10 Foods That Are High in Muscle-Building Nucleotides

Show of hands: Who knows what a nucleotide is?

If you’ve forgotten everything from high school chemistry, we’ve got you: Nucleotides are tiny organic compounds that are essential in nearly all biological processes.

For one, these buggers glom together to build nucleic acids DNA and RNA, which are the foundation of your body’s genetic material, explains registered dietitian Georgie Fear, R.D., C.S.S.D., author of Lean Habits for Lifelong Weight Loss. Together, nucleotides’ specific sequences (or patterns) make us look and act like mom, dad, and uncle Al.

Nucleotides also carry out several essential functions needed for cell replication and general health. Nucleotides are classified as either pyrimidines or purines, depending on whether they have a single- or double-ring chemical structure. Put simply, purines are twice the size.

Purines and pyrimidines play similar roles in the body. They pair together to store genetic information and help cells replicate, explains nutritionist Jonathan Valdez, R.D.N., owner of Genki Nutrition and a spokesperson for the New York State Academy of Nutrition and Dietetics. Some neutralize toxins, regulate cellular metabolism, bolster the immune system, and help antioxidants do their thing. Others help promote cell and tissue (yes, even muscle tissue) growth and recovery.

That’s why, when it comes to putting the most into (and getting the most out of) your workouts, nucleotides really shine. ATP, the body’s basic energy storage molecule, is a nucleotide that’s responsible for fueling every cell in the human body, Fear says. Meanwhile, other nucleotides, including NAD, FAD, and coenzyme A, are vital in helping the body break down food to release that ATP.

Where Do Nucleotides Come From?

With such essential roles, it’s no surprise that our body is capable of producing these molecules itself, as well as recycling, repairing, and repurposing used nucleotides in the body.

However, when there is an increased need for nucleotides, as a result of injury, radiation, fast growth, or severely weakened immune system—or a particularly tough training week—we may need an increase in nucleotides to help the body recover and repair itself.

One study published in Nutrition argues that under conditions like these, consuming nucleotides through diet may help promote recovery. A second study published in the Journal of Strength & Conditioning Research found that when athletes supplemented strength training with increased nucleotide intake (they took NuBound), their muscles repaired faster.

When we eat foods that are high in nucleotides, enzymes in the small intestine (like protease and nuclease) break the nucleotides into smaller, absorbable bits. In fact, according to one 2012 study published in Nutrition of Clinical Practice, 90 percent of the nucleotides we eat are absorbed into and transported to our cells for use. And the rest, well, we excrete them.

While research on nucleotide intake through diet is limited, current evidence finds that more may be better. One promising study published in the Journal of Pediatric Gastroenterology and Nutrition found that weanling rats who were fed a diet high in nucleotides matured faster and digested food better compared to those not on a high nucleotide diet. A second study published in Nutrition found that the presence of nucleotides in a rat’s diet improved their ability to recover from intestinal surgery.

Moreover, a study published in Journal of Sports Medicine and Physical Fitness found that when healthy adults increased their nucleotide intake through food, their cortisol levels were actually lower. While the sample size was small, it does suggest that a long-term increased intake of nucleotides could help blunt the hormonal response associated with stress—and even aid in workout recovery.

How Do You Boost Your Nucleotide Intake?

Given the wide range of potential benefits, it’s worth figuring out how to increase your consumption of nucleotides. Here’s the good news: You will find some in every food you eat, says Valdez. Some foods just have more (and different types) compared to others. Because muscle is naturally rich in ATP and ATP-generating nucleotides, meats and organ meats are among the richest sources out there, he says. But green-leafy vegetables, fruit, and other vegetables have decent amounts of other nucleotides, he explains.

There isn’t yet a scientific recommendation on how much we should eat, but some is likely better than none. And most of us could probably be eating more than we do.

(Important note: If you have gout, you shouldn’t increase your intake of purines unless you are also taking a digestive enzyme supplement recommended by your doctor, says Fear, noting that—in people with gout—purines can increase the risk of uric acid crystals to form in joints.)

Here are 10 foods that are high in all types of nucleotides. Good news: If you’re following a balanced, whole-foods-rich diet, you’re probably eating many of them already.

1. Shrimp

These guys are loaded with both purine and pyrimidine nucleotides, says Valdez, noting that it’s not unusual for foods to be high in both types. “All foods that are high in purines are high in pyrimidines too,” he explains. Add them to pastas, salads, or serve them solo as a main dish.

2. Anchovies

Add these salty swimmers into your Caesar dressing for a purine and pyrimidine-packed salad. Or eat them straight from the can, suggests Valdez. When it comes to nucleotide content, how you prepare the anchovies is less important than how many you eat, he says.

3. Milk

Animal milk products contain a significant amount of purine nucleotides, according to research published in the Journal of Dairy Research. A glass of cow’s milk with breakfast (or any time of day) is a great way to up nucleotide intake while also packing an am protein punch, says Valdez.

4. Liver

Organ meats, especially liver, are high in both purine and pyrimidine nucleotides, says Fear, because that’s a major site of nucleotide synthesis in the body. And according to research published in NHD Clinical, both raw liver and liver pate were shown to more than 600 milligrams of nucleotides for every 100 grams of food, the most of any food reviewed by the scientists. Order some liver pate at your local deli and smear it on carrot sticks or celery for a high-protein, high-nucleotide snack.

5. Steak

Pull out the butcher board and get grilling, suggests Valdez, because most animal meats are high in both purine and pyrimidine nucleotides. Just watch your portion sizes: 3 to 4 ounces per meal is all you need, he says.

6. Chicken

If you’re more of a white- than red-meat carnivore, opt for chicken. NHD Clinical research shows that chicken offers more than 250 milligrams of nucleotides for every 100 grams of food.

7. Lentils

When it comes to street cred, lentils don’t get enough. One cooked cup delivers 16 grams of fiber and 18 grams of protein, but weighs in at only 220 calories, according to the United States Department of Agriculture. They also deliver a sizable serving of both types of nucleotides for a non-animal source, says Valdez. Mash them up into a beanie chip-dip, or serve them instead of rice on the side.

8. Mushrooms

A type of fungus, mushrooms pack more of both nucleotide types than any other vegetable, according to NHD Clinical research. That, of course, means that they’re the perfect base for vegetarian versions of classic meat dishes: burgers, tacos, hot dogs, Bolognese, even steak. Try out Portobello mushrooms for a meatless filet, or sauté shitakes for an awesome pasta add-in.

9. Asparagus

These stalks are full of fiber, iron, vitamin A, and both purine and pyrimidine nucleotides. Roast them with balsamic for a tasty side dish, or steam and chop them up and add to any salad, Valdez recommends.

10. Spinach

Popeye was right, and now we know why. This low-cal superfood is high in fiber, protein, and vitamins A, C, and K, as well as both purines and pyrimidines. This makes it the perfect addition to smoothies, omelets, and pastas.