Pizzas can make blood glucose levels rise quickly
Women who eat diets heavy in certain carbohydrates may be at greater risk of coronary heart disease, according to researchers.
A study of over 47,000 Italian adults found that women alone whose diets contained a lot of bread, pizza and rice doubled their heart disease risk.
These foods have a high glycaemic index (GI), meaning they release energy and raise blood sugar quickly.
The findings are published in Archives of Internal Medicine.
The experts say much more research is needed to understand why these high GI foods, rather than carbohydrates per se, appear to pose a risk - and why the risk applies to women and not men.
Low GI carbohydrates, such as pasta, which release energy and raise blood sugar far slower, showed no such link with heart disease.
The doctors who produced the report studied 15,171 men and 32,578 women who completed dietary questionnaires over many years.
This allowed the researchers to calculate overall carbohydrate intakes as well as the average glycaemic index of the foods eaten and the glycaemic loads of the diets.
The glycaemic index (GI) is a measure of how much a food raises blood glucose levels compared with the same amount of glucose or white bread.
The glycaemic load is calculated based on the glycaemic index of a given food and also on the total amount of carbohydrates it contains.
After seven years, 463 participants had developed coronary heart disease.
The researchers found that the women whose diet had the highest glycaemic load had more than double the risk of heart disease compared with those women with the lowest glycaemic load.
The authors concluded: "Thus, a high consumption of carbohydrates from high-glycaemic index foods, rather than the overall quantity of carbohydrates consumed, appears to influence the risk of developing coronary heart disease."
The researchers believe that a high-glycaemic diet may dampen 'good' cholesterol levels in women more than in men.
But further research is needed to verify the absence of a link between high-glucose foods and cardiovascular disease in men, says the study.
Victoria Taylor, senior heart health dietician at the The British Heart Foundation, said that for women, choosing lower GI foods could be useful in helping them to reduce their risk of coronary heart disease.
She said: "They could try broadening the types of bread and cereals they eat to include granary, rye or oat; including more beans, pulses; and accompanying meals with a good helping of fruit and vegetables."