Sugar: worse than cholesterol in cardiovascular disease?

There is clear evidence of the link between sugar consumption and cardiovascular disease. Strangely enough, this relationship is practically unknown even to cardiologists. There is a good reason for this. This article describes how the sugar industry has shifted its focus from sugar as a (co-)cause of cardiovascular disease to fat and cholesterol. It is a typical example of how industry pays scientists to deceive doctors, legislators and the general public.

By C.F. van der Horst
11 December 2016, updated 12 September 2022
Photo by jcomp on freepik.com

Though sugar is sweet it occasionally carries a very bitter taste. Such was the case in a discovery by a University of California research group led by Professor of Medicine Stanton Glantz. In mid-September 2016, this team uncovered that the sugar industry has largely shaped the medical curriculum (what a student learns when he or she becomes a doctor) and thus physicians’ thoughts about the cause of cardiovascular disease. And that steering had far-reaching implications for health advice, policymakers, and what is published in the media.

The sugar producers used their lobbying organization, The Sugar Research Foundation (SRF), founded in 1947, to do this. In 1967 the name changed to The International Sugar Research Foundation and since 1978 it has been registered as the World Sugar Research Foundation (WSRO). In their investigation, the California researchers consulted internal documents of the SRF. These revealed that this foundation was secretly sponsoring a review (overview study summarizing the medical literature on a topic) by Harvard University researchers. The purpose of this funding was to show that there was no causal relationship between cardiovascular disease and sugar.

International Sugar Research Foundation is now the World Sugar Research Foundation

In the late 1950s, there were two camps regarding the cause of cardiovascular disease. In the US, Ancel Keys launched the idea that these conditions were caused by fat consumption and cholesterol. Shortly thereafter, however, in 1957, John Yudkin, a renowned British physiologist and nutritionist, wrote in the British medical journal The Lancet that common hypotheses at the time stated that the higher the fat consumption is, the higher the mortality is from myocardial infarction (coronary mortality). He contended, however, that “these simple hypotheses do not explain some of the epidemiological data.” Yudkin suggested that other factors, including sucrose (sugar), were at least as important as (saturated) fat. Although international statistics showed a moderate association between fat consumption and coronary mortality, the association with sugar consumption was more evident. Yudkin’s sugar experiments showed a significant increase in hormone levels (40% more insulin, 300-400% more adrenaline) in volunteers with elevated blood insulin levels after only two weeks; many patients also showed an increase in estrogen. Yudkin suggested that hormonal imbalance caused by sugar could be the underlying cause of coronary disease.

Ancel Keys versus John Yudkin: Cholesterol or sugar as a cause of heart disease?

Ancel Keys (left) versus John Yudkin (right): fat or sugar as a cause of heart disease?

Today, few people know the relationship between added sugars and cardiovascular disease, while the association of fat and cholesterol with these conditions is well known. Why is that?

Yudkin’s publications on the link between sugar consumption and deteriorating health since 1957 made him a threat to the sugar industry. Moreover, a publication by the American Medical Association’s Council on Food and Nutrition was of concern. The Council had found evidence of an increase in serum cholesterol (amount of cholesterol in the blood) from a low-fat, high-sugar diet. The British nutritional expert compounded this two years later by stating that sugar and sugary foods contribute to several diseases, including obesity, caries (tooth decay), diabetes mellitus (diabetes) and heart attacks.

Other researchers also saw sugar as a culprit with regard to cardiovascular disease, as in 1965 two studies (Ostrander and Epstein) using the results of an epidemiological study concluded that blood sugar levels were better at predicting atherosclerosis (artery hardening) than serum cholesterol levels or hypertension.

The sugar industry was concerned about the sale of sugar products and took action through the SRF.

To protect the sugar industry’s market interests, the SRF decided to steer the scientific debate. In secret, this lobbying organization sponsored a number of renowned Harvard University scientists under the name Project 226. The Harvard team was given a clear message: Yudkin (sugar as a [mede] cause of heart disease) had to be neutralized. A systematic review (survey of the scientific literature) was needed that refuted that sugar was a cause of symptoms previously attributed to fat alone. With such a driving force, the outcome was not surprising.

The Harvard team excluded both Yudkin’s work and that of a University of Iowa research group that had linked sugar consumption to elevated serum cholesterol levels. These would contain questionable data or misinterpretation. Moreover, the reviewers argued that there were too few epidemiological, animal and mechanistic studies linking sucrose (white sugar) to heart disease. Consequently, there was no evidence base for the risks of cardiovascular disease from sucrose. They did not investigate the possibility further but decided to include only randomized clinical trials in the review that used serum cholesterol levels as a biomarker (measurable indicator) for cardiovascular disease. The high sugar content of the American diet was completely left out of consideration. The obvious conclusion of their review was that consumption of fat and cholesterol was the only way the diet could cause vascular disease.

Half a century later after publication of the authoritative review, Glantz’s research group wrote: “The SRF set the review’s objective, contributed articles for inclusion, and received drafts. The SRF’s funding and role was not disclosed.”

The SRF paid the Harvard researchers a sum of 6,500 dollars, which, converted to today, would be around 50,000 dollars. A very good investment, because such a review study carries a lot of weight. Cristin Kearns, one of the researchers who had uncovered the undisclosed sponsorship, said when asked, “Systematic reviews are highly influential in policymaking.”

The impact was indeed profound because today you don’t hear or read anything about the danger of sugar for cardiovascular disease in official health advice. The emphasis is entirely on fat and cholesterol.

For more than half a century, people have been trying to lower fat and cholesterol levels with dietary recommendations and, since 1987, with dangerous cholesterol-lowering drugs, statins. Despite all the measures during that time, cardiovascular disease is still the number one cause of death, according to the World Health Organization.

What does that say about fat and cholesterol as a major cause? Could Yudkin have been right after all?

The Harvard review was not the only way the SRF tried to secure the sugar market. Tooth decay (caries) was another threat to sugar sales. To get ahead of problems, the SRF was heavily involved in the National Caries Program (NCP) in the US. Researchers wrote: “The sugar industry could not deny the role of sucrose in dental caries given the scientific evidence. They therefore adopted a strategy to deflect attention to public health interventions that would reduce the harms of sugar consumption rather than restricting intake.” Industry tactics included the following:

Funding research on enzymes to break up dental plaque;
A vaccine against tooth decay with questionable potential for widespread application;
A lobby by cultivation of relationships with the National Institute of Dental Research (NIDR) leadership that determined the NCP;
Consulting of members on an NIDR expert panel;
A submission of a ‘ready-made’ report to the NIDR.

That final step, the report, proved to be a hit, as it became the foundation of the first request for proposals issued for the NCP. A whopping seventy-eight percent of the sugar industry submission was incorporated into the NIDR’s call for research applications. Thus, restrictive measures on sugar consumption could be avoided.

This mode of operation has ensured that both scientists (and advisory bodies that often consist of them), policymakers, and public opinion have been misinformed for decades. Professor Stanton Glantz, one of the authors of the study that shone light on the manipulation, said, “They were able to derail the discussion about sugar for decades.”

Professor Stanton Glantz, professor of medicine at the University of San Francisco (UCSF)@2x

Stanton Glantz, professor of medicine at the University of San Francisco (UCSF) was one of the researchers who uncovered the manipulation by the sugar industry.

As a result, Yudkin’s findings were ignored and Keys’ were accepted as true, while it was revealed that Keys in his “Seven-Country Study” in which he “proved” his cholesterol theory deliberately omitted the data from 15 other countries because they did not support his conclusion. The book Deadly Lies: How Doctors and Patients Are Deceived does a detailed exposé of this matter.

The above account is the story of sugar. It is not an isolated story as the industry (pharmaceutical, chemical, and food) tries to influence legislators and public opinion to secure its market. In doing so, researchers are funded. It has been noted repeatedly that sponsored studies often have predictable results—to the benefit of the sponsor, of course. There is an extraordinary amount of conflict of interest.

However, conflicts of interest are not always obvious—for example, self-enrichment through monetary gain is only one of its manifestations. The book Deadly Lies: How Doctors and Patients Are Deceived, describes five types of conflict of interest.

“Deadly Lies. How Doctors and Patients Are Deceived” describes the conflicts of interest of government officials and scientists, the mass marketing of the pharmaceutical industry, and the lies used to deceive both physicians and you.

The above manipulation by the sugar industry shows that one must establish the independence of researchers before one can assign any value to scientific studies. Industrial sponsorship of scientific studies should be banned so that the university, as an independent institution, becomes the quality institute of old.