Q. My friends think that soy is the perfect health food, but I've heard too much soy can increase your risk of breast cancer! How much is too much and is there a safe amount that can be eaten?
A. Early research suggested that certain compounds in soy products, called phytoestrogens, might protect against breast cancer. But more recent studies are less clear. Some researchers have found that these same phytoestrogens may promote tumor growth in the breast, especially in pre-menopausal women. And, it seems that the phytoestrogens in soy are more harmful to women who have already had breast cancer. It really is too early to say whether soy is absolutely helpful or harmful where breast cancer is concerned; if someone in your family has had breast cancer, you may want to be more aware of your soy intake until more definitive research is available.
But that's not to say that soy is necessarily a dangerous food. The American Heart Association recommends 20-25 grams of soy protein per day to protect against heart disease, and the FDA has authorized this as a safe amount for food labeling purposes. One glass of soymilk contains about 6 grams of soy protein. If you think you may be at increased risk of breast cancer, it may be wise to stick to the lower end of the current recommendations.
Q. Lately in the dining hall I've been seeing this grain-like stuff called "quinoa." What is it and is it good for you?
A. Quinoa (pronounced KEEN-wah) is often thought of as a grain, though it is actually a seed. It is native to South America, and has been cultivated for nearly 5,000 years. Quinoa seeds, or "grains," as they are often called, are small and bead-shaped, and range in color from ivory to red to black. This "grain" is rich in good quality protein (more so than rice or corn) because it contains a complete range of amino acids, the building blocks of protein. It is also a good source of several B vitamins and minerals such as iron, potassium, calcium, and magnesium. Quinoa can be substituted for almost any grain due to its relatively bland flavor; so next time you see it in the dining hall, try it with your stir-fry instead of rice. It'll boost your protein intake, and taste good too!
Q. I am determined to shed some winter fat and gain lean muscle before parading around in any kind of bathing suit this summer. I've heard that you are supposed to eat pre- and post- workout snacks, but I'm afraid of eating too many calories and sabotaging my efforts. What are the benefits to eating before and after exercising, and what should I be eating?
A. Proper nutrition before and after exercise helps you get the most out of your workout. Eating before your workout gives your body energy so you can work harder, and eating after your workout allows you to recover from your workout faster. Failing to provide your body with enough energy pre- and post-workout can lead to muscle loss and increased fatigue, and possibly injury.
In general, your pre-workout meal should be low in fat and fiber (to avoid stomachaches or cramps), and higher in carbohydrates. You may also want to include a high quality protein source with your snack - such as a hardboiled egg (without the yolk if you want to keep it lower in fat), some tuna (minus the mayo) on crackers, or a small piece of leftover chicken breast - if you will be performing strength training exercises. Eating high quality protein within one hour after strength training helps to maximize protein synthesis and muscle growth. Your post-workout meal should consist of carbohydrates, protein, and fat, and should be eaten soon after working out to maximize recovery and replete energy stores.
Remember, your pre- and post-workout snacks should fit in to your total daily calorie intake. Spread your calories throughout the day to accommodate pre- and post-workout snacks. By eating a little bit less at each meal, you can have snacks that will give you plenty of energy for exercise - and won't sabotage your workout efforts.
Sara Wilson is a graduate student in nutrition communications at the Friedman School. She has a BS in nutrition from Syracuse University and is a registered dietitian. Prior to coming to Tufts, Wilson worked as a clinical dietitian in an intensive care unit of Legacy Emanuel Hospital in Portland, Ore.
