Low-fat diet advice was based on undercooked science

Lobster Spring Roll - Japonais
Lobster Spring Roll.

As a follow-up to revision to the US government’s advice about cholesterol, we read this tidbit yesterday…

An international team of health scientists has completed a systematic study of the evidence available back in the 1970s and ’80s and concluded that a relationship of causation between fat consumption and coronary heart disease was never established. The researchers found just six studies that fit the criteria to be considered proper randomized controlled trials, all limited to male subjects and most addressing the proportion of fat in the diet only indirectly.

“Government dietary fat recommendations were untested in any trial prior to being introduced,” writes Zoe Harcombe of the University of the West of Scotland, lead author of the study. Despite this, “to date, no analysis of the evidence base for these recommendations has been undertaken,” which is what prompted Harcombe and her team to conduct their investigation.

From among the data on various diet types that was available, there were no differences in the number of deaths from all causes, and no statistically significant changes in death from cardiovascular disease. Eating less fat was not shown to improve a person’s heart health, even where changes in diet led to a reduction in blood cholesterol levels. “It seems incomprehensible that dietary advice was introduced for 220 million Americans and 56 million UK citizens, given the contrary results from a small number of unhealthy men,” comments Harcombe.

At the time of issuing the original 1977 Dietary Goals for the United States, better known as the McGovern report, the Senate Committee’s lead nutritionist, Dr. Hegsted of Harvard University, admitted that the evidence base was for the advice was somewhat lacking. “There will undoubtedly be many people who will say we have not … demonstrated that the dietary modifications we recommend will yield the dividend expected,” remarked Hegsted. But his counterargument was that there was more to gain from switching to the recommended diet than there was to lose. Beyond reducing fat intake, the Dietary Goals also urged a reduction in the consumption of salt and sugar, whose deleterious health effects have been far better established.

(click here to continue reading Low-fat diet advice was based on undercooked science | The Verge.)

Oh boy, so 40 years of bad advice from the government and corporate allies all based on incomplete science. Seems like someone should have said something, oh, maybe a few years later? Ten years later? Twenty years later? Ten years ago? 

US poised to withdraw longstanding warnings about cholesterol

Cajun Campfire Breakfast
Cajun Campfire Breakfast

An amazing sea change in nutritional policy. Just think of all the times you’ve heard to avoid cholesterol-laden foods like eggs.

The nation’s top nutrition advisory panel will drop its caution about eating cholesterol-laden food, a move that could undo almost 40 years of government warnings.

The group’s finding that cholesterol in the diet need no longer be considered a ‘‘nutrient of concern’’ stands in contrast to its findings five years ago, the last time it convened. During those proceedings, as in previous years, the panel deemed ‘‘excess dietary cholesterol’’ a public health concern.

The new view does not reverse warnings about high levels of ‘‘bad’’ cholesterol in the blood, which have been linked to heart disease. Moreover, some experts warn that people with particular problems, such as diabetes, should continue to avoid cholesterol-rich diets.

But the finding follows an evolution of thinking among many nutritionists who now say that, for a healthy adult, cholesterol intake may not significantly affect the level of cholesterol in the blood or increase the risk of heart disease.

The greater danger, according to this line of thought, lies in foods heavy with trans fats and saturated fats.

The panel’s report will be the basis for the next version of the ‘‘Dietary Guidelines,’’ a federal publication that has broad effects on the American diet. A person with direct knowledge of the proceedings said the cholesterol finding would make it into the group’s final report.

(click here to continue reading US poised to withdraw longstanding warnings about cholesterol – Nation – The Boston Globe.)

For me, I’ve never particularly hewed closely to these guidelines (I’ve eaten eggs more mornings than not the last 45 years, sometimes with bacon, or cooked in butter!), but still will be happy to see these guidelines revised.

O'Shaughnessy's Irish Breakfast
O’Shaughnessy’s Irish Breakfast

HHS’s Office of Disease Prevention and Health Promotion has the administrative leadership for the 2015 edition and is strongly supported by USDA’s Center for Nutrition Policy and Promotion in Committee and process management, and evidence analysis functions. The Departments jointly review the Committee’s recommendations and develop and publish the revised Dietary Guidelines for Americans policy document.

Recommendations from the Dietary Guidelines for Americans are intended for Americans ages 2 years and over, including those at increased risk of chronic disease, and provide the basis for federal food and nutrition policy and education initiatives. The Dietary Guidelines encourage Americans to focus on eating a healthful diet—one that focuses on foods and beverages that help achieve and maintain a healthy weight, promote health, and prevent disease.

The first edition of the Dietary Guidelines for Americans was released in 1980. As mandated in Section 301 of the National Nutrition Monitoring and Related Research Act of 1990 (7 U.S.C. 5341), the Dietary Guidelines for Americans is reviewed, updated, and published every 5 years in a joint effort between the U.S. Department of Health and Human Services (HHS) and the U.S. Department of Agriculture (USDA).

Beginning with the 1985 edition, HHS and USDA have appointed a Dietary Guidelines Advisory Committee (DGAC) consisting of nationally recognized experts in the field of nutrition and health. The charge to the Committee is to review the scientific and medical knowledge current at the time. The Committee then prepares a report for the Secretaries that provides recommendations for the next edition of the Dietary Guidelines based on their review of current literature.

(click here to continue reading Dietary Guidelines for Americans, 2015 | Dietary Guidelines for Americans | Health.gov (ODPHP).)