Background

The development of the Dietary Guidelines in the USA during the 1970s and 1980s has had a huge impact on food consumption patterns ever since. Because the advice to reduce fat was enthusiastically taken up by the food industry with the promotion of “low fat” products, this message was successfully conveyed to consumers. As a consequence, there has been an increase in the consumption of sugar and carbohydrates.

Many other countries, especially in the English-speaking world, followed the lead given by the Americans and devised nutrition policies, which were essentially the same. Looking back, it is now evident that the huge increases in the incidence of obesity and Type 2 Diabetes (T2D) commenced at the same time as the dietary recommendations began to take effect.

The debate about how the dietary patterns contribute to the development of heart disease boils down to the relationship between fat and sugar/carbohydrates. From the perspective of the 1950s and 1960s the question was:

“Do we need to reduce fat or sugar?”

Despite rearguard action, there is little doubt that dietary sugar really is the “bad guy”, which is one of the primary causes not only of heart disease but also of T2D, cancer and Alzheimer’s Disease (AD).

New research

It is especially interesting that a paper has recently been published which reveals the interactions between the sugar lobby in the USA and some of those who had a critical influence on the contents of the US Dietary Guidelines (1). The authors have been able to access some of the relevant correspondence, which is absolutely devastating.

In order to appreciate the significance we need to understand what the position was in the US at the time. In his book “The Diet Delusion” this is described by Gary Taubes (2). He explains that the focus of the debate was on the importance of dietary fat and the role of cholesterol-lowering in relation to heart disease. Although the “Dietary Goals” was drafted by a researcher Nick Mottern, he relied almost entirely on the advice of Mark Hegsted, a Harvard nutritionist. He was an ardent advocate of reducing the intake of fat as a means of tackling heart disease, although he recognized that that this view was controversial.

At the press conference announcing the first draft of the document, Hegsted stated that:

“The question to be asked is not why we should change our diet but why not? There are [no risks] that can be identified and important benefits can be expected.”

Doubts expressed

Even the American Medical Association had genuine doubts and advised the Senate Select Committee that:

“there is a potential for harmful effects for a radical long term dietary change as would occur through adoption of the proposed dietary goals”.

Despite this and other criticisms from many distinguished researchers, these concerns were brushed aside by the Committee, which effectively endorsed the first draft and concluded that:

“..no physical or mental harm could result from the dietary guidelines recommended for the general public.”

Subsequently Hegsted was appointed as head of the USDA Nutrition Center, which would be responsible for implementing the guidelines.

The role of the sugar industry lobby

The recent report is especially significant because it is based on internal sugar industry documents which describe how the industry sought to influence the scientific debate over the dietary causes of heart disease in the 1950s and 1960s.

The sugar industry lobby was especially concerned about emerging research which indicated that there was an association between the level of blood glucose and the incidence of heart disease. There was also convincing research that the level of triglycerides (TG) or fat in blood was determined by the amount of sugar consumed. When the starch which is the dominant carbohydrate in foods, such as rice and bread, only glucose is released. However when sugar (sucrose) is digested, glucose and fructose are released. There were indications that there could be a specific issue with fructose, which in my view, has been confirmed by recent developments.

An editorial in the New York Herald Tribune concluded that the new research strengthened the case that sugar increased the risk of heart attacks.

As a direct result of this editorial, the Sugar Research Foundation (SRF) established Project 226. Effectively this had the object of countering this threat to the sales of sugar. So in July 1965, Mark Hegsted was commissioned by the SRF to produce a review, which would be helpful to the sugar industry. During the next year, he worked on the project. At one point he commented in a letter to the SRF:

““Every time the Iowa group publishes a paper we have to rework a section in rebuttal [emphasis added].”

The Iowa group was responsible for most of the research which worried the SRF.

It is pretty clear from this that Hegsted was not exactly objective in the way he approached the review. Just before the review was submitted for publication, the SRF executive commented:

“Let me assure you this is quite what we had in mind and we look forward to its appearance in print.”

Shortly afterwards, the review was published in the New England Journal of Medicine (3). Unfortunately there is restricted access. From what I can make out, the review simply discounts most of the evidence which suggests that sugar could be a cause of heart disease. According to Kearns et al (1), the authors were guilty of double standards. They note that:

“Despite arguing earlier in the review that epidemiologic evidence was irrelevant to determining dietary causes of CHD, the review implied that the epidemiologic evidence pointed to dietary cholesterol and saturated fat as the primary dietary causes of CHD.”

Conclusion

To put it bluntly, they produced a “hatchet-job” which met the objectives of the SRF. We now know from this latest research that the 3 authors (one of whom was Hegsted) were paid $6,500 (almost $50,000 in current value). This was not disclosed, which is the real scandal. It was clear that there was an obvious agenda and the last thing in the mind of the authors was to produce a balanced, objective evaluation of the evidence. Since then, evidence has emerged, which shows conclusively that the source of funding does influence the results of scientific studies and more importantly the way they are presented. This example is particularly blatant but unfortunately has had a much greater impact than anyone could ever have anticipated. Given the controversy at the time, it is possible that without this intervention the Dietary Guidelines in the US might have been totally different. As a consequence, we may well have avoided the current disastrous level of obesity and T2D.

References

  1. C E Kearns et al (2016) http://archinte.jamanetwork.com/article.aspx?articleid=2548255
  2. Gary Taubes (2007) “The Diet Delusion” Vermillion: London
  3. http://www.nejm.org/doi/full/10.1056/NEJM196707272770405