New research published in the American Journal of Clinical Nutrition shows that both plant-based protein and meat build muscle equally well however because plant-protein comes with less 'baggage' in the form of harmful components it's the more beneficial protein source to use.

A study published last week in the American Journal of Clinical Nutrition found that dietary protein derived from plant sources built muscle just as well as protein from meat sources. However meat also comes with additional components that are harmful to our health, including antibiotic residue, hormones, saturated fat, trans-fats, endotoxins, cholesterol, Neu5Gc, heterocyclic amines and contaminants such as high levels of metals including copper and arsenic. These undesirable elements increase inflammation and promote various diseases thus making meat a less desirable option when building muscle and long term health are considered.

From 2002 to 2005, researchers from the Hebrew Senior Life's Institute for Aging Research and University of Massachusetts Lowell observed the muscle mass, strength, and bone density of 3,000 participants with varied dietary habits in the 17 to 72 age range. They found that while higher protein intake led to better overall musculoskeletal health, the source of dietary protein—plant or animal—was irrelevant. “We know that dietary protein can improve muscle mass and strength,” lead researcher Dr. Kelsey M. Mangano said. “However, until now, we did not know if one protein food source was better than another in accomplishing optimal results.”

And there’s no comparison between animal foods and plant foods when it comes to providing immune-boosting and cancer-fighting nutrients. Animal foods are either exceedingly low or devoid of antioxidants and tend to offer concentrated amounts of individual nutrients, like protein or calcium, while being deficient in many others. By contrast, plant foods are rich in antioxidants and provide a wide spectrum of vitamins, minerals, and other health-promoting nutrients.

Only plants contain powerful substances called phytochemicals, which scientists are now discovering protect us from cancer, heart disease, and other serious illnesses. Plants are also the primary source of all minerals in our diet. Minerals are derived from the earth and make their way into the food supply via plants. The only reason animal foods contain any minerals at all is because the animals eat plants. And plants are our only sources of dietary fiber, which binds in our intestines with fat, cholesterol, environmental pollutants and disease-causing hormones to eliminate these dangers from the body. Fiber also protects against bowel cancers, yet 97% of Americans don't meet the daily requirements for fiber intake.

Professional bodybuilders and weightlifters such as Mr Universe Barny Du Plessis, multiple world-record holding strongman Patrik Baboumian, or Icelandic weightlifting champion Hulda B. Waage, amongst many others, are living proof of Mangano’s findings. People are already ditching whey in favor of vegan protein powders, which have seen a significant increase in sales, and a few months ago the largest collection of vegan muscle ever gathered in London for the Vegan Athlete's Summit.

Additional discussion:

The study published February 8, 2017 confirmed (as we long suspected) there were no differences in muscle mass based on people’s dietary pattern, and those eating mostly legumes were benefitting as much as those eating red meat.

So now we know that there is no disadvantage in muscle gained whilst using plant-based protein. Now, there isn't much point in looking at this study in isolation, so let's look at other critical factors to determine which is the more ideal protein source for building muscle. Whatever protein source bodybuilders and those wanting to gain muscle mass choose, they're going to eat a much higher amount of protein so careful consideration of the source is required.

And we already know from countless other experiments even small amounts of animal protein causes inflammation and promotes disease (including heart disease and cancer), and most recently: "Red meat intake, particularly unprocessed red meat, was associated with an 58% increased risk of diverticulitis".

Regarding the inflammatory effect of animal protein:

The beneficial anti-inflammatory properties of a plant-based diet come from the avoidance of inflammatory foods such as animal products, as well as the inclusion of micronutrient-rich, whole plant foods. Plant foods are a rich source of phytochemicals, which support our endothelial cells that line the inside of our entire vascular system. These cells play an important role in maintaining the elasticity and dilation of our blood vessels by producing a gas called nitric oxide. The health and performance of these cells is determined by the types of foods that we eat. Saturated animal fats as well as refined vegetable oils are two factors that have been shown to damage these cells. When these cells become damaged, the blood vessels become stiff, inflamed, and paralyzed, impairing the flow of blood. This damage also promotes the development of plaque formation, causing atherosclerosis (hardening of the arteries). This damage can occur after consuming a single high-fat meal of animal products and lasts for several hours. This same inflammation takes place throughout our entire body, including our lungs, causing both immediate and long term damage. Scientists have now discovered that bacterial endotoxins found in our bloodstream following a meal of animal products is what causes this inflammatory response and occurs within hours after eating. Watch this two-part video response by Dr. Michael Greger, as he explains this process in greater detail. "After a meal of animal products, people suffer from endotoxemia, their bloodstream becomes awash with bacterial toxins, known as endotoxins. A single meal of meats, eggs, and dairy can cause a spike of inflammation within hours that can stiffen one's arteries." Normal blood flow can be significantly reduced up to 50% lasting for up to 5-6 hours. Repeating this cycle with more animal products continues the progression of this inflammatory process. "This can set us up for inflammatory diseases such as heart disease, diabetes, and certain cancers one meal at a time."

When considering what we already know about the harmful effects of animal protein from previous studies in addition to the findings from this study (showing there is no disadvantage in using plant-based protein for building muscle) it's clear that plant-based protein is a much better source for those wanting to gain muscle, particularly as higher amounts of protein are typically going to be ingested.