The latest food-shaming headlines attack a vegetable! Yes, it’s the poor potato, the latest poster child for a “bad” food. No less than a Harvard professor declared potatoes “starch bombs” in a recent New York Times article that also claimed potatoes’ “high glycemic index” is linked to heart disease, diabetes and obesity.
While the study cited in the story is actually about the relationship between fried potatoes and health, the story itself seems to be more of an all-out assault on potatoes in general. As my stock-in-trade is “Eating Beyond the Headlines,” let’s take a closer look at the claims in this article and the real facts and science related to potatoes and their place on your plate.
Claim #1: Potatoes rank near the bottom of healthful vegetables.
This first claim continues with, “and lack the compounds and nutrients found in green leafy vegetables.” While it’s true that potatoes and other white vegetables don’t contain the beta-carotene plentiful in deep orange and dark green ones, that doesn’t mean potatoes don't deliver valuable nutrients. A small baked potato with the skin contains a mere 130 calories and 3.6 grams protein along with 22% of the daily recommendation for potassium, 19% for vitamin C, 13% for fiber, 10% for magnesium and 9% each for folic acid and niacin.
To further validate potatoes’ nutritional contributions, a 2012 Purdue University roundtable session, “White Vegetables: A Forgotten Source of Nutrients” brought together researchers and scientific experts who provided substantial evidence that eating white vegetables, such as potatoes, can increase shortfall nutrients, especially fiber, potassium and magnesium, as well as help increase overall vegetable consumption in the U.S.
Claim #2: Potatoes are “starch bombs.”
Starch, the main source of carbohydrate in our diets, is composed of hundreds of glucose molecules. Therefore, it’s known as “complex” carbohydrate as compared to sugars, which are “simple” carbohydrate. Glucose, a simple carbohydrate or sugar, is the body’s primary fuel source. Without it our bodies couldn't function!
There’s really nothing bad about starch. If fact, some of the starch in potatoes is not even digested - resistant starch. “Resistant starch acts as a prebiotic or food for the gut bacteria (probiotic)," explains registered dietitian nutritionist, Angela Lemond, owner of Lemond Nutrition in Plano, Texas. "Potatoes become even more of a resistant starch when they are cooked and then cooled down. Either let them cool before eating or refrigerate them and cut them cool into a salad.” At a time when many folks are concerned about gut health and getting more prebiotics and probiotics to enhance their intestinal microbiome, potatoes offer a natural way to do that without expensive supplements.
Claim #3: Potatoes have a high glycemic index, linked to higher risk of obesity, diabetes and heart disease.
According to Melissa Joy Dobbins, a registered dietitian nutritionist and certified diabetes educator in the Chicago area, it's not the glycemic index of individual foods that matters, but the glycemic load of the entire meal. "Most people don’t eat a potato by itself but instead as part of a mixed meal with other foods, likely including some protein and fat. Therefore, the glycemic load of the meal counteracts the glycemic index of individual foods," she says.
More evidence to dispute this claim is documented in a 2016 study published in the American Journal of Clinical Nutrition. Researchers reviewed 13 studies investigating the role of potatoes in obesity, diabetes and heart disease and concluded that they did not provide strong evidence of an association between intake of potatoes and risks of these conditions.
Claim #4: “Two-thirds of the 115.6 pounds of white potatoes Americans eat in a year are in the form of French fries, potato chips and other frozen or processed potato products according to the U.S. Department of Agriculture.”
When you break it down it’s not as bad as it might sound. Dividing 115.6 pounds by 365 days a year equals just 5 ounces of potato per day or the size of the small potato mentioned above.
Furthermore, 2009–2010 National Health and Nutrition Examination Survey (NHANES) data confirmed that white potatoes provide only 4% and French-fries just 2% of an American’s total calories intake.
The survey also revealed that Americans average a mere 1.5% of their daily calories from French fries or 31 calories for a typical 2,080 calories/day. And just one in 8 males and one in 10 females consumes French fries on any given day. Even for those with the highest French fry intake (90th percentile of consumption or higher), men ate 134 calories and women 118 calories/day, the equivalent of half a small serving of fast-food fries.
The Bottom Line
A single ingredient, food or meal is not responsible for weight gain, nutrition status or health. The total diet over time is what matters. Singling out one food and blaming it for chronic disease or obesity is not only wrong but is counterproductive to encouraging healthful eating habits. Potatoes have long been a popular staple food in the American diet and deliver taste, nutrition and health benefits at an affordable price.
As most of you know, misleading headlines about food and nutrition are a huge concern of mine, thus the brand of my business and blog, “Eating Beyond the Headlines.” A recent set of headlines drew my ire even though they weren’t related to my usual stock-in-trade of refuting fear and misinformation about foods, ingredients and modern agriculture. Instead it was an article about a study that evaluated the effect of diet and lifestyle changes in people at risk for type 2 diabetes.
I first came across the headline in my Academy of Nutrition and Dietetics SmartBrief email that arrives daily in my email box filled with headlines and brief summaries of food and nutrition stories in the popular press. Imagine my surprise when I read “Diabetes risk reduction not tied to lifestyle advice, study shows.” Hmmm. I learned and have always promoted diet, exercise and lifestyle as key components in preventing and managing type 2 diabetes.
Clicking the link to navigate to the news story, I find a different headline, “Lifestyle advice alone fails to reduce type 2 diabetes risk.” The key word here is "alone." That's not reflected in the SmartBrief email headline. Reading the article, it states, "Participants attended four 2.5-hour group education sessions at 2, 6, 12 and 24 months after baseline. Sessions covered general information about diabetes and diabetes risk/prevention, nutrition and dietary recommendations, advice on moderate physical activity, and information on physical activity opportunities." And just 50% attended at least 3 of the sessions. So we might conclude that it wasn't the lifestyle interventions that failed, but the subjects’ failure to use them.
Next I downloaded the original journal article, “Basic lifestyle advice to individuals at high risk of type 2 diabetes: a 2-year population-based diabetes prevention study,” published in BMJ Open Diabetes Research & Care. Note that this title is not at all negative about the role of diet and lifestyle in type 2 diabetes as the previous ones. In the conclusions the authors state, "In summary, the substantial 2-year diabetes incidence, the consistent increases in glycemia and BMI, the relatively low participation, and the low proportion achieving substantial weight reduction indicate that our low-grade intervention with basic lifestyle advice did not have clinically meaningful effect on diabetes prevention overall or in subgroups by age, sex, education level, depressive symptoms, BMI, physical activity, or family history of diabetes." Key terms to note are "low participation," "low proportion achieving weight loss" and “low-grade intervention with basic lifestyle advice.”
I haven’t worked in clinical dietetics or medical nutrition therapy for years but even I know that a “low-grade intervention with basic lifestyle advice” is not the ideal way to treat patients with or at risk for type 2 diabetes. So I went to the Academy of Nutrition and Dietetics position paper, “The Role of Medical Nutrition Therapy and Registered Dietitian Nutritionists (RDNs) in the Prevention and Treatment of Prediabetes and Type 2 Diabetes.” This paper documents the effectiveness of medical nutrition therapy (MNT) provided by RDNs for the management of diabetes, advising that individuals with prediabetes or type 2 diabetes should be referred to an RDN for individualized MNT upon diagnosis and at regular intervals throughout life as part of their treatment regimen.
Specific evidence cited includes:
According to registered dietitian nutritionist, Melissa Joy Dobbins, also a certified diabetes educator and spokesperson for the American Association of Diabetes Educators, “Nutrition counseling for diabetes is more than just giving someone information or 'lifestyle advice.' It takes time. While group classes can provide an overview, meeting with a registered dietitian nutritionist is more likely to be effective because of the individualized plan that is created together between the patient and dietitian. And research shows that more than 10 hours of diabetes self-management education and support is necessary to achieve benefits that have major impact.”
The bottom line: when you read a headline in the popular press that tells you nutrition therapy is not effective or a food or ingredient is bad for you, don’t accept it as fact without further investigation. Contact a registered dietitian nutritionist or check the website of the Academy of Nutrition and Dietetics for more information. And please, please do not tweet or post the story to social media without getting the facts.
In May, I began consulting with the California Leafy Greens Marketing Agreement to help spread the word about the safety and nutritional value of leafy greens. I was not compensated for writing this blog and the information is based on facts from a variety of sources.
As a registered dietitian nutritionist working as a communications consultant to the food, nutrition and agriculture industries, I address misinformation and sensational headlines about food and nutrition on a daily basis. I try to reassure people that it’s safe to eat foods and ingredients like red meat, eggs, wheat, potatoes and sugar for which there is no scientific evidence of harm when eaten in moderation as part of a balanced meal pattern. But sometimes scary headlines can take a real food concern and create more fear than is warranted. So how do we know when the fear is real and when it’s not? The recent romaine lettuce E. coli outbreak is a perfect example.
TRACKING THE SOURCE
On April 13, officials confirmed that the lettuce contaminated with E. coli came from the Yuma, Arizona area. Agencies like the U.S. Centers for Disease Control and the Food and Drug Administration sprang into action to make sure the affected lettuce was removed from the food supply. Supermarkets and restaurants were alerted to stop selling and serving lettuce from Yuma and consumers were advised to throw out any romaine in their refrigerators if they could not identify where it was grown. Obviously, caution about eating romaine was essential.
If you read past the scary headlines, government officials were clearly limiting the alert to romaine produced only in the Yuma region. Meanwhile, leafy green industry groups were updating consumers that romaine currently being sold in stores and restaurants was from California, not Arizona. Both were advising consumers not to eat romaine unless they could confirm it wasn’t grown in Yuma.
On April 29, I ate lunch with my mother in the dining room of her independent living retirement community here in Dallas. As we filled our plates at the salad table, one resident remarked, “I will be so glad when we have romaine again. I am so tired of pale lettuce.” More than two weeks after stores and restaurants were advised to pull romaine from the Yuma area, fear continued to reign about any romaine lettuce. Granted, as we age our body's immune system is less effective and the elderly are more susceptible to foodborne illness. So I can give my mom’s place a pass for their extreme caution, even though there was virtually no chance any tainted romaine was still in the food supply.
On May 16, the CDC said the last shipments of romaine lettuce from the Yuma growing region were harvested on April 16, the harvest season was over and it was unlikely any romaine lettuce from the Yuma growing region was still available in stores or restaurants due to its 21-day shelf life. Yet when I had lunch with my mom again on May 27, romaine lettuce was still not being served. And as of June 22, she reported, “we probably won't ever have it again.”
We are fortunate in the U.S. to have the safest food supply in the world. However, an occasional outbreak of foodborne illness does occur but this is by far the exception and not the rule. Along with USDA and FDA regulations for farming and food processing, additional safety nets are in place to further assure safety and decrease health risk, like the Leafy Greens Marketing Agreement (LGMA). This past March I attended the Produce for Better Health Foundation conference in Scottsdale, Arizona where I met an LGMA representative and learned about their safety program to help ensure leafy greens produced in our country are safe to eat. The majority of leafy greens in the U.S. are grown and harvested under the LGMA initiative to minimize food safety risks on the farm.
Every day, over 130 million servings of leafy greens are safely produced under this mandatory government food safety program. It verifies farming practices using government audits and requires that members be in 100% compliance at all times. They must create a written food safety plan, test irrigation water and monitor worker practices, like proper handwashing. In fact, many major restaurant and supermarket chains require the LGMA certification for leafy greens they purchase.
After this outbreak, the produce industry created a special task force to examine how romaine came to be the source of illnesses. No one wants these kinds of tragic outbreaks to occur – least of all leafy greens farmers. The leafy greens community is committed to producing a safe product and we need to trust they will continue to improve on their already excellent safety record.
As a registered dietitian nutritionist, leafy greens are my go-to vegetable. I enjoy them every day and recommend them to others. They are nutrient-rich, boasting vitamins A and K, folate, potassium, iron, calcium and fiber while low in fat and calories. So be assured that romaine is a nutritious choice and safe to go back on your plate.
For more information and tips and videos on how to keep your greens safe in your home: http://safeleafygreens.com
Photo credit: pixabay.com
MS, RDN, LD, FAND
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