This should help reduce the risk of heart disease.
LDL, or so-called "bad" cholesterol, also dropped during this time period, and HDL, or "good," cholesterol levels increased.
Researchers examined data from over 35,000 individuals, and found a similar decline in triglycerides, which are fat like substances in the blood.
Here's what they are telling the Journal of the American Medical Association:
"The increase in the good cholesterol is probably due in part to decreasing smoking rates," said CDC's Margaret Carroll, MSPH. "The decrease in the bad cholesterol is due in part to the decrease in the intake of trans fatty acids and also to the increase in cholesterol lowering medications.
Healthier lifestyles are also credited with the positive changes.
This study is published in this week's JAMA.