A new study has found that avocados can help improve cholesterol and triglyceride levels, helping to lower heart attack and cardiovascular disease risk, CBS News reports. The researchers gathered data from 45 overweight, but otherwise healthy adults who followed three different diets aimed at lowering cholesterol. They found that those who ate an avocado a day had lower levels of bad cholesterol and triglycerides. This may be a result of the fiber and phytosterol content in avocados. However, the authors cautioned against too many avocados, as the high caloric content can lead to weight gain if too many are consumed.