Fruit: Friend or Foe For Managing Diabetes?

Eat your fruits and vegetables! That’s probably the first nutritional advice you ever heard. There are several recognized health benefits of consuming fresh fruits. However, there’s a lot of advice on the Internet that fruit is bad for you because it contains relatively lots of carbohydrates. People living with diabetes all over the world are confused about fruit, sometimes abstaining from it all together. 

And from a logical point of view, on the surface, it makes sense. You see, out of the three macronutrients—carbs, fats and protein—carbs impact blood sugars the most. (Eating a large portion of animal protein can cause a large insulin spike, so do keep protein intake moderate with each meal.) Because fruit contains very little protein and fat, it would make sense that if you have diabetes and you’re trying to limit carb consumption, you should avoid fruit, and the main fruit sugar, fructose. 

This is certainly the case when it comes to consuming anything with high fructose corn syrup. But we’re strictly talking about fresh fruits here, not processed foods. 

What Does Research Say About Diabetes and Fresh Fruit Consumption?

A 2007 study in the American Journal of Clinical Nutrition implicates fructose in heart and kidney diseases. More bad news for fruit: A study the following year published in the Journal of Nutrition found that vegetables but not fruit was helpful in preventing type 2 diabetes in Chinese women. 

So that’s it? Ditch the fruit if you’re trying to manage diabetes? Well, not quite. 

More recent research suggests that even if you have diabetes, you may not want to avoid eating fruit. 

A 2017 study of 500,000 adults in China published in PLoS Medicine, showed that in individuals who already had diabetes prior to the start of the study, consuming fresh fruit more than three days a week was associated with a 17% lower relative risk of dying from any cause and a 13%–28% lower risk of developing diabetes-related complications affecting large blood vessels (heart disease and stroke) and small blood vessels (i.e., kidney diseases, eye diseases, and neuropathy) than those who consumed fruit less than one day per week.

The researchers claimed, “To our knowledge, this is the first large prospective study demonstrating similar inverse associations of fruit consumption with both incident diabetes and diabetic complications.” 

As for participants in the study who did not have diabetes when the study began, daily consumption of fresh fruit was associated with a 12% lower relative risk of developing diabetes, compared to never or rarely consuming fresh fruit.

“These findings suggest that a higher intake of fresh fruit is potentially beneficial for primary and secondary prevention of diabetes,” concluded the researchers. But what about for those who already developed diabetes during the period of the study (2004-2008)? “For individuals who have already developed diabetes, restricted consumption of fresh fruit, which is common in many parts of the world… should not be encouraged.” 

An earlier meta-analysis in BMJ from 2013 concluded similar findings: “Greater consumption of specific whole fruits, particularly blueberries, grapes, and apples, is significantly associated with a lower risk of type 2 diabetes, whereas greater consumption of fruit juice is associated with a higher risk.” 

Don’t Let Conflicting Nutrition Advice Confuse You: Moderate Fruit Consumption Is Good!

So is the lesson here, fruit ok, fruit juice bad? To be sure, eating a whole piece of a non-tropical fruit is always a better choice than drinking a glass of fruit juice. But the reductionism that fruit juice should be vilified isn’t entirely accurate.

As Miracle Noodle President and Founder, Jonathan Carp, M.D. wrote in a related blog post about fructose, “Even without the fiber of the fruit [in fruit juice] there are polyphenols in fruits that regulate the uptake of sugar so that the blood sugar spike in fruit juice is quite different from water with a similar amount of sugar.”

Conflicting nutrition advice is extremely frustrating for anybody trying to manage weight (let alone diabetes) and meet their health goals. Like cholesterol and fat (especially saturated fat), the question of whether to eat fruit or not to eat fruit is among the most confounding subjects in nutrition. 

But the truth about fructose from whole-food sources is that it has a relatively low glycemic index of 19. Compare that to table sugar which has a glycemic index of 65. The interesting thing about this comparison is that fructose comprises roughly 50% of table sugar (sucrose), which is also half glucose. The reason why table sugar is so high is that pure glucose has a glycemic index of 100. As you can see, fructose helps lower the glycemic index of sucrose. 

If you want to severely restrict your intake of fruits because you’re on a low-carb diet, make sure you’re consuming lots of low-starch vegetables. Fruits contain a plethora of polyphenols (antioxidants) and other phytonutrients (plant compounds) that confer several health benefits, though you won’t see them listed on nutrition labels. (Think resveratrol, quercetin, anthocyanins, etc.)

Eating Fruit Can Prevent Cravings For Sweet, Processed Foods

Dr. Carp, in his blog post about fructose, brings up a great point: fructose has a very high perceived sweetness. Although it ranks relatively low on the glycemic index, fructose measures 130-180 on the perceived sweetness scale. By comparison milk sugar (lactose) measures only 15-40. 

By consuming fruit, your brain recognizes the natural sweetness. And perhaps maybe, just maybe, by eating 2-3 servings of fresh fruit every day, spread throughout the day, you will satisfy your sweet tooth and won’t be tempted by artificial, highly-processed sweet snacks such as cookies. 

Tips For Eating Fruit

If you have diabetes, it’s a good idea to monitor your blood sugar levels with a continuous blood glucose device. Over time, you’ll learn how, say, eating a handful of blueberries will affect your blood sugar levels. You can also experiment by eating a little bit of natural fat with the serving of fruit. Perhaps eating fruit alone won’t raise your blood sugar levels dramatically. But maybe it will. Maybe eating a handful of walnuts with half an apple will lower your blood sugar level. 

Because every person is unique, there is no one size fits all recommendation. Even the glycemic index alone won’t necessarily predict blood sugar spikes. (If anything, pay more attention to glycemic load.) 

Eating fresh fruit in moderation seems to provide more benefits than risks for people with diabetes. Keep these tips in mind, however, to safely enjoy fruit:

• Eat fruit that’s in season. 

• To purchase the freshest, most nutrient-dense fruit, support farmers markets and community-supported agriculture (CSA) delivery services. (Or grow your own.)

• Limit your servings to four servings per day (spread throughout the day)

• Never eat dried fruit.

• Avoid fruit juice.

• Pay attention to “Green Drink” juice labels; most have lots of added sugars in the form of fruit juice; make your own veggie drinks at home.

• Limit intake of tropical fruits like pineapple, melon and ripe bananas. 

What do you think about consuming fruit for those who have diabetes?