Yellow 5 is an artificial food dye added to processed pastries, brightly colored soda, and colored candy. Consuming more than the recommended amount may cause hyperactivity in children and other health effects over time.

Have you been reading food labels more carefully these days? If so, you may have noticed “yellow 5” popping up in many of the ingredient lists you scan at the store.

Yellow 5 is an artificial food color (AFC) that was approved for use in foods in 1969 by the FDA. Its purpose to is make foods — particularly highly processed foods like candy, soda, and breakfast cereals — appear more fresh, flavorful, and appetizing.

Between 1969 and 1994, the FDA also approved yellow 5 for the following uses:

  • drugs taken by mouth
  • topical medications
  • cosmetics
  • eye area treatments

Other names for yellow 5 include:

  • FD&C yellow no. 5
  • tartrazine
  • E102

Along with a handful of other AFCs, yellow 5’s safety has been called into question over the last several decades. Studies have found a possible link between fruit juices containing a mix of AFCs and hyperactive symptoms in children. Research also suggests moderate to high amounts of this AFC over time may have harmful effects.

Let’s take a closer look at the possible effects of yellow 5 so you can determine whether it’s something you want to avoid.

Regulatory bodies in different countries have different opinions about the safety of yellow 5. Following the release of a groundbreaking 2007 study linking AFCs to hyperactivity in preschool and school-aged children, the Food Standards Agency of the European Union (EU) deemed six AFCs unsafe for kids. In the EU, a warning label is required on all foods containing:

  • yellow 5
  • yellow 6
  • quinoline yellow
  • carmoisine
  • red 40 (allura red)
  • ponceau 4R

The EU warning label reads, “May have an adverse effect on activity and attention in children.”

In addition to taking action with warning labels, the British government actively encourages food makers to drop AFCs from their products. In fact, the British versions of Skittles and Nutri-Grain bars, both popular products in the United States, are now dyed with natural colors, such as paprika, beetroot powder, and annatto.

On the other hand, the Food and Drug Administration (FDA) didn’t choose to adopt a similar approach. In 2011, the advisory committee for the FDA voted against using labels like these in the United States, citing lack of evidence. However, the committee did recommend ongoing research on AFCs and hyperactivity.

Thanks in part to the influx of highly processed foods, people in the United States are ingesting AFCs at four times the rate they did 50 years ago, when these dyes were first introduced.

Yellow 5 is banned altogether in Austria and Norway.

Yellow 5 is considered an azo compound with the formula C16H9N4Na3O9S2. That means in addition to carbon, hydrogen, and nitrogen — typically found in natural food dyes — it also includes sodium, oxygen, and sulfur. These are all naturally occurring elements, but natural dyes aren’t as stable as yellow 5, which is made from the byproducts of petroleum.

Yellow 5 is often tested on animals, so it’s up for debate as to whether it’s vegetarian- or vegan-friendly.

There are a number of health areas that include research into food dyes in general or yellow 5 in particular.

Hyperactivity in children

Some studies suggest that 50 milligrams (mg) of AFCs per day is enough to cause behavior changes in children. This might seem like a significant amount of food coloring that would be tough to consume in a day. But with all the eye-popping, fully flavored processed food available on today’s market, it’s not that hard. For example, a 2014 study found that one serving of Kool-Aid Burst Cherry contained 52.3 mg of AFCs.

Between 2004 and 2007, three landmark studies revealed a relationship between fruit juices flavored with AFCs and hyperactive behavior in kids. These are known as the Southampton Studies.

In the Southampton Studies, groups of preschoolers and 8- to 9-year-olds were given fruit juices with different mixes and amounts of AFCs. Results of one study showed that those preschoolers who were given Mix A, containing yellow 5, demonstrated a much higher “global hyperactivity” score compared to preschoolers who were given the placebo.

Preschoolers weren’t the only ones affected — the 8- to 9-year-olds who ingested AFCs showed more signs of hyper behavior, as well. In fact, researchers found that all children in the experimental group showed slight increases in hyperactive behavior. The behavior issues weren’t unique to children who already met the criteria for attention-deficit/hyperactivity disorder (ADHD).

But children with ADHD may be extremely sensitive. In an earlier review by Harvard University and Columbia University, researchers estimated that “removing artificial food colorings from the diets of children with ADHD would be about one-third to one-half as effective as treatment with methylphenidate (Ritalin).” Although this 2004 review is dated, it supports findings from the Southampton Studies.

For now, scientists and the FDA agree that diet alone is not to blame for ADHD symptoms in children. Rather, there is strong evidence to support a biological component for this disorder. More research is needed.

Cancer

A 2015 study looked at how human white blood cells were affected by yellow 5. Researchers found that although this food coloring wasn’t immediately toxic to white blood cells, it did damage the DNA, causing the cell to mutate over time.

After three hours of exposure, yellow 5 caused damage to human white blood cells in every concentration tested. Researchers noted that cells exposed to the highest concentration of yellow 5 weren’t able to repair themselves. This may make tumor growth and diseases like cancer more likely.

Researchers concluded that since the cells of the gastrointestinal tract are exposed directly to yellow 5, these cells may be more likely to develop cancer. Most of the AFCs you eat are metabolized in your colon, so colon cancer may be of the greatest risk.

However, it’s important to note that this study was conducted in isolated cells and not in the human body.

Other health effects

A 2019 study measured the toxicity of yellow 5 on flies. Results showed that when yellow 5 was delivered to the flies at the fourth highest concentration, it became toxic. About 20 percent of flies in the group didn’t survive, but there may have been other factors at play in addition to this being an animal study.

In the second part of this study, human leukemia cells were exposed to different food colorings. Researchers found that while yellow 5 and other AFCs can increase tumor cell growth, they don’t cause damages or changes to human DNA at their allowed concentrations. The researchers concluded, however, that “a high chronic intake of food colorings throughout the entire life is not advisable.”

Here are a few common foods that contain yellow 5:

  • processed pastries, such as Twinkies
  • neon-colored sodas, like Mountain Dew
  • kids’ fruit drinks, such as Sunny D, Kool-Aid Jammers, and several varieties of Gatorade and Powerade
  • brightly colored candy (think candy corn, M&Ms, and Starburst)
  • sugary breakfast cereals like Cap’N Crunch
  • pre-packaged pasta mixes
  • frozen treats, such as Popsicles

These may seem like rather obvious sources of yellow 5. But some food sources can be deceptive. For example, would you ever expect the jar of pickles you have in the fridge to contain yellow 5? Well, in some cases, it does. Other surprise sources include medicines, mouthwashes, and toothpastes.

If you’re looking to lower your intake of yellow 5, try scanning food labels more often. Steer clear of ingredient lists that contain yellow 5 and these other AFCs:

  • blue 1 (brilliant blue FCF)
  • blue 2 (indigotine)
  • green 3 (fast green FCF)
  • yellow 6 (sunset yellow FCF)
  • red 40 (allura red)

It may give you some reassurance to know that many brands in the food industry are making the switch to natural colors. Even larger companies like Kraft Foods and Mars Inc. are replacing AFCs with alternatives like these:

  • carmine
  • paprika (the go-to natural alternative for yellow 5)
  • annatto
  • beetroot extract
  • lycopene (sourced from tomatoes)
  • saffron
  • carrot oil

Next time you hit the grocery store, pay extra attention to nutrition labels. You may find that some of your go-to products have already made the switch to natural colors.

Keep in mind that natural colors are not a silver bullet. Carmine, for example, is derived from crushed beetles, which not everyone is eager to eat. Annatto is known to cause allergic reactions in some people.

Here are some simple swaps you can make to cut down on yellow 5 in your diet:

  • Choose Squirt over Mountain Dew. The citrusy sodas taste similar, but regular Squirt is free of AFCs. That’s why it’s clear.
  • Pass on prepackaged pasta mixes. Instead, buy whole-grain noodles and make homemade pasta dishes. You can whip up a delicious, healthier mix at home.
  • Drink homemade lemonade over yellow store-bought juices. Sure, it may still contain sugar, but you can make sure it’s AFC-free.

The FDA and top researchers have reviewed the evidence and concluded that yellow 5 doesn’t pose an immediate threat to human health. However, research does suggest that this dye may harm cells over time, especially when cells are exposed to greater amounts than the recommended intake.

If you’re concerned about what the research says about yellow 5, one of the best things you can do is to cut back on sugary, processed foods. Aim to get more of these whole foods instead:

  • healthy fats like avocado
  • unrefined grains
  • fruits and vegetables
  • omega-3 fatty acids (found in fish like salmon)
  • flaxseed
  • lean protein like chicken and turkey

Eating a diet rich in these foods will keep you full longer. This means you’re less likely to be tempted by colorful, packaged foods. Plus, with whole foods, you don’t have to worry about whether you’re ingesting a questionable food coloring, which might bring you some peace of mind.