What's the difference between a food and a functional food? If you're hungry, and you eat something, hasn't that food served a function? Yes, but the term functional food refers to a food that has functions beyond sating your hunger and giving you basic nutrition. These foods have additional health benefits making them smart choices anytime, according to the International Food Information Council Foundation.

Some of these functional foods, like the much-hyped acai berry, can be expensive and difficult to get. But there are others that are probably sitting in your pantry or refrigerator right now. Here are a few kitchen staples that are also functional foods.

Oatmeal

oatmeal Oatmeal helps with blood glucose levels.(Photo: Robyn Mackenzie/Shutterstock)

Plain oats contain beta glucan, which may reduce the risk of coronary heart disease, according to the European Food Safety Authority. Whole grains also reduce the risk of heart disease plus some types of cancers. Oatmeal also supports maintenance of healthy blood glucose levels.

Apples

Young girl eating an apple Apples may help with everything from heart health to some cancers. (Photo: Maria Uspenskaya/Shutterstock)

You might not have acai berries in your fridge, but chances are you have an apple or two. Apples contain flavanols that support the maintenance of heart health, soluble fiber that may reduce the risk of coronary heart disease and some types of cancer, and procyanidins and proanthocyanidins that support the maintenance of urinary tract health. Oh, and the combination of fiber and flavanols will also help prevent weight gain.

Tuna

tuna Tuna may help with eye health and will keep your brain sharp. (Photo: David Lifson/flickr)

If there's a tin of tuna in your pantry, it has more functions than just making one of the world's fastest sandwich spreads. It has omega-3 fatty acids, which may reduce the risk of coronary heart disease and support maintenance of eye health and mental function.

Garlic

Onions and garlic on a wooden surface
Garlic doesn't have to be fresh to have health benefits — but you may notice a difference in the flavor. (Photo: Antonova Anna/Shutterstock)

Fresh or jarred garlic contains selenium, which neutralizes free radicals that may damage cells. Garlic also supports maintenance of immune and prostate health.

Eggs

Eggs on a blue background with one egg cracked open Eggs are good for your eyes, bones and immune system. (Photo: Olga Miltsova/Shutterstock)

An egg contains lutein and zeaxanthin, which support maintenance of eye health and selenium that, like garlic, neutralizes free radicals. The vitamin A in eggs is also good for the eyes, boosts immune and bone health, and contributes to cell integrity.

Carrots

carrots It's true. Carrots are good for your eyes! (Photo: Roberto Verzo/flickr)

Carrots contain beta carotene, which neutralizes free radicals, bolsters cellular antioxidant defenses and can also be turned into vitamin A by the body. These vegetables also have the same lutein and zeaxanthin that eggs have for eye health, and they contain lignans that support maintenance of heart and immune health.

Olive oil

Olive oil in a small glass bottle on a wooden table Olive oil has good fats that may help lower the risk of heart disease. (Photo: mythja/Shutterstock)

This Mediterranean staple contains monounsaturated fatty acids, which may reduce the risk of coronary heart disease.

Beans

beans in rows Beans are good for everything from heart health to bone health. (Photo: Madlen/Shutterstock)

Dried or canned beans like black, pinto, kidney or white contain potassium, which may reduce the risk of high blood pressure and stroke — particularly in combination with a low sodium diet — and magnesium, which supports maintenance of normal muscle and nerve function, immune health and bone health.

Onions

Onions in a bag Onions can help maintain cell health. (Photo: Emily Carlin/flickr)

Onions contain inulin, fructo-oligosaccharides (FOS) and polydextrose, all probiotics that support maintenance of digestive health and calcium absorption. They also contain various flavanols that neutralize free radicals that may damage cells and bolster cellular antioxidant defenses.

Coffee

Cup of coffee Your morning coffee can help with eye and heart health. (Photo: Valentyn Volkov/Shutterstock)

This oh-so-important morning beverage contains caffein acid and ferulic acid, which bolster cellular antioxidant defenses and also support maintenance of eye and heart health.

Robin Shreeves ( @rshreeves ) focuses on food from a family perspective from her home base in New Jersey.