Are You as Nutrition-Smart as You Think You Are?

We thought it might be fun to answer some of the questions we’ve received, but in the form of a little nutrition quiz. Just to make it more interesting, some of the questions have more than one correct answer.

1. You know you should lower your blood cholesterol, and you’ve read that eating more fiber will help. But not all types of fiber affect cholesterol levels. Which of the following foods will not help lower your cholesterol level?

A. Oat bran

B. Wheat bran

B. Kidney beans

D. Grapefruit

E. Apples

2. True or false? Yogurt is so good for you that even those laced with fruit jam should be included in a low-fat, low-calorie diet.

3. Scientists have been debating the merits of vitamin C for decades. Now there’s pretty solid evidence that its antioxidant properties may be protective against cancer and other diseases. When we think about getting enough vitamin C in our diets, we usually think about oranges, but ounce for ounce, some foods have even more vitamin C. Which of the following foods fall into that category?

A. Broccoli

B. Red peppers

C. Kale

D. Kiwis

4. True or False? Because protein is so important to your diet, you should eat as much as possible and/or take supplements.

5. How do frozen vegetables stack up nutritionally against fresh veggies?

A. Fresh are always better.

B. Frozen are sometimes better.

C. Flash-frozen vegetables may contain more nutrients than the fresh vegetables you find in most grocery stores.

D. Fresh vegetables have more fiber.

Answers

1. B. This answer (wheat bran) may surprise you, since we’ve

heard so much about oat bran and cholesterol, but keep in mind: Plant foods contain two different kinds of fiber, insoluble and soluble. Both are important in your diet, but for different reasons.

Insoluble fiber, such as the kind found in wheat bran and whole wheat, is the type that keeps you regular and may also protect against certain forms of cancer (colorectal cancer, for example). Soluble fiber, such as that found in oat bran, beans and fruit, has been shown to help lower blood cholesterol levels, primarily by bringing down the level of LDL (bad cholesterol).

2. False. Yogurt is great, especially the low-fat or nonfat varieties. It’s a good source of protein and a pretty good source of calcium. But the varieties that contain fruit jams may have as many calories as a can of nondiet soda (8 to 9 teaspoons of sugar per 8-ounce container).

In order to get this much sugar into a cup of yogurt, you have to displace some of the yogurt, and thus the valuable nutrients it contains. If you like flavored yogurts, try adding your own fresh fruits to plain yogurt.

3. All of the above. In addition, Brussels sprouts, arugula, green peppers, red cabbage and strawberries have more vitamin C by weight than do oranges. Sweet red peppers have almost three times as much, and hot red peppers have even more. Of course, you probably couldn’t eat enough hot peppers to get very much of the vitamin.

Obviously, you can also take vitamin C supplements, but there’s not too much evidence to suggest that supplements are really more helpful than making sure there’s plenty in your diet. Moreover, by taking pills, you miss out on the other protective nutrients, such as beta carotene and fiber, that you get by eating fruits and vegetables.

4. False. Most Americans eat plenty of protein without even working at it (100 grams of protein per day, nearly twice the recommended dietary allowance). Eating a diet high in protein doesn’t offer any real advantages and does have a few disadvantages. Most of the animal foods that are high in protein (meat and dairy products) are also very high in fat. High-protein diets also tend to interfere with calcium absorption and may be preventing you from getting enough of that important mineral.

Vegetarian protein foods--such as legumes and grains, which are generally low in fat--can be combined to provide an ample supply of complete protein for most people.

For non-vegetarians, eating a diet that includes 5 ounces of lean meat and two glasses of low-fat or nonfat milk, or a combination of animal and vegetable foods, will provide plenty of protein and only a moderate amount of fat.

5. B and C. If the produce in your market is wilted and pale, or if you’ve kept some fresh vegetables too long in your refrigerator, then frozen vegetables are a better nutritional bargain because they tend to hold on to more of their nutrients. Fiber content doesn’t change, even when produce has been badly mishandled.

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Dr. Sheldon Margen is a professor of public health at UC Berkeley; Dale A. Ogar is managing editor of the UC Berkeley Wellness Letter. Send questions to Dale Ogar, School of Public Health, UC Berkeley, Berkeley, CA 94720-7360, or e-mail to daogar@uclink4.berkeley.edu. Eating Smart appears the second and fourth Mondays of the month.