Review exposes lack of scientific evidence for Bulletproof’s claims and highlights potential health risks.
IRVINE (2 February 2024): Since its inception in 2009, Bulletproof has made numerous breathless claims for its unusual coffee concoction. Most of the promised benefits center on increased energy, improved mental clarity, and weight loss from appetite suppression and increased metabolism. However, a new literature review by Goldman et al. debunks those claims and raises additional concerns about serious potential health risks posed by the Bulletproof fad.
According to the Bulletproof website, founder Dave Asprey, a tech entrepreneur and self-described “biohacker,” introduced Bulletproof coffee in 2011. By 2014, the New York Times was already writing about the “cult of the Bulletproof Diet.” As noted integrative cardiologist, Dr. Joel Kahn, recently opined (in a private message; “No health trend more represents the ‘Emperor is Wearing No Clothes’ than Bulletproof Coffee. It’s the worst nutrition advice in history.”
Butter coffee—of which Bulletproof is the best-known brand—became fashionable with adherents of low-carb diets like Keto, Paleo and intermittent fasting—especially after the first Bulletproof store opened in 2015. But as Bulletproof claims on its website; “While there is overlap with some of their philosophies, the Bulletproof Diet is more akin to a comprehensive way of supporting a healthy lifestyle.”
At the core of that “lifestyle” is the beverage, consisting of brewed hot coffee with added fat in the form of grass-fed butter and medium-chain triglyceride (MCT) oil. Variations substitute ghee or coconut oil for the butter. The beverage contains no added sweetener or carbohydrate source such as milk.
Bulletproof markets its coffee as a breakfast meal replacement, as well as the foundation of an entire “food philosophy” based on “fueling your body with healthful, nourishing foods—especially quality fats.” They’re not kidding about the fats. Goldman et al. note one cup (237 mL) of Bulletproof coffee contains 230 calories, 25 g total fat, 21 g saturated fat, 0 g carbohydrates, and 0 g protein.” That is 84% saturated fat, widely acknowledged as a leading cause of cardiovascular disease. As nutrition expert Nanci Guest, PhD, RD, noted (in a private message): “You don’t have to be a professional dietitian to know that adding a saturated fat bomb to your coffee every day is a bad idea.”
Scientific reviews are a valuable source of informed commentary on health claims because they examine several studies across a broad base of evidence to derive consensus from multiple researchers. The consensus on Bulletproof Coffee indicates that the evidence for its claims is weak, muddled, or just plain absent.
Consider the claim that Bulletproof coffee boosts energy. Reviewing several studies of “subjective perceptions of alertness and energy,” Goldman at al. found “significant increases” reported after consuming either Bulletproof Coffee or regular black coffee, but no meaningful improvement for Bulletproof versus regular black coffee. In other words, the energy boost seems to come from the caffeine—a known stimulant—versus any additional ingredients in Bulletproof Coffee, such as fats.
When looking at cognition, Goldman et al. found similar results: i.e., no meaningful improvements for Bulletproof versus regular black coffee. Any potential improvement in cognition derives from caffeine’s “stimulatory effects in the central nervous system (CNS),” not from butter or MCT oil.
In a recent article, Cleveland Clinic Registered Dietitian, Kayla Kopp, RD, LD described Bulletproof Coffee as “super high in calories and saturated fats with almost no nutrients.” That characterization is at odds with Bulletproof’s description of their coffee beverage as “a comprehensive way of supporting a healthy lifestyle.” Kopp recommends “skipping this trend, as there just isn’t enough research to back up the claims.” Notably, Kopp singles out three groups who should definitely avoid Bulletproof Coffee: people with diabetes, gastrointestinal issues, or heart problems.
This is an important aspect of the Bulletproof “cult” that often gets overlooked. It’s not just that they overreach with their performance claims, which the Goldman review dismantles. The bigger problem is that their products pose serious health risks, especially for medically vulnerable people. As Goldman et al. concludes; “the review highlights potential health concerns linked to butter, which is a major ingredient of Bulletproof Coffee.” Echoing Kopp’s warning to those with gastrointestinal issues, Goldman notes, “Some evidence suggests possible elevation in serum cholesterol, and gastrointestinal intolerance has been reported following consumption of Bulletproof Coffee.”
Not surprisingly, the butter in Bulletproof Coffee is particularly risky from a cardiovascular health perspective. As Kopp notes, “People with high cholesterol and other heart issues are often advised to scale back on butter, due to its high amounts of saturated fat. Bulletproof coffee (sic) is definitely not part of a low-cholesterol diet.”
But Goldman’s concerns are not limited to potential gastrointestinal and cardiovascular risks. He would also like to see future research to explore the “impact of regular Bulletproof Coffee consumption on hydration status, kidney stones, reflux, gallstones, blood pressure, sleep quality, gastrointestinal motility, and hyperlipidemia.” Until then, anyone considering Bulletproof Coffee might want to ponder Bulletproof’s own guidance: “What you put into your body matters. It’s important to make mindful choices about the food that fuels you and the impact food can have on your body in the long term.”
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Read Switch4Good’s in-depth analysis of the Bulletproof Coffee “hoax” here.
Contact: Antony Sloan, Director of Communications, Switch4Good