***TASK***
the task is to simplify the input abstract of a biomedical literature

***INPUT***
the input is the abstract of a biomedical literature

***OUTPUT***
the output is the simplified abstract for the input abstract of a biomedical literature

***DOCUMENTATION***

***EXAMPLES***

Input: Twenty-one RCTs were included, with a total of 2538 participants randomised to low GI intervention (1288) or high GI (1250). All 21 included studies reported the effect of low GI diets on risk factors for cardiovascular disease, including blood lipids and blood pressure. Twenty RCTs (18 of which were newly included in this version of the review) included primary prevention populations (healthy individuals or those at high risk of CVD, with mean age range from 19 to 69 years) and one RCT was in those diagnosed with pre-existing CVD (a secondary prevention population, with mean age 26.9 years). Most of the studies did not have an intervention duration of longer than six months. Difference in GI intake between comparison groups varied widely from 0.6 to 42. None of the included studies reported the effect of low GI dietary intake on cardiovascular mortality and cardiovascular events such as fatal and nonfatal myocardial infarction, unstable angina, coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty, and stroke. The unclear risk of bias of most of the included studies makes overall interpretation of the data difficult. Only two of the included studies (38 participants) reported on adverse effects and did not observe any harms (low-quality evidence). There is currently no evidence available regarding the effect of low GI diets on cardiovascular disease events. Moreover, there is currently no convincing evidence that low GI diets have a clear beneficial effect on blood lipids or blood pressure parameters.
Output:

In this review update, we examined 21 randomised studies that assessed the effects of low GI diets compared to diets with a similar composition but a higher GI on cardiovascular disease events and levels of cholesterol in the blood or blood pressure (major risk factors for cardiovascular disease, such as heart attacks or stroke). Studies were included up to July 2016. Participants were adults with a mean age of between 19 and 69 years. In most studies, participants had cardiovascular risk factors such as overweight or obesity or abnormal blood fat levels, and one study included participants with existing heart disease. The diets were followed for at least 12 weeks but most studies had unclear of bias and some of the compared diets only had small differences in GI. Cardiovascular disease events were not reported and no evidence of differences in effects of the diets on blood cholesterol and blood pressure were seen. Most studies did not report harms but the two that did found no harmful effects of the diets, however the evidence was poor. There was insufficient evidence from randomised controlled trials to recommend consumption of low GI diets for the purpose of improving blood lipids or blood pressure.