The Fruit Factor
One after-meal high was enough to doom the suspected perpetrator to indefinite exile. And, as I became more serious about controlling my blood sugar and precisely dosing insulin, foods with nothing against them except a difficult-to-judge carbohydrate content landed on the list as well.
Fruits were among the first I banned. One day I carefully counted out 17 grapes – a serving size – and dosed insulin appropriately, only to have a sky-high blood sugar two hours later. I was DONE with grapes. After spending way too long contemplating various apples, trying to decide whether they were small (16 grams of carbohydrate) or large (32 grams of carbohydrate), I dismissed them as not worth the stress. And bananas? They’re packed with sugar, right? They were a given on the list.
A study published in the December 2009 issue of the journal Diabetes Care shows I wasn’t alone in my thinking. Researchers found some type 1 children and their parents preferred packaged, processed foods to "whole" foods like fruits because the carb content was readily available on the product labels. Some parents also limited their children's intake of fruit and whole grains because of their carbohydrate content. This study, and others like it – such as the SEARCH for Diabetes in Youth study (Journal of the American Dietetic Association, May 2006), which found most children were not eating the recommended amounts of fruit and other healthy foods – has dietitians and diabetes educators worried about the food choices of all people with diabetes, regardless of age.
While acknowledging competing priorities, among both clinicians and people with diabetes, between glycemic impact and overall health, Hope Warshaw, registered dietitian, diabetes educator and author of “Complete Guide to Carb Counting,” says: “I fear way too many people with diabetes are eating unhealthfully (limiting whole grains, fruits, vegetables and low-fat dairy) with the understandable priority of glycemic control. There are unique benefits of eating a variety of fruits and sufficient amounts of fruit. It provides various amounts – differing by fruit – of vitamins, minerals, fiber and energy.” On average, Americans eat half the amount of fruit we need (1 cup vs. 2 cups per day), according the U.S. Centers for Disease Control and Prevention’s 2009 Report on Fruits and Vegetables. “There’s no reason to believe people with diabetes across the board do any better consuming adequate fruit. In fact, research shows consumption may be even lower than average,” says Warshaw, who practices in Northern Virginia.
Siri Casey, registered dietitian and certified diabetes educator with ABQ Health Partners, a physician-owned medical group headquartered in Albuquerque, N.M., notes fresh fruit contains fewer calories than most other carbohydrates and provides antioxidants that help limit and possibly repair cell and tissue damage for which people with diabetes are at high risk. “Fruit is one of the healthiest foods to eat,” Casey says. “It is low in calories and rich in nutrition and shouldn’t be restricted by people with type 1 diabetes.”
In theory, a certain amount of carbohydrate – regardless of food type – raises blood glucose to about the same degree within a similar amount of time, Warshaw says. But if you’ve lived with type 1 diabetes a significant amount of time and compared your experiences to those of others, you know that, as Casey puts it, “people with diabetes have very individual responses in terms of blood sugar rise from different foods.”
Still, unexpected blood-glucose results are no excuse to eliminate healthy options like fruit from your diet, most diabetes educators say. “One needs to get to know one’s body and how certain fruits affect blood sugar, if there’s a difference,” Warshaw says. Higher- or lower-than-expected blood glucose results after eating fruit or other healthy carbohydrate sources should prompt a person to increase or decrease his/her insulin dose next time around rather than limit such foods, Warshaw says.
Jennifer Smith, a Washington-based registered dietitian and certified diabetes educator/insulin-pump trainer who has lived with type 1 diabetes for 22 years, recommends keeping a food/blood-glucose log for a few weeks to determine what works best when you incorporate fruit into your meals or snacks.
All three dietitians/diabetes educators interviewed for this article said some of their type-1 patients avoid fruit either because of the amount of carbohydrate it contains or because relying on a label for carbohydrate counting is easier. If you’ve subscribed to these beliefs and are thinking of giving fruit a second chance, or if you already eat fruit and want to improve your glycemic control, consider these additional tips and advice they give their patients:
- Use a food scale – at least at first. This is key since pieces of fruit vary in size and can’t be measured easily in a measuring cup. If you don’t know how many carbs are in the food you’re eating, you can’t accurately dose insulin, and therefore can’t begin to determine why a high or low occurred afterwards. “Weighing food is one of the best ways to get the exact amount of carbs,” Smith says. “You may find an apple you would have guessed was 15 grams [of carbohydrate] actually weighs in at 26 grams. The scale can be a useful tool when you don’t have it available – because if you’ve weighed a similar size piece of fruit and choose something similar when you don’t have access to the scale you’ll likely be able to guess a lot closer to the actual carbohydrate amount than if you hadn’t weighed it before.” You can buy a simple food scale that measures weight in grams for less than $10. You’ll need to multiply this weight by the particular fruit’s carb percentage or “factor,” which can be found in the appendices of books such as “Using Insulin,” and “The Ultimate Guide to Accurate Carb Counting,” authored by certified diabetes educators John Walsh and Gary Scheiner, respectively. These books contain carbohydrate factors for hundreds of foods. (See an abbreviated list in the sidebar on page XX.) Fancier scales do the math for you when you enter a code for the type of food you’re weighing.
- Know how to estimate carb counts when a scale isn’t available. A simple rule of thumb is a piece of fruit about the size of a baseball or hockey puck contains 15 grams of carb, Smith says. If the fruit is cut up – strawberries, melon or pineapple, for instance – one measuring cup equals 15 grams of carbohydrate.
- Administer the necessary amount of insulin. “I think sometimes people believe taking more insulin to ‘cover’ the healthy amount of carbohydrate they eat is a negative thing,” Warshaw says. “Not really. You need the amount of insulin you need to cover the rise of blood glucose from the foods you eat within the context of a healthy plan.” Low-carb diets for people with type-1 diabetes do have proponents in the medical community, most notably Dr. Richard K. Bernstein, who recommends limiting carbs to 30 per day in an effort to normalize blood sugar. But Warshaw says she’s not a fan. “If you eat a marginal intake of carbohydrates, say less than 45 percent of your calories, you simply can’t eat the amount of whole grain, fruit, vegetable and dairy servings that you need,” she says.
- Those comforting nutrition labels might not be as accurate as you think. Warshaw says she worries people believe the nutrition information on food labels is more exact than it is – or is required to be should it be inspected. “Carbohydrate counting is truly guestimating at best,” she says.
- Build a personal food/carb-count database. It should record foods you regularly eat, including fruits. Over time, this will become a handy, valuable resource.
- Evaluate insulin doses using blood-glucose monitoring and adjust based on past experience. Write down blood-sugar reactions (consistently high after eating pineapple, for example) and try adjusting insulin doses accordingly. This could be part of your personal food database.
This summer I began visiting a local farmer’s market and decided to give fresh fruit another try. Armed with a $7 kitchen scale I bought online and a list of carb percentages, I proceeded with caution, one fruit at a time. To my surprise, I found these forbidden treats had a steady, consistent effect on my blood sugar compared to most processed foods, including whole-wheat breads. I also discovered I’d been under-dosing insulin in most cases, erring on the side of less rather than more when I wasn’t sure (dosing for a small apple, for example). Seventeen of the large grapes I had eaten contained more like 30 carbs instead of 15.
For the past few months, I’ve been eating fruit as part of almost every meal, with no negative effect on my blood sugar. I feel healthier, and it’s liberating to taste food I thought I’d never enjoy again. I understand better each day what people mean when they say managing diabetes is a complicated process that never ends. Even when we think we’re being “good” and making the best choices for our health, we can get off track. Some foods remain on my do-not-eat list, but in the future I won’t be so quick to peel any item from my plate.
Carb factors for common fruits
To accurately determine the carbohydrate content of any food, including fresh fruit, weigh it on a kitchen scale that measures in grams and multiply the weight by the food’s carb percentage or “factor.” Here’s a rundown of carb factors for common fruits:
Fruits offer various nutrients and benefits depending on type. Following are some examples provided by Siri Casey, registered dietitian and certified diabetes educator.
Orange and red fruits including cantaloupe, papaya and mango: Vitamin A and beta carotene
Berries, melon, citrus fruit and kiwi: Vitamin C
Apples, citrus fruit and pears: High in soluble fiber/ Slows blood-sugar rise, helps control cholesterol levels
Brightly colored fruits such as berries, red and purple grapes, pomegranates and cherries: Antioxidants/Help limit and possibly repair damage to cells and tissues created by oxygen use