- A new study suggests white-fleshed produce may reduce GI cancer risk by 36%.
- Red and purple vegetables may lower risk by up to 32%.
- Gastrointestinal cancers are on the rise globally and in the U.S.
Gastrointestinal cancers include any cancer of the GI tract—stomach, liver, esophageal, pancreatic and colorectal. They represent more than 25% of all cancers, with 5 million new cases of gastrointestinal cancers and 3 million associated deaths in 2018. What’s more, the rate of gastrointestinal cancers in people under 50 is rising at an alarming rate, according to a July 2025 report.
As with many other diseases, lifestyle plays a large role in cancer risk. The American Cancer Society focuses especially on diet, physical activity, smoking and alcohol intake as areas that have the most influence over cancer risk.
While there is a lot of evidence regarding the role fruits and vegetables can play in reducing cancer risk, researchers from Korea wanted to see if certain colors of produce made a bigger difference than others. They published their findings in Nutrition Research. Let’s break them down.
How Was This Study Conducted?
Researchers enrolled more than 11,000 participants who were attending health check-ups at the National Cancer Center (NCC) in Korea between October 2007 and December 2021. Participants were followed for an average of eight years, during which time 214 gastrointestinal cancers were diagnosed; researchers gathered diagnosis data from the Korea Central Cancer Registry and NCC electronic medical records.
Researchers collected data via two baseline questionnaires. One gathered demographic information, including age, sex, smoking status, alcohol consumption, educational level, household income, occupation, marital status, physical activity and family history of cancer. The other one was a food frequency questionnaire that asked about consumption of 106 culturally-relavant foods, including frequency and amounts.
Researchers also classified fruits and vegetables according to their colors. But instead of going by the exterior color, they went by the color of the flesh. So where some might consider apples as falling into red fruits, pears into green or yellow and bananas as yellow, those examples were categorized as being white for this study, since their flesh is white. This is partly because people in Korea tend to remove the peel of fruits like apples and pears, so researchers felt this was more applicable to real life.
What Did This Study Find?
After running statistical analyses, including adjusting for demographics, researchers found the following major findings:
Researchers also point out several limitations to this study. First, because it was specifically done with a Korean population, it is unknown if these results extend to other populations. Also, a follow-up of eight years is relatively short for cancer development, so a longer follow-up may offer more accurate results. Lastly, all gastrointestinal cancers were lumped together, so researchers can’t say if certain colors are more effective for certain types of gastrointestinal cancers.
How Does This Apply to Real Life?
While we can’t perfectly convert the 188 g/day of white fruits and veggies into cups, we can get close by offering examples. For instance, 188 grams would be about 1 ¾ cups chopped cauliflower, a large golden delicious apple or two small bananas. As for the red and purple fruits and veggies, 34 grams would be about two medium slices of tomato or a couple of large strawberries. These amounts can all contribute to the USDAs recommendation of 2 cups of fruit and 3 cups of vegetables per day.
Eating enough fruits and vegetables has been shown to have many health benefits, including a reduced risk of heart disease, stroke and cancer, as well as improved brain health and longevity. And while you can certainly eat fruits and veggies “as is,” there are also many delicious ways to prepare them. And light cooking processes may even increase the bioavailability of certain nutrients, like lycopene, beta-carotene and calcium, as can eating produce with a little bit of fat.
It’s easy to toss veggies into egg dishes or create dips to scoop up with veggies. Some of our other favorite ways to prepare veggies include:
Of course, vegetables don’t have to have all the fun. While fruit is easy to grab and go, it’s also amazing in baked oatmeal, in a smoothie bowl or in a breakfast parfait. You can also add sliced fruit on top of toast or turn it into fresh fruit butter or chia seed jam. Did someone say dessert? You’ll love our Lemon-Blueberry Tiramisu, Easiest Apple Tarts and our simple Baked Peaches.
Our Expert Take
This study suggests that eating more fruits and vegetables may reduce your risk of gastrointestinal cancers. They found that white-fleshed produce seemed to have the most impact, followed by red and purple produce. Researchers credit the antioxidants in produce for most of their protective effects. Find fun, tasty new ways to incorporate produce into your day, shooting for at least 2 cups of fruit and 3 cups of vegetables each day.
