Across America, food “scraps” are often trimmings, skins and seeds tossed in the garbage. But as I started investigating these “waste products,” I quickly found many of these actually serve as edible food parts with robust nutrition. In fact, many ancient cultures, including Chinese medicine and Native American remedies, tapped the healthy compounds in some of the edible food parts below.
Beyond that, using every part of food we can also helps reduce food waste. In the United States, organic waste is the second highest component of landfills, which serve as mega methane emitters. And get this: 30 to 40 percent of the food we eat in this country is wasted. That’s 20-plus pounds of food per person per month. (1)
Learning more about edible food parts not only enhances your nutrition, but also helps solve a waste problem, too. A true win-win. Let’s dig in…
Edible Food Parts You Never Knew You Could Eat
1. Squash Scraps
Squash blossoms. Squash blossoms aren’t just for honeybees. In fact, scientists found that the spinasterol compound isolated from squash flowers harbored anticarcinogenic potential. The concentrated form of spinasterol applied to skin tumors in a mice study decreased the number of tumors by 65 percent. (2) You can eat the blossoms raw in salads, but they are notoriously delicious fried. For a healthier version, coat in egg whites, almond flour and lightly fry in avocado oil.
While you may be hard-pressed to find the edible flower of squash in the grocery store, you can often score them at the farmer’s market or in your own garden.
Squash skins. Ever peel a squash? Chances are, you were thanking your lucky stars if you didn’t knick a finger or worse. The great news? Unless you’re dealing with rough spaghetti squash skin or waxed squash skin, you can leave it on. (I always recommend choosing organic to avoid pesticide residues.)
The interesting backstory on squash skin nutrition: Portuguese scientists published a study in 2015 aiming to figure out if the edible food parts of squash had any value. In essence, they were trying to figure out if this waste byproduct of the food industry could be utilized for other healthy purposes. Turns out, the skin is raging with powerful antioxidants that mop up harmful free radicals. Perhaps the best part? The oven-dried samples showed higher phenolics and antioxidant activity values, perhaps due to increased bioactivity after roasting it in the oven. The authors concluded: (3)
“This work shows that the residues produced from agro-food industries, like pumpkin shells and seeds are potentially good sources of antioxidant compounds like polyphenols, beneficial for human health.”
No more skinning squash means my kitchen will be a much safer place during squash season.
2. Kiwi Skins
Growing up, my favorite way to enjoy kiwi nutrition consisted of cutting the fruit in half and then scooping the green, juicy flesh out with a spoon. The skin was always trashed — or compost-bound until I learned about the health benefits of kiwi skin.
Kiwifruit serves as a powerful prebiotic, serving as fuel for the beneficial organisms in your microbiome. (4) It also helps improve sleep quality. Eating two kiwis before bed can improve total sleep time and efficiency by up to 13 percent, thanks to medically useful compounds like antioxidants and serotonin. (5)
But what about the skin? The fuzzy texture of kiwi fruit is strange to some, but others liken it to the skin of a pear or a peach. The kiwi industry encourages people to eat the fruit’s skin, noting that the skin contains triples the amount of fiber as the fruit. Not peeling the skin also provides more vitamin C. (6) Always wash the skin and choose organic whenever you can.
3. Corn Silk
When you’re shucking corn on the cob, chances are you toss the silk. (Or even get annoyed by it when it sticks to the cob and stuck in between your teeth.) Turns out, there are some health benefits of this edible food part. I recommend sticking to food amounts and avoiding mega-doses, though.
Based on folk remedies, corn silk has been used as an oral antidiabetic agent in China for years, thanks to its potential impact on blood sugar levels. Corn silk contains proteins, vitamins, carbohydrates, calcium, potassium, magnesium, fixed and volatile oils, steroids such as sitosterol and stigmasterol, alkaloids, saponins, tannins and flavonoids. Over time, researchers also discovered corn silk harbors anti-fungal properties, too. Corn silk has also been used in many parts of the world for the treatment of edema, as well as for cystitis (a common cause of cloudy urine), gout, kidney stones and certain prostate problems. (7)
Some people actually chew on the mildly sweet, threadlike strands, but it’s common made into a tea, too. Known as a diuretic, some people drink corn silk in tea form to ease urinary tract infection symptoms. (8, 9) People with high blood pressure symptoms are known to turn to corn silk tea, too, thanks to its diuretic properties. (10) Because of that, it can decrease potassium levels in the blood, so be sure to consult with your doctor to make sure it’s the right fit for you and won’t interact with your medications. If you’re allergic to corn, it’s best to avoid this edible food scrap, too. (Hey, you can always compost it!)
While corn silk is relatively safe for many, here’s one more word of caution: Always look for organic corn products when consider edible food parts. Nonorganic versions are likely genetically modified with residues of glyphosate, the main ingredient in Monsanto’s Roundup. Glyphosate is toxic and an endocrine disruptor in human cell lines. (11)
4. Strawberry Stems
Strawberry nutrition usually focuses on the fruit’s robust manganese and vitamin content, but it turns out, the leaves are potent health powerhouses, too. In fact, the berry’s fresh leaves contained higher ORAC values than the actual fruit part. (12) Just a quick refresher: Antioxidants are evaluated by an ORAC Score (oxygen radical absorption capacity) and tests the power of a plant to absorb and eliminate free radicals.
In researching edible food parts, I stumbled upon several studies investigating the “value-added” potential of certain food parts. In other words, scientists are actively looking at scraps like strawberry leaves and the potential to turn into healthy products. But to keep things simple, I suggest just tossing the leaves into your blender for smoothies or sprinkling on top of salads. Here’s why…
As it turns out, strawberry leaves are teeming with bioactive compounds, including anti-inflammatory, disease-fighting flavonoids like quercetin and kaempferol. Studies show us that kaempferol inhibits cancer cell growth and induces cancer cell death, all while appearing to preserve normal cell viability.
In addition, scientists identified ellagitannins as one of the distinguishing compound classes in strawberry leaves. The functional food industry is very interested in ellagitannin compounds, thanks to their potential to improve vascular health and prevent degenerative disease.
5. Onion Skins
Tossing away onion skins is a major no-no in my household, and for many reasons. First, you can actually use the skins to add nutrition and flavor to your homemade bone broth recipes. I throw onion skins and even whole onions (with skins) into a pot and simmer bones to create the base of a nourishing tonic. After a long, slow simmer, I strain out the skins and onions and build the rest of my soup from there.
While most studies looking at onion skin nutrition focus on extract forms, you can still obtain some added nutrition when you use the skins, particularly in a broth. (Plus, skipping store-bought broths helps save money, packaging, and in the case of canned broths, BPA toxic effects. Onion skins used for broth creation also helps with a high blood pressure diet.
Quercetin and other compounds in onion skins possess blood sugar-lowering potential. In fact, onion skins may improve your gut health in a way that helps blunt the negative side effects associated with eating a high-carb meal. Studies also suggest that onion skin compounds potentially help:
- lower inflammation
- improve insulin resistance
- thin the blood, reducing the risk of clots
- lower cholesterol
6. Broccoli Leaves
If your favorite farmer’s market stand sells broccoli with most of the leaves stripped, they’re doing you a disservice. Turns out, broccoli nutrition isn’t limited to just the florets; the leaves are loaded with antioxidants ready to take on free radicals circulating in your body. These harmful free radicals are linked to cancer, accelerated aging and all sorts of health problems. In fact, broccoli leaves pack potent anticancer activity, according to a 2015 study published in Preventive Nutrition & Food Science.
Try boiling the leaves for a few minutes to use as a wrap alternative or chop and sauté like other greens.
7. Cauliflower Leaves
Ever tap into romaine lettuce nutrition by grilling the greens? You can do the same type of thing with cauliflower leaves. Most people choose to only cook and consume the white “head” of cauliflower, since the tougher stem and leaves can cause digestive upset for some people and tend to be tougher in texture. But others can tolerate the greens. If that’s the case, I suggest trying out this roasted cauliflower leaf recipe.
8. Watermelon Rinds
When studying the potential toxicity of watermelon rinds, scientists were pleasantly surprised that it appeared safe to eat. In fact, a 2015 study published in Research Journal of Environmental Sciences, researchers tout eating watermelon rinds as a way to obtain nutrients while also reducing food waste.
Researchers at Texas A&M University found the rind is loaded with citrulline, the precursor to the circulation-improving amino acid arginine.