What You Need to Know About Juice and Your Immune System

The immune system and immunity are complex topics. There are several ways to boost and benefit the immune system, but can juice help with immunity?

Juice infographic

Pit a can of soda against a juice box, and most will think the juice is the far healthier option. Not so fast! Soda and fruit juice have much in common: both contain between 20 and 26 grams of sugar and around 110 calories per cup. The majority of juices are highly processed, which strips them of most, if not all, of the fruits’ original balanced nutrition. The truth is, neither soda nor fruit juice are going to do wonders for the immune system. For the most strengthening power, it’s important to go to the most natural source—the thing that has nothing stripped away and nothing added. Whole fruit is just that: whole.

Some people may not understand the massive void that separates concentrated juices and whole foods due to the "healthy" advertisements and images that adorn the labels of juice products. Unfortunately, the main victims of this propaganda are the parents of young children. Juice is hardly as nutrient-packed as the packaging might lead parents to believe with phrases like, “May help support immune health.”

The beverage has been dubbed “sugar water” for a reason: it’s a concentrated source of sugar for kids. It has fruit flavoring, sometimes instead of real fruit, and ascorbic acid so the product can claim a high percentage of the recommended daily allowance of vitamin C. Synthetic vitamins don’t come close to what whole fruits provide, either. Nutrients are the strongest when they come from real food. “They are accompanied by many nonessential but beneficial nutrients, such as hundreds of carotenoids, flavonoids, minerals, and antioxidants that aren’t in most supplements," says Dr. Clifford Lo, an associate professor of nutrition at the Harvard School of Public Health.

Nothing compares to the real deal!

One-hundred percent fruit juice, as the name suggests, delivers more nutrients from whole fruit than its other juice counterparts. Still, the Dietary Guidelines for Americans recommends no more than 4 ounces of it—or one serving—as part of the daily intake of fruit. A UC Davis Health study revealed that even popular 100 percent fruit juices can contain between 14 and 18 grams of sugar per serving.

The rest of the fruit juices, concludes a Harvard report, are loaded with high-fructose corn syrup, sugar, and other high-calorie sweeteners. Probably not what you had in mind when buying a “healthy” beverage. The ingredients add up to a lot of calories and very few nutrients.

High-fructose corn syrup may play a role in obesity and diabetes. High fructose is a liquid sweetener made from corn and chemicals to change corn starch into corn syrup. It has become more widely used along with higher prevalence of various health problems. Coincidence? Perhaps. At the least, there’s definitely a correlation.

Global Public Health observed that diabetes prevalence was twenty percent higher in countries where high-fructose corn syrup was more available. Many cite a higher intake of calories and inactivity as causes of obesity; well, consuming high-fructose corn syrup may lead to higher caloric intake and less energy expenditure.

In addition, due to its high sugar count, drinking fruit juice on the regular can lead to weight gain, which could snowball to an increased risk of type 2 diabetes, high blood pressure, stroke, hypertension, and other health problems. That doesn’t sound like a recipe for building the immune system.

Conversely, choosing an apple, bowl of grapes, or even just a single strawberry, is a much better, healthier option. The things that make whole fruit so beneficial to the immune system—seeds, membranes, pulp, and skin— are precisely the things that are left behind during the juicing process. This means the amount of phytonutrients, antioxidants, vitamins, and minerals in juice isn’t remotely close to the amount that’s available from whole fruit.

For example, an apple’s skin contains the phytonutrients rutin and ursolic-acid. Rutin is anti-allergic, anti-apoplectic, antiatherogenic, antibacterial, anticonvulsant, antidementia, antidermatic, antidiabetic, antiedemic, antiglaucoma, antihistaminic, antihypertensive, anti-inflammatory, antimalarial, antioxidant, anti-platelet, anti-tumor, antiulcer, antivaricose, antiviral, myprotective, myorelaxant, an immunomodulator, inhibitor of many enzymes, and much more. Ursolic-acid does a lot of the same, but is also anti-alzheimeran, anticancer, anticariogenic, antiHIV, antileukemic, antilymphomic, antimestatic, antimutagenic, and more.

Apple skin contains phenolic compounds too. According to Rutgers University Food Chemistry Professor Chi-Tang Ho, PhD, these are closely related to the sensory and nutritional quality of plant foods. They can also act as antioxidants and inhibit mutagenesis and carcinogenesis, playing a role in cancer prevention.

One review in the Nutrition Journal found that apple juice created through pulping and pressing had only 10 percent of the antioxidant activity of fresh apples; after pulp enzyming it contained only 3 percent and 58 percent less catechin, 44 percent less chlorogenic, and 31 percent less phloridzin. Forty-two percent of the phenolics were also extracted. Apple juice is missing a lot of the nutrients and benefits available in a whole apple. The same is true for other types of juice.

Furthermore, fiber—one of whole fruit’s greatest benefits of all—is almost completely absent in fruit juice. Why do we need it? Found in the fruit’s pulp and skin, fiber controls blood pressure, decreases the risk of colon cancer, and helps lower cholesterol. It’s particularly beneficial for gut health; it’s filling and slows the absorption of sugar, resulting in smaller insulin spikes. Type 2 diabetes can develop when our bodies can no longer keep up with our need for insulin. Studies even reveal that fiber is associated with longevity. The nutrient makes whole fruit more filling than fruit juice, hence being a healthier, more satisfying snack.

Fiber is directly tied to building the immune system: “Eighty percent of your immune system is in the gut, so when it's healthy, we tend to be able to fight off infections faster and better,” says Yufang Lin, M.D., of the Center for Integrative Medicine at the Cleveland Clinic. “When it’s not, our immune system is weaker and more susceptible to fighting off infection.”

A healthy gut also decreases inflammation and improves absorption of vitamins, minerals, and other nutrients. Your gut microbiota is all the microorganisms within the gut. This includes bacteria, fungi, viruses, and other microbes. The gut microbiota affects many aspects of health, and fiber is good for that microbiota.

Within the gut microbiota are both good and bad bacteria, and fiber helps ensure the population is balanced and healthy. Fiber provides the surfaces for microbial growth, allowing microbes to grow their populations. Dietary fibers also supply energy for microbiota in the cecum and colon.

A diet low in fiber intake and high in fat and sugar alter specific bacteria groups that can result in “dysfunctions” that increase the risk of developing chronic inflammatory diseases. Dietary fiber can help prevent such diseases. Low dietary fiber intake also leads to less microbial diversity and metabolite production. It also causes gut microbial metabolism to use unfavorable surfaces for habitation.

People need at least 20 to 30 grams of fiber a day for good health; most of us don't come close to that! Whole fruits, vegetables, and other plant foods can be great sources of fiber—something you can’t get in a juice. To lower your risk of developing certain health conditions like heart diseases, diabetes, and constipation, eat more foods high in fiber.

The next time you, your kids, or your grandkids are thirsty, go with water and pair it with a whole apple or slice of watermelon. That’s the juice that will work to build the immune system and help keep the body healthy. Remember, whole fruit equals whole nutrition. Even making your own juice is a much better option, have some as an occasional treat.

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