I am discussing a public health issue to modernize the definition of protein quality.
In 2019, Dr. David Katz and colleagues, including one of my favorite researchers, David Jenkins, published “A public health case for modernizing the definition of protein quality.” The current explanation seems to have more to do with biochemistry than overall effects on human health. The common belief that protein is “good,” and the better, combined with a definition of protein quality that favors animal protein, gives the impression that eating more meat, eggs, and dairy is desirable and desirable. But this directly contradicts the healthy eating guidelines that most plants are trying to push. Although protein malnutrition is still common in many parts of the world, it is much rarer in industrialized countries, where “the major threats to public health…come from chronic diseases,” not something like kwashiorkor, acute protein and calorie malnutrition.
In 2016, a landmark study from Harvard was published, involving more than 100,000 people, which found that replacing animal protein with plant protein was associated with a lower risk of premature death. The worst offenders seemed to be processed meats like bacon, and egg proteins (egg whites). But swapping just 3% of plant protein for any animal protein, such as processed meat, lean meat, chicken, fish, eggs, or milk, was associated with a significantly lower risk of the most important outcome of all: death. See below and at 1:32 in my video Animal Protein vs. Plant-Based Proteins.
But how do we know it’s a protein? The researchers adjusted for things like saturated fat intake, which suggested it wasn’t just animal fat. But how can our bodies distinguish between plant proteins and animal proteins? Isn’t protein…protein? No. In general, plant proteins are low in branched-chain amino acids, unlike animal proteins, and reduced consumption of branched-chain amino acids improves metabolic health. It could be IGF-1, a cancer-promoting growth hormone that is boosted by so-called high-quality animal protein, though. We suspect that the IGF-1 connection is cause and effect, since people born with high levels of IGF-1, regardless of what they eat, appear to suffer higher rates of killers like type 2 diabetes and heart disease. Or, it could be something that the Harvard researchers did not control, such as toxic pollutants such as dioxins and polychlorinated biphenyls (PCBs), as they tend to accumulate in the food chain into cows, pigs, chickens, and fish and therefore end up on our plates. Therefore, “plant-based proteins, apart from other health benefits, stand as an important step to reduce the body’s burden of harmful pollutants of animal origin.”
If you don’t think a study with 100,000 people is enough, how about 400,000 people? The US National Institutes of Health–AARP Diet and Health Study is the largest food group study in history, and, again, researchers found that simply replacing 3% of calories from animal protein with plant protein was associated with 10 percent lower mortality—and you get double the benefit if you eliminate eggs, too. That’s not surprising, because egg consumption is associated with a greater risk of cardiovascular disease.
Combine all the studies on protein intake and mortality, and people who eat more protein tend to live shorter lives. But this is “primarily driven by the dangerous combination of animal proteins.” A plant protein diet actually on the contrary associated with death, meaning that those who eat plant protein tend to live longer lives. More animal protein may mean more deaths, while more plant protein is associated with less death, as you can see below and at 3:30 in mine. video.
Therefore, the best of both worlds would be to increase the intake of plant proteins instead of animal proteins. In other words, as one meta-analysis concluded, “People should be encouraged to increase their intake of plant proteins to reduce the risk of death.”
Doctor’s Note
The benefits of calorie restriction may come from the reduction in animal protein. Look Caloric Restriction vs. Animal Protein Restriction to find out more about this.
I also discuss branched-chain amino acids Are BCAA (Branched Chain Amino Acids) Healthy?.
Do you need to combine plant proteins, such as rice and beans? Look A Myth That Contains Proteins.
How much protein do we need? Look Are Vegetarians Getting Enough Protein?.
What about plant meat? Is Over Meat and the Impossible Burger Healthy?
