From Dr. Mercola:
Protein is essential for your health as it’s a structural component of enzymes, cellular receptors, signaling molecules, and a main building block for your muscles and bones.
Proteins also perform transport carrier functions, and the amino acid components of proteins serve as precursors for hormones and vitamins. But, when it comes to how much you need on a daily basis, there is a wide variety of opinions.
With advancing age, getting adequate amounts of high-quality protein is especially important, as your ability to process protein declines with age, as does the level of age-related muscle loss (sarcopenia), thereby raising your protein requirements.
That said, you’d be wise to monitor your intake to make sure you’re not overdoing it. Americans consume the most meat per capita in the world — more than 175 pounds of pork, poultry, and beef per year,1 and evidence suggests this is far too much for optimal health.
Making matters worse, the vast majority of this meat comes from animals raised in concentrated animal feeding operations (CAFOs), the quality of which is significantly inferior to organically raised, pastured, or grass-fed and grass-finished meats.
CAFO meats are also associated with an increased risk for antibiotic-resistant disease, and may be a source of prion-like proteins associated with mad cow disease and Alzheimer’s.
Adverse Consequences of Excessive Protein Intake
It’s important to realize that there is an upper limit to how much protein your body can actually use. And, on the average, Americans consume anywhere from three to five times more protein than they need, along with far too many carbohydrates and insufficient amounts of healthy fats.
Too much protein could actually be worse than eating too many carbs. To understand why eating too much protein is a bad idea, consider the following:
First, if you eat more protein than your body requires, it will simply convert most of those calories to sugar, and then fat. Increased blood sugar levels can also feed pathogenic bacteria and yeast, such as Candida albicans, as well as fueling cancer cell growth. When you consume more protein than your body needs, your body must remove more nitrogen waste products from your blood, which stresses your kidneys.2 Chronic dehydration can result, as was found in a study involving endurance athletes.3 Excessive protein can have a stimulating effect on an important biochemical pathway called the mammalian target of rapamycin (mTOR). This pathway has an important and significant role in many cancers. It’s also a significant regulator of the aging process.
When you reduce protein to what your body requires, mTOR remains inhibited, which helps minimize your chances of cancer growth, and boosts longevity. Animal research4,5 has revealed protein restriction alone may increase lifespan by as much as 20 percent.
Research6 by Dr. Valter Longo at the University of Southern California shows that people who get 20 percent or more of their daily calories from protein have a 400 percent higher cancer rate, compared to those who get only 10