Last updated: Sep 03, 2008

Q: If one slice of bread has mold on it, is it safe to eat another slice from the same loaf?

A: Best to toss the loaf and start fresh. Bread is very porous, so mold can spread quickly and easily, particularly in organic products that dont contain preservatives. Plus, mold, which has roots, could be thriving below the surface, even after you scrape it off. The same goes for meats, jams, and fruits or vegetables—when you see mold, its time to pitch them. (Individual fruit such as strawberries that has come in contact with moldy pieces can simply be washed and eaten. The mold in blue cheese is considered safe, too, unless youre pregnant.) Eating a tiny amount of moldy bread isnt likely to cause a serious illness, though it could give you a stomachache.

To avoid mold, store food in a cool, dry place or in the fridge. Also, always check the expiration dates and eat any leftovers within three or four days.

Q: How risky is just one visit to a tanning salon?

A: Too risky to bother. Skin cancer is on the rise in women under 50—the deadliest type, melanoma, is up 50% since 1980—and the use of tanning beds is partly to blame. While most research has examined people who tan regularly, some studies show that even one session makes you two-and-a-half times more likely to get squamous cell skin cancer and one-and-a-half times more likely to get basal cell skin cancer, the two most common forms of the disease. And, according to the National Cancer Institute, women who use tanning beds more than once a month are 55% more likely to develop skin cancer. Plus, you wont get a golden glow or keep your tan with just a single session; youd have to go several times.

Going for a base tan before a tropical vacation might sound reasonable, but the protection this gives you is equivalent to using an SPF of 3. Not worth it. Instead, achieve a faux glow the safe way: Self-tanning products and cosmetic spray tans are more goof-proof than ever—and risk-free. Also, be sure to schedule regular skin checks with your dermatologist, especially if youve frequented a tanning bed (or have a history of bathing under real rays). She will be able to spy a changing mole before it becomes a bigger problem.

Q: I take fish-oil pills for the omega-3s. How can I avoid fishy burps?

A: Foul-smelling belches are, alas, a common annoyance for many people who pop fish oil pills. Here, a few solutions.

Try a different brand. Cheap pills are made with cheap oil and may not come from reputable producers. Whats more, they not only are more likely to cause smelly burps but also could contain questionable levels of toxins such as mercury.

Check the label. The pill should be “pharmaceutical grade,” which means the oil is taken from healthy fish raised in clean water and has been processed in a high-quality facility.

Take your pill with food—and eat slowly to avoid swallowing air, which causes burps.

Freeze your pills. Theyll break down slower in your stomach, which means less gas and belching. Note: Some manufacturers advise against this, because the pills may lose some of their healthful qualities if frozen. This isnt true for all varieties, so be sure to read the label and freeze accordingly.

You can also get your omega-3 fix by eating more salmon or tuna, or from flaxseed-oil pills (or sneak in some flaxseed powder, which has a pleasant nutty flavor, by sprinkling it on yogurt). Common foods like orange juice and eggs are now fortified with omega-3s, too. Bonus: Your body may absorb the nutrients better when they come directly from food.

Roshini Rajapaksa, MD, is an assistant professor of medicine at NYU Medical Center.