Sparkling water has become one of the fastest-growing beverage categories in recent years. Sales have skyrocketed, with brands like La Croix, San Pellegrino, and Spindrift becoming household names. Many people reach for these fizzy drinks as a healthier alternative to soda. On the surface, they seem like the perfect choice: zero calories, zero sugar, zero sodium, and just enough carbonation to make them feel like a treat. But as with many “better for you” products in today’s food industry, the reality isn’t so straightforward. Not all sparkling waters are created equal, and some of the most popular brands contain hidden ingredients that can disrupt your health in ways most consumers never realize.

The Hidden Ingredient: Natural Flavors

The biggest issue with most sparkling waters comes down to one ingredient: “natural flavors.” At first glance, the term looks safe. After all, if it’s natural, it must be good for you, right? Unfortunately, “natural flavors” is more of a marketing phrase than an accurate indicator of what’s in your drink. Legally, a natural flavor must only be derived from something in nature, like a fruit, vegetable, or even animal product. However, once extracted, that base ingredient can be highly processed, mixed with chemical solvents, preservatives, or emulsifiers, and turned into a lab-engineered flavoring that no longer resembles the original food source. By the time it reaches your can of sparkling water, it’s essentially a chemical cocktail designed to trick your brain into tasting fruit that isn’t actually there.

The U.S. Food and Drug Administration allows food and beverage companies to list all of this simply as “natural flavors.” Companies don’t have to disclose what those flavors are derived from, how they were processed, or what other chemicals were used. This lack of transparency makes it impossible for consumers to know exactly what they consume.

How Natural Flavors Impact Your Health

While natural flavors are generally considered safe in small amounts, the long-term impact of daily exposure hasn’t been well studied. For many people, these drinks are a daily habit. Some people consume several cans daily, believing they’re making a healthy choice. Over time, that repeated exposure adds up.

The gut microbiome is particularly sensitive to additives like natural flavors. The trillions of bacteria in your digestive system play a critical role in digestion, immunity, metabolism, and mood regulation. Emerging research suggests that chemical additives, even ones considered safe, can disrupt the delicate balance of gut bacteria. This can lead to bloating, irregular digestion, increased cravings, and a weakened immune response.

Natural flavors may also interfere with how your brain perceives sweetness and flavor. Because they’re designed to mimic the taste of fruit without providing actual nutrients, they can confuse your taste receptors and potentially increase cravings for sweeter, more processed foods. In other words, the more you drink them, the harder it may become to stick to whole, real foods.

Popular Sparkling Water Brands to Avoid

Let’s look at some of the most common sparkling water brands at Costco and other big retailers.

La Croix: This brand became a cultural phenomenon for its fun flavors and colorful cans. The label proudly states “0 calories, 0 sweeteners, 0 sodium,” which makes it sound like the ultimate guilt-free drink. But the catch is that every can is flavored with “natural flavors.” This means you still drink a lab-engineered chemical blend whenever you open one.

San Pellegrino: Known for its Italian branding and reputation as a high-end sparkling water, San Pellegrino’s flavored varieties carry the same problem. The flavor comes from natural flavors, not from real fruit. The elegant branding might make it feel like a sophisticated choice, but the reality is the same as with other mainstream sparkling waters: you’re drinking lab-based flavorings.

Talking Rain (including flavors like Peach Nectarine): Another brand that seems innocent at first glance but relies on the same natural flavor additives. The marketing highlights refreshing fruit flavors, but none come from fruit juice.

The bottom line is that if the label lists “natural flavors,” you’re not drinking a clean beverage.

The Safer Option at Costco

The good news is that Costco has at least one sparkling water brand that’s safer and cleaner: Spindrift. Unlike the other brands, Spindrift flavors its drinks with real, squeezed fruit. The ingredient list is transparent and straightforward: sparkling water and real fruit juice. There are no mystery chemicals, hidden additives, just real food ingredients your body recognizes.

Yes, Spindrift contains small amounts of natural sugars from fruit juice. But that’s not a negative. Those natural sugars are part of whole food ingredients, not the result of artificial sweeteners or lab-made flavorings. This makes Spindrift a safer alternative for anyone who wants the fizz without the toxins.

Why This Matters for Long-Term Health

Some people dismiss concerns about natural flavors by pointing out they’re used in tiny amounts. While that’s technically true, it overlooks the reality of how people consume these drinks. Sparkling water is often a daily staple, and the more it replaces plain water in your routine, the more your body is exposed to additives it doesn’t need. Over time, this can contribute to subtle but meaningful disruptions in your health.

Your body thrives when it gets nutrients from whole, unprocessed foods and clean water. Whenever you choose a drink with natural flavors, you give your body a chemical compound instead of real nutrition. While the immediate effects might not be apparent, the long-term trade-off can show up in digestive discomfort, food cravings, and even issues with energy and focus.

How to Choose Better Sparkling Waters

If you enjoy sparkling water but want to avoid the health risks, here are a few practical tips:

• Always read the ingredient list. If you see “natural flavors,” put it back.
• Look for brands that use real fruit juice for flavoring.
• Be cautious of zero-calorie claims: if it tastes like fruit but has no calories, that flavor is almost lab-made.
• Drink in moderation. Even the cleanest sparkling waters should supplement, not replace, plain filtered water in your daily routine.

DIY Sparkling Water Alternatives

If you want complete control over what’s in your drink, the best option is to make your own sparkling water at home. A simple carbonator machine can turn filtered water into fizzy water in seconds. From there, you can add natural flavor by infusing it with:

• Fresh citrus slices like lemon, lime, or orange
• Crushed berries like strawberries, blueberries, or raspberries
• Herbs like mint, basil, or rosemary
• A splash of 100% organic fruit juice

This way, you get the refreshing fizz and flavor without any hidden chemicals. Plus, making your own allows you to experiment with flavor combinations and enjoy sparkling water tailored precisely to your taste.

The Bottom Line

Not all sparkling waters are created equal. Brands like La Croix, San Pellegrino, and Talking Rain rely on natural flavors: chemical flavor blends that aren’t nearly as natural as they sound. Over time, these additives can disrupt your gut health, metabolism, and overall well-being. The one cleaner choice you’ll find at Costco is Spindrift, which uses real fruit juice for flavoring. Better yet, you can easily make sparkling water at home using filtered water, a carbonator, and real ingredients like fruit and herbs.

Plain filtered water is always the best choice if you want to hydrate. Don’t let marketing slogans and flashy packaging fool you into consuming hidden chemicals.

References:

1. Goodman, M. J. (2017). The “natural” vs. “natural flavors” conflict in food labeling: A regulatory viewpoint. Food and Drug Law Journal, 72(1), 78–102. PMID: 29140655
2. Hossain, M. S., Wazed, M. A., Asha, S., Hossen, M. A., Fime, S. N. M., Teeya, S. T., Jenny, L. Y., Dash, D., & Shimul, I. M. (2025). Flavor and well-being: A comprehensive review of food choices, nutrition, and health interactions. Food Science & Nutrition, 13(5), e70276. https://doi.org/10.1002/fsn3.70276
3. Murley, T., & Chambers, E., 4th. (2019). The influence of colorants, flavorants, and product identity on perceptions of naturalness. Foods, 8(8), 317. https://doi.org/10.3390/foods8080317