Cultivated from the acai palm tree native to the tropical regions of Central and South America, acai is widely touted for its superfood properties, with advocates claiming it can lower cholesterol, speed up weight loss and aid arthritis, detoxification and general health. Consumed either raw or as a juice, acai has up to four times more antioxidants than non-berry fruits and 10 times more than vegetables.
Laboratory studies have found acai demonstrates cholesterol-lowering capabilities, as well as anti-cancer and anti-inflammatory activity. However, there is no definitive scientific evidence based on studies on humans to support the use of acai for a specific health-related purpose. Regarding weight loss, researchers in one study found there were no weight changes in rats given acai juice, and there are no published independent studies to substantiate the claim that acai supplements alone promotes rapid weight loss.
Even before chef Pete Evans made headlines with talk of activated almonds, products containing the ingredient and the kernel itself were piled high on health food store shelves.
Almonds are a rich source of healthy fats and contain natural vitamin E, helpful for heart health. A handful of almonds eaten regularly as part of a healthy diet may reduce the risk of heart disease and type-2 diabetes, and help with weight management. But is it worth paying extra for the activated type?
According to accredited nutritionist Catherine Saxelby, the answer is no. Nuts for Life, the industry body for the Australian tree nut industry, says activation (presoaking) converts some of the starch in almonds to simple sugars and some of the protein to simple amino acids. As the activation theory goes, the broken-down nutrients are easier for the enzymes in our stomach to digest. As the science goes, there is almost no research on almonds - and therefore no proof - to indicate whether or not activation improves their digestibility and nutrition.
A cousin of the cactus, aloe vera is a substance derived from the clear "jelly" found in the inner part of the aloe plant leaf. Consumed for ailments such as osteoarthritis, bowel disease and stomach ulcers, as well as a general tonic, and used topically for burns, sunburn, frostbite and psoriasis, aloe has been a popular home remedy for years.
While research has found topical use is possibly effective for psoriasis and other skin conditions, there is insufficient evidence to prove it works orally as a general tonic or for other claimed benefits. Beware – diarrhoea, caused by the laxative effect of ingested aloe, can decrease the absorption of many drugs.
Cacao (or cocoa) beans are technically not beans or legumes, but rather the seeds of the fruit of the Theobroma cacao tree. Chocoholics may be thrilled to hear the cacao fruit is botanically classified as berry-like, but sadly it's not as healthy as a berry when eaten in the form of chocolate. While some of the favourable properties do turn up in the final product, so too does a great deal of sugar.
Compared with other fruit powders, including acai, blueberry, cranberry and pomegranate juice, cocoa powder and dark chocolate have equivalent or greater levels of antioxidants. It is important to note that Dutch (or Dutched) cocoa has a severely diminished antioxidant capacity due to an alkalisation process used to mellow flavours.
Including a sprinkle of raw cacao in a smoothie or munching on antioxidant-rich dark chocolate in small amounts, as part of a healthy diet, may promote cardiovascular health.
Believed to have been a staple in the ancient Aztec diet, chia seeds come from a desert plant that is a member of the mint family. A far cry from their Central American origins, chia is now being grown in the Kimberley region of WA.
Low in carbs, high in fibre and containing an impressive dose of omega-3 fatty acids, these tiny, unprocessed seeds can pack a nutritional punch when sprinkled on muesli or into smoothies or yoghurt. However, there's little published evidence to substantiate claims made about chia's ability to improve cardiovascular risk factors, such as by lowering cholesterol, triglycerides and blood pressure.
This chemical is the green pigment in leaves, and can also be found in spinach, asparagus, parsley, lettuce, green beans, celery and even Brussels sprouts. Bottles of liquid chlorophyll have made their way into the fridges at health food shops, claiming to boost energy and general wellbeing, as well as to counteract acidity of processed foods.
The US National Library of Medicine says that while chlorophyll is a non-poisonous ingredient, in rare cases it can cause loose bowel movements or stomach cramps. By regularly eating green vegetables such as those listed above, you can get the dietary chlorophyll intake comparable to the recommended three teaspoon dosage listed on both the Swisse and Grants of Australia liquid chlorophyll products.
While coconut milk has long been a tasty addition to Thai cooking, coconut oil and water have popped back onto the scene with a raft of health claims – oil for its "good fats" and water for its high source of minerals, and ability to rehydrate and aid with weight loss.
Coconut oil is 85% saturated fat, with an unsaturated content of just nine percent. (By comparison, olive oil only has 16% saturated fat.) The Dietitians Association of Australia says while coconut water is unlikely to be harmful, it doesn't have a high nutrient content and there is little scientific evidence to support the wonder health-drink claims.
Also known as wolfberries, these bright-red berries, native to China and the Himalayan region, are available as a juice and dried health food snack and can also be found added to some chocolate and muesli bars.
Marketed as a "life tonic", weight-loss aid and even as one of the world's "most powerful foods", goji berries are high in antioxidants, particularly a carotenoid that may be associated with reducing the risk of age-related macular degeneration.
Goji has been used in Chinese medicine for centuries for numerous conditions, but there are no large, quality trials demonstrating that it works. In fact, it may decrease the liver's ability to break down some medications, as well as interact with the anti-clotting warfarin. It is therefore not recommended for those who take medications changed by the liver, such as diazepam and ibuprofen, antihypertensive drugs and anti-diabetes drugs. Speak to your healthcare professional before deciding whether or not to use goji as a supplement.
A flowering herb native to the Mediterranean region, milk thistle seeds contain silybin, an antioxidant believed to be the biologically active part of the herb.
Taken for liver disorders, lowering cholesterol levels, reducing insulin resistance in those with diabetes and reducing the growth of some cancer cells, laboratory studies have found milk thistle may have some liver-protective qualities, although there is insufficient evidence to rate its effectiveness against other ailments outside the lab.
Full of anthocyanins that act as antioxidants, as well as vitamin C, dietary fibre and essential minerals, blueberries pack a nutritious punch. Dietitian Dr Rosemary Stanton says they are a worthwhile addition to your diet, but that there are many other antioxidant-rich fruits and vegetables. Preliminary studies suggest blueberries are high in flavonoids and may be associated with slower rates of cognitive decline.
The national dietary guidelines encourage eating all fruits on the basis that there is now strengthened evidence between the consumption of fruit and decreased risk of some cancers.
Fish, especially oily fish, is a great addition to a healthy diet, with iron to help transport oxygen and regulate cell growth, zinc for the immune system, and vitamin B12 for healthy blood cells and a good dose of omega-3 polyunsaturated fats.
According to Stanton, dozens of research studies support the value of omega-3s in reducing the risk of heart disease and type-2 diabetes, as well as offering a benefit to rheumatoid arthritis sufferers. Additionally, clinical trials have shown a dramatic drop in second heart attacks in those who eat fish twice a week.
To introduce more fish into your diet, eat tuna or salmon at lunch. When shopping for canned tuna, beware of the added sodium in those canned in brine, the additional kilojoules of those canned in oil, and the added sugars and preservatives in flavoured varieties.
The US National Institutes of Health says ginger is possibly effective for nausea and vomiting following surgery, as well as dizziness, menstrual pain, arthritis pain and for preventing morning sickness. It may also reduce cholesterol and possibly help to decrease the risk of cardiovascular disease, although further human trials are needed to confirm this.
Another popular flavour, chillies contain vitamin C and minerals, including potassium (to maintain normal body growth and break down carbohydrates), and some B vitamins. Red chillies offer a good boost of betacarotene – an important antioxidant and precursor to vitamin A, essential for immune function, vision, reproduction and the normal function of the heart, lungs, kidneys and other organs. Although the amount of these nutrients consumed in chillies is fairly small, as a condiment they're far healthier than bottled sauces, which can be higher in sugar and salt.
Based on Australian consumption data, we should be eating more legumes, which provide a valuable low saturated fat source of protein as an alternative to meats.
The Heart Foundation recommends legumes and pulses for their high fibre content and low glycaemic index (which keeps you feeling fuller for longer). They’re also a good source of iron for vegetarians. Legumes and pulses can be added to soups, casseroles and meat sauces, such as bolognese, to extend the meal and use less meat, making these dishes lower in fat and cheaper.
When buying legumes and pulses, we recommend choosing reduced-salt tinned brands or buying dried varieties, some of which need to be soaked overnight before cooking.
Accredited practising dietitian Melanie McGrice names spinach and broccoli as some of the most nutritious foods – spinach for its good source of vitamin A (important for vision) and broccoli for its high vitamin C content – twice the daily recommended intake in just 100g.
Green veggies such as bok choy, broccoli, cauliflower, spinach and cabbage are generally high in folate, which is essential for the development of new cells (especially for pregnant women) and other valuable nutrients, while being low in kilojoules.
Accredited nutritionist Catherine Saxelby elevates broccoli to "powerhouse" status as it appears to switch on cancer-fighting enzymes, as well as maintain bowel health and boost vitamin intake.
Grains consist of three major parts: bran – the outer layer (a good source of fibre, omega-3 fatty acids, vitamins and minerals); endosperm – the main part of the grain (mainly starch); and germ – the smallest part of the grain (rich in vitamin E, folate, thiamine, phosphorus and magnesium). Wholegrains, such as brown rice, barley and oats, provide you with all three components, as opposed to refined grains (white pasta, white rice and white flour). Wholegrains are free from cholesterol, low in saturated fats and an excellent source of carbohydrates.
There is evidence that dietary patterns consistent with relatively high amounts of wholegrains, in conjunction with a balanced diet, may be associated with excellent nutritional levels, quality of life and survival in older adults. There is also a positive association between consumption of wholegrain cereals and decreased risk of heart disease and excessive weight gain.
Oats deserve special attention, according to Saxelby. They're high in beta-glucan (a soluble fibre that helps keep your cholesterol down), low GI (to keep diabetes at bay) and full of B vitamins and minerals.
Regarded as a source of protein, vitamins B2 and B12, iodine and zinc, yoghurt and its beneficial good bacteria can do wonders for your health as part of a balanced diet.
Yoghurt is also full of calcium in a readily absorbable form. Probiotics – live organisms that are similar to the beneficial micro-organisms found in the stomach – may help with some digestive issues and diarrhoea associated with antibiotics.
Dietary guidelines indicate there’s now strengthened evidence to suggest eating two or more serves of (mostly) low-fat dairy foods per day is probably associated with reduced risk of heart disease and stroke. Beware of fruit-flavoured yoghurts as many include added sugar.
Olive oil has high levels of the healthy dietary fat known as monounsaturated fatty acids (MUFAs). Consuming MUFAs instead of saturated fats (for example, choosing olive oil instead of butter for baking and pan-frying) may help lower your risk of heart disease by improving blood lipids related to cardiovascular disease.
Studies have also shown that olive oil may have a protective role against breast, colon, lung, ovarian and skin cancer development.
Compounds specific to olive oil, known as phenolics, are antioxidants that may be able to reduce oxidative damage to DNA.