Olive oil retains healthful qualities even when heated

Q. Is it true that olive oil loses its health benefits when cooked and should only be used for salad dressings and other uncooked foods?

A. Olive oil is a very healthful oil, and most people are aware of its heart-healthy monounsaturated fat.

Olive oil also contains phenolic phytochemicals that seem to lend anti-inflammatory and antioxidant effects that may work along with an overall healthy diet to help lower risk of both heart disease and cancer.

Some studies suggest that heat destroys phenolic compounds or their biological activity in extended heating times, such as when olive oil is reused for frying. However, the studies show decreases of only 5 percent to 30 percent in those protective compounds, so olive oil may still be providing more of these compounds than other oils.

Other concerns relate to potential negative substances released when cooking with olive oil. Reusing and, thus, reheating oil to high temperatures may lead to free radical formation, but this is not how most people cook with olive oil.

Extra virgin olive oil's smoke point is generally given as 410 degrees, which gives plenty of room for the 250 to 350 degrees that covers most cooking. For very high temperature stir-frying, however, oils like canola oil or peanut are typically preferred for their even higher smoke point.

As for reports that toxins are released when olive oil is heated, I can only find research studies showing this result when the oil is heated at high temperatures for hours.

Q. Can a healthy lifestyle lower risk of benign prostate enlargement?

A. Benign prostatic hyperplasia, known as BPH, is an enlargement of the prostate gland that is not malignant (cancerous). Although common in men as they age, it can cause substantial problems for men's quality of life.

Research increasingly links the tendency to develop BPH with factors also tied to risk of heart disease and diabetes, including obesity and low physical activity. Large human studies so far suggest that including plenty of vegetables in your diet may lower BPH risk by 10 percent to 35 percent.

Limited evidence particularly identifies vegetables rich in vitamin C, beta-carotene and lutein, such as leafy green and dark orange vegetables, as well as onion, garlic and legumes, with lower risk.

These choices all provide antioxidant nutrients and phytochemicals, but antioxidant supplements have not shown protective benefits. A few studies also suggest that a diet low in fat and red meat may also help lower risk.

Q. I know that breast-feeding is good for my baby. When I go back to work and pump breast milk, how long can I store it?

A. If you pump breast milk during the workday and have access to a refrigerator for storage until you leave for home, that's ideal. However, breast milk can be safely stored up to 24 hours in an insulated cooler bag if the milk is in a clean, sturdy container kept in contact with an ice pack. It can even be kept at room temperature up to 77 degrees for a few hours if necessary.

Once home, it can be stored safely up to five days in the refrigerator if you keep it at the back where temperatures are most constant.

Some moms create a little "stash" by pumping extra before returning to work or over weekends. This milk can be frozen for two weeks in a freezer compartment within a refrigerator, three to six months if the freezer has a separate door that keeps the freezer colder, or six to twelve months in a completely separate standing freezer, although quality is lower at the longer end of these ranges. Once you thaw breast milk, refrigerate what you don't need rather than refreezing it.

• Provided by the American Institute for Cancer Research. Learn more at aicr.org.

Breast-feeding does offer many health advantages for babies and is a health-plus for mothers, too, reducing risk of both pre- and postmenopausal breast cancer. Using breast milk for your baby's only food for six months and adding other foods after that is highly recommended, so the closer you can come to that goal as you juggle changing schedules, the better.