Tuesday, March 10, 2015

Cholesterol and the Dietary Guidelines for Americans - Are Changes Coming?


I was not sure if I should write a response to the wide-spread media attention surrounding the draft report submitted by the 2015 Dietary Guidelines for Americans (DGA) Committee. I am hesitant because the 2015 DGA are in-process. They will not be adopted until the end of 2015 with a publication release scheduled in early 2016.  I am concerned that the attention given to the DGAs right now is hyper-focused on the opportunity to eat more cholesterol while losing focus on the rest of the message – eat less saturated fat, and more whole grains, fruits and vegetables, fat-free and low-fat dairy, lean proteins and seafood, and get enough physical activity. 

While it is widely expected that the report and recommendations will be adopted into policy, at this juncture the 2015 DGAs do not exactly exist. We still live in 2010. Disclaimer stated.

By rovingI (flickr) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons

As you probably know, the draft report included a statement that removes cholesterol from the “watch-list” – cholesterol is no longer considered a nutrient of concern. I imagine certain players in agriculture and industry are delighted. 

"Three fried eggs". Licensed under CC BY-SA 3.0 via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Three_fried_eggs.jpg#mediaviewer/File:Three_fried_eggs.jpg

Scientists and medical practitioners now understand dietary cholesterol does not directly impact blood cholesterol for most people. In terms of diet, saturated fat has a larger influence on your cholesterol level than dietary cholesterol. It impacts cholesterol synthesis and your body’s production of the cholesterol receptors that pick up cholesterol from the blood (1). A combination of genetics and dietary saturated fat have more to do with your blood cholesterol than the dietary cholesterol you eat.

1. Fernandez ML, West KL. Mechanisms by which dietary fatty acids modulate  
      plasma lipids. J Nutr. 2005;9(135):2075-2078.

What are the Dietary Guidelines for Americans (DGA)?

  • The DGAs were first published in 1980 and have been updated every 5 years since.
  • DGAs encourage healthy eating to promote health and prevent disease.
    • They are a joint effort of the Department of Health & Human Services and the United States Department of Agriculture. 
    • The DGA are revised and published every 5 years per a mandate under the 1990 National Nutrition Monitoring and Related Research Act (Public Law 101-445, Section 301 [7 U.S.C 5341], Title III).

  • Following federal procedures, a committee of experts in the fields of human nutrition, public health and medicine are appointed to the DGA committee and are tasked with revising the current set of guidelines. They do this by conducting methodical and systematic reviews of current scientific and medical information. As experts, they come to the committee current in the literature and with knowledge of what areas should be more scrutinized.
    • For example, the 2015 committee came in knowing that a publication for health practitioners came out in 2013 (after the last DGA review) that questioned cholesterol recommendations. They knew in advance that this was something they had to consider and further investigate. 
  • As of March 10, 2015, we follow the 2010 DGA. Highlights in the 2010 DGAs include
    • Balance calories with physical activity to achieve and maintain a healthy body weight;
    • Consume more fruits and vegetables, fat-free and low-fat dairy, whole grains, and seafood;
    • Reduce your intake of salt-containing foods (sodium), saturated fat, trans fat, added sugars, refined sugars and cholesterol.
  • In the 2015 DGAs it is expected that the limit on cholesterol intake will be removed. The other highlights listed above are expected to remain the same.
  • The DGAs influence and inform nutrition policy, nutrition education, health care spending, other public policy, food and diet trends, and food and agriculture aspects of our economy.
  • Examples of programs and resources related to the DGAs:





Why Recommend Cholesterol Changes Now?  

In recent years the ability to compare and analyze outcomes from different research studies has increased. New laboratory and data analysis techniques expanded and enhanced our knowledge. As a result, scientists have learned more about how different types of diets and nutrients impact blood lipids (cholesterol – LDL and HDL).

In 2013, the American Heart Association and the American College of Cardiology, in coordination with other professional groups, published practitioner guidelines about assess risk of cardiovascular disease risk in adults (1). To do this, the research consortium systematically analyzed the available research about whether different types of interventions, particularly dietary interventions, reduced the risk of disease as determined by factors such as LDL-cholesterol (bad), HDL-cholesterol (good), blood pressure, body weight, and inflammatory markers like C-reactive protein. Their results showed strong evidence to support that diets low in saturated fat reduced the  risk of cardiovascular disease as reflected in improved blood cholesterol levels. However, when they looked at all of the research together, lower dietary cholesterol intake did not reduce the risk of cardiovascular disease - it did not lower blood cholesterol. 

As I mentioned above, because the 2010 DGA committee did not have this 2013 research study available it was not part of their scientific and medical review. The 2015 DGA Committee systematically and critically reviewed this study and other evidence, including data collected from the National Health and Nutrition Examination Surveys (NHANES).


1. Eckel RH, Jakicic JM, Ard JD, et al. 2013 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. Journal of the American College of Cardiology. 2014;63(25_PA):2960-84.

Examples of the Media Frenzy:



Implications

I wrote a blog about cholesterol a few months ago (Nutrition Tuesday - Cholesterol). Even though the 2015 DGA Committee proposes removing the cholesterol intake limit from the guidelines, not much has changed when you get right down to it. Saturated fat contains cholesterol. Limiting saturated fat was part of the 2010 DGAs and is part of the proposed 2015 DGAs. If this change becomes public policy as expected, I anticipate changes to food labels. Right now manufacturers are required to indicate how much cholesterol is in a serving of food. If cholesterol is no longer considered a nutrient of concern, we may eventually see cholesterol numbers phased off of food labels. We will have to wait and see.

A healthy diet contains moderate portion sizes and variety. A healthy lifestyle includes a healthy diet and a physically active lifestyle. Eggs and seafood provide lean protein and other nutrients like unsaturated fats. Elevated LDL-cholesterol, low HDL-cholesterol, high blood pressure, as well as diabetes, overweight and obesity are among the risk factors for cardiovascular disease. If a combination of diet modification and exercise does not improve abnormal cholesterol, you may be prescribed cholesterol lowering medication. Discuss your questions and concerns with your physician. It is your right as a patient to understand what is being said and to get answers to your questions. If you get vague dietary information, ask for help or resources. Help is out there but sometimes people forget to share it.