Lemons are popular in many cuisines, but they also have a long history of medicinal uses. You may wonder about the benefits of lemon for cancer prevention or as part of your diet during cancer treatment. Here's what the research says.
Read more: Benefits and Side Effects of Lemon Juice
What Makes Lemons So Healthy?
Lemons contribute little in terms of calories, carbs or fiber. They contain just a trace of most vitamins and minerals. Instead, their superpower comes from phytonutrients — health-promoting plant compounds.
One key nutrient is vitamin C. The pulp of one lemon provides 34 milligrams of it, according to the USDA. (That's about a third to half of your daily value, per Mayo Clinic.) This vitamin plays many roles in your body. The Office of Dietary Supplements explains that one of its most important functions is as a powerful antioxidant. Antioxidants prevent oxidative damage to your cells and DNA from free radicals, harmful molecules generated both inside your body and in the environment.
According to a January 2020 review study in the journal Plants, lemons are a source of many other important antioxidants, found in nearly every part of the fruit — pulp, juice, seeds and peel. They include:
- Flavonoids naringin, hesperidin and quercetin, among others.
- Phenolic acids like ferulic acid and synaptic acid.
Lab tests on these compounds show that they have anti-inflammatory and anti-cancer properties, according to the review.
Benefits of Lemon for Cancer
As for a link between lemons and fighting cancer, research has focused on how isolated compounds in lemons affect cancer cells in the lab. According to the Plants study, the active compounds inhibit the growth of some cancer cells and tumors and can induce apoptosis, or cell death, in others.
Naringin and hesperidin are two of the most abundant and well-researched antioxidant compounds in lemons and other citrus fruits. According to a study published in November 2016 in Nutrients, they have anti-cancer benefits for prostate, breast, stomach, liver, cervix, pancreas and colon cancer cells.
It's important to note that these findings are from controlled studies on cancer cells in a lab. There is no direct evidence that eating lemons or drinking lemon juice can kill cancer cells or inhibit their growth in people. Instead, human studies look at diet patterns in large groups of people to see if there might be a link between certain foods and cancer risk. It turns out that citrus fruit-eaters do, in fact, have a lower risk of several different types of cancer.
For example, an analysis of 17 small studies, published in the May 2018 issue of the journal Pharmacological Research, looked at the risk of oral cancer in people who ate citrus fruits. Compared to people who ate very little citrus fruits, those who ate the most had a 50 percent reduced risk of oral and pharyngeal cancers. Still, population studies don't show a cause and effect, only an association, so it's not clear if one type of citrus played a role or if other lifestyle factors contributed to the lower cancer risk.
Lemons and Anti-Cancer Diets
The National Cancer Institute cautions that no one food can prevent or cure cancer. But the combination of a healthy diet and lifestyle may reduce your risk. A whole food, plant-based diet is what most cancer specialists recommend.
Kim Dalzell, PhD, RD, founder of Cancer Nutrition Advisor and an oncology nutrition specialist in Colorado Springs, Colorado, believes in the power of plants, and especially citrus fruits, for those with cancer or anyone who wants to reduce their risk. "Citrus fruits are full of bioflavonoids, which help repair DNA, support immunity and reduce inflammation," says Dalzell. "Those functions positively impact several cancer control pathways."
The best way to include lemons in an anti-cancer diet isn't to eat them whole or drink lemon juice all day. Indeed, the American Dental Association lists citrus as one of the top foods that can damage teeth and irritate your mouth.
Instead, add various parts of the fruit to other healthy foods. Use lemon juice on fish, add a bit of the pulp to your smoothie, and make good use of the peel by zesting it. Says Dalzell, "Use a pinch of lemon zest to brighten up sauces, vinaigrettes and baked goods because the peel contains more vitamin C per ounce than the fruit itself."
Read more: The Best Foods to Eat if You Have Cancer
- U.S. Department of Agriculture: “Lemon, Raw”
- National Institutes of Health Office of Dietary Supplements: “Vitamin C Fact Sheet for Consumers”
- Plants: “Citrus limon (Lemon) Phenomenon—A Review of the Chemistry, Pharmacological Properties, Applications in the Modern Pharmaceutical, Food, and Cosmetics Industries, and Biotechnological Studies”
- Nutrients: “Chemopreventive Agents and Inhibitors of Cancer Hallmarks: May Citrus Offer New Perspectives?”
- Pharmacological Research: “Citrus Fruits Intake and Oral Cancer Risk: A Systematic Review and Meta-Analysis”
- National Cancer Institute: “Diet”
- American Dental Association: “9 Foods That Damage Your Teeth”
- Kim Dalzell, PhD, RD, registered dietitian, founder, Cancer Nutrition Advisor, Colorado Springs, Colorado
- Mayo Clinic: "Is It Possible to Take Too Much Vitamin C?"