Getting your antioxidants from soda? Crush this bad habit now.

When thinking about where to find healthy, disease-fighting antioxidants, a can of soda probably doesn't come to mind. Still, the company that manufactures 7UP has been marketing a few of its beverage products as antioxidant drinks, a move that's prompted a lawsuit.

7UP's parent group, Dr Pepper Snapple Group, is being sued for the way it's marketing antioxidants in its regular and diet Cherry Antioxidant, Mixed Berry Antioxidant, and Pomegranate Antioxidant 7UP products. The lawsuit calls the antioxidant claim misleading because the images on the products show photos of fruits and vegetables. The antioxidants actually come from a small amount of added vitamin E, not naturally occurring antioxidants, which boast the biggest health benefits.

Instead, the 7UP products contain many questionable chemicals. For instance, 7UP Cherry Antioxidant lists heart- and brain-harming high-fructose corn syrup as a main ingredient, along with fake food dye Red 40, a petroleum-based ingredient linked to ADHD and other health problems.

Read More: 8 Healthy Sodas

"Non-diet varieties of 7UP, like other sugary drinks, promote obesity, diabetes, tooth decay, and other serious health problems, and no amount of antioxidants could begin to reduce those risks," says Michael F. Jacobson, executive director of the Center for Science in the Public Interest (CSPI). "Adding an antioxidant to a soda is like adding menthol to a cigarette—neither does anything to make an unhealthy product healthy."

Read More: 9 Toxic Rip-Offs in the Kitchen

CSPI is involved in the lawsuit.

8 Cheap & Healthy Ways to Get Your Antioxidant Fix

1. Oats. Oats are rich in avenanthramide, an antioxidant that protects the heart. Other oat accolades? The superfood lowers cholesterol and has been shown to possess disease-zapping antimicrobial activity, making organic oatmeal the perfect affordable breakfast item for cold and flu season.

2. Dried beans. Forget expensive steak and sausage. Dried beans and dried lentils pack a healthy low-fat, plant-based protein punch. Dried beans beat the canned version because it helps you avoid harmful the BPA chemical that leeches from the lining of the cans. Known as a "perfect food," just one cooked cupful can provide as much as 17 grams of fiber. Beans are also loaded with protein and dozens of key nutrients, including a few most people fall short on—calcium, potassium, and magnesium. Studies tie beans to a reduced risk of heart disease, type 2 diabetes, high blood pressure, and breast and colon cancers. Bonus tip: Soak beans overnight and rinse them well to eliminate most of the flatulence-causing compounds.

3. Garlic. This onion relative contains more than 70 active phytochemicals, including allicin, which studies show may decrease high blood pressure by as much as 30 points. High consumption of garlic lowered rates of ovarian, colorectal, and other cancers, according to a research review in The American Journal of Clinical Nutrition. To boost garlic's health effects, be sure to crush the cloves and let them stand for up to 30 minutes before heating them.

4. Cayenne pepper. If you can handle the heat, this powerhouse pepper is worth your while. The heat in cayenne peppers come from a phytochemical called capsaicin, which can help clear congestion, fight cholesterol, melt away body fat, and jump-start your metabolism. Sprinkle it over veggies and beans to sneak it into your diet.

5. Celery. Eating four sticks of celery a day can produce modest reductions in blood pressure, thanks to the vegetable's rich supply of phthalides, phytochemicals linked to cardiovascular health. Bonus for the guys: Celery is loaded with androstenone and androstenol, pheromones that help attract women.

6. Tomatoes. Tomatoes are our most common source of lycopene, an antioxidant that may protect against heart disease and breast cancer. Avoid canned tomatoes when possible: The epoxy can coating usually contains the harmful plastic chemical BPA. Instead, load up on in-season, organic tomatoes in bulk and preserve them for year-round enjoyment.

7. Onions. This bulb boasts far-reaching health benefits, including immunity-boosting compounds that can help prevent everything from the common cold to cancer. Onions are also rich in quercetin, a flavonoid shown to keep your blood healthy. It's also a must-have for natural allergy prevention.

8. Popcorn. Popcorn kernels contain more of the healthy antioxidant substances called polyphenols than fruits and vegetables. Just be sure to avoid most microwave popcorn varieties. Most bags contain harmful nonstick chemicals linked to obesity, thyroid problems, and ADHD. Instead, choose a chemical-free version from Quinn Popcorn, or make stovetop popcorn the old-fashioned way, or use this homemade microwave popcorn trick.