I discuss a public health case for improving the definition of protein quality.
In 2019, Dr. David Katz and colleagues, including one of my favorite researchers, David Jenkins, was published “the public health case for updating the definition of protein quality.” It seems that the preferred definition has more to do with biochemistry than with the overall effect on human health. The general belief that protein is “good” and the more the better, combined with a definition of protein quality that favors animal protein, creates the impression that eating more meat, eggs, and dairy is desirable and preferable. But this is in direct opposition to the dietary guidelines, which instead try to push for more plants. Although protein deficiency is still common in many parts of the world, it is rare in the industrialized world, where “the most serious threats to public health … are chronic diseases,” not something like kwashiorkor, a severe protein and calorie deficiency.
In 2016, there was an important study was published from Harvard, which included more than 100,000 people, 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 as well as egg protein (egg whites). But replacing even 3% of plant protein with any animal protein, such as processed meat, unprocessed meat, chicken, fish, eggs, or milk, was associated with a very low risk of arguably the most important endpoint: death. See below and at 1:32 in my video Animal protein and vegetable protein.
But how do we know it’s protein? Researchers has been adjusted for factors such as saturated fat intake that indicate it is not just animal fat. But how can our body distinguish between protein from plants and protein from animals? Is protein… not protein? No. In general, vegetable protein is less branched chain amino acids and less branched chain amino acids compared to animal protein makes it better metabolic health. It could to be IGF-1, a cancer growth hormone that is increased by consuming so-called high-quality animal protein, though. We suspect that the IGF-1 connection is cause and effect because humans was born with higher levels of IGF-1, regardless of what they eat, appears to have higher rates of killers like type 2 diabetes and heart disease. Or, it could to be something the Harvard researchers didn’t control for, such as toxic pollutants like dioxins and polychlorinated biphenyls (PCBs), because they usually make their way up the food chain in cattle, pigs, chickens, and fish, and therefore end up on our plates. So, “vegetable protein, along with other health benefits, is an important step toward reducing the burden of harmful pollutants from dietary animal protein.”
If not think one study with 100,000 people is enough, how about 400,000 people? The US National Institutes of Health – The AARP Diet and Health Study is the largest dietary cohort study in history, and again, researchers found that replacing just 3% of calories from animal protein with plant protein is associated with a 10% reduction in total mortality – and you even get double the benefits if you get rid of eggs. This is not surprising because of the consumption of eggs related with a high risk of developing cardiovascular diseases.
Put up All the studies on dietary protein intake and mortality and people who consume more protein have a shorter lifespan. But this is “mainly caused by the harmful association of animal protein.” Consuming plant protein is a fact on the contrary is associated with death, meaning that those who eat more plant protein live longer. More animal protein may lead to more deaths, while more plant protein is associated with less death, as you can see below and at 3:30 in my video.
So it’s the best of both worlds growth consuming plant protein instead of animal protein. In other words, as another meta-analysis concluded“People should be encouraged to increase their plant protein intake to reduce their risk of death.”
Dr.’s comment
The benefits of calorie restriction may come from reduced animal protein intake. see Calorie restriction and animal protein restriction for more on 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? see Myths of protein synthesis.
How much protein do we need? see Are vegetarians getting enough protein?.
What about plant-based meat? Is the meat and burger impossible healthy?
