Issue date: June 6, 1999
The potato debate
Is
America's No. 1 vegetable good or bad for you?
 RE
WHITE POTATOES good or bad for you? Do they help you lose weight
or gain weight? How do they affect your mood? Surprisingly, experts
don't agree. Some praise potatoes; others believe they can be a
health hazard.
DOWNSIDE:
As bad as sugar
White potatoes are like white sugar and white bread, says Harvard's
head nutritionist, Walter Willett, M.D.: They spike blood sugar
and are a "high-glycemic-index" food. Such foods, he says, raise
bad triglycerides and depress good-type HDL cholesterol, boosting
the risk of heart attack, especially in people with insulin resistance
(up to a quarter of the population, some studies contend).
Two recent Harvard studies found high potato consumption raised the odds of developing type 2 (adult-onset) diabetes. Unlike other vegetables, potatoes don't seem to reduce cancer risk. Willett's advice: Eat potatoes as you do candy, cookies and desserts - "sparingly." You can blunt the ill effects of high-glycemic-index foods, says expert David Jenkins, M.D., at the University of Toronto. One way: At the same meal, eat high-fiber and low-glycemic-index foods, such as lentils, dried beans and peanuts. They slow digestion and help counteract a potato-induced rise in blood sugar. Examples: Eat the skin of a baked potato or combine potatoes in stews with other vegetables and legumes. The worst in spiking blood sugar: instant mashed potatoes. Preferable: baked, boiled and even mashed potatoes, Jenkins says. He notes that refrigerating cooked potatoes produces chemical changes that substantially reduce their glycemic index. This suggests a cold potato salad with vegetables and a low-fat dressing may be the most healthful potato dish of all.
UPSIDE:
A nutritious mood-lifter
Other researchers say white potatoes are low-fat, low-sodium, high in certain nutrients and antioxidants, and able to lift mood and suppress appetite. Per calorie, they contain more potassium than bananas. Eating lots of potassium lowers the risk of high blood pressure and strokes. One classic study found that eating only 400 milligrams of extra potassium daily cut stroke risk 40%. Potato detractors argue you can get potassium in low-glycemic-index foods such as green leafy vegetables, dried beans and skim milk.
Mood food? Potatoes are often called "comfort" food. No
wonder. Some researchers say such high-carbohydrate foods soothe
the brain by raising levels of the feel-good neurotransmitter serotonin.
Judith Wurtman, M.D., a leading carbohydrate researcher at MIT,
says many people who avoid sugars and starches have "serotonin hunger"
that makes them depressed and likely to binge.
San Francisco nutritionist Kathleen DesMaisons even titled her recent book Potatoes Not Prozac. The idea: For millions of "sugar-sensitive" people, carbohydrates like potatoes are antidepressants. She recommends a plain baked potato at bedtime to lift your mood and aid sleep. She insists such complex carbohydrates can help fight overeating and addictions, including alcoholism.
Diet food? French researchers recently declared potatoes
a "diet food" because they make you feel full. A "satiety index"
by Australian researchers put potatoes at the very top of the list,
twice as satisfying as the next food, whole-wheat bread, and three
times as satisfying as ice cream.
But others insist high-glycemic white potatoes rapidly push up blood sugar, leaving you hungry and inclined to binge later. The authors of the best-selling diet books Sugar Busters and The Zone put potatoes high on their lists of forbidden "high-sugar" foods. Unfortunately, most people eat potatoes covered with high-fat sour cream, butter or gravy, or as greasy French fries. These are definitely not diet foods, nor good nourishment for your heart and arteries, in anyone's book.
Putting
potatoes in context
They are OK for most people as part of a good low-fat, high-fiber
diet. If you are diabetic or prediabetic, have a family history
of diabetes, or gain excessive weight from eating carbohydrates,
it makes sense to restrict potatoes.
Go to the top
Sugar-Busting
Mexican Stuffed Potato
Total cooking time: 35 minutes
2 large baked potatoes
3 Tbs. each, non-fat sour cream and fat-free milk
1 cup cooked red kidney or pinto beans, drained
1 cup yellow corn kernels, cooked, drained
2 Tbs. chopped cilantro Salt and pepper to taste
1/2 cup shredded sharp cheddar cheese
1/2 cup spicy tomato salsa
Bake potatoes in microwave. Cut in half lengthwise. Remove pulp.
Mash with sour cream and milk. Combine with beans, corn, cilantro,
salt and pepper. Pile mixture into skins. Top with cheese. Bake
20 minutes in 400-degree oven. Serve with salsa. Serves: 4.
Per serving: 264 calories, 11g protein, 44g carbohydrates, 5.5g
fat (3.1g saturated), 4.8g fiber, 432mg sodium.
TIPS
Nutrient Profile
1/2 cup boiled potato has
Calories: 67
Protein: 1.3g
Carbohydrate: 15g
Fat: 0.1g
Vitamin C: 6mg
Folic acid: 7mcg
Sodium: 4mg
Calcium: 6mg
Potassium: 256mg
Magnesium: 15mg
Go to the top
Willett, W., Amer. J Clinical Nutrition, March 1999; 69 (3):572
Salmeron J. Diabetes Care 1997 Apr; 20 (4):545-50
Salmeron J., et al. JAMA 1997 Feb 12; 277 (6):472-7
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