Science is supposed to be the gold standard for truth. But what happens when peer review is misused? From peer review flaws and scientific gatekeeping to corporate influence on science, the reality is that industries have learned how to bend research to their will. The sugar industry scandal is one of the most striking examples: decades of industry-funded studies shifted the blame for obesity and heart disease away from sugar, rewriting public health guidelines. Coca-Cola-funded research did something similar, pouring millions into studies designed to downplay the link between sugary drinks and obesity.
The Volkswagen diesel scandal (a.k.a. Dieselgate) shows that it’s not just food and nutrition — corporate manipulation of science stretches across industries. How industries influence scientific research is not always obvious, but failed peer review cases and hidden conflicts of interest have allowed misleading studies to pass as credible. This article explores how peer review flaws, corporate interests, and a broken review system can create a false sense of scientific certainty, from Coca-Cola’s healthwashing campaigns to the diesel emissions scandal explained. If we don’t question the peer review system and call out corporate manipulation of science, we risk trusting research that was never meant to reveal the truth.
How Peer Review Got Played: Hidden Scandals Behind Science’s Gatekeepers
Peer review is often called the backbone of scientific integrity. Before any study gets published, it is supposed to pass through the hands of neutral experts—peers who evaluate the quality, reliability, and originality of the work. In theory, this system acts like a security checkpoint: nothing questionable should slip through. But what happens when the very guards at the gate are influenced, or when powerful interests quietly set the rules of the game?
The idea of peer review sounds simple, but the process is anything but flawless. Reviewers can be biased, overworked, or too close to the established ideas they are supposed to challenge. Sometimes, powerful industries take advantage of the system by funding studies that are then rubber-stamped through peer review, creating a false sense of credibility.
The result: some of the world’s biggest public health and environmental scandals were not just caused by corporate greed or weak regulations but were amplified by a broken scientific filter. This article looks at three notorious cases where the peer-review system—or its misuse—allowed flawed or misleading research to dominate public discourse: the sugar vs. fat scandal, Coca-Cola’s healthwashing, and Volkswagen’s Dieselgate.
Case 1: Sweet Lies – How Sugar Won the War Against Fat
In the 1960s, America’s waistlines were growing, and the health community was scrambling to find the culprit. Was it fat? Sugar? Processed carbs? The answer, as it turns out, depended on who was paying for the research.
The Sugar Research Foundation (today known as the Sugar Association) secretly funded studies that blamed fat—not sugar—for heart disease. In 1967, they paid Harvard researchers (roughly the equivalent of $50,000 today) to publish a “landmark” review in the New England Journal of Medicine. This review downplayed the role of sugar while aggressively pointing fingers at dietary fat.
It wasn’t until 2016 that internal documents revealed the sugar industry’s covert influence. By then, millions of consumers had spent decades believing fat was the enemy, while sugar quietly fueled an obesity and diabetes epidemic.
Case 2: Coca-Cola and the Art of Healthwashing
Fast forward a few decades. By the 2010s, the sugar debate was back—this time with soda in the spotlight. As public health researchers began linking sugary drinks to obesity, Coca-Cola decided to launch a PR counterattack. Their strategy? Not denial, but distraction.
Coca-Cola funded a group called the Global Energy Balance Network (GEBN), a nonprofit that pushed the narrative that “you can drink soda as long as you exercise enough.” The group claimed that the real problem was a lack of physical activity, not sugar consumption. Several of their studies—many with Coca-Cola’s fingerprints on them—passed peer review and made it into reputable journals.
The peer-review system didn’t catch the conflict of interest because funding disclosures were often vague or downplayed. It was only after investigative journalists exposed the ties in 2015 that the GEBN dissolved and Coca-Cola faced a wave of public backlash.
This episode highlighted a critical flaw: peer review checks methods and data, but it rarely questions the motives behind the research. When money shapes the questions being asked—or the ones not being asked—peer review becomes a silent accomplice.
Case 3: Dieselgate – When Emissions Were Too Clean to Be True
If sugar scandals feel distant from your life, consider this: the air you breathe was part of one of the most brazen corporate deceptions of recent decades. In 2015, Volkswagen was caught installing “defeat devices” in diesel cars—software that manipulated emissions tests to make vehicles appear cleaner than they were.
But here’s the twist: several studies published during this time, including research funded by European carmakers, suggested diesel was surprisingly eco-friendly. Some of this research was funneled through peer-reviewed outlets or industry-backed “independent” institutes.
Peer review didn’t save the day because the deception wasn’t in the raw science, but in what was not disclosed. Data supplied by the automakers was cherry-picked, and independent replication was scarce. The scandal only came to light thanks to a small team at West Virginia University, which conducted real-world tests that contradicted lab results.
Dieselgate is a sobering reminder that peer review is only as good as the data and transparency it’s built on. If you hand a reviewer polished lies, they can still pass as truth.
The Bigger Problem: Peer Review Is a Gate, but Who Holds the Keys?
What ties these cases together isn’t just corporate greed; it’s the vulnerability of peer review to outside influence. In theory, peer review is about quality. In practice, it can become a game of optics, where well-funded actors know how to push certain narratives through respected journals.
Unlike open democratic debates, the peer-review process is often opaque, slow, and dominated by insiders. Reviewers are unpaid and sometimes overwhelmed, which means they might not have the time—or incentive—to dig deep into conflicts of interest.
Does this mean peer review is useless? Absolutely not. Without it, the scientific landscape would descend into chaos, full of unverified claims and sensational pseudoscience. But we need to admit its weaknesses: it can be gamed by money, power, or simple inertia.
Lessons for the Future
The sugar and soda scandals show us how industries can manipulate science for decades before the truth emerges. Dieselgate teaches us that even in highly regulated sectors, peer-reviewed research can be a smokescreen if nobody questions the underlying assumptions.
So what can be done? Greater transparency in funding disclosures is a start. Journals should enforce stricter conflict-of-interest checks and encourage open peer review, where reviewers’ comments (and identities) are public. Independent replication studies—often seen as unglamorous—should be rewarded, not sidelined.
Peer review remains the heartbeat of credible science, but it’s time we recognize that a heartbeat can be faint—or artificially induced—if we don’t keep checking its pulse.
References
Kearns, C. E., Schmidt, L. A., & Glantz, S. A. (2016). Sugar industry and coronary heart disease research: A historical analysis of internal industry documents. JAMA Internal Medicine, 176(11), 1680–1685. https://doi.org/10.1001/jamainternmed.2016.5394
O’Connor, A. (2015, August 9). Coca-Cola funds scientists who shift blame for obesity away from bad diets. The New York Times.