There are more than 3,000 ingredients on the FDA’s list of “safe” food additives, but while researching Eat This, Not That!, we found more than a few preservatives, dyes, sweeteners, and flavoring agents that gave us a reason for concern. That’s why we packed the book with a Food Additive Glossary—so that even if you don’t have a Ph.D. in chemistry, you can still understand the foods you’re putting into your body every day. 

We’ve compiled nine of the most controversial food additives from our glossary below. We’re not trying to scare you, but we do believe in informed eating. Next time you come across an ingredient list that reads like an O-chem final, you’ll be ready to ace the test.

Artificial Flavoring

Denotes any of hundreds of allowable chemicals such as butyl alcohol, isobutyric acid, and phenylacetaldehyde dimethyl acetal. The exact chemicals used in flavoring are the proprietary information of food processors, used to imitate specific fruits, butter, spices, and so on.

Found in: Thousands of highly processed foods such as cereals, fruit snacks, beverages, and cookies.

What you need to know: The FDA has approved every item on the list of allowable chemicals, but because they are permitted to hide behind a blanket term, there is no way for consumers to pinpoint the cause of a reaction they might have had. If you’re looking to cut the unknowns out of your diet, search the ingredient list for “Artificial Flavoring”—if a product contains any of the hundreds of allowable chemicals, it’ll be on the list. And you can look for something else.

Bonus tip: Beverages too often boast artificial flavoring. See the 20 worst drinks in America to learn which drinks you should always skip.

Aspartame

A near-zero-calorie artificial sweetener made by combining two amino acids with methanol. Most commonly used in diet soda, aspartame is 180 times sweeter than sugar.

Found in: More than 6,000 grocery items including diet sodas, yogurts, and the table-top sweeteners NutraSweet and Equal.

What you need to know: Over the past 30 years, the FDA has received thousands of consumer complaints due mostly to neurological symptoms such as headaches, dizziness, memory loss, and, in rare cases, epileptic seizures. Human studies have shown aspartame to be completely harmless; a few rodent trials implicate the additive as a carcinogen.

Bonus tip: Learn more about diet soda—and why it might actually make you gain weight.

BHA and BHT (Butylated HydroxyAnisole and Butylated Hydroxytoluene)

Petroleum-derived antioxidants used to preserve fats and oils.

Found in: Beer, crackers, cereals, butter, and foods with added fats.

What you need to know: Of the two, BHA is considered the most dangerous. Studies have shown it to cause cancer in the forestomachs of rats, mice, and hamsters. The Department of Health and Human Services classifies the preservative as “reasonably anticipated to be a human carcinogen.”

High Fructose Corn Syrup (HFCS)

A corn-derived sweetener representing more than 40 percent of all caloric sweeteners in the supermarket. In 2005, there were 59 pounds produced per capita. The liquid sweetener is created by a complex process that involves breaking down cornstarch with enzymes, and the result is a roughly 50/50 mix of fructose and glucose.

Found in: Although it can be found in every grocery aisle—in products such as ice cream, chips, cookies, cereal, bread, ketchup, jam, canned fruits, yogurt, barbecue sauce, frozen dinners—about two-thirds of the HFCS consumed in the United States is in beverages. Check out our list of the 20 Unhealthiest Drinks in America to see some of the worst examples. You’ll be shocked.

What you need to know: Since around 1980, the US obesity rate has risen proportionately to the increase in HFCS, and Americans are now consuming at least 200 calories of the sweetener each day. Some researchers argue that the body metabolizes HFCS differently, making it easier to store as fat, but this theory has not been proven. But recent research shows another potential concern: a study published in Environmental Health tested 55 common products with HFCS listed as one of the top three ingredients, and found that a third of them contained mercury.

Bonus tip: In the end, too much sugar is bad for you, no matter its molecular form. Which is why you should avoid all items on this list of the 15 worst desserts in America.

Partially Hydrogenated Vegetable Oil

A manufactured fat created by forcing hydrogen gas into vegetable fats under extremely high pressure, an unintended effect of which is the creation of trans fatty acids. Food processors like this fat because of its low cost and long shelf life.

Found in: Margarine, pastries, frozen foods, cakes, cookies, crackers, soups, and nondairy creamers.

What you need to know: Dozens of studies have linked trans fat to heart disease, which is why the cities of Boston and New York, and the state of California, have approved legislation to phase out trans fat in restaurant kitchens. Most health organizations recommend keeping trans fat consumption as low as possible, but a loophole in the FDA’s labeling requirements allows processors to add as much as 0.49 grams per serving and still claim zero in their nutrition facts.

Bonus tip: One of our rules for good nutrition is to buy foods with as few ingredients listed on the label as possible. That ensures you’re consuming maximum nutrients, and minimum chemical filler. The next time you’re at the grocery store, toss the items on this list of 10 foods for a longer life into your cart. Ingredients: 1.

Red #3 (Erythrosine) and Red #40 (Allura Red)

Food dyes that are orange-red and cherry-red, respectively. Red #40 is the most widely used food dye in America.

Found in: Fruit cocktail, candy, chocolate cake, cereal, beverages, pastries, maraschino cherries, and fruit snacks.

What you need to know: The FDA once considered imposing a ban on the use of Red #3 in food, but thus far has not. However, after the dye was linked to thyroid tumors in rats, the FDA had the liquid form of the dye removed from external-use drugs and cosmetics.

Saccharin

An artificial sweetener that’s 300 times sweeter than sugar. Invented in 1879, saccharin is the oldest of the five artificial sweeteners used in the United States.

Found in: Diet foods, chewing gum, toothpaste, beverages, sugar-free candy, and Sweet ‘N Low.

What you need to know: Rat studies in the early ‘70s linked high doses of saccharin with bladder cancer, and the FDA moved to ban it. Congress, reacting to public pressure, intervened and mandated that a warning be printed on the label of every product containing saccharin. The warning was removed after 23 years, in the wake of findings that the cancer process saccharin triggers in rats does not apply to humans, and that no human studies found any cancer risk. More recent research found that rats on saccharin-sweetened diets gain more weight than those on sugar-sweetened diets.

Bonus tip: If you want to lose weight, make the simple swaps on our list of the top swaps for weight loss. You could shed 10, 20, or even 30 pounds in a year.

Sucralose

A zero-calorie artificial sweetener made by joining chlorine particles and sugar molecules. It’s 600 times sweeter than sugar.

Found in: Sugar-free foods, pudding, low-calorie beverages, some diet sodas, and Splenda.

What you need to know: Despite the controversy surrounding Splenda, sucralose is considered by many scientific bodies to be the least damaging of the artificial sweeteners. After reviewing 110 human and animal studies, the FDA concluded that the use of sucralose does not cause cancer. The sweetener is one of only three artificial sweeteners deemed safe by the Center for Science in the Public Interest.

Yellow #5 (Tartrazine) and Yellow #6 (Sunset Yellow)

The second and third most common food colorings, respectively.

Found in: Cereal, pudding, bread mix, beverages, chips, cookies, and condiments.

What you need to know: Researchers in the Untied Kingdom found that 3-year-olds given a drink containing both dyes (and other additives) showed more symptoms of hyperactivity than those who didn’t ingest the chemicals. One study found that mice fed high doses of sunset yellow had trouble swimming straight and righting themselves in water.

If you’re eating most of them already, good for you! If not, now’s the time to load up your shopping cart and supercharge your health!

1. Eggs

Egg yolks are home to tons of essential but hard-to-get nutrients, including choline, which is linked to lower rates of breast cancer (one yolk supplies 25 percent of your daily need) and antioxidants that may help prevent macular degeneration and cataracts. Though many of us have shunned whole eggs because of their link to heart disease risk, there’s actually substantial evidence that for most of us, eggs are not harmful but healthy.

People with heart disease should limit egg yolks to two a week, but the rest of us can have one whole egg daily; research shows it won’t raise your risk of heart attack or stroke. Make omelets with one whole egg and two whites, and watch cholesterol at other meals.

2. Greek yogurt

Yogurt is a great way to get calcium, and it’s also rich in immune-boosting bacteria. But next time you hit the yogurt aisle, pick up the Greek kind—compared with regular yogurt, it has twice the protein (and 25 percent of women over 40 don’t get enough). Look for fat-free varieties like Oikos Organic Greek Yogurt (90 calories and 15 g of protein per 5.3-ounce serving).

3. Fat-free milk

Yes, it does a body good: Studies show that calcium isn’t just a bone booster but a fat fighter too. Recent research from the University of Tennessee found that obese people who went on a low-calorie, calcium-rich diet lost 70 percent more weight than those who ate the least. Vitamin D not only allows your body to absorb calcium, it’s also a super nutrient in its own right. Recent research found that adequate D levels can reduce heart disease risk, ward off certain types of cancer, relieve back pain, and even help prevent depression, but most of us don’t get nearly enough of the 1,000+ IU daily that most experts recommend.

A splash of milk in your morning coffee isn’t enough to provide the calcium and vitamin D you need. Use milk instead of water to make your oatmeal, have a glass with breakfast, or stir some chocolate syrup into it for an after-dinner treat.

4. Salmon

Salmon is a rich source of vitamin D and one of the best sources of omega-3s you can find. These essential fatty acids have a wide range of impressive health benefits—from preventing heart disease to smoothing your skin and aiding weight loss to boosting your mood and minimizing the effects of arthritis. Unfortunately, many Americans aren’t reaping these perks because we’re deficient, which some experts believe may be at the root of many of the big health problems today, like obesity, heart disease and cancer.

Omega-3s also slow the rate of digestion, which makes you feel fuller longer, so you eat fewer calories throughout the day.

5. Lean beef

Lean beef is one of the best-absorbed sources of iron there is. (Too-little iron can cause anemia.) Adding as little as 1 ounce of beef per day can make a big difference in the body’s ability to absorb iron from other sources, says Mary J. Kretsch, Ph.D., a researcher at the USDA-ARS Western Human Nutrition Research Center in Davis, Calif. Beef also packs plenty of zinc (even minor deficiencies may impair memory) and B vitamins, which help your body turn food into energy.

If you can, splurge on grass-fed. Compared with grain-fed beef, it has twice the concentration of vitamin E, a powerful brain-boosting antioxidant. It’s also high in omega-3 fatty acids. Because this type of beef tends to be lower in overall fat, it can be tough—so marinate it, and use a meat thermometer to avoid overcooking.

6. Beans

It’s hard to imagine a more perfect food than beans. One cooked cupful can provide as much as 17 g fiber. They’re also loaded with protein and dozens of key nutrients, including a few most women 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.

The latest dietary guidelines recommend consuming at least three cups of beans a week—three times the measly one cup we usually get. Keep your cupboards stocked with all kinds: black, white, kidney, fat-free refried, etc. Use them in salads, stuffed baked potatoes, and veggie chili or pureed for sandwich spreads.

Did you take your vitamin today? Be sure you’re not missing these 5 important nutrients most women miss.

7. Nuts

In a nutshell: USDA researchers say that eating 1.5 ounces of tree nuts daily can reduce your risk of heart disease and diabetes. Walnuts are rich in omega-3s. Hazelnuts contain arginine, an amino acid that may lower blood pressure. An ounce of almonds has as many heart-healthy polyphenols as a cup of green tea and a half cup of steamed broccoli combined; they may help lower LDL cholesterol as well.

The key is moderation, since nuts are high in calories. Keep a jar of chopped nuts in your fridge, and sprinkle a tablespoon on cereal, salads, stir-fries, or yogurt. Or have an ounce as a snack most days of the week.

8. Edamame and tofu

Soy’s days as a cure-all may be over—some claims, such as help for hot flashes, don’t seem to be panning out—but edamame still has an important place on your plate. Foods such as tofu, soy milk and edamame help fight heart disease when they replace fatty meats and cheeses, slashing saturated fat intake. Soy also contains heart-healthy polyunsaturated fats, a good amount of fiber and some important vitamins.

Soy’s isoflavones, or plant estrogens, may also help prevent breast cancer. Some researchers believe these bind with estrogen receptors, reducing your exposure to the more powerful effects of your own estrogen, says Prevention adviser Andrew Weil, M.D. But stick with whole soy foods rather than processed foods, like patties or chips, made with soy powder. Don’t take soy supplements, which contain high and possibly dangerous amounts of isoflavones.

Get more nutrition, natural medicine and healthy living advice from Dr. Weil’s blog.

9. Oatmeal

Fiber-rich oats are even healthier than the FDA thought when it first stamped them with a heart disease-reducing seal 10 years ago. According to new research, they can also cut your risk of type 2 diabetes. When Finnish researchers tracked 4,316 men and women over the course of 10 years, they found that people who ate the highest percentage of cereal fiber were 61 percent less likely to develop type 2 diabetes.

To reap the benefits, eat a half cup daily—preferably unsweetened. For a versatile breakfast, top with different combinations of fruit, yogurt and nuts. You can also use oats to coat fish or chicken or add texture to meatballs.

10. Flaxseed

Flaxseed is the most potent plant source of omega-3 fats. Studies indicate that adding flaxseed to your diet can reduce the development of heart disease by 46 percent—it helps keep red blood cells from clumping together and forming clots that can block arteries. It may also reduce breast cancer odds. In one study, women who ate 10 g of flaxseed (about 1 rounded tablespoon) every day for two months had a 25 percent improvement in the ratio of breast cancer—protective to breast cancer—promoting chemicals in their blood.

Sprinkle 1 to 2 tablespoons of flaxseed a day on your cereal, salad or yogurt. Buy it preground, and keep it refrigerated. Find more high-fiber power foods here.

11. Olive oil

Olive oil is full of heart-healthy monounsaturated fats (MUFAs), which lower “bad” LDL cholesterol and raise “good” HDL cholesterol. It’s rich in antioxidants, which may help reduce the risk of cancer and other chronic diseases, like Alzheimer’s.

Look for extra virgin oils for the most antioxidants and flavor. Drizzle small amounts on veggies before roasting; use it to sauté or stir-fry, in dressings and marinades, and to flavor bread at dinner in lieu of a layer of butter or margarine.

12. Avocado

These smooth, buttery fruits are a great source of not only MUFAs but other key nutrients as well. One Ohio State University study found that when avocado was added to salads and salsa, it helped increase the absorption of specific carotenoids, plant compounds linked to lower risk of heart disease and macular degeneration, a leading cause of blindness. “Avocados are packed with heart-protective compounds, such as soluble fiber, vitamin E, folate and potassium,” says Elizabeth Somer, R.D., author of 10 Habits That Mess Up a Woman’s Diet.

But they are a bit high in calories. To avoid weight gain, use avocado in place of another high-fat food or condiment, such as cheese or mayo.

13. Broccoli

Pick any life-threatening disease—cancer, heart disease, you name it—and eating more broccoli and its cruciferous cousins may help you beat it, Johns Hopkins research suggests. Averaging just four weekly servings of veggies like broccoli, cabbage and cauliflower slashed the risk of dying from any disease by 26 percent among 6,100 people studied for 28 years.

For maximum disease-fighting benefits, whip out your old veggie steamer. It turns out that steaming broccoli lightly releases the maximum amount of sulforaphane.

14. Spinach

We’ll spare you the Popeye jokes, but spinach has serious health muscles. For one thing, it contains lots of lutein, the sunshine-yellow pigment found in egg yolks. Aside from guarding against age-related macular degeneration, a leading cause of blindness, lutein may prevent heart attacks by keeping artery walls clear of cholesterol.

Spinach is also rich in iron, which helps deliver oxygen to your cells for energy, and folate, a B vitamin that prevents birth defects. Cook frozen spinach leaves (they provide more iron when cooked than raw) and serve as a side dish with dinner a few times a week.

15. Tomatoes

Tomatoes are our most common source of lycopene, an antioxidant that may protect against heart disease and breast cancer. The only problem with tomatoes is that we generally eat them in the form of sugar-loaded jarred spaghetti sauce or as a thin slice in a sandwich. For a healthier side dish idea, quarter plum tomatoes and coat with olive oil, garlic powder, salt and pepper. Roast in a 400 degree Fahrenheit oven for 20 minutes, and serve with chicken.

16. Sweet potatoes

One of the best ways to get vitamin A—an essential nutrient that protects and maintains eyes, skin, and the linings of our respiratory, urinary, and intestinal tracts—is from foods containing beta-carotene, which your body converts into the vitamin. Beta carotene-rich foods include carrots, squash, kale and cantaloupe, but sweet potatoes have among the most. A half-cup serving of these sweet spuds delivers only 130 calories but 80 percent of the DV of vitamin A. Replace tonight’s fries with one medium baked sweet potato (1,096 mcg) and you’re good to go—and then some.