Functional foods could be the rage today in advanced countries. But consumers seeking shortcuts to good health had better ask some tough questions before they decide to go in for the aggressively marketed brands.
Currently the international functional foods market is a $40 billion industry.
Functional foods include:
* Margarines that lower bad cholesterol (LDL).
* Probiotic yoghurts - laced with cultures of bacteria that promote healthy digestion.
* Omega3-enriched muffins, bread and dairy products - for cardiovascular and mental health benefits.
* A2 milk - contains naturally produced a2 beta-casein to help avoid health problems linked with plain milk such as coronary heart disease, childhood diabetes and autism.
* Manuka honey - healing properties, also used as cure for stomach ulcers.
* Herbs and herb-derived products that include echinacea, which studies say can more than halve the risk of catching a cold. More than 800 products containing echinacea are now available.
* Breakfast cereals enriched with vitamins and minerals.
* Kiwifruit extracts - products designed to relieve the symptoms of common digestive complaints such as constipation and heartburn.
* Sports drinks that boost energy.
* Functional foods due to be launched include: Cosmetic yoghurts which claim to "nourish the skin from the inside", soft drinks with added vitamins and minerals, a pasta enriched with grape seed extract claiming to protect the retina in diabetics and cranberry chewing gum to prevent gum disease.
So it goes and constantly expanding. But experts are warning that the actual benefits of these foods could be dubious and hence suggest consumers to be wary of falling prey to aggressive brand advertising.
"Millions of people are consuming these foods and the people who make functional foods are trading on people's insecurity and looking for an insurance to give them better health," says Dr. Dr.Geoffrey Savage, a senior lecturer in Food Biochemistry in Lincoln University, Newzealnd.
The term functional food was a curious and confusing concept, he said.
Clearly all foods are functional, because they provide taste, aroma or nutritive value. But it is interesting to note that the majority of the foods being marketed as functional are plant based.
There is overwhelming evidence from epidemiological and clinical trials to show that a plant-based diet can reduce the risk of chronic disease, particularly cancer, but this does not mean that meat, fish, or milk should be removed from our diets.
Functional foods were now popular because health-conscious baby boomers had made them the leading trend in the United States food industry, he said.
"When you extract something from a food and put into a pill, you don't necessarily know it is still active.
"It may be more concentrated but it may not be biologically active and in many cases this is not being tested."
When products were tested the results could prove disappointing and there should be more rigorous and regular testing of functional foods available in pill or other forms.
Original food offered the best and cheapest way to source the functional ingredients, Dr Savage said.
There was evidence foods such as oats, soy, flaxseed, tomatoes, garlic, cabbage-like vegetables, citrus fruits, cranberry, tea and red wine could all deliver impressive health benefits.
The problem was that considerable quantities of these would have to be consumed daily to achieve maximum effect and hence the shortcuts.
Researchers warn that the medicinal effects of some of the functional foods, also known as nutraceuticals or designer foods, could rebound to produce unexpected side-effects.
A British newspaper reported they were banned in some countries because of the risks.
Other researchers have said there is no evidence so far that functional foods cause harm, but the data is limited to five or six years of use.
Duth Institute project director Nynke de Jong wrote in the British Medical Journal that his research on the potential risks of cholesterol-lowering margarines and yoghurts did not augur well for some users of the products.
"These products could trigger reactions in people taking statins - drugs that do the same job but act more powerfully - which might actually increase their risk of heart disease."
Canada had banned the sale of those products, the institute report said.
Dr Savage said cholesterol-lowering margarines were one of the best examples of a functional food with effective health benefits - lowering the risk of heart attacks.
Food products from larger, well-known companies would have undergone testing and monitoring, so tended to be more reliable, he said.
Still, Savage concludes, "We should not allow the baby-boomers to turn eating into a serious quest for eternal health. Food should be savoured, enjoyed and shared with friends. Food has an enormous psychological impact on our lives and we should follow the advice given consistently by dieticians: eat a wide range of foods, because each one offers different characteristics and a particular function."