Super foods - making each mouthful count

Hardly a month goes by without us reading about a new “super food” or “magic ingredient” that can prevent cancer, lower our cholesterol, boost the immune system or keep us looking young.

Evaluating the claims

Sometimes the headlines are premature; sometimes they don’t tell you the huge quantities you need to eat to see a clinical effect.

• Cranberry juice, for instance, with solid research to show that it can keep urinary tract infections at bay, requires you to drink at least 300 mL (a large glass) every day to see any benefit.
• To be free of hot flushes during those menopausal years means a commitment to soy – around 1 litre (4 cups) of soy beverage a day is what’s needed to get enough of those mighty phyto-oestrogens.
• Garlic, king of the super foods, has been shown to lower cholesterol in many - but not all studies - but the volunteers were taking in at least 4 cloves a day, or equivalent in garlic extract or powder.

What makes a food a super power?

Despite the hype, it’s clear that foods are not created equal.

Although there is no formal definition on what exactly is a superfood, here’s what I look for in deciding whether a food is ‘super’ or not. It should have one or more of these 8 qualities (mine do):

1. Be rich in vitamins, minerals, omega-3 fat or fibre compared to its kilojoule/calorie count (have a high nutrient density). They stand out from the rest!

2. Have 25 per cent or more of the recommended intake of two or more nutrients in a serve OR be outstanding rich in one nutrient, having 50 per cent or more of its recommended intake for the day.

3. In addition to the normal nutrients, contain significant quantities of what could be regarded as health-promoting and/or protective substances such as phytonutrients or other substances not usually found in foods in its class.

4. Be minimally processed without being enriched.

5. Provide essential nutrients without overloading the body with salt, saturated fat, trans fat, sugar or other compounds linked to poor health.

6. Have research linking it to a potential reduced risk of illness or poor health.

7. Be easily available and affordable

8. Have medicinal or healing qualities which have been acknowledged by traditional medicine - effects beyond nutrition (think of the folklore behind garlic or ginger).

In a nutshell, they’re nutrient-rich, natural and won’t overload you. AND they’re easy to incorporate into your daily diet.

Apples ain’t apples

A dietitian may encourage you to “eat a piece of fruit” but the choice you reach for can bring vastly differing nutrients. Put simply, an orange is not equivalent to an apple.

• An orange has 10 times more vitamin C and beta-carotene, 4 times more thiamin and a huge 40 times more folate, a B vitamin that prevents birth defects than an apple.
• Broccoli is nutritionally superior to beans, zucchini or other green veges (so are its relatives cauliflower, cabbage, kale and Brussels sprouts).
• Liver towers over red meats including kangaroo and venison.
• Garlic lords it over leeks onion, shallots and chives, even though they are all cousins.
• Dark chocolate is the one with the catechin antioxidants (the more bitter, the better). Milk chocolate has only around one-third and white chocolate - forget it!

New super powers on the food scene

Research can morph everyday foods into “healing foods” overnight. Cinnamon (3 grams a day, about half a teaspoon) has been shown to lower blood glucose in people with diabetes.

Rosemary and oregano are documented to have strong antioxidant contents along with anti-bacterial qualities which is thought to be the reason why they helped preserve meat dishes in early times before refrigeration.

Tea doesn’t have to be green to be good. A cuppa of regular tea now appears to contain the same antioxidant potential – both come from the same bush Camellia sinensis.

So how to make each kilojoule count?

Smart choices within each food group

Dr Adam Drewnowski, Director of the Centre for Public Health Nutrition at the University of Washington believes, in today’s climate of obesity concern, we should “make each kilojoule count”. Using the concept of nutrient density, he’s ranked hundreds of natural foods against the kilojoules they provide to come up with what he calls “naturally nutrient-rich foods”.  “These are the power kilojoules that maximize the vitamins, minerals and protein from every kilojoule you consume,” explains Drewnowski.

His research is backed up by a classification of over 1113 foods ranked them for their total content of antioxidant compounds by a Norwegian research group.  Putting these analyses together and weighing up the research from other papers over the years leads me to my master list of super foods or star foods within each food group.

Vegetables

All vegetables are a nutritionist’s delight but the superstars that turn up time and time again are spinach, members of the cruciferous family (cabbage, broccoli, Brussels sprouts), dark-green lettuces (mignonette, rocket, baby spinach leaves), avocadoes, beetroot and orange sweet potato (kumera). You get the highest quantities of vitamin C, folate, fibre, and minerals without overloading your system. Also included in this group is fresh garlic thanks to its ability to fend off bacteria and viruses, reduce cholesterol levels and thin the blood.

Grains and grain foods

Concentrated sprinkles such as wheatgerm and lecithin rank highly for B vitamins and minerals. They are an easy nutrition supplement for your breakfast.

Brans have fibre concentrated and make a handy addition to top up fibre and prevent constipation e.g. wheat bran, rice bran, oat bran and psyllium.

Dairy

Hardly surprisingly, it’s low-fat yoghurt (and milk) that gives you the most bang for your nutrition buck.

Proteins

Top of the class are pink or red salmon, lean beef steak, pork loin and eggs. Liver and kidney are concentrated in things like iron and vitamin A but have long suffered in popularity with their strong flavour.

Nuts and seeds

Almonds, walnuts, hazelnuts and peanuts rank the highest for nuts.  Flaxseed and chia tick the most boxes for the seeds.

Legumes

It’s soy that shines over the other beans and peas.

Fruits

While all fruit is nutritious and variety is important, you can still notice two main types as outstanding. Go for the berries especially blueberries (but also strawberries, raspberries, blackberries and cranberries) and any of the citrus fruit (grapefruit, oranges, mandarins). Kiwi fruit come close as a contender.

Herbs and spices

Of all the foods, spices and dried herbs are the most concentrated in phytonutrients. Those that pack the most powerful punch are cloves, cinnamon, turmeric, oregano, sage, rosemary, thyme, marjoram, sage, mint, saffron and ginger. Chilli also makes this list. Just remember you need to use culinary herbs and spices in generous quantities – not just a garnish - and consume them regularly.

References quoted:  ♦ Darmon N, Darmon M, Maillot M, Drewnowski A. A nutrient density standard for vegetables and fruits: Nutrients per calorie and nutrients per unit cost. J Am Diet Assoc. 2005; 105:1881-1887.  ♦ LC Tapsell, I Hemphill, DR Sullivan et al. Health benefits of herbs and spices: the past, the present, the future. Medical Journal of Australia (supplement), volume 185 number 4, 21 August 2006.  ♦ Bente L Halvorsen, Monica H Carlsen, Katherine M Phillips, Siv K Bøhn, Kari Holte, David R Jacobs, Jr, and Rune Blomhoff Content of redox-active compounds (ie, antioxidants) in foods consumed in the United States Am J Clin Nutr 2006 84: 95-135.  ♦ Carlson MH et al. The total antioxidant content of more than 3100 foods, beverages, spices, herbs and supplements used worldwide. Nutrition Jrnl 2010;9 22 Jan.