The Cancer Research
Cherries contain numerous phytochemicals and nutrients, many of which are well studied in the laboratory. They also contain dietary fiber, which is linked to lower risk of colorectal cancer. Consuming high amounts of dietary fiber may also help people control their weight by giving a feeling of fullness. That is important to cancer risk because excess body fat increases the risk of 12 cancers.
Current Evidence: AICR/WCRF Expert Report and its Updates (CUP)
Cherries are fruits that contain fiber. After a systematic review of the global scientific literature, AICR/WCRF analyzed how these factors affect the risk of developing cancer. This comprehensive review of decades of research concluded that there is strong – probable - evidence that:
- foods containing dietary fiber DECREASE the risk of colorectal cancer
- a diet high in fruits along with non-starchy vegetables DECREASE the risk of lips, mouth, tongue and other aerodigestive cancers
Evidence categorized as "probable" means there is strong research showing a causal relationship to cancer – either decreasing or increasing the risk. The research must include quality human studies that meet specific criteria and biological explanations for the findings. A probable judgement is strong enough to justify recommendations.
Source: AICR/WCRF. Diet, Nutrition, Physical Activity and Cancer: A Global Perspective, 2018.
”Cherries are a good example of how fruits and vegetables can give you important amounts of fiber, nutrients and phytochemicals without needing to have 'superstar' levels.”
—Karen Collins, MS, RD, CDN.
Open Areas of Investigation: Laboratory Research
Laboratory research is extensive on the group of compounds in cherries called anthocyanins. In laboratory studies, anthocyanins inhibit the growth of cancer cells and stimulate their self-destruction, without affecting healthy cells. These compounds also show anti-inflammatory and strong antioxidant effects. Lab studies on dietary fiber suggest it reduces cells’ exposure to cancer-causing substances. Healthful gut bacteria use dietary fiber to produce short-chain fatty acids that protect colon cells.
In comparison, there are relatively few studies on the cancer effects of the phytochemical perillyl alcohol. Limited studies suggest that perillyl alcohol acts as an antioxidant and stimulates self-destruction of abnormal cells. It also may inhibit cancer growth in animals, at least in part by inhibiting the process of angiogenesis, the formation of new blood vessels that tumors rely on to spread.
Open Areas of Investigation: Human Studies
Most human studies look at overall fruit consumption. Comparing people who develop cancer with those who do not, studies show lower risk of several cancers in those who eat more fruits compared to those who eat relatively few. Beyond the impact of overall fruit consumption in large population studies, more research is needed to understand the impact of cherry consumption in particular on cancer risk.
Clinical Trials: A few short-term human trials have shown that sweet cherries and tart cherry juice improve antioxidant effects and reduce signs of inflammation. These studies used two to three servings daily of cherries or cherry juice.
In some short-term intervention trials, scientists have seen promise in cherries' perillyl alcohol. Researchers have tested this isolated compound among people at high risk for or with some types of cancer. But researchers have much to learn about dose, form and effective methods of delivery, as well as how to identify who might benefit most. Researchers cannot yet translate the clinical trial findings on perillyl alcohol to how consuming cherries may affect cancer development. When a compound such as perillyl alcohol is consumed in foods, the amount and way it is absorbed is likely different than when consumed in isolation.