You’ve heard the old saying, “An apple a day keeps the doctor away.” But can it also keep cancer away? It just might. In fact, apples are among a number of fruits that have been found to play an important part in cancer prevention. Still, most of us are probably more familiar with the role vegetables—especially green vegetables like spinach and cruciferous vegetables like broccoli, kale, Brussels sprouts, and even cauliflower—play in preventing this dreaded disease. But what about their dietary counterparts, the fruits? In this article, we’re going to take a look at these unsung nutritional powerhouses and uncover everything you need to know about the best anti-cancer fruits around.
Phytochemicals and Fruits
Fruits are filled with vitamins, minerals, and fiber, but when it comes to protecting us from cancer, heart disease, cognitive decline, and other degenerative conditions, their real superpower may actually lie in their phytochemicals.
Phytochemicals, also called phytonutrients, are the biologically active compounds in plants that help them grow and thrive. They’re also the components that give fruits their characteristic taste, color, and smell.
There are literally thousands of different phytochemicals, with potentially thousands more yet to be discovered—and research remains in its early stages. However, science is already showing us that phytochemicals have the potential to boost the immune system, prevent harmful substances from turning into carcinogens once inside the body, regulate hormones, and reduce oxidative stress, DNA damage, and inflammation, which can lead to tumor growth and proliferation of cancer cells.
In fact, a study published in Nutrition Journal concluded that a healthy diet that includes at least four servings of fruits a day may not only reduce the risk of cancer but also increase the possibility of reversing the disease in current cancer patients.
This recommendation is backed up by the American Cancer Society, who recommends reducing cancer risk by eating at least 2-1/2 cups of fruits and vegetables each day. Likewise, the American Institute for Cancer Research recommends that two thirds of every meal be made up of plant foods.
But how do the phytochemicals in fruits fight cancer, and which fruits pack the most punch?
Fighting Cancer with Phytochemicals
As mentioned, investigations into the myriad health benefits of phytochemicals are in their infancy, and we likely still have thousands of more phytochemicals to discover. But of those we know about, two groups have garnered a growing level of attention due to their cancer-fighting effects.
Polyphenols make up the largest known category of phytochemicals. Comprised of flavonoids, phenolic acids, and the so-called non-flavonoid polyphenols—which include the tannins in green tea, lignans in flaxseeds, and curcuminoids in curcumin (turmeric)— polyphenols possess antioxidant and anti-inflammatory properties as well as the ability to modulate the signaling pathways that lead to cancer cell proliferation and cancer growth.
Studies have already demonstrated the anti-cancer effects of numerous polyphenols, including the anthocyanins in blueberries, resveratrol in red wine, isoflavones in soy, and epigallocatechin gallate (EGCG) in green tea.
What’s more, investigations have found a link between consumption of polyphenols and a decreased risk of several cancers, including lung, breast, colon, cervical, and stomach cancers.
Among the polyphenols, flavonoids are some of the most researched, with studies demonstrating that this group can lower the risk of prostate cancer as well as lung, breast, and colon cancers.
One particular flavonoid, quercetin, is also widely recognized for its ability to inhibit various types of cancers, including breast, lung, kidney, colon, prostate, pancreatic, and ovarian cancer. Moreover, quercetin has even been found to increase the effectiveness of traditional cancer treatment.
Fruits that are rich in polyphenols include:
Terpenes are another major category of phytochemicals and include the carotenoids, such as beta-carotene, lycopene, lutein, astaxanthin, and zeaxanthin.
Like the polyphenols, terpenes have been shown to fight cancer by reducing inflammation and preventing cancer cell growth. Terpenes have also been shown in studies to help decrease the risk of colorectal cancer as well as prostate, liver, and breast cancers.
The carotenoids, which are made up of more than 600 known types, are especially notable for their ability to reduce levels of DNA-damaging free radicals. The antioxidant properties of carotenoids have also been found in studies to be helpful in preventing specific types of cancer, including throat, breast, lung, prostate, and colon cancers.
Fruits that are rich in terpenes include:
So What Are the Best Anti-Cancer Fruits?
There are as many fruits to choose from as there are tastes in the world, and we can’t possibly discuss the benefits of them all here. But when we’re talking about cancer prevention, there are certainly some standouts that immediately come to mind. These include:
- Berries: From blackberries and blueberries to strawberries and raspberries, berries are a rich source of both vitamin C and polyphenols, including ellagic acid, anthocyanins, and lignans, which have been shown to help prevent a variety of cancers, including bladder, skin, esophageal, breast, and lung cancers.
- Grapes: All things grape, including the fresh fruit, grape juice, grape skins, and red wine, contain high levels of resveratrol. This non-flavonoid polyphenol has been found to prevent cancer cells at all stages of growth, from initiation to proliferation, and to be especially helpful in the prevention of leukemia as well as skin and breast cancers.
- Tomatoes: This popular fruit is rich in several cancer-fighting carotenoids, including lutein, beta-carotene, and lycopene.
- Winter squash: This group of colorful fall fruits includes acorn and butternut squash as well as pumpkins. As you might imagine, the brilliant yellows and oranges of this group indicate high levels of carotenoids, including beta-carotene, lutein, and zeaxanthin.
- Grapefruit: This tasty citrus fruit contains a number of phytochemicals, including flavonoids, carotenoids, and several types of terpenes.
- Cherries: These small stone fruits contain a wide variety of both polyphenols and terpenes and are known for their strong antioxidant activity.
- Pomegranates: The high levels of polyphenols in pomegranates—over 100 at last count—make this fruit a definite superfood. Pomegranates have also been shown to be effective in preventing and treating a number of different cancers, including skin, breast, prostate, lung, and colon cancers.
When it comes to nature’s cancer-fighting foods, fruits have no problem standing on their own as some of the best. But when they’re included in a diet that limits red meat and emphasizes omega-3 fatty acids and plant foods like whole grains, veggies, and olive oil, their impressive array of cancer-fighting phytochemicals truly becomes a force to be reckoned with.