You're probably used to reaching for a handful of nuts when hunger strikes and you want a healthy snack. Nuts are naturally high in unsaturated fat, which is easily oxidized by free radical molecules, causing it to turn rancid. But nuts also contain antioxidants, such as vitamin E, that protect their healthy fats from oxidation.
This is food synergy in action, the idea that the naturally occurring compounds in a whole food work together to create greater health benefits than can be achieved by any of its individual components, be it a vitamin, mineral, fatty acid or particular antioxidant.
You won't find this orchestrated web of beneficial compounds in highly processed foods. Nor will you find it in a vitamin pill or other nutrition supplements.
Another example of food synergy relates to the "buffering" effect of whole, intact foods. A case in point: dairy products versus calcium supplements.
While not conclusive, there's concern that consuming calcium in large doses may contribute to coronary artery calcification (the buildup of calcium in fatty plaques in the heart's artery walls). Studies suggest, though, that the highest risk for calcium buildup occurs among supplement users, people who get most of their calcium from foods have the lowest risk.
It's thought that the natural food matrix of dairy products – the structure and nutrient content – slows the rise in blood calcium. Consuming a large amount of calcium from supplements, however, can cause quick, large rises in blood calcium that could lead to calcium depositing in artery walls.
Food synergy also occurs when two different foods interact to deliver greater nutritional value – and greater potential health benefits – than if they're eaten alone. Consider adding these smart food combinations to your menu to make these nutritious foods even better for you.
Eggs and spinach
Adding whole eggs to a spinach salad does more than increase your protein intake. Thanks to the fatty yolk, eggs also boost the body's absorption of vitamin E, a fat-soluble nutrient that's needed for a healthy immune system, skin and eyes.
According to a small study from Purdue University published in 2016, when three whole eggs were added to a salad (baby spinach, romaine lettuce, carrot, tomato), the amount of vitamin E absorbed from the vegetables was four- to seven-fold higher than when the salad was eaten without eggs.
The researchers also found that the addition of eggs enhanced the absorption of beta-carotene, lutein and lycopene, antioxidants that, like vitamin E, are best absorbed with fat.
Blueberries and strawberries
Both types of berries contain polyphenols, potent antioxidants thought to help guard against Alzheimer's disease and cancer. But research from Cornell University suggests you'll reap even more health benefits if you eat them together.
The researchers found that, compared to any single fruit studied, combinations of fruit had the highest antioxidant activity. It's thought that the additive and synergistic properties of antioxidants in fruits (and vegetables) are responsible for their protective effects.
Don't stop at berries. Serve a mixed fruit salad for dessert, add a variety of chopped fruit to oatmeal, or eat a clementine and an apple for a midday snack.
Quinoa and red pepper
Besides delivering a decent amount of fibre and protein, quinoa is also a good source of iron. The problem, though, is that the iron from plant foods (called non-heme iron) isn't as easily absorbed as the iron in meat (heme iron).
Adding a food that's high in vitamin C, like red bell pepper (95 mg per one-half cup), to a quinoa salad or pilaf can enhance non-heme iron absorption by four-fold. Vitamin C helps transform non-heme iron into a well-absorbed form.
To increase iron absorption from plant foods, add 25 to 100 mg of vitamin C to the meal. Other excellent sources include broccoli, cauliflower, sweet potato, cantaloupe, kiwifruit, mango, oranges and strawberries.
Green tea and lemon
Green tea is packed with EGCG (epigallocatechin gallate), a flavonoid antioxidant linked to protection from cancer and cardiovascular disease. According to Purdue University, you'll make more of these antioxidants available for your body to absorb if you add citrus, like lemon, to green tea.
And if you're drinking tea with a plant-based meal, adding lemon juice helps neutralize the iron-binding effect of compounds in tea called tannins.
Brussels sprouts and walnuts
Brussels sprouts are an excellent source of vitamin K, supplying 109 mcg per one-half cup. You'll get more of this bone-building vitamin, though, if you eat your sprouts with a little fat.
Add chopped walnuts to salads with raw Brussels sprouts or sprinkle them over steamed sprouts. Along with their heart-healthy fats, they also deliver an omega-3 fatty acid called alpha linolenic acid.
Serve kale, collard greens, spinach and Swiss chard – also very high in vitamin K – sautéed in olive, grapeseed or avocado oil.
Leslie Beck, a Toronto-based private practice dietitian, is Director of Food and Nutrition at Medcan.