A large study from Harvard Medical School, Boston, MA showed that plant protein is better than animal protein.
They showed this with a large group of study participants. And they used a fixed end point, namely mortally rates.
The prospective cohort study of US health care professionals included 131 342 participants from the Nurses’ Health Study (1980 to end of follow-up on June 1, 2012) and the male Health Professionals Follow-up Study (1986 to end of follow-up on January 31, 2012). 64.7% (85 013) were women and 35.3% (46 329) were men. Both male and female participants had a mean age of 49 at the time of enrollment.
Other factors interfering with mortality
Four lifestyle factors had a strong influence on life expectancy. Smoking, heavy alcohol intake, overweight or obesity, and physical inactivity. In many of the subgroups at least one of these unhealthy lifestyle factors was present. When in these a portion of processed or unprocessed red meat intake was replaced with plant protein, mortality was significantly reduced.
Findings that plant protein is better than animal protein
The participants had a median protein intake of 18% (expressed as percentage of energy), where 14% derived from animal protein and 4% from plant protein. An increase of 10% of animal protein increased mortality by 8%, mainly due to cardiovascular mortality. Conversely, an increase of 3% plant protein reduced mortality by 10%. As already stated, these statistical associations were most clear when at least one unhealthy lifestyle factor was present. Substituting 3% of energy from plant protein for 3% of protein from processed meat reduced mortality by 34%. When plant protein was replacing the equal amount of unprocessed red meat the mortality was reduced by 12%. Replacing 3% of egg protein by the same percentage of plant protein reduced the mortality by 19%. These are significant and important numbers!
What is plant protein and what is animal protein?
Basically anything growing in soil are plants that have a certain amount of protein in them. Anything that walks on soil or swims in water are animals (cows, poultry, pigs, sheep, fish, shrimp or mussels).
The source of protein matters. Red meat from cows is the least desirable. Hamburger meat, sausages, bacon, hot dogs, salami, bologna and processed meat sandwiches are the worst protein sources associated with the highest mortality. In contrast, plant protein including bread, cereals, pasta, nuts, beans, and legumes are associated with the lowest mortality rates.
Unhealthy and healthy behavior patterns
Obese people or people with other unhealthy lifestyle factors consumed more processed and unprocessed red meat. On the other hand the healthy-lifestyle group consumed more fish and chicken as animal protein sources. Apart from the unhealthy lifestyle factor the protein source dictated the final mortality outcome. The study further showed that when only 3% of energy from protein of the unhealthy type was replaced by healthy plant protein the mortality fell by 10%. The average consumer can easily achieve this. The key is to gradually cut out the processed red meat in your diet. Eat more fiber, more vegetables, more nuts and fruit.
One other group of patients, the diabetics, were found to have poor diet habits with too little fiber, too much processed food and too much processed red meat products. Replacing animal protein sources with plant protein improved diabetes and lowered mortality from cardiovascular disease.
More evidence that plant protein is better than animal protein
The authors looked again at replacing only 3% of energy from plant protein to substitute 3% of protein from animal meat. A surprising reduction of mortality was noted.
Replacement of processed meat: 34% reduction of mortality
Replacing unprocessed red meat: 12% reduction of mortality
Replacement of poultry or fish: 6% mortality reduction for each
Replacing egg protein: 19% reduction of mortality
Replacing of dairy products: 8% reduction of mortality
Usually it was a reduction of cardiovascular mortality that reduced the overall mortality after replacement of animal protein. The only exception was egg protein where there was a 17% reduction of cancer mortality when 3% of egg protein was replaced with plant protein.
The more animal protein we eat, the higher the mortality rates are. Conversely, plant protein decreases mortality. But it does not mean that you should panic. Instead replace just 3% of your present animal protein intake with the same amount of plant protein. This will prolong your life expectancy. It does so by cutting down mortality from cardiovascular disease and cancers. The other factors that help your longevity are to keep your body weight below a body mass index of 25.0, to not smoke, to not drink excessively and to exercise regularly. Remember: plant protein is better than animal protein.