I’m a surgeon and gut health expert: 9 'healthiest' fruits for a longer life—one of them I eat every day

Most people assume all fruit is healthy. Not quite. While fruit delivers valuable vitamins, minerals and antioxidants, some varieties pack far more sugar than you think. And even natural sugar can impact gut health, metabolism, and weight when eaten in excess.

That's why, as a heart surgeon, I always recommend choosing lower-sugar, higher-polyphenol fruits. I also treat fruit more like "nature's candy": enjoyed mindfully, not endlessly.

Here are nine low-sugar fruits I consider some of the healthiest choices you can make.

Grapefruit, tangerines and kumquats are naturally low in sugar and high in vitamin C. They also contain flavonoids, which are polyphenols that support a healthy gut microbiome.

Don't strip away the white pith. It's one of the most nutrient-dense parts. And kumquats? You eat them whole, peel and all, making them an easy, tangy addition to salads or stir-fries.

Blueberries, raspberries, and blackberries are some of my absolute favorites. They're low in sugar yet packed with fiber and polyphenols.

Whenever possible, I always recommend eating berries in season. Opt for wild blueberries versus the giant-sized ones you see in grocery stores; they tend to have more antioxidants than the oversized store-bought ones.

Pomegranates are true superstars. They're loaded with polyphenols like punicalagin, which may support heart and cellular health. Despite their sweet flavor, they're relatively low in sugar compared to other tropical fruits.

Plus, those crunchy seeds add extra fiber, making them a double win for your gut and metabolism.

Yes, avocado is technically a fruit, and one of the very best. They are almost sugar-free, rich in healthy monounsaturated fats, and packed with potassium and fiber.

In my opinion, avocados are the most perfect fruit you can eat. They keep you full, support your heart, and nourish your gut without causing sugar spikes. I basically eat an avocado every day to glean the maximum health benefits.

Surprised? Olives are fruits, too, and they're high on my list. They contain virtually no sugar and are rich in healthy fats and powerful polyphenols, especially hydroxytyrosol, one of the best types of polyphenols that feed our gut buddies.

That's why olives and extra virgin olive oil are staples in my recommended diet for supporting heart, brain, and gut health.

Kiwi (in moderation) earns a spot on my list because it's lower in sugar than many tropical fruits, and it's loaded with vitamin C, fiber, and antioxidants.

Here's a secret: Eat the skin! Yes, the fuzzy part, because that's where much of the fiber and polyphenols are found. Due to the serotonin-rich content of kiwi, they can also help you sleep better, according to a recent study.

Unripe bananas aren't sweet — and that's exactly the point. They contain resistant starch, a prebiotic fiber that feeds beneficial gut bacteria and supports stable blood sugar. Once bananas ripen, that starch converts to sugar, reducing those benefits.

I recommend blending green bananas into smoothies or mixing chopped pieces with yogurt, cinnamon, or low-sugar sweeteners. Green banana flour is another easy option.

Like green bananas, green (unripe) mangoes offer resistant starch, antioxidants, and significantly less sugar than their ripe, orange counterparts. They support digestion and metabolism while providing vitamin C.

Try a green mango salad (a staple in many Thai restaurants) for an easy way to add them to your diet.

Small but nutrient-dense, passionfruit is lower in sugar than many tropical fruits and filled with polyphenols, vitamin A, and fiber. Its crunchy seeds act as natural prebiotics.

I was just in France and Italy, and passionfruit was featured all over the place, from salads to desserts. Look for it if you're traveling there in July or August or even in the fall months, when it's in season.

For better long-term health, my approach is simple: Choose fruits that are low in sugar and high in fiber and polyphenols — the compounds that support gut health and more stable energy. But of course, you should always consult with your doctor before making any drastic changes to your diet.

Dr. Steven Gundry, MD, is a former cardiac surgeon, founder of GundryMD, and author of the bestselling books "The Gut-Brain Paradox″ and "The Plant Paradox." For over two decades, his research has focused on the microbiome's role in chronic disease and longevity. He received his degrees from Yale University and the Medical College of Georgia, and completed his surgical residency at the University of Michigan. Follow him on Instagram @drstevengundry.

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