Recently, the New York City Board of Health decided to ban trans fat â€” widely used in making a variety of foodstuffs including French fries and bakery products â€” from the cityâ€™s restaurants. The directive is set to be effective from July 2007. Following in the footsteps of New York City is the council of Waverly, Australia, where a campaign to banish trans fat from eating joints is in the offing.
So what is trans fat and why the ban?
According to the Center for Food Safety and Applied Nutrition of the US Food and Drug Administration (FDA), â€œTrans fat (also called trans fatty acids) is a specific type of fat formed when liquid oils are made into solid fats like shortening and hard margarine. However, a small amount of trans fat is found naturally, primarily in some animal-based foods.â€ Researchers suggest trans fat is hazardous to health, contributing to a number of dreaded conditions such as heart attack, stroke, diabetes, cognitive decline and so on.
â€œA high intake of trans fatty acids contributes to the risk of coronary heart disease,â€ says an article in the medical journal, Lancet. The study, done on a Dutch population with a fairly high trans fat intake, concludes, â€œThe substantial decrease in trans fatty acid intake, mainly due to industrial lowering of trans contents in Dutch edible fats, could therefore have had a large public-health impact.â€
Various studies have proved that consumption of trans fats lowers the good cholesterol (HDL) level in blood while raising the bad cholesterol (LDL) count. This phenomenon has been strongly implicated in the development of atherosclerosis or hardening of arteries, ultimately resulting in heart attack or stroke. Research also reveals that trans fat intake can contribute to the development of Type-2 diabetes. Further, a study in Atherosclerosis Supplements suggests that trans fatty acids consumption during pregnancy can adversely affect foetal growth.
According to a New England Journal of Medicine (NEJM) article by a team of researchers led by Dariush Mozaffarian, a researcher at Bostonâ€™s Harvard School of Public Health, trans fats are formed during partial hydrogenation of vegetable oils, a process that turns these oils into semisolid fats for use in margarines, commercial cooking oils, etc.
From the perspective of the food industry, partially hydrogenated vegetable oils are attractive because of their long shelf life, their stability during deep-frying and their semisolidity, which can be customised to enhance the palatability of baked goods and sweets,â€ Mozaffarian and his associates write in NEJM. â€œThe average consumption of industrially produced trans fatty acids in the US is two-three per cent of total calories consumed. Major sources of trans fats are deep-fried fast foods, bakery products, packaged snack foods, margarines and crackersâ€¦ Naturally occurring trans fats are consumed in smaller amounts (about 0.5 per cent of the total energy intake) in meats and dairy products from cows, sheep and other ruminants (animals like cattle, sheep, goats, deer, etc),â€ the researchers add.
Trans fat doesnâ€™t have any beneficial health effect, asserts Prof. Harsh Mohan, head of the pathology department at Government Medical College and Hospital, Chandigarh, and editor-in-chief of the Indian Journal of Pathology & Microbiology.
â€œItâ€™s just that some people have a liking for foods cooked in trans fats rather than those cooked in polyunsaturated fatty acids or monounsaturated fatty acids. Oil manufacturers produce trans fats to satisfy such people or to cater to the market demand for increased shelf life of products cooked in them,â€ he says. â€œOf late, there have been movements in many parts of the world to ban products containing trans fats. Denmark was the first country to lay down regulations as early as March 2003 limiting the use of trans fats. FDA in the US issued guidelines in January 2005. Canada and the UK, too, have issued recommendations in this regard.â€
Restrictions on trans fat have led to impressive results in countries like Canada. Canada began labelling foods containing trans fatty acids since 2003 and according to a recent study in the Journal of Nutrition, the initiative could significantly benefit breast-fed infants. In the 1990s, high amount of trans fat could be found in breast milk, because of significant intake of trans fats by lactating mothers.
Trans fatty acids in human milk have raised concerns because of possible adverse effects on infant growth and development,â€ write the researchers from the Child and Family Research Institute, University of British Columbia, Vancouver. But the scenario changed following the restrictions. â€œOur studies show trans fatty acids have decreased in human milk in Canada, which suggests a concomitant decrease in trans fatty acids intake among lactating women and breast-fed infants,â€ write the researchers.
There is reason for much concern in India, too, dubbed the diabetes capital of the world. Given the link between trans fat and the disease, steps to control its consumption are badly needed, say experts. â€œThere should be regulations on industrial processes employed in the production of partially hydrogenated oils,â€ suggests Prof. Mohan.
â€œOtherwise its large-scale consumption is likely to continue to account for the higher incidence of heart disease and diabetes mellitus in India,â€ he told KnowHow. â€œWe need to follow a two-pronged strategy â€” educate the masses on the harmful effects of hydrogenated oils and exercise greater control on the manufacturing processes. A nation-wide campaign to substitute trans fats with polyunsaturated fatty acids should be launched.â€
Source:The Telegraph (Kolkata,India)