The plant-based protein market was valued at $16.5 billion in 2018 and is forecasted to triple, to $40.5 billion by 2025, with a myriad of varieties of vegan protein powder on the market. If you want to avoid soy, you have plenty of choices, whether you prefer pea- or rice- or hemp-based protein or some combination. If you don’t care for glyphosate in your powder, you can now choose from dozens of organic options.

However, as more and more consumers are coming to realize, billion-dollar industries don't always optimize their products for human health. Perhaps the most common question posed to vegans or people who eat plant-based has been, “Where do you get your protein?” The more apt question might be: Do you really need all that protein? There is growing evidence that a low-protein diet is healthier, helps fight aging, and prevents disease. And yet, we are sold on the hype that getting an abundance of protein is a requirement of a fit, active body, and the more the better.

The USDA dietary guidelines appear to have a fixation on protein—it's a food group—and since meat products contain some of the highest concentrations of protein per serving among all foods sold at grocery stores, the requirement for protein has proven an invaluable marketing tool. No matter whether you're selling plant-based products or those from animals, our obsession with protein intake has been a powerful marketing tool. Americans have been taught that protein helps build muscle. No protein, no strong bodies. But what if I told you that we don't need nearly as much protein as we've been told? And in fact, there are significant health benefits from getting less?

How protein works, and why too much can lead to aging, heart disease, and cancer

As for building strong muscles, one of the mechanisms in the body that facilitate this process is the hormone known as insulin-like growth factor 1(IGF-1), which is synthesized by the liver and muscles in higher quantities in people who eat more protein. Vegans, vegetarians, and flexitarians alike may rejoice that there are so many plant-based protein powders to help them raise their IGF-1 levels, but they may also be interested to learn about some of the unintended consequences of elevated IGF-1 levels.

Perhaps the most concerning studies are those that show elevated levels of IGF-1 have been associated with cardiovascular disease and cancer, which respectively are the first and second most common causes of death for Americans (cardiovascular disease alone kills over 650,000 Americans a year if you include heart attacks and strokes). The cancer study specifically states: "Epidemiological evidence is accumulating and suggests that the risk of cancers of the colon, pancreas, endometrium, breast, and prostate are related to circulating levels of insulin, IGF-1, or both."

The cardiovascular study states "Numerous studies have investigated the effect of serum IGF-I concentration on aging and different aging-related diseases, e.g. cardiovascular disease (CVD) and cancer. Decreased as well as increased levels have been reported to be associated with reduced life expectancy in humans." Essentially, too much protein as we age is as deadly as too little.

Accelerated aging and high protein consumption have been measured since 1996 when a study in the American Journal of Epidemiology showed that dietary protein increases calcium loss in the urine, putting high-protein consumers at risk of osteoporosis. The study found that women who ate more than five servings of red meat a week had a significantly higher risk of forearm fracture than women who ate less than one serving of meat a week. The study notes that an increased risk of bone fracture was not associated with higher consumption of vegetable protein (the study makes no mention of vegetable-derived protein powder), so it appears that protein consumption in the form of whole vegetable sources is healthiest.

In most cases, Americans eat far more protein than they need each day. The recommended daily amounts are 45 grams for a woman and 58 grams for a man, per day, though you can safely add more if you are actively training for an event or hitting the gym daily. Protein deficiency is not a serious problem in the American diet, whereas overeating is. (For a handy calculator, enter your age and weight and find out how much you need.)

Dr. Joel Fuhrman, bestselling author, doctor, and plant-based lifestyle champion, takes the position on IGF-1 is that to be your healthiest, you should maintain lower levels throughout your adult life by eating plant-based. In his blog on the topic, he writes:

"Excessively low or high IGF-1 levels could lead to health problems. In adults, a high IGF-1 level is linked to accelerated aging and an increased risk of cancer and premature death. Maintaining a relatively low IGF-1 level throughout most of one’s adult life is thought to be an important factor by which centenarians are able to live that long without developing cancer."

So what is the right amount? Furhman tackles that as well: "The European Prospective Investigation into Cancer and Nutrition (EPIC) study reported an average serum IGF-1 level of 200-210 ng/ml, suggesting that this is a typical level for adults on a Western diet. The amount of animal products consumed by most Americans drives their IGF-1 into this danger zone (above 200), increasing their risk of cancer."

Keeping your IGF-1 lower as you age is will minimize the risk of disease, including cancer, heart disease, and stroke, according to studies. To get the amount of protein you need (but not more) Dr. Furhman suggests you eat a varied plant-based diet incorporating more beans, greens, and seeds as you age to maintain healthy bone mass, muscle mass, and brain function.

Modern science has endowed us with the power to choose how high our IGF-1 hormone levels are and has also proven which choice–high protein or low protein–is associated with longevity. If you decide not to consume protein powder from any source, you may live longer than your gym buddy who takes it by the scoopful. You'll also save money on groceries.