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Summer Superfoods

Part 7 in this series takes a look at just what are SuperFoods, some key differences and sources.

What are ‘superfoods?’

‘Superfood’ is a ‘buzz word’ at the moment but what does it really mean? The term is often used to describe a food that offers additional health benefits beyond basic nutrition. There is no legal definition of superfoods, but generally they are some combination of the following:

  • Contain phytochemicals (also called phytonutrients) that have potent antioxidant properties.
  • Contain significant amounts of omega-3 fatty acids or monounsaturated fatty acids.
  • High fibre.
  • Rich in vitamins and minerals.
  • Low in unhealthy substances such as saturated fats, trans-fats or refined sugars.
  • Low in kilojoules/calories.

Antioxidants, what are they and how do they work?

Antioxidants are compounds that neutralise or destroy free radicals (oxidants). Free radicals are created and released by the body, both as a byproduct of our metabolism (when oxygen is metabolised), and in response to other factors such as stress, cigarette smoke, sunlight and pollution. An overload of free radicals can damage the body’s DNA and can contribute to the development of certain types of cancer, Alzheimer’s disease, heart disease, liver disease, arthritis, and many other degenrative conditions. Our body has an in-built mechanism to deal with these free radicals, but this becomes less efficient as we get older.

There are different two different types of antioxidants:

  1. Nutrient antioxidants - vitamins A, C and E, and the minerals copper, zinc and selenium,
  2. Non-nutrient antioxidants such as phytochemicals from plants and zoochemicals from animal products.

Phytochemicals are the naturally occurring chemicals within plants that provide the plant its own protection against disease. Zoochemicals are the naturally occurring chemicals within some animal products that provide the animal with protection against disease, noting that zoochemicals are derived from the plants that animals eat. When we eat foods that contain phytochemicals or zoochemicals we also benefit from their disease-preventing properties. Phytochemicals and zoochemicals have very potent antioxidant properties and are believed to have greater effects than individual vitamins or minerals.

It’s important to eat a diet rich in antioxidants to reduce the level of free radicals in the body and thereby reduce the risk of many diseases. There are many different antioxidant compounds and these are found abundantly in fresh fruits and vegetables as well as some grains, seeds and herbs.

Table 1. Good Sources of Antioxidants

Antioxidant compound Good sources include
Allium sulphur compounds leeks, onions and garlic.
Anthocyanins eggplant, grapes and berries.
Beta carotene pumpkin, mangoes, apricots, carrots, spinach and parsley.
Catechins red wine and tea.
Copper seafood, lean meat, milk and nuts
Cryptoxanthins red capsicum, pumpkin and mangoes.
Flavenoids tea, green tea, citrus fruits, red wine, onion and apples.
Indoles cruciferous vegetables such as broccoli, cabbage and cauliflower.
Isoflavenoids soybeans, tofu, lentils, peas and milk.
Lignans sesame seeds, bran, whole grains and vegetables.
Lutein leafy greens like spinach, and corn.
Lycopene tomatoes, pink grapefruit and watermelon.
Manganese seafood, lean meat, milk and nuts.
Polyphenols thyme and oregano.
Selenium seafood, offal, lean meat and whole grains.
Vitamin C oranges, blackcurrants, kiwi fruit, mangoes, broccoli, spinach, capsicum and strawberries.
Vitamin E vegetable oils (such as wheatgerm oil), avocados, nuts, seeds and whole grains.
Zinc seafood, lean meat, milk and nuts.
Zoochemicals red meat, offal and fish.

Source: Deakin University, Better Health Channel, Factsheets, Antioxidants, 2008
http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Antioxidants

Antioxidant supplements are readily available on the market. However, studies have suggested that antioxidants are less effective when isolated from food and consumed in tablet form. You’re better off eating a well balanced healthy diet that is rich in antioxidants consumed from whole foods.

Kyann’s Top 10 Superfoods for summer

There are hundreds of antioxidants and many more superfoods, but here are my top 10 for summer.

1. Blueberries
are nature’s true superfood. They are packed with phytochemicals, flavenoids vitamins and minerals and have one of the highest total antioxidant capacities of any food. The major antioxidants in blueberries are anthocyanins, they are what gives the berries their blue-red colour. Anthocyanins are believed to boost memory and brain function as we age. Anthocyanins work together with lutein, also found in blueberries, to protect the eyes from cataracts and glaucoma and maintain healthy vision.

In addition to having a sweet mouth-watering flavour, blueberries are low in kilojoules/calories, have a low Glycaemic Index (GI), provide vitamin C, and fibre. They also offer beta-carotene (which gets converted to vitamin A in the body), vitamin E, as well as B vitamins such as folate (which helps prevent birth defects in babies) and niacin (which releases energy from food), and in lesser amounts, a number of essential minerals including manganese, potassium, magnesium and phosphorus. Blueberries have been referred to as ‘anti-cancer’ and ‘anti-ageing’ berries.

Blueberries are ranked number one by researchers at the USDA Human Nutrition Centre for antioxidant capacity when compared to other fresh fruits and vegetables.

2. Salmon
is a nutritious high protein superfood. It is an excellent source of Omega-3 fatty acids and zinc and also contains iodine and potassium. Omega-3s are considered ‘essential’ fatty acids as we need them for good health. Unfortunately our bodies can’t make them so we have to rely on our dietary intake. Omega-3s have been linked with protecting against breast and other cancers and relieving autoimmune diseases like rheumatoid arthritis and inflammatory bowel disease with their anti-inflammatory properties. They are essential for brain and heart health, help lower blood pressure and triglycerides, reduce blood clotting and are good for your eyesight.

Omega-3s have been linked with accelerated learning and attention span in children and helping mental function in the elderly. One Omega-3 called DHA plays a vital role in the development of babies' brains and eyesight, so it’s great for breastfeeding mums. Salmon can be eaten fresh, smoked or tinned. In addition the small edible bones in tinned salmon provide a good source of calcium - a small 95g tin can give you around 200-230mg of calcium, which is almost the amount contained in a 250ml cup of milk.

3. Spinach
if you don’t like your leafy greens you're missing out on a bunch of disease fighting phytochemicals. Spinach contains antioxidants like lutein and zeaxanthin which are great for your eyes and prevention of macular degeneration. It also boasts vitamins C and E, folate and beta carotene. Spinach does contain iron however the type of iron spinach contains, which is called non-haem iron, is poorly absorbed so only small amounts get into the body. Spinach is low in kilojoules/calories and a source of dietary fibre.
4. Tomatoes
by cultivation and use they are vegetables, but botanically they are classified as fruit. They are our second favourite vegetable after potatoes, and are extremely versatile. There are dozens of varieties to choose from including: vine-ripened, cherry, plum and beefsteak. You can eat them raw, grilled, oven-roasted, sun-dried, tinned, bottled, juiced or in sauces and pastes.

Tomatoes are the best dietary source of lycopene, a powerful antioxidant, in our diets. A number of studies found that men with high intakes of lycopene, from tomato-based foods, had a much lower risk of developing prostate cancer, and lycopenes may possibly reduce the risk of cancer of the colon, bladder and lungs.

Tomatoes also contribute vitamin C, folate, other B vitamins, and potassium, are low in kilojoules/calories and provide dietary fibre. There are no increased benefits from eating tomatoes raw. In fact cooking and processing tomatoes eg. tomato pastes, pasta sauces, tomato sauce and tomato juice, softens the cell walls of the tomato and actually increases the availability of lycopene.

5. Yoghurt
is a nutrient dense superfood that’s easy to digest, low GI, convenient and versatile. In the early 1900’s renowned scientist Dr Metchnikoff (1845-1919) claimed yoghurt was responsible for the longevity of the Bulgarians. Metchnikoff believed the ‘friendly' live bacteria in yoghurt (known as probiotics) played a major role in our intestinal health. Studies show that the live cultures in yoghurt helps keep the intestines healthy by enhancing the growth of ‘good’ or ‘friendly’ bacteria and suppressing the ‘bad’ or harmful bacteria.

Yoghurt is easier to digest than milk because the live active cultures create lactase, the enzyme that lactose intolerant people lack. For this reason, people with lactose intolerance should be able to tolerate a small amount of yoghurt without experiencing any nasty symptoms.

If you’re looking for an in between meal snack that won’t ruin your appetite yoghurt is a great choice because it not only satisfies your hunger but offers nutrients in a concentrated form. It’s a great source of protein, B vitamins (particularly riboflavin needed for healthy skin and eyes) and calcium which helps prevent osteoporosis. A 200g (single serve tub of yoghurt) is equivalent to drinking a 250ml glass of milk.

Research shows that the consumption of 3 serves of dairy per day can actually help our bodies to burn more fat and lose more weight than simply reducing our energy (kilojoule/calorie) intake alone. So as an added bonus this superfood may help people that are trying to lose weight.

While all yoghurts contain acidophilus and bifidus bacteria (known as A/B cultures), the content of live bacteria varies between different brands. Not all of the bacteria reaches the large intestine where it has its beneficial effect. So if you have gastrointestinal issues and have been recommended to take probiotics, make sure you choose one of the two brands, Vaalia or Yakult, both have conducted research to show that good amounts of bacteria from their products, are able to survive the journey through the upper digestive tract and reach the large intestine.
6. Herbs
have been highly prized by natural practitioners for centuries due to their numerous reputed healing qualities. Herbs are often overlooked, in terms of nutritional value, because we eat them in such small quantities, but if you compare them weight for weight against other fruit and veggies, they certainly pack a nutritional punch. Up there with the best of them are basil, marjoram, mint, oregano, rosemary, sage and thyme. Basil and parsley have almost twice as much vitamin C as oranges, whilst dill has six times more beta-carotene than cantaloupe or pumpkin, though of course we usually only eat 1-2 grams of basil or parsley versus 100-150 grams of an orange!

Oregano, rosemary and thyme are rich in polyphenols, a group of antioxidants that may reduce the risk of heart disease, while basil, mint and parsley are high in mono-terpenes, which are believed to have cancer-delaying properties, especially where breast tumours are concerned. Parsley also contains a sufficient amount of coumarins which are noted for their anti-coagulant and anti-bacterial properties.

Research is currently being conducted with extracts of rosemary being tested to see if they can be used as a natural food-grade preservative. Mint, a well known mouth and breath freshener is high in polyphenols but better known for its menthol content, a compound that can relieve indigestion and increase digestive secretions. We all know that mint has a refreshing taste and that’s why it’s used to flavour toothpaste, chewing gum, lozenges and lollies.

Most herbs are packed with powerful antioxidants, vitamins and minerals, of course they are low in energy and contribute towards our fibre intake. Fresh herbs can easily be grown at home in the garden, in a pot or in a window box.

7. Flaxseeds
(also called linseeds) are small shiny dark-brown seeds about the size of sesame seeds. They are a great source of Omega-3s. In fact flaxseeds are the richest plant source of alpha-linolenic acid (ALA), a type of fatty acid that is the building block of the omega-3 oils found in fish. Due to their high Omega 3 content, it is important for vegans (and vegetarian who don’t eat eggs or fish) to include flaxseeds in their diet.

Flaxseeds can be very useful for women going through menopause due to their high lignan content. Lignans are a type of plant oestrogen that lowers female oestrogen levels and helps to minimise the unpleasant side effects of menopause like flushing. Lignans also have anti-tumour properties and contain DHA – another type of Omega-3 fatty acid.

8. Asian leafy greens
such as bok choy, pak choy, choy sum and gai lum are great summer superfoods. They’re rich in vitamin C, beta-carotene and many B vitamins, are a good source of fibre and are low in energy and fat.

Asian greens are low in oxalic acid, a compound that interferes with iron absorption and can contribute to the development of kidney stones. This means they can supply significant amounts of iron and calcium, as opposed to more commonly eaten leafy greens like spinach and silverbeet, which are high in oxalic acid.

9. Cinnamon
has very high antioxidant properties mainly due to its phenolic properties. As well as its delicious aroma and flavour, it brings to the table beta-carotene, certain B vitamins and the potential to lower cholesterol, blood triglycerides and blood sugar levels in type 2 diabetes. That’s right, recent research has shown that half a teaspoon of cinnamon per day can lower blood sugar levels by around 20 per cent.
10. Chillies
pack a mighty punch in both taste and nutrition. They are a key ingredient to many cuisines including: Thai, Mexican, Indian, South American and African. They contain more vitamin C than an orange, are a good source of beta-carotene, folate, potassium and some of the B vitamins. Chillies can aid digestion and are thought to have antibacterial qualities. They range in potency from mild and flavourful to blisteringly hot, and because of this we usually eat them in very small quantities. The heat in chillies comes from a compound called capsaicin, which is found in the seeds, white membranes, and a lesser extent the flesh.

When we eat chillies our bodies release endorphins, the body’s ‘feel good’ chemicals, giving an instant uplift. Chillies are low in fat, but as an added bonus studies have shown that they’re one of the few foods that can increase our metabolic rates and help to burn energy faster. Of course it’s not all good news when it comes to chillies, their sheer potency can cause irritation to the mouth and gut when eaten and the skin and eyes during preparation and or handling.

Remember, if you do eat a hot chilli meal and are looking for something to put the fire out don’t drink water, capsaicin is fat-soluble so the best thing to do is drink milk or have a spoon or two of yoghurt.

Quick & easy ways to incorporate superfoods into your summer meals and snacks

Blueberries
  1. Add to a bowl of whole grain breakfast cereal with a dollop of yoghurt for a nutrient packed start to the day.
  2. Stir fresh blueberries into vanilla yogurt for a quick and easy snack or a fresh, light dessert.
  3. Add fresh or frozen blueberries with a banana and low-fat milk for a nice thick smoothie.
Salmon
  1. Bake or BBQ fresh salmon fillets in aluminium foil with a squeeze of fresh lemon juice and dill/pepper or fresh lime juice for a tangy summer treat. Cooks in 15-20mins.
  2. Add tinned or smoked salmon to pastas or stir fries.
  3. Empty a small flavoured tin of salmon onto wholegrain crackers for a snack or light lunch.
  4. Tinned or smoked salmon are great for dips or entrees when entertaining.
Spinach
  1. Use baby spinach leaves in sandwiches and salads in place of regular lettuce.
    Add well-drained frozen chopped spinach to meat based rissoles or veggie patties.
  2. Add a handful of baby spinach leaves to your stir fry to warm just before serving.
  3. Add spinach to omelets, zucchini slice or frittata or serve as a side.
Tomatoes
Of course we all use tomatoes in our summer salads, pizzas, stir fries, and as sauces for our BBQ’s, but here are some other suggestions:
  1. Use tomatoes for bruschetta – Lightly toast thick sliced bread or flat bread and top with a mixture of chopped tomato, crushed garlic, olive oil, chopped basil leaves and a grind of pepper.
  2. Drink a glass of tomato juice for a quick rich antioxidant fix.
  3. Make your own salsas to use in place of tomato sauce on your steaks, sausages, chicken and burgers.
  4. Add cherry or grape tomatoes to fruit/vegetable platters.
Yoghurt
  1. Add yoghurt to your wholegrain cereal or use in place of milk for a thick rich Bircher-style breakfast.
  2. Freeze yoghurt or buy frozen yoghurt desserts as an alternative to ice-cream on a hot summer night.
    Use low fat yoghurt as a healthier alternative to sour cream on baked potatoes, burritos, and fajitas.
  3. Mix yoghurt with herbs and spices to make dips, salad dressings or accompaniments to your BBQ’d meats.
  4. Make your own tsatziki by stirring chopped cucumber and fresh parsley through yoghurt, and serve with fish, chicken or lamb kebabs.
  5. Top fresh fruit or fruit salad with yoghurt for a light and healthy dessert or between meal snack.
Herbs
  1. Use herbs to add flavour to your meals instead of using salt.
  2. Add herbs to dressings and marinades.
  3. Regularly serve tabbouleh – a salad dish from the Eastern Mediterranean. It’s primary ingredients are finely chopped parsley, bulgur (you can substitute quinoa as a wheat free, gluten free alternative), mint, tomato, spring onion, lemon juice and olive oil.
  4. Pesto is another great way to get a good quantity of herbs into your diet in one sitting. Basil is usually the pesto base, but coriander or other herbs and leafy greens may be substituted. Pestos can be used in lasagnas, pastas, pizza, pastries or to top bruschetta or canapés.
Flaxseeds
  1. Sprinkle over breads, cakes and biscuits just before baking.
  2. Add to your breakfast cereal or include in your homemade muesli mix.
  3. Add to pancakes, wholemeal scones and pastry to give them an instant nutritional boost.
  4. Add to rissoles, vegetable burgers or casseroles.
    Scatter over a mixed green salad.
Bok Choy
  1. Add to stir fries
  2. Make a warm bok choy and feta salad
  3. Steam bok choy and serve as an accompaniment to your barbecued meats or baked fish
  4. Add bok choy as an ingredient in your rice paper rolls
Cinnamon
  1. Sprinkle cinnamon over your wholegrain breakfast cereal.
  2. Top vanilla ice cream with cinnamon for a quick dessert.
  3. Sprinkle cinnamon over plain/vanilla yoghurt for a between meal snack.
Chillies
  1. Add to stir fries and salsas.
  2. Make your own sweet chilli and cream cheese dip.
  3. Use in dipping sauces for fresh vegetables.
  4. Serve a bowl of freshly chopped chillies with your main meal.

If you want to eat your way to good health this summer, be sure to consume a healthy balanced diet that includes many superfoods daily. For expert advice, contact an APD or AN in your local area. You can go to the Dietitians Association of Australia website www.daa.asn.au and click on ‘Find an APD’, call your local hospital or check the yellow pages under ‘D’ for Dietitian. For people living outside Australia contact the Dietitians Association in your country.


Kyann Calvi is an Accredited Practising Dietitian (APD) who specialises in Food Allergy/Intolerance, Coeliac Disease and other gastrointestinal disorders such as Irritable Bowel Syndrome. For the past seven years she has helped people with food allergies/intolerance meet their nutrient needs through special diets. Kyann works in private practice locations in the Eastern suburbs of Melbourne.Contact Us

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