Some foods have increased health benefits when eaten together
Some foods not only taste better when paired, they have increased health benefits if eaten together, writes Bhavna Sakhrani
Conventional wisdom champions a balanced diet, filled with whole, natural foods that contribute to our overall health and well-being.
Your granny's recipes, passed down through generations, have withstood the test of time because the ingredients naturally taste better together.
According to Miles Price, a nutritionist at Life Clinic, "For generations people were eating locally produced foods that kept them healthy, so there is a genetic and even regional aspect to our dietary needs."
Health experts now suggest that we have always enjoyed certain foods in combination with each other because they are more nutritious together than when eaten on their own.
There are fat-soluble vitamins A, D, E and K that are always best absorbed with a small amount of fat, and a number of foods that just work better in pairs.
In fact, knowing that nutrients can actively work together to increase their bioavailability - that is, the amount of nutrients absorbed and utilised by the body - can lead to claimed benefits such as faster metabolism, prevention of chronic disease and healthier cell growth.
Nutrition experts call it food synergy. "There is a scientific basis behind these food pairings. These are time honoured traditions and they are passed down for a reason," says Benita Perch, a naturopathic physician at Integrated Medicine Institute.
We've highlighted some of the most powerful food duos that are found in kitchens around the world.
Tomato and olive oil
When researchers discovered that tomatoes are loaded with lycopene, they realised the real potential of this fruit that acts like a vegetable. Tomatoes are rich in a class of yellow to red pigments called carotenoids (alpha and beta-carotene, lutein and lycopene) as well as vitamins A, C, and K. Lycopene, a powerful antioxidant, has been shown to reduce the risk of prostate cancer and skin cancer, and has been linked to a lower incidence of heart disease by up to 30 per cent.
Lycopene is fat-soluble, which means combining it with a healthy, monounsaturated fat, such as olive or sunflower oil, helps boost absorption. A study at the University of Tasmania found that a diet high in olive oil and rich in lycopene may decrease the risk of coronary heart disease by improving the serum lipid profile compared with a high-carbohydrate, low-fat, lycopene-rich diet.
Perch suggests a serving of olive oil in your pasta sauce, or an avocado with your tomatoes: "The Italians love their buffalo mozzarella and drizzle olive oil on their tomatoes."
Steak and rosemary
Red meats aren't considered a health food, but who doesn't love a grilled steak once in a while? The potential problem with grilled beef is the presence of cancer-causing heterocyclic amines (or HCAs), influenced by cooking time and pressure.
Price explains: "If you look at protein in restaurants these days, it is being cooked at a very high temperature, and is usually very well done … it loses important enzymes and ends up becoming more of a dead product."
Research shows that marinating lowers the risk of some cancers by preventing the formation of toxins, and herbs such as rosemary with a high antioxidant content can literally soak up the meat's harmful free radicals.
A study conducted at Kansas State University found that when using rosemary extract in cooked beef, HCAs were reduced in levels ranging from 30 to 100 per cent. Rosemary contains phenolic compounds rosmarinic acid, carnosol and carnosic acid that block the HCAs before they can form before grilling, frying, broiling or barbecuing.
The experts agree that a sprig of rosemary extract could not only help temper the cancer causing effects of HCAs, but could also add a punch of flavour to your next burger.
Salmon, soya and seaweed
These form a power trio. Seaweed is often overlooked as a leafy green, but it is nutrient dense in calcium as well as high amounts of vitamin B and A.
Perch advocates a side of seaweed with your edamame. "Eat soya [foods] together with seaweed, because some people worry about excessive amounts of soya affecting thyroid levels … but if you eat it the way it's meant to be eaten, as in local Japanese diets, they always have soya and seaweed together, and seaweed has a lot of iodine that balances out the soya."
Even better is the effect of soya foods and seaweed when combined with vitamin D-rich salmon. The body needs vitamin D to absorb bone-strengthening calcium, both of which are essential to preventing diseases such as osteoporosis.
Turmeric and black pepper
Widely cultivated in India, turmeric offers health benefits as a powerful antioxidant, anti-inflammatory, antiseptic and antibacterial spice.
The potent anti-cancer component of turmeric is curcumin, a chemical compound that has been used to treat inflammatory conditions such as rheumatoid arthritis as well as heart conditions, excessive cholesterol and obesity.
It has made headlines for its potent anti-cancerous properties, and is best used with another Indian favourite, black pepper.
On its own, curcumin's bioavailability levels are low because it is metabolised before it gets absorbed. But piperline, the key active ingredient in black pepper, has been shown to increase the bioavailability of curcumin by over 1,000 per cent because it inhibits digestive enzymes.
It may be prudent to have a spicy Indian curry regularly as this power couple has been touted for its effect on the prevention of certain cancers. A recent study by the University of Michigan shows that a combination of turmeric and piperline can significantly limit the growth of stem cells for breast cancer, and can prevent mammosphere formation.
Corn tortillas and lime
Taking a cue from the ancient Aztec diet, corn tortillas were traditionally made by soaking corn kernels in limewater - an alkaline mineral unrelated to the acidic fruit - to remove the skin, and then grinding them into a corn dough. The practice increases the nutritional value of the grain. Perch says that there are missing amino acids you can't get from corn alone.
"Maize cooked with lime [calcium hydroxide] provides niacin; it's one of the amino acids that would normally not be able to be produced," he says.
In the print article entitled Complements to the Chef on food synergy published last Tuesday, Dec 10, 2013, the writer stated that soaking corn kernels in a lime solution was a process called nixtamalisation that increased the nutritional value of the grain. It was therefore suggested to pair corn with lime (the fruit) when eating. This is incorrect. Nixtamalisation involves steeping cooked whole kernel corn in limewater, an alkaline mineral that is unrelated to the acidic fruit.