghetti sauce, are prepared in cast iron, a small amount of iron dissolves into the food. The actual amount of iron drawn into food depends on the condition of the cookware; a cast-iron pan that's frequently seasoned with oil tends to give off less iron, although it will still provide some.
In any discussion of iron, it is important to remember not to overdo it. Excess iron can be dangerous. Most bodies do a good job of regulating iron, and there is a protein needed for iron absorption; less becomes available when the body's iron stores are full. There is, however, a serious genetic iron-storage disease called hemochromatosis that does not allow the body to rid itself of excess iron. There is an excellent discussion of this at the National Institutes of Health (tinyurl.com/95opbcj).
Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to email@example.com. Due to the volume of mail, personal replies cannot be provided.