The offspring of lactating rats fed a diet containing partially hydrogenated vegetable oil, or trans fats, were found to have decreased heart function for the transport of glucose, as well as exhibiting signs of insulin sensitivity problems, according to finding published online ahead of print in the journal Nutrition .
"Our data strongly suggest that trans fats ingestion during early life is particularly related to insulin resistance and to the consequent impairment of cardiac glucose metabolism in adulthood," wrote lead author Fernanda Silveira Osso from the State University of Rio de Janeiro.
"Although more studies are required to understand the mechanisms underlying the early- and long-term actions of these fatty acids, our data point to the necessity of investigating the risks associated with trans fats consumption, particularly in the mother/infant population."
Though trace amounts of trans fats are found naturally, in dairy and meats, the vast majority are formed during the partial hydrogenation of vegetable oil (PHVO) that converts the oil into semi-solids for a variety of food applications.
Trans fats are attractive for the food industry due to their extended shelf life and flavour stability, and have displaced natural solid fats and liquid oils in many areas of food processing.
But scientific reports that trans fatty acids raise serum levels of LDL-cholesterol, reduce levels of HDL-cholesterol, can promote inflammation can cause endothelial dysfunction, and influence other risk factors for cardiovascular diseases (CVD), has led to a well-publicised bans in New York City restaurants, and other cities, like Boston and Chicago, considering similar measures.
In the food industry this has been mirrored by an increase the in pressure on food manufacturers to remove trans fatty acids from their products and reformulate.
You are what your mother eats The Brazilian researchers divided the lactating rats into two groups and fed one a control diet containing soybean oil, and the other a diet containing partially hydrogenated vegetable oil.
The total trans fat concentration was 11.75 per cent of the total fat in the diet.
Once the pups were weaned, they were all fed the same diet until the age of 60 days, when the measurements were recorded.
Silveira Osso and co-workers state that pups from mother fed the trans fats-containing diet had a significant decrease in measures of glucose metabolism in the heart muscle.
Moreover, impaired insulin sensitivity was documented once the same pups reached adulthood.
A decrease in the body's sensitivity to means that specific tissues in the body like muscles and adipose tissue do not absorb glucose.
As a result blood glucose levels remain higher than normal.
This is increases the risk of developing insulin resistance and subsequently metabolic syndrome and type-2 diabetes.
While further studies are required to verify the results, it is clear that the study may heap more pressure on the food industry to reformulate and remove trans fats, one of the food industry's bête noir , from products.
Alternatives to trans fats The food industry as a whole has expressed its commitment to removing trans fatty acids from its products, but such reformulation is not straightforward and presents challenges.
Paul Wassell and Niall Young from Danisco's Multiple Food Application Group reviewed the options available to formulators and stated that designing foods with trans-fat alternatives must be a "multidisciplinary' approach" ( International Journal of Food Science and Technology , Vol. 42, pp 503-517).
"Successful replacements of trans fatty acids is not easily achieved by simply removing the trans isomer, because of a host of beneficial functional characteristics that are readily attributable to trans fatty acids," wrote Wassell and Young, pointing out that the presence of the trans isomer influences melting behaviour, oxidative stability and textural properties.
Source: Nutrition (Elsevier) Published online ahead of print, doi: 10.1016/j.nut.2008.03.006 "Trans fatty acids in maternal milk lead to cardiac insulin resistance in adult offspring" Authors: F. Silveira Osso, A.S.B. Moreira, M.T. Teixeira, R.O. Pereira, M.d.G. Tavares do Carmo, A. Sanchez Moura,