Are some foods better for you when paired, than when eaten alone?
That’s the basics behind food synergy – the idea that certain foods have nutritional ‘friends.’ Eating two complementary foods at the same time enables your body to more effectively absorb the nutrients that each provides.
We asked Jennifer Glockner, a registered dietitian nutritionist and creator of Teddy Tries a Veggie, the first book in the Smartee Plate nutrition e-book series for kids.
According to Jennifer, certain nutrients can work together in a synergistic manner.
Here are some examples of food pairings that can help your body get a boost of important nutrients:
Iron Is Important For Energy, Focus, and Fighting Infections
Iron is needed for your body to make hemoglobin, a protein your red blood cells use to carry oxygen from your lungs to the rest of your body.
Not getting enough iron can lead to constantly feeling fatigued, an inability to focus, and even an increased risk of infections, as your immune system depends on oxygen-rich blood to fight them off.
We Get Iron From Meat, Leafy Greens & Legumes
There are two types of iron: Iron from meat, fish, and poultry (heme iron) and plant-based iron (called non-heme iron). Especially important for vegetarians, the plant-based version of this essential nutrient can be found in legumes, including peas, beans, lentils, and chickpeas.
The catch? Plant-based (non-heme) iron is more difficult for our bodies to absorb. Also detrimental to your diet, sources of non-heme iron often contain phytates—these antioxidants bind to iron and carry it through the digestive tract unabsorbed.
As a result, foods with high iron content aren’t necessarily the best sources of iron.  By weight, soybeans have roughly twice the iron of beef. But only about 7% of the iron in soybeans is absorbed. Spinach is also high in iron, but less than 2% of the iron in cooked spinach is absorbed.
Pump Up Your Iron by Adding Vitamin C
According to Jennifer Glockner, you can improve your body’s ability to absorb non-heme iron by adding a little vitamin C to iron-rich meals:
- Squeeze citrus juice, such as lime or lemon, over beans, chickpeas, or lentils.
- Got hummus? Instead of scooping the chickpea paste with chips, use vitamin C-rich red bell peppers.
How effective is vitamin C? One study reported that adding just 63 mg of vitamin C to a meal rich in plant-based iron helped your body absorb three times as much of the nutrient. 
Mixing Legumes With Meat for B12 Also Boosts Your Iron
Adding meat to a meal can also make a big difference in how well your body absorbs iron. Researchers suggest that combining 50 to 85 grams of meat with iron-rich foods results in a 1.5- to 4-fold increase in your body’s iron absorption. 
Just in case you’re wondering which meat is best, beef may be the most effective. In one study, beef protein enhanced iron absorption 80% better than did chicken protein. 
Tip: Cooking with iron cookware can add iron to your diet, particularly if you cook acidic foods at high temperatures. Learn more about the pros and cons of iron cookware in Comparing Cookware Materials.
Eat a Serving of Meat With Your Sweet Potatoes to Absorb More Vitamin A
Vitamin A is needed for multiple functions, including keeping your vision healthy, your immune system in top shape, as well as helping your heart, lungs, and kidneys work their best. The nutrient is most often consumed as beta-carotene, which can be found in orange and yellow-colored veggies. During digestion, your body converts the beta-carotene to vitamin A.
In the short-term, a vitamin A deficiency can affect your vision, making it difficult to see in low light. 
However, there are even better long-term benefits to packing your diet with vitamin A. Researchers believe that people who eat lots of vitamin A-rich foods might have a lower risk of certain types of cancers, including lung and prostate cancer. 
Increase Your Vitamin A Absorption by Adding Zinc-Rich Foods
You might think you’re getting plenty of vitamin A from a sweet potato casserole. But, eating vitamin A-packed spud without getting enough zinc – found in meats like chicken, beef, and pork – means much of the nutrient goes to waste.
That’s because you need zinc to metabolize and carry vitamin A throughout your body. Without it, essential vitamin A passes through your GI tract, unabsorbed.
How to mix a serving of meat with sweet potatoes?
If you’re in a hurry, just microwave a sweet potato (roughly 8 minutes), then serve up side-by-side with some pre-rotisseried chicken. (The link also includes multiple ‘how to’ recipes for sweet potatoes, including mashed, fries, casserole, and soup!)
Chicken and yams
However, if you’ve got about forty minutes to make a meal, we thought this recipe for chicken roasted on sweet potatoes and garlic was so good, we made it two days in a row. It requires minimal ingredients on hand; just garlic, oregano, and olive oil (plus the chicken and sweet potatoes, of course).
Boost Your Heart’s Health My Mixing Two Breakfast Foods
Some foods need an additional nutrient to increase absorption, but others just make sense together. Take oatmeal, for example. Alone, oatmeal is already a breakfast with many benefits:
- Oats contain both soluble and insoluble fiber. Soluble fibers form a viscous gel that helps to lower cholesterol and stabilize blood glucose levels. The insoluble fiber in oats helps to curtail constipation and improve your intestinal health.
- Oats make an easy, balanced breakfast. One cup of cooked oatmeal contains about 150 calories, four grams of fiber (about half soluble and half insoluble), and six grams of protein.
- Oats provide important minerals. Nutrient-rich oatmeal contains thiamin, magnesium, phosphorus, zinc, manganese, selenium, and iron.
- Oats could help you control your weight by keeping you feeling fuller longer. Carbs are often shunned and feared by those looking to drop a few pounds, yet choosing whole grains could squash hunger and simultaneously provide that pleasant “ahhhh” feeling carb-lovers crave.
While it’s healthy, eating straight oats every morning can get boring. Pump up your breakfast bowl’s flavor and heart-health quotient by tossing in a chopped apple. (Keep the skin on—that’s where all the nutrients live.)
Oatmeal and apples
Apples are filled with flavonoids, which are major-league antioxidants that also zap free radicals and take on inflammation to boot. If you have time, saute slices in a touch of butter and ground cinnamon, then chop and mix into your hot cereal.
Pair Tomatoes and Olive Oil For Healthy Skin (and Less Wrinkles)
Lycopene, a powerful antioxidant found mostly in tomatoes, can help prevent sun damage. But eating raw tomatoes alone only provides your body with a small fraction of the lycopene you’ve eaten. That’s because the lycopene in raw tomatoes is tightly bound to fiber that’s difficult for your body to digest.
On the other hand, heating up tomatoes releases more lycopene, meaning that cooked tomato products such as paste or sauce, are a much better source of the antioxidant for your skin. Even then, the majority of the fat-soluble nutrient gets absorbed into fat-rich organs, like your adrenal glands, colon, and liver.
To help your body get the most out of each lycopene-rich tomato, drizzle them with olive oil before baking. This one-two punch starts with heat causing the tomatoes to release more lycopene, while the healthy fats in olive oil allow lycopene to be better absorbed by your body.
Heating tomatoes are as simple as slow-roasting plum tomatoes in olive oil at 225°F. However, we tried these baked parmesan tomatoes (subbing feta since it was on hand) and were super-pleased with the fast (and delicious) results.
Eat Greens With Your Salmon for a Boost In Calcium
To get the most out of your calcium intake, consuming enough vitamin D is key. That’s because vitamin D makes it easier for your body to absorb calcium from your GI tract into the blood, and helps to maintain normal calcium levels over prolonged periods.
Calcium can be found in dairy, beans, and green leafy veggies.
Dairy, tofu, sardines, and green, leafy veggies are all great sources of calcium. To increase their bone-boosting abilities, be sure to add eggs, mushrooms, or fatty fish—all of which are good sources of vitamin D.
What are some easy, calcium-boosting combos? Jennifer Glockner suggests:
- Add cheese to your scrambled eggs
- Top grilled salmon with some leafy veggies
- Stir fry mushrooms, tofu, and greens
- Add beans to chicken tacos
The National Institutes of Health recommends adult women get 600 IU of vitamin D daily. Bare skin exposed to sunlight triggers vitamin D production in your body, but it’s important to supplement your vitamin D by eating certain foods to ensure your body—and bones—get the boost they need.
Other Examples of Food Friends?
Rebecca Lewis, the in-house dietitian at HelloFresh, sent over the following additional food combinations that help you reach peak nutrition.
Vitamin C + Vitamin E = Double the Antioxidants
According to Rebecca, combining vitamin C with vitamin E doubles the power of these already-impressive antioxidants. As mentioned above, you can find vitamin C in brightly colored fruits and veggies (red bell peppers, carrots, oranges, strawberries). Vitamin E can be found in nuts and seeds, trout, and avocados.
For simple ways to mix the two, squeeze citrus juice over your fish, throw some seeds into your salad, or use red bell peppers to scoop your guacamole.
Vitamin B6 + Vitamin B12 + Folate = Triple Heart Protection
Another tip is to combine vitamin B6, vitamin B12, and folate into a meal. Vitamin B6 can be found in lentils, pistachios. Vitamin B12 can be found in animal-based foods, such as meats, fish, and dairy.
Folate, a water-soluble form of vitamin B, is found mostly in vegetables. Spinach, turnip greens, bok choy, parsley, and romaine lettuce are all rated as excellent sources of folate. Other vegetables can be strong sources as well, including asparagus, cauliflower, broccoli and beets join the excellent group. Legumes, and even some fruits, like avocados and mangos, are also high in folate.
What’s the benefit in combining all three nutrients? According to Rebecca, they work together to decrease your risk of heart disease and strokes.
Potassium + Magnesium + Calcium = A Whole Lot of Goodness
What happens when you make a meal with potassium, magnesium, and calcium? Rebecca says, “this trifecta work together to regulate our electrolyte balance, manage nerve functioning, and decrease blood pressure.”
To create a beneficial nutrient balance, you can pick one from each of the following categories:
- Potassium can be found in beans, dark leafy greens, potatoes, squash, yogurt, fish, avocados, mushrooms, and bananas.
- Magnesium can be found in dark leafy greens, nuts, seeds, fish, beans, whole grains, avocados, yogurt, bananas, dried fruit, and dark chocolate.
- Calcium can be found in dark leafy greens, cheese, low-fat milk and yogurt, bok choy, fortified tofu, okra, broccoli, green beans, almonds, and fish canned with their bones.
The Good News: Nutrient Combinations Don’t Need to Be in the Same Bite
Short of eating dark, leafy greens for every meal (we get it, they’re good for you!), or bananas mixed with almonds and yogurt, how to take advantage of multiple nutrients abilities to boost each other?
Thankfully, these nutrients don’t have to be combined in every bite. While there’s no exact time frame, experts suggest that as long as complementary foods are eaten within 15-30 minutes of each other, your body gets all the benefits.
Some Foods Are More Nutritious When Eaten Far Apart
Dr. Adam Splaver, a South Florida cardiologist, explains that there are also things we should not pair together, like green tea and kale. “While you may be tempted to add both to your smoothie, iron-rich foods like kale strip tea of its antioxidant powers,” he says.”
Other food pairings to avoid?
If you’re concerned about getting enough iron, avoid your iron-rich foods with ones that contain iron absorption inhibitors, including:
- Egg protein (from both the white and the yolk)
- Minerals that compete with iron for absorption: calcium, zinc, magnesium, and copper
- Tannic acid (in tea)
- Certain herbs, including peppermint and chamomile
- Coffee and cocoa
Note that you still need all the nutrients that the above foods provide, including calcium, zinc, phosphorus, and fiber. However, if you’re concerned about iron deficiency, it’s helpful to avoid the above-listed foods before, during, or after eating those that are rich in iron.
Choose Your Foods With Specific Goals in Mind
How to apply the concepts of food synergy to your daily diet? Dr. Adam Splaver suggests the simplest way is to have specific goals in mind when selecting what, and when, to eat. For example, you can consciously tailor your diet to help you:
- Build muscle mass
- Keep your heart healthy
- Strengthen your bones
- Maintain hydration
“Think of it as new math,” says Dr. Splaver. By adding two or three ingredients, you can triple the health benefits from any given meal.
“For example, what if we paired superfoods like oatmeal with blueberries and cinnamon? This triple header creates food synergy.”
Dr. Splaver suggests looking for combinations that can easily fit into your regular meal plan, such as serving salmon with spinach and create a double barrier against memory loss. Or, enjoying a daily cup of Greek yogurt with flaxseed, which is good for your bones and your digestive tract, and adding blueberries which help to prevent chronic diseases and facilitates processing new information.
“Add regular exercise training,” says Dr. Splaver, “and you’ve increased your chances for feeling, sleeping, and thinking better. And living longer.
More on Healthy Living:
- Sugar Versus Artificial Sweeteners: What’s Better for You?
- An Overview of 4 Popular Gyms and How to Choose the Best Membership
- What’s in Your Sports Drinks? A Guide to Ingredients and Who Should Be Drinking Them
- Scrimshaw NS. 1991. Iron deficiency. Sci Am. 265(4):46-52.
- Fidler MC, Davidsson L, Zeder C, and Hurrell RF. 2004. Erythorbic acid is a potent enhancer of nonheme-iron absorption. Am J Clin Nutr. 2004 Jan;79(1):99-102.
- Baech SB, Hansen M, Bukhave K, Jensen M, Sørensen SS, Kristensen L, Purslow PP, Skibsted LH, and Sandström B. 2003. Nonheme-iron absorption from a phytate-rich meal is increased by the addition of small amounts of pork meat. Am J Clin Nutr. 77(1):173-9.
- Hurrell RF, Lynch SR, Trinidad TP, Dassenko SA, and Cook JD. 1988. Iron absorption in humans: bovine serum albumin compared with beef muscle and egg white. Am J Clin Nutr 47:102–7.
- “Vitamin A Fact Sheet for Consumers.” U.S. Department of Health & Human Services National Institutes of Health, n.d. Web.
- “Beta-carotene.” University of Maryland Medical Center. N.p., n.d. Web. 26 Aug. 2016.