Here’s the exact wording by the DGAC on cholesterol:
Cholesterol. Previously, the Dietary Guidelines for Americans recommended that cholesterol intake be limited to no more than 300 mg/day. The 2015 DGAC will not bring forward this recommendation because available evidence shows no appreciable relationship between consumption of dietary cholesterol and serum cholesterol, consistent with the conclusions of the AHA/ACC report. [2, 35] Cholesterol is not a nutrient of concern for overconsumption.
Notice those two references, 2 and 35. Kenney investigated them:
2. AHA/ACC Guideline On Lifestyle Management To Reduce Cardiovascular Risk: A Report Of The American College Of Cardiology/American Heart Association Task Force On Practice Guidelines, Circulation, June 2014
About this one he said that Eckel, et al. relied on data from observational studies, and:
The Eckel review and the new DGAC’s report ignored far more reliable data from controlled clinical trials. These trials have demonstrated that for most people, increasing dietary cholesterol does in fact increase total serum cholesterol, LDL cholesterol (LDL-C), and apo B levels.
35. Egg Consumption In Relation To Risk Of Cardiovascular Disease And Diabetes: A Systematic Review And Meta-analysis, American Journal of Clinical Nutrition, July 2013
About this one he said that Shin, et al. also relied heavily on observational studies, and did find a link between eggs, diabetes, and coronary artery disease (CAD):
Dr. Shin did report that eating more eggs (and presumably cholesterol) was significantly associated with a 42% greater risk of developing type 2 diabetes. … And in those who developed type 2 diabetes, … a greater risk of developing serious CAD.
Clinical trials do indeed show that eating cholesterol raises serum cholesterol. Kenney covered Mattson et al.’s prison study which I blogged about here: Eating Cholesterol (Egg Yolk) Found To Raise Blood Cholesterol. He also mentions Sacks et al.’s study, which I also blogged about:
Ingestion Of Egg Raises Plasma Low Density Lipoproteins In Free-living Subjects, The Lancet, March 1984
In this study, 17 lactovegetarians were fed one extra large egg a day:
Ingestion of the egg increased dietary cholesterol from 97 to 418 mg per day. Mean plasma low density lipoprotein (LDL) cholesterol was 12% higher (p = 0·005) and mean plasma apolipoprotein B was 9% higher (p = 0·007) when eggs were being consumed than during the eggless period.
12% means that if you ate an egg a day, in 3 weeks your LDL would rise:
- From 100 mg/dl to 112 mg/dl
- From 150 mg/dl to 168 mg/dl
Kenney cited several other studies that support his argument … that dietary cholesterol increases serum cholesterol.
Why would the DGAC omit these controlled trials from their analysis and proceed to drop the 300 mg/day cholesterol guideline? Kenney says it’s likely due to pressure from special interests, e.g. the Egg Nutrition Center, the American Egg Board, and other producers of cholesterol-containing foods.