What are the healthiest fruits? This one has cognitive and cardiovascular benefits.

An apple a day keeps the doctor away, right?

We grew up hearing the cliched expression, but do you know how much fruit you should actually be eating per day? The recommended intake depends on several factors, but adults should generally consume 1.5 to 2 cups of fruit daily, the Centers for Disease Control and Prevention says. One cup of fruit could be an apple, a banana, a cup of blueberries, three medium-size plums or seven slices or chunks of mango, for example.

Here’s your guide to the health benefits of fruit, plus tips for including more in your diet.

What is the healthiest fruit?

While all fruits are healthy, registered dietitian nutritionist Danielle Crumble Smith recommends one nutrient-packed fruit in particular – wild blueberries.

Blueberries contain lots of fiber, which keeps you fuller for longer. They also rank among the fruits and vegetables with the highest antioxidant content. Antioxidants prevent or delay cell damage.

"From a cognitive standpoint, there are a lot of benefits in terms of memory, and some studies show cardiovascular benefits or cancer-fighting compounds," Crumble Smith says. "Overall, [they] decrease inflammation."

Still, Crumble Smith says eating wild blueberries is not essential to getting the healthy nutrients of fruits. Eating fruit of any kind will yield healthy results, though some fruits have nutrients that serve different purposes.

For example, apples contain pectin, a fiber that acts as a prebiotic that can aid colon function and digestion.

Vitamin C-rich fruits should also be on your radar, including citrus (oranges, grapefruit and lemons, to name a few) and strawberries.

"Vitamin C helps with collagen production, and in our generation, people are concerned about decreasing wrinkles and hair, skin and nail health," Crumble Smith says. "Vitamin C is actually really crucial for that."

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Is the sugar in fruit OK for you?

Some fruit fears come from their sugar content. Does the high amount of sugar mean fruit is bad for you? Absolutely not, says Crumble Smith.

"Fruit has so many vitamins, minerals, fiber, water and other nutrients that our body needs," she says.

In fact, fruit can combat the afternoon slump when most people reach for another cup of coffee. Because natural sugar is a healthy source of energy, pairing fruit with protein will give you a similar boost you’d get through caffeine.

Crumble Smith does recommend caution for people with diabetes, insulin resistance or blood sugar issues. In that case, be mindful of portion size or try to pair your afternoon raspberries with a protein, like yogurt or cheese.

Fruit smoothies are an easy and accessible way to get your daily fruit content. Crumble Smith recommends making them at home rather than grabbing one from a smoothie bar or a pre-packaged drink from the store. If you’re going for bottled juice, make sure to read the nutritional label and ingredients thoroughly.

"Just because something says 100% fruit … oftentimes that’s not the best choice," Crumble Smith says. "Because in that case, all the concentrated fruit tends to be really high in sugar and don’t have any protein to help stabilize blood sugar levels."

Is the fat in avocados good for you?

Contrary to popular belief, yes, avocados are fruits and yes, their fat content is an important part of a healthy, balanced diet.

"People sometimes fear fat, but healthy fats coming from avocados, nuts, seeds, olives, olive oil, fatty fish, they have so many anti-inflammatory benefits," Crumble Smith says.

Avocados are rich in potassium, which can help lower blood pressure and cholesterol. They also contain large amounts of fiber, which can keep you feeling satisfied for longer and help with blood sugar regulation, according to Crumble Smith.

"Oftentimes fruits and veggies can be great sources of fat-soluble vitamins A, E and K," Crumble Smith says. “With fat-soluble vitamins, we need a fat source for our body to be able to actually absorb them. So having an avocado with a salad enhances your body’s absorption of those nutrients.”

How to incorporate fruit into your diet

Other than upping your smoothie and fruit salad intake, an easy way to get yourself to eat more fruit is to experiment at the grocery store. Crumble Smith says she tells her clients to put a fruit they’ve never tried in their basket every week when they go to the store.

"It’s a great way to expose yourself to that which you’ve never tried and potentially find something you love," Crumble Smith says. "And it’s not overwhelming; you’re not coming home with all of these different things that you’re afraid are going to go bad."

But if you’re hesitant to try something new, there’s no harm in eating the same ol' fruit every day. You’ll still get a host of benefits. And once you’re feeling more adventurous, you can try swapping – maybe blueberries in your oatmeal instead of a banana, or snack on an orange instead of an apple.

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This article originally appeared on USA TODAY: What is the healthiest fruit? Experts say this is the most nutritious.