Although eating a balanced diet will always be one of the best ways to stay healthy, some nutrients are actually more effective when taken as supplements. Do you know which ones are … or aren’t?

Read on to find out when to eat whole foods and when to pop a pill.

True or false?

1. Soy foods are better than soy supplements for heart health.
2. Taking a lycopene supplement is the best way to protect against prostate cancer.
3. Vegetarians have a hard time getting enough selenium from the foods they eat.
4. Eating fish of any type will give you all of the omega-3 fatty acids you need.

Answers

1. True. A recent study at Wake Forest University in Winston-Salem, North Carolina, found that the benefits of soy—lower triglycerides, lower total cholesterol and LDL (bad) cholesterol, and higher HDL (good) cholesterol—apply possibly only to soy protein isolates, such as powders, and foods—not soy supplements. To reap these heart-healthy benefits, you need to eat 25 grams of soy protein a day, equivalent to about two to three glasses of soy milk or a half pound of tofu.

2. False. The evidence so far is inconclusive. A few years ago, lycopene became a best seller when it was shown to help prevent prostate cancer. But last year, scientists studying rats at the University of Illinois at Urbana-Champaign discovered that lycopene’s punch is much more potent when combined with the other phytochemicals found in tomatoes, especially those that are cooked or processed into juice, sauce, paste, and even ketchup. For the final answer, scientists will need to do comparative studies on humans.

3. True. Although many plants contain the antioxidant selenium, including whole grains, nuts, garlic, and asparagus, the levels depend on the soil content where the plant was grown. Because modern farming techniques have depleted much of the soil of its selenium content, consider taking 200 mcg of supplemental selenium a day, particularly if you are a vegetarian.

4. False. The all-American diet is full of essential fatty acids—omega-6 fatty acids, that is. Although our bodies need this important fat, it must be balanced with omega-3 fatty acids in a ratio of 4 to 1 to prevent inflammation. Fish is an excellent source of omega-3 fatty acids, but some fish can expose you to high levels of toxins, such as mercury and PCBs. Instead, you can safely boost your omega-3 levels with “clean” fish, such as wild salmon or sardines, or a purified fish-oil supplement containing both DHA (docosahexaenoic acid) and EPA(eicosapentaenoic acid).