Debunking A Just-Published Study On High Protein Diets And Cardiovascular Disease

Vivian Goldschmidt, MA Nutrition

Evidence-Based
6 min Read

A study published in February 2024 in the journal Nature Metabolism drew an association between dietary protein intake and the risk of cardiovascular problems. However, a closer look at the details of the study reveals flawed methodologies that undermine the researcher's conclusions.

Unsurprisingly, despite the weaknesses of the study, the media rushed to publish headlines about a link between arterial plaque and protein.

Today, we'll take a closer look at this study, identify where it went wrong, and discuss what it can teach us about the Medical Establishment. Savers will surely notice the parallels between this flawed study, osteoporosis, and Big Pharma.

A Study On Protein And Arteries

Researchers at the University of Pittsburgh conducted a study concluding that consuming more than 22% of dietary calories from protein can lead to increased atherosclerotic plaque and a higher risk of cardiovascular problems. They linked the increase in atherosclerosis, or stiff, hardened arteries, to the amino acid leucine.
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The researchers observed that leucine impeded immune cells called macrophages tasked with removing debris from arteries. The breakdown of macrophage function causes buildup that hardens arteries.

The study had multiple phases, including small human trials, studies with mice, and laboratory experiments using cells in petri dishes.

In the first experiments, the researchers observed the dose-response relationship between consuming protein and the functioning of immune cells. Participants in one study received liquid meals with differing amounts of protein. In another study, participants received either high or low-protein mixed meals.

The scientists used blood tests to measure changes in participants' immune cells and found that the higher-protein groups had impaired macrophage function.

To isolate the impact of specific amino acids the study authors conducted in vitro studies, observing the impact of those amino acids on immune cells in the laboratory. Then they tested their findings using the cells of mice, before completing studies with living mice. In the mice, they also found that increasing leucine levels past a certain point impaired the functioning of immune cells and increased arterial plaque.

Synopsis

Researchers in Pittsburgh conducted a series of experiments with human participants, mice, and immune cells observed in vitro. They observed a dose-dependent relationship between the amino acid leucine and macrophage function that resulted in hardened arteries.

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Overlooked Details Undermine Study Results

This complex study goes to great lengths to associate dietary protein with arterial plaque. However, considering that diet was one of the subjects of the study, it is surprising that the researchers didn't pay more attention to that element. While good studies control for as many variables as possible, the liquid protein meal chosen by the researchers introduced a significant number of variables.

The portion of the study's “liquid diet” responsible for introducing protein was a product called Boost Plus. However, this protein supplement beverage contains far more than just the protein. The ingredient list includes the following.

  • Water
  • Glucose Syrup
  • Sugar
  • Vegetable Oil (Canola, High Oleic Sunflower, Corn)
  • Milk Protein Concentrate,
  • Soy Protein Isolate
  • Calcium Caseinate
  • Sodium Caseinate
  • Vitamins And Minerals
  • Gum Acacia
  • Fructooligosaccharides
  • Inulin (From Chicory)
  • Soy Lecithin
  • Salt
  • Natural And Artificial Flavor
  • Carrageenan

The researchers mixed the Boost Plus with other processed food compounds, including Unjury (a commercial protein isolate product), non-fat dry milk powder, and Sol Carb (a commercial nutritional carbohydrate polymer made from genetically-modified corn).

They combined these elements in different amounts to create higher and lower protein meals for participants. However, using Boost Plus as a source of protein overlooks all of the other ingredients included in that drink.

In essence, the study is flawed as it did not isolate the protein, so it’s impossible to identify the true cause of the biological changes that took place during the study,

When the researchers conducted a follow-up study using whole foods instead of processed beverages, they liquified the foods. This allowed them to create exact percentages of different food sources in each “meal”, and include unspecified ingredients such as “fats” or “broth”. This “real meal” hardly resembles any meal eaten by a normal person in real life.

These collections of highly processed foods likely had a variety of negative impacts on participants. However, this study did not isolate the variable they hoped to observe. As a result, this study draws dubious conclusions.

Synopsis

The study used a commercially produced protein supplement beverage as a source of protein. To observe the impact of eating more protein they increased the amount of this beverage in each meal. However, the beverage contains a long list of other ingredients. We cannot conclude that protein alone caused the study’s results, as other ingredients were also included.

Not Every Headline Is Trustworthy

This study may contain valuable observations about the impact of the amino-acid leucine on the functioning of immune cells in the cardiovascular system. However, the overall assertions of the researchers, and the headlines they inspired in the media, don't reflect that level of technical detail.

A typical article covering this study would trumpet a new link between eating protein and hardening arteries. They might provide the detail that the effects were observed once 22% of the calories in participants' diets came from protein. But without reading the whole study you wouldn't know about the liquid meals made from compounds and powders, or the liquified version of “real meals”. Neither of those are likely to resemble any meal you've prepared at home.

The Medical Establishment has a tendency to value attention-grabbing headlines, so it's important to take a closer look at flashy news stories about health and wellness.

The history of osteoporosis contains many such instances in which the story the Medical Establishment tells doesn't bear much resemblance to reality.

Take for example the over-insistence on bone mineral density as the single most important measurement of bone health. In truth, there are many other factors that make you more or less likely to break a bone. However, BMD is a diagnostic tool that Big Pharma could use to prescribe more osteoporosis drugs. The story created by the Medical Establishment served Big Pharma, instead of serving us.

What This Means To You

Become your own best advocate as you navigate health and wellness information. Look beyond the headlines and seek out trusted sources to keep your knowledge up-to-date. The more you learn, the easier it will become to recognize suspicious headlines and to dig deeper.

The Osteoporosis Reversal Program is not based on any one study. It's built on decades of studies by countless scientists, and confirmed by the experience of Savers.

You can take a simple, common-sense approach to improving your health and strengthening your bones without drugs. The changes you make along the way will positively transform your life and how you live it.

References

1 https://www.nature.com/articles/s42255-024-00984-2

Rebuild Your Bones Naturally—Without Drugs or Side Effects

Stronger, healthier bones are possible—at any age. The Osteoporosis Reversal Program gives you a step-by-step, science-backed plan to naturally rebuild bone health, improve mobility, and regain confidence—100% risk-free with a 1-year, no-questions-asked guarantee.

Discover the Program