Protein, Muscle Mass, and Cancer

In my bodybuilding days, it was critical that I ate the right foods at the proper intervals to fuel my body’s production of lean muscle mass. The most important nutritional element for muscle growth is protein, which was a staple of my daily dietary regimen throughout my fitness career.

Protein is essential for maintaining the muscle mass that I had gained, and so I still adhere to a high-protein diet today. Men and women of all ages require protein in order to support the body’s musculature system, which some experts call the “organ of longevity.”

Protein is the primary building block of muscle tissue, which is the largest endocrine, or hormone-producing, organ in the body. Muscle tissue is one of the key regulators of hormone production, and protects the body against diseases like cancer.

But the government’s official dietary guidelines seem to regard protein as less essential than it actually is for health maintenance and disease prevention. The Recommended Dietary Allowance (RDA) of protein is a mere 0.8 grams per kilogram of body weight (about 15 – 25% of total caloric intake. For a 175lb man, this equates to roughly 64 grams of protein per day – far from enough for optimal health.

How Healthy Muscle Mass Supports a Strong Metabolism

Personally, I wouldn’t be able to keep up my strenuous lifestyle on just 64 grams of protein per day. When I fail to eat enough protein, I can feel the negative effects throughout my body. My metabolism is off, I feel fatigued and irritable, and I experience stress more quickly and easily than when I optimize my protein intake.

That’s because muscle mass is the engine that drives metabolism, converting fuel into energy. Your muscles are the body’s primary energy source, where complex carbohydrates are packed away in the form of glycogen, a stored form of glucose.

This may contradict what you thought you knew about muscles, given that they consist of protein and amino acids. But your muscles are simply where all of this glycogen is stored as it awaits conversion back into glucose, the body’s primary source of energy.

Every cell in your body is primed to receive and use glucose, as are many of your vital organs. And glucose is the easiest and most efficient fuel for the body to mobilize, especially during strenuous activities like sports or exercise. 

The brain loves glucose, too. While the brain itself consists of cholesterol and other fatty compounds, glucose is essentially the only fuel that it can use.

Muscle Glycogen Regulates Glucose Release and Blood Sugar Balance

But isn’t glucose sugar, and isn’t sugar bad? In excess. Unregulated blood sugar can be lethal, but without regulated glucose release, you would die. This is what glycogen is for, and it relies on healthy muscles to do so.

Glycogen functions as a type of control valve for the body’s release of glucose for specific purposes throughout the body. This regulatory system maintains healthy blood-glucose levels, preventing dramatic insulin spikes that can lead to type-2 diabetes and other disorders.

Glycogen is also stored in the liver, but the majority is found inside muscle tissue – which is why a lack of muscle tissue can cause the entire regulatory process to malfunction. This can lead to disease and even death.

Muscle tissue serves many purposes beyond just holding our skeletons in place; it represents a critical command post from which our bodies process and use nutrients, as well as supporting healthy body composition, bone strength, and resilience to stress and chronic illness. It can even protect against cancer.

Lack of Muscle Mass Linked to Increased Risk of Cancer and Premature Death

When discussing weight and cancer, health experts often focus on the problems associated with being overweight. But being underweight is also a risk factor, as multiple studies have linked low muscle mass (known as sarcopenia) with increased cancer risk. A study published earlier this year in JAMA Oncology found that sarcopenia, poor muscle quality, and excess abdominal fat are all associated with higher rates of metastatic breast cancer.

Sarcopenia and the immobility that often accompanies it are byproducts of metabolic breakdown and anabolic resistance – two things that involve unhealthy muscles. These factors of aging traditionally arrive with middle age, beginning as early as the 40s and really kicking in by the 60s. But increasingly, people in their 30s are experiencing premature muscle aging, probably due to the fact that society is becoming increasingly more sedentary.

The loss of muscle function, strength, and mass that results from this persistent inactivity is typically followed by increased levels of fat, leading to more inflammation, free radical damage, cortisol and insulin resistance, and disease. This highly damaging process can also make the body less able to recover from disease.

In women who have breast cancer, are in remission, or are nearing the end of their treatments, low muscle mass is directly associated with poor long-term prognosis and survival. Lead author Dr. Bette Caan of Kaiser Permanente’s Northern California Division of Research stated that low muscle mass is an “underappreciated” aspect of breast cancer, and that it’s just as problematic as being overweight or obese in terms of cancer risk and survival outcomes.

Men are similarly harmed by a lack of muscle mass. Science has found that males with the strongest one-rep max on both the bench press and leg press have a 40% reduced risk of colon cancer. A direct product of muscle mass, strength has further been shown to decrease both men’s and women’s risk of dying from all causes, suggesting that there’s something uniquely special about muscle mass in the way that it helps to protect against illness.

If you think of muscle mass as a complex, independent organ, it all makes sense, since this system is responsible for regulating hormones, insulin, metabolism, and even inflammation throughout the body. Not having enough muscle mass is a recipe for total health disaster. And the problem is multiplied if you’re already sick with a disease like cancer, which can cause the body to become even more muscle-depleted.

Keep in mind that stress, a known and prominent cause of cancer, is also a muscle-killer. Dr. Toni Bark from The Center for Disease Prevention & Reversal talked all about this at our 2017 The Truth About Cancer LIVE event in Orlando, explaining that whenever the body is in “fight or flight” mode resulting from heavy stress, its response is to pull glucose from wherever it can in order to cope. If there’s no glucose to be found from food or other readily-available sources, then the body resorts to stealing it from muscle mass, fat reserves, and anywhere else it can be found. This “wasting” process can quickly lead to all sorts of chronic health failures.

You Can Build Muscle Mass Even in Old Age

So how do we stimulate muscle tissue to avoid all of this? When you’re young, it’s a largely automatic process driven by natural hormones like insulin and human-growth hormone (HGH), which tend to support robust muscle health. As you age, however, exercise and a proper, high-protein diet become even more important. 

Prominent research suggests that consuming a minimum of around 100 grams of protein each day, broken down into at least 30 grams per meal, and three meals per day. This is the baseline recommended by Dr. Gabrielle Lyon of The Ash Center in New York City, though higher amounts are necessary if you want to thrive as opposed to just survive.

Dr. Lyon is one of the world’s leading experts on protein consumption and is actually the person who coined “organ of longevity” to describe the muscle system as a whole. Her philosophy is deeply rooted in science, which shows that healthy muscle mass is one of the keys to normalizing things like blood-sugar, antioxidant balance, inflammation control, and fat mediation. Your muscles are your largest bodily unit for glucose disposal and fat oxidation, both of which are at the core of human health and longevity.

This is why aging adults need to do everything they can to keep their muscles healthy and strong, especially as they lose the sex steroid hormones that would otherwise handle this process. It all starts with protein… and eating the right amounts and types of protein at just the right times.

Amino Acids in Protein Drive Critical Muscle Signaling Process That Supports Longevity

The amino acids found in high-quality protein are the driving force behind the “lock and key” effect, or mTOR (mechanistic target of rapamycin). mTOR is a natural anabolic process that involves the activation of muscle tissue at key intervals throughout the day, sparked either by protein consumption or intense exercise. Let’s take a closer look at the influence of protein on this process.

Since anabolic resistance naturally declines with age, protein is necessary to fill the gap. It does so by promoting modulated mTOR signaling to build more muscle mass – which is not the same thing as insulin-mediated, or chronic, mTOR signaling. Chronic mTOR signaling can actually be a cause of muscle-wasting and the formation of cancer, usually resulting from poor dietary and lifestyle habits that drive blood-sugar levels through the roof.

“It’s the chronic feeding, the grazing of carbohydrates throughout the day” that causes this bad type of mTOR signaling, says Dr. Lyon, adding that this extremely common bad habit is “the worst thing you can do” for your body. That’s because it often leads to major insulin spikes that can evolve into type-2 diabetes and other serious health problems.

The type of beneficial mTOR signaling to which I’m referring couldn’t be more different, as it involves short-duration signaling “bursts” that are virtually identical to what occurs while lifting weights or exercising. This type of mTOR signaling tells your body that it’s time to grow stronger and more robust, utilizing the amino acids found in the protein you should be eating.

Leucine: The Ultimate Muscle Amino

There’s one protein-based amino acid, leucine, that carries much of the load in spurring the growth of new muscle tissue and maintaining existing muscle tissue. This essential amino acid, which only comes from diet and isn’t produced in the body, is considered to be the premiere muscle-building amino acid, possessing a significantly higher ability to promote muscle synthesis compared than other amino acids.

Leucine falls into a special category of amino acids known as branched-chain, or BCAA, and is one of the three essential amino acids that the body requires in order to build muscle tissue but cannot make on its own. The others are isoleucine and valine. Each of these BCAAs stimulate skeletal muscle protein synthesis, but leucine is by far the most effective – especially in older people who have a tougher time building muscle due to anabolic resistance.

How to Eat for Leucine Maximization (or Supplement If You’re on a Restricted Diet)

For leucine to actually benefit muscle tissue and achieve what’s known as the leucine threshold, you have to consume it alongside full-spectrum protein. The body’s first priority is to distribute any ingested amino acids into cellular tissue located throughout the digestive tract, liver, kidneys, cardiovascular system, smooth muscles, and skin. Whatever’s leftover is then used to synthesize new muscle mass.

To make sure that you’re maximizing leucine’s use for this latter purpose, Dr. Lyon and others recommend eating three or four meals per day, depending on your routine level of physical activity. These meals should be evenly distributed throughout the day with 3- to 5-hour gaps in between, each meal containing high levels of protein in the 40- to 50-gram range. This is an optimal eating pattern for both stimulating and resetting mTOR while promoting healthy muscle maintenance and growth.

Once your body has reached the leucine threshold during a single meal, it needs time to utilize it all before being replenished. Experts seem to agree that the best way to optimize this is by eating large, high-protein meals high in leucine, followed by refractory periods, followed by another high-protein meal, and so on.

In Dr. Lyon’s view, optimal protein intake per day should be around 1.6 grams per kilogram of weight. For the average person, this amounts to about 150 grams of protein per day, or even higher if your weekly routine involves resistance training or other high-intensity exercise. Current research seems to suggest a per-meal intake level of between 2.5-5 grams, depending on body weight, for reaching the leucine threshold. Eating a six-ounce cut of chicken breast or six large eggs during a single meal is roughly the amount needed to reach this leucine threshold.

Supplementing with leucine is another option, especially if you’re not a heavy eater. Just add a 10-gram scoop of BCAAs – roughly one-third of which will be leucine – to your favorite beverage. A 25-gram scoop of pure whey protein isolate also contains about 3 grams of leucine, so whipping up a quick protein shake to accompany your meal is another option. Just remember to eat and supplement all at once rather than “graze,” as this will ensure optimal protein-muscle synthesis.

Why Animal Protein Is Better Than Plant Protein for Protein-Muscle Synthesis

The quality of the protein you eat determines how effectively that protein will help your body – and gram for gram, animal-based protein is superior for supporting proper muscle synthesis. You simply won’t find high enough amounts of leucine and other BCAAs in plant-based proteins and foods to achieve this goal, which is why it’s much more difficult for vegetarians and vegans to reach the leucine threshold without considerable supplementation – not to mention the fact that many vegetarian and vegan diets are heavy on carbs and low on protein as it is.

Take soy and wheat protein, for instance. According to Dr. Lyon, you would need to consume more than 40 grams of either at one time in order to stimulate the mTOR signaling response that’s critical for muscle growth – and even then, this response would be exceptionally weak. 25 grams of whey protein isolate, on the other hand, is enough to do the trick, easily breaching the 2.5-gram leucine threshold that Dr. Lyon believes is a healthy baseline for triggering muscle-protein synthesis.

“There’s so much agenda-driven information out there about ‘sustainability’ and those kinds of things that really affect people’s health,” she says, referring in part to the claims that vegetable-based foods and proteins are equal to animal protein. 

“I saw obese patients, and I also saw the cognitively-impaired, I saw geriatric patients – the other end of longevity. And through a lifetime of yo-yo dieting and low protein, their brains and their muscle tissue is gone. And it’s totally preventable,” she warns about low-protein diets that may do more harm than good.

Unless you have a pre-existing health condition, you should have no problem consuming the amount of protein that you need.

Even brain studies in which cognition, wiring, and other metrics were measured using imaging scans have shown that, roughly 4-5 hours after eating a high-protein meal, the brain actually “lights up” in a positive way. The same cannot be said for high-carbohydrate meals and snacking, however, which Dr. Lyon says actively inhibit brain activity and harm cognition.

Protein is Good for Virtually Everyone, Regardless of Dietary Restrictions

I tend to side with Dr. Lyon’s view that protein supports our body’s primary longevity organ: our muscles. There are various reasons why some folks might need to utilize a lower-protein dietary protocol, at least for a while – perhaps one of the most well-known protocols being the ketogenic diet, which involves intentional methionine restriction. But low-protein diets are generally intended to be temporary for a very specific purpose – not necessarily a long-term dietary approach.

You can integrate a high-protein diet within other dietary protocols like time-restricted eating and intermittent fasting, both of which synchronize quite well with heavy protein meals. Dr. Lyon actually suggests starting off your day with a 50-gram protein meal if you’re a man, or a 35-gram protein meal if you’re a woman and doing so as part of an intermittent fasting routine.

Even if you’re currently on a ketogenic diet that involves only moderate amounts of protein intake, you can take BCAAs, which don’t get converted to glucose the same way as other forms of protein. Since the standard keto diet offers little in the way of muscle stimulation, BCAAs are probably the best way to get your protein and stimulate protein-muscle synthesis while remaining in ketosis.

A helpful tip is to start training your body to endure periods of hunger and avoid the temptation to snack or graze, which completely disrupts the healthy mTOR signaling process. By disciplining your body to eat just three or four high-protein meals per day, with nothing in between, you’ll be able to reset your metabolic and mTOR signaling baselines to allow for maximum muscle-protein synthesis every time you eat. This is critical for maintaining metabolic flexibility, which is important for stabilizing your blood sugar throughout the day.

As for amino acids like glutamine and arginine, Dr. Lyon recommends focusing on feeding your muscles first, which means getting as much natural protein from animal-based foods as possible and adding in BCAAs and whey protein as necessary to supplement. If you’re doing all of this right, then the rest of the amino acid chain will take care of itself.

“When you are really hitting enough to look at the macroscopic view of the big tissue, then everything on the cellular level is able to be met,” says Dr. Lyon. “If we use food as medicine and we get the food right on a large tissue level, then everything follows suit.”

Exercise Boosts Insulin Sensitivity While Improving Muscle-Protein Synthesis

Finally, exercise is also important for muscle growth. Nothing revs up your metabolism and gets your muscles primed for oxygenation and growth like high-intensity training, which I believe is best done first thing in the morning before your first high-protein meal of the day. Such activities include things like resistance training, weightlifting, and interval sprints. Long-distance running and other low-intensity endurance exercises can actually work against the protein-muscle synthesis process because they induce muscle hypertrophy.

According to Dr. Lyon, it’s not necessary to stimulate insulin through diet before high-intensity exercise, because the exercise does this itself. Because your muscles are already primed and ready to efficiently intake protein after you’re done, Dr. Lyon further says that a reduced post-workout meal containing roughly 25-grams of protein should suffice, while the normal 40-50-gram protein meals are better suited for non-workout days to achieve the same levels of muscle-protein synthesis.

The post-workout insulin spike resulting from both exercise and eating is necessary to optimize your body’s glucose and amino acid uptake. Fortunately, it’s very brief, and only for the benefit of muscle tissue. Once the BCAAs and other protein molecules are inside your cells and working their magic, insulin levels quickly return to normal. Conversely, carb- or sugar-induced insulin spikes can last hours, causing prolific damage to the body.

This is why a brief, post-workout insulin spike, contrary to popular belief, does not ruin ketosis, since these lower levels of circulating insulin actually spur the production of ketones. Sugar-induced insulin spikes are prolonged and highly inflammatory.

Another benefit of strength training is that it helps to protect against cancer. A study out of Spain found that high-intensity interval training (HIIT) significantly reduces levels of cancer-causing hormones like insulin-like growth factor (IGF), too much of which can spur the growth and spread of cancer cells. It does this by increasing levels of an IGF-binding protein known as IGFBP3 that helps to regulate IGF levels, thwarting cancer potential.

If you’re able, engaging in complex, full-body movements like deadlifts and squats are among the most beneficial for prompting protein-muscle synthesis and protecting against diseases like cancer. If you’re unable, you can still identify your maximum strength ability for any given exercise and work out a routine where you’re able to perform multiple sets of roughly 10 reps each before reaching fatigue. Just be sure to avoid taking antioxidant supplements or foods right after you’re done, as low levels of free radical signaling – which antioxidants prevent – are actually important for promoting protein-muscle synthesis.

Most importantly, listen to your body. Start to incorporate some of these dietary and lifestyle habits into your daily routine and pay close attention to how you feel. If you start small and work your way up, I’m confident that you’re going to feel some major improvements.

If you’re unsure about your diet and exercise, you should always consult a qualified professional who can offer support and further tips.