Too much snacking on potato chips may increase the risk of hardening of the arteries, and raise the risk of cardiovascular disease, says a joint Polish-Swedish study.
According to findings published in the new issue of the American Journal of Clinical Nutrition, consuming 160 grams of potato chips per day may increase levels of compounds linked to oxidative stress and inflammation, both of which may increase the risk of certain chronic disease.
“These novel findings seem to indicate that chronic ingestion of acrylamide-containing products induces a pro-inflammatory state, a risk factor for progression of atherosclerosis,” wrote lead author Marek Naruszewicz from the Medical University of Warsaw.
Acrylamide is a suspected carcinogen that is formed by a heat-induced reaction between sugar and an amino acid called asparagine. Known as the Maillard reaction, this process is responsible for the brown colour and tasty flavour of baked, fried and toasted foods.
The compound first hit the headlines in 2002, when scientists at the Swedish Food Administration first reported unexpectedly high levels of acrylamide, found to cause cancer in laboratory rats, in carbohydrate-rich foods.
Since the Swedish discovery a global effort has been underway to amass data about this chemical. More than 200 research projects have been initiated around the world and their findings co-ordinated by national governments, the EU and the United Nations.
Despite being a carcinogen in the laboratory, many epidemiological studies have reported that everyday exposure to acrylamide in food is too low to be of concern.
The new study, while making no reference to cancer, does appear to increase the pressure on food manufacturers to reformulate in order to reduce or eliminate the levels of the compound in their products.
In collaboration with researchers from Stockholm University, the Warsaw-based researchers recruited 14 healthy volunteers with an average age of 35. Eight of the volunteers were women, and six of the volunteers were smokers.
All of the volunteers were assigned to eat 160 grams of potato chips per day for four weeks. The daily amount of acrylamide ingested from the chips was 157 mg, a concentration that is three times the current level consumed by the general population consuming a Western diet.
At the end of the 28 days of study, blood samples showed an increase in acrylamide-haemoglobin adducts in all the study subjects, with average increases of about 43 picomoles per litre per gram of haemoglobin in non-smokers, and about 59 picomoles per litre per gram of haemoglobin in smokers.
Additionally, increases in compounds such as oxidised LDL-cholesterol, interleukin-6 (IL-6), and C-reactive protein (CRP), were recorded in smokers and non-smokers. All of these compounds have strong links to inflammation. Chronic inflammation has been linked to range of conditions linked to heart disease, osteoporosis, cognitive decline and Alzheimer's, type-2 diabetes, and arthritis.
Markers of oxidative stress were also increased as a result of consuming the chips.
“In this study, we have shown for the first time that chronic ingestion of dietary acrylamide might induce oxidative stress in humans through leukocyte activation and increased production of reactive oxygen radicals,” wrote Naruszewicz and his co-workers.
Despite noting that their study needs confirmation from other studies, Naruszewicz and his co-workers concluded: “Long-term ingestion of high-acrylamide doses with food may cause chronic inflammation and contribute to the development of early atherosclerosis as well as increase the risk of coronary artery disease.”
Source: American Journal of Clinical Nutrition 2009, Volume 89, Pages 773-777“Chronic intake of potato chips in humans increases the production of reactive oxygen radicals by leukocytes and increases plasma C-reactive protein: a pilot study”Authors: M. Naruszewicz, D. Zapolska-Downar, A. Kosmider