People who cut saturated fats while increasing intake of refined carbohydrates like white bread and pasta have a higher risk of heart attack, according to a study published in the American Journal of Clinical Nutrition.
However, the Danish researchers found that reducing saturated fats while increasing intake of non-refined carbohydrates – such as wholegrain bread and vegetables – could improve heart health. A recent meta-analysis published in the same journal earlier this year called into doubt the widely held theory that high saturated fat intake is linked to high rates of heart disease – but the researchers behind that review said that other dietary elements of the 350,000 subjects involved could be more important.
This latest study, from researchers at Denmark’s Aarhus University Hospital, suggests that saturated fat does indeed play an important role in heart attack risk, but that it is dependent on the sort of carbohydrate prevalent in the diet. The study’s authors looked at 53,644 people over a period of 12 years, during which time nearly 2,000 of them suffered heart attacks.
They found a statistically significant correlation between replacing saturated fat calories with refined carbohydrates – those described as ‘high-GI’ and thought to cause a spike in blood sugar levels – and heart attack risk. For those subjects with the highest average dietary glycemic index, heart attack risk increased by 33 percent for every five percent increase in calorie intake from carbohydrates.
The authors concluded: “This study suggests that replacing SFAs [saturated fatty acids] with carbohydrates with low-GI values is associated with a lower risk of MI [myocardial infarction], whereas replacing SFAs with carbohydrates with high-GI values is associated with a higher risk of MI.”
The researchers said that determining the public health impact of glycemic index-based diets could be difficult, but recommended consumption of “less-refined foods, nonstarchy vegetables, fruit, and legumes” as the most practical way to reduce heart disease risk.
“Indeed, these recommendations would also tend to promote dietary patterns high in fiber and micronutrients, dietary factors also considered to play a role in the prevention of IHD [ischemic heart disease],” they wrote.
Source: American Journal of Clinical Nutrition
2010; 91: pp. 1764–8
“Intake of carbohydrates compared with intake of saturated fatty acids and risk of myocardial infarction: importance of the glycemic index”
Authors: Marianne U Jakobsen, Claus Dethlefsen, Albert M Joensen, Jakob Stegger, Anne Tjønneland, Erik B Schmidt, and Kim Overvad