Many people with lung cancer are curious about how natural products might enhance their standard medical treatment. In recent years, sarunashi juice — a type of kiwifruit juice — has gained some attention with claims that it may benefit people with lung cancer. Although consuming natural products like fresh fruit can improve overall health and well-being in people with lung cancer, some of these products can be expensive while not offering any proven benefits.

Sarunashi fruit has been studied for its nutritional value, but so far, only one published study has scientifically investigated its potential benefits for lung cancer. Here’s more information about sarunashi juice that you may want to discuss further with your doctor.

What Is Sarunashi Juice?

Sarunashi fruit are small, about the size of a hen’s egg. They originated in Korea, Japan, Northern China, and Russian Siberia. “Sarunashi” is a Japanese word, and the fruit is more commonly known in the West as “hardy kiwi” or “kiwi berry.” Its botanical name is Actinidia arguta. In scientific studies, sarunashi juice is referred to as “sar-j.”

The sarunashi plant is hardier than the vines that the larger, more common kiwifruit (or kiwi) grow on. Kiwi berries can easily grow in cold climates, while kiwifruit grows best in very warm environments.

Unlike kiwis with brown, fuzzy skin that are often seen in American groceries, sarunashi fruit has an edible, smooth skin that is reddish brown and green. Both fruits look similar on the inside, with bright green, juicy flesh. Sarunashi fruit can taste like fuzzy kiwi, pineapple, strawberry, or banana, depending on the particular variety.

Sarunashi fruit may be sold under names such as “kiwi” or “kiwi berry.” They’re available as a whole fruit, dried fruit, or juice or as an ingredient in another product such as a juice or dietary supplement.

Nutrients in Sarunashi Fruit

Sarunashi fruit is relatively new to the global market, which has raised interest in its nutritional value and led to a number of scientific studies on its potential health benefits. It contains more than 20 essential nutrients our bodies need to function properly.

Some of the key nutrients found in sarunashi fruit include:

• High concentrations of vitamin C, with approximately 430 milligrams per 100 grams of fresh fruit
• Myoinotisol, a natural sugar that promotes cell growth
• Lutein, a carotenoid (a yellow or red compound found in some food plants) that promotes eye and brain function and helps reduce LDL (bad cholesterol)
• Phenolics (or polyphenolics), antioxidant compounds found in plants that promote cell health
• Essential minerals, including potassium, calcium, and zinc, which support normal function of cells and the immune system

Kiwifruit species, such as sarunashi, and papaya are considered two of the most nutritious edible fruits. For instance, of any fruit, kiwi berry has been shown to have the highest concentration of myoinositol.

Kiwi berry is also considered especially nutritious because of its edible skin, which contains as much as 15 times the amount of antioxidants as its pulp (flesh). Antioxidants are compounds found in plants that combat damage to cells, which can occur due to aging or exposure to environmental risk factors such as cigarette smoke, toxic chemicals, sunlight, and air pollution.

Sarunashi and Lung Cancer

Research is very limited on the effects of sarunashi juice on lung cancer, with only one published study by a research team at Okayama University in Japan. The 2022 study, published in the scientific journal Genes and Environment, was conducted as lab research with mice. Lung tumors in mice were chemically induced with nicotine-derived nitrosamine ketone (NNK), a tobacco carcinogen (cancer-causing substance).

The study showed promising results and potential anticancer properties in sarunashi juice. The number of tumor nodules in each mouse lung was lower in mice that consumed sarunashi juice. There was indication that kiwi berry juice may inhibit lung cancer cells and tumor growth and may also help with DNA repair and limit DNA damage. Interestingly, mice that drank sarunashi juice had fewer lung tumors than mice that were injected with the juice.

Other lab research with mice has shown that drinking sarunashi juice may help suppress cancer in skin. Some studies with mice have also indicated that sarunashi juice may protect against Parkinson’s disease, which is a neurodegenerative disease that destroys nerve cells in the brain and nervous system.

It’s important to know that while cancer research with mouse models may lead to clinical trials with humans, mice studies have limitations. They often do not lead to successful treatment of cancer in humans.

The Nutritional Value of Juice vs. Whole Fruit

Fruit juices, such as sarunashi juice, tend to be viewed as healthy, particularly beverages that are 100 percent juice. Some people may be interested in juicing for lung cancer — but eating whole fruit is probably the better option.

Fruit contains natural sugars that can be unhealthy in high concentrations. A typical glass of juice takes several pieces of fruit to produce and can contain a considerable amount of sugar. In fact, a modest 6-ounce glass of 100 percent fruit juice has between 15 grams and 30 grams of sugar, which amounts to between 60 and 120 calories. Excessive consumption of sugar is linked to diabetes and other health issues.

Some research has shown that for every 250 milliliters (approximately 8.5 ounces) of 100 percent fruit juice a person consumes each day, their overall cancer risk may increase as much as 31 percent.

Whole fruit, on the other hand, is high in fiber (which is generally removed in juice). Fiber is good for digestion and can help you feel full with fewer calories. Furthermore, research has indicated that diets rich in whole fruits and vegetables may decrease a person’s risk of developing cancer and other chronic diseases. Regular consumption of fruit was linked to a 14 percent lower risk of lung cancer in people who smoke and a 9 percent lower risk in people who used to smoke.

If you’re interested in the health benefits of sarunashi, look for whole kiwi berries in your local grocery store. You might also consider adding them to a smoothie. Remember, smoothies differ from juices — they generally contain whole fruits and vegetables, meaning all the nutrients and minerals remain intact.

Discuss Dietary Supplements With Your Doctor

Extracts from sarunashi fruits and other types of kiwifruit may be found in dietary supplements. Before starting any dietary supplement, you should always speak with your oncology health care team. This is because some supplements may interact poorly with your medication or have a risk of unwanted side effects. If you are undergoing chemotherapy, you may have particular sensitivities that you should discuss with your oncologist.

Some dietary supplements, such as vitamin E and beta-carotene, have been found to increase the risk of lung cancer and should be avoided.

For people living with lung cancer, the American Lung Association recommends eating a healthy diet rich in fruits and vegetables, rather than taking supplements, to ensure you are getting all the nutrients you need. Your doctor can provide a referral to a registered dietitian if you need help with eating a well-balanced diet. In some cases, your doctor may recommend specific supplements if they determine you’re lacking nutrients, such as vitamin D.

Talk With Others Who Understand

MyLungCancerTeam is the social network for people with lung cancer and their loved ones. On MyLungCancerTeam, more than 13,000 members come together to ask questions, give advice, and share their stories with others who understand life with lung cancer.

Have you talked to your doctor about sarunashi juice? What else have you done to eat a healthier diet? Share your experience in the comments below, or start a conversation by posting to your Activities page.