“Crucially, the researchers found that plant-based proteins, such as those from beans, did not seem to have the same mortality effects as animal proteins. Rates of cancer and death also did not seem to be affected by controlling for carbohydrate or fat consumption, suggesting that animal protein is the main culprit.”
That chicken wing you’re eating could be as deadly as a cigarette. In a new study that tracked a large sample of adults for nearly two decades, researchers have found that eating a diet rich in animal proteins during middle age makes you four times more likely to die of cancer than someone with a low-protein diet — a mortality risk factor comparable to smoking.
“There’s a misconception that because we all eat, understanding nutrition is simple. But the question is not whether a certain diet allows you to do well for three days, but can it help you survive to be 100?” said corresponding author Valter Longo, the Edna M. Jones Professor of Biogerontology at the USC Davis School of Gerontology and director of the USC Longevity Institute.
Not only is excessive protein consumption linked to a dramatic rise in cancer mortality, but middle-aged people who eat lots of proteins from animal sources — including meat, milk and cheese — are also more susceptible to early death in general, reveals the study to be published March 4 in Cell Metabolism. Protein-lovers were 74 percent more likely to die of any cause within the study period than their more low-protein counterparts. They were also several times more likely to die of DIABETES.
But how much protein we should eat has long been a controversial topic — muddled by the popularity of protein-heavy DIETS such as Paleo and Atkins. Before this study, researchers had never shown a definitive correlation between high protein consumption and mortality risk.
Rather than look at adulthood as one monolithic phase of life, as other researchers have done, the latest study considers how biology changes as we age, and how decisions in middle life may play out across the human lifespan.
In other words, what’s good for you at one age may be damaging at another. Protein controls the growth hormone IGF-I, which helps our bodies grow but has been linked to cancer susceptibility. Levels of IGF-I drop off dramatically after age 65, leading to potential frailty and muscle loss. The study shows that while high protein intake during middle age is very harmful, it is protective for older adults: those over 65 who ate a moderate- or HIGH-PROTEIN diet were less susceptible to disease.
The latest paper draws from Longo’s past research on IGF-I, including on an Ecuadorian cohort that seemed to have little cancer or DIABETES susceptibility because of a genetic mutation that lowered levels of IGF-I; the members of the cohort were all less than five-feet tall.
“The research shows that a low-protein diet in middle age is useful for preventing cancer and overall mortality, through a process that involves regulating IGF-I and possibly insulin levels,” said co-author Eileen Crimmins, the AARP Chair in Gerontology at USC. “However, we also propose that at older ages, it may be important to avoid a low-protein diet to allow the maintenance of healthy weight and protection from frailty.”
Crucially, the researchers found that plant-based proteins, such as those from beans, did not seem to have the same mortality effects as animal proteins. Rates of cancer and death also did not seem to be affected by controlling for carbohydrate or fat consumption, suggesting that animal protein is the main culprit.
“The majority of Americans are eating about twice as much proteins as they should, and it seems that the best change would be to lower the daily intake of all proteins but especially animal-derived proteins,” Longo said. “But don’t get extreme in cutting out protein; you can go from protected to malnourished very quickly.”
Longo’s findings support recommendations from several leading health agencies to consume about 0.8 grams of protein per kilogram of body weight every day in middle age. For example, a 130-pound person should eat about 45-50 grams of protein a day, with preference for those derived from plants such as legumes, Longo explains.
The researchers define a “HIGH-PROTEIN” diet as deriving at least 20 percent of CALORIES from protein, including both plant-based and animal-based protein. A “moderate” protein diet includes 10-19 percent of calories from protein, and a “low-protein” diet includes less than 10 percent protein.
Even moderate amounts of protein had detrimental effects during middle age, the researchers found. Across all 6,318 adults over the age of 50 in the study, average protein intake was about 16 percent of total daily calories with about two-thirds from animal protein — corresponding to data about national protein consumption. The study sample was representative across ethnicity, education and health background.
People who ate a moderate amount of protein were still three times more likely to die of cancer than those who ate a low-protein DIET in middle age, the study shows. Overall, even the small change of decreasing protein intake from moderate levels to low levels reduced likelihood of early death by 21 percent.
For a randomly selected smaller portion of the sample – 2,253 people – levels of the growth hormone IGF-I were recorded directly. The results show that for every 10 ng/ml increase in IGF-I, those on a HIGH-PROTEIN diet were 9 percent more likely to die from cancer than those on a low-protein diet, in line with past research associating IGF-I levels to cancer risk.
The researchers also extended their findings about HIGH-PROTEIN diets and mortality risk, looking at causality in mice and cellular models. In a study of tumor rates and progression among mice, the researchers show lower cancer incidence and 45 percent smaller average tumor size among mice on a low-protein diet than those on a high-protein diet by the end of the two-month experiment.
“Almost everyone is going to have a cancer cell or pre-cancer cell in them at some point. The question is: Does it progress?” Longo said. “Turns out one of the major factors in determining if it does is is protein intake.”
Can you remember when smoking was recommended by doctors? Smoking was allowed in hospitals, airplanes and grocery stores! I am sure if we travelled back in time to tell those people; one day smoking will be prohibited almost everywhere, they would say “dream on”!
Last week, a study was published that found eating meat and dairy may be as detrimental to your health as smoking cigarettes. What was really exciting, though, was how much media attention the story received. The study’s findings were published on a number of major news sources such as CBS and Fox News, as well as many other media outlets.
For those of us who are already familiar with the science backing a whole food, plant-based diet, this is old news. For far too much of the population, however, this was completely new information. And not only that, but also information that contradicts many of the nutrition teachings they have been exposed to over the years. I mean, sure, a bacon cheeseburger is unhealthy, but lean meats and low-fat dairy products are good for us, right? Don’t we need fish for omega-3s? And without dairy, how will we get our calcium? …No, no, and hakuna matata, you’ll get plenty.
Here’s the thing: the science is there. And it’s growing. More and more, we are seeing studies like this published, and the evidence just keeps mounting. At this point, the science supporting that eating animals and their by-products promotes disease, whereas eating a plant-based diet promotes health, is basically indisputable. The studies and experience of far too many doctors, patients, and populations have proven this to be true.
More and more progress towards making this knowledge widespread, and making a plant-based lifestyle more mainstream, is happening all the time. It seems that so wonderfully often I’m learning about new doctors who are incorporating dietary interventions into their practice or new people who have adopted a plant-based diet. But despite this, the fact that a whole food, plant-based diet is not only healthy, but also optimal, continues to go unknown or disputed.
The problem is not that the information isn’t available. It is. The problem is that somehow people just aren’t receiving the message. I think there are two main reasons for this. The first is that it’s not given the attention that it should. Medical institutions, cancer and disease organizations, and nutrition societies still (for the most part) promote the standard American diet with an emphasis on “moderation.” Often, they do not even acknowledge the powerful influence that diet can have on one’s health—sometimes due to their own unawareness, and other times perhaps due to a conflict of interest, but either way denying the reach and access of this important information. When they do acknowledge diet, it is typically not given the emphasis that it deserves (and, as I mentioned earlier, the dietary recommendations often aren’t up to par with what the science proves to be optimal).
The second reason is that there is so much conflicting information. With books like Wheat Belly and Grain Brain, or diet crazes such as Paleo or Low-Carb, getting just as much (and usually more) media attention than plant-based nutrition, it can be difficult for people to know what to believe. Plus, the meat and dairy industries are full of money and connections that enable them to promote their products and fool us into thinking that they are healthy (for a little more info on this, see our post on the dairy industry), and that doesn’t help either.
A lot of this is stuff that we have no control over. What I want to focus on is what we CAN do. How can we get the word out? How can we help others to find this information and become educated, enabling them to take control of their health? I have a few ideas, but I also want to know what you think. For starters, though, here are my thoughts.
First of all, being a living example is the easiest, best thing you can do. Without even doing anything other than your typical routine, just living life plant-strong exposes those around you to the ease and awesomeness of eating this way. Some people have pre-conceived, negative notions of vegans and a plant-based diet, and we can help them to gain a more positive view of this lifestyle. Eating delicious meals, exuding health, and enjoying this way of life shows others the positivity involved with being plant-strong. (And sharing a yummy meal or two never hurts either).
Another way to spread the word is to actively share and promote it. When you see an article (such as the one mentioned at the beginning of this post) or a blog post that you think is important for people to know about, share it on facebook or email it to friends. If you’re on twitter, retweet things from resources like Engine 2, Dr. McDougall, Dr. Barnard, Rich Roll, Jeff Novick, Dr. Esselstyn, etc. Give books, documentaries, and retreat/study weekend sign-ups (both Engine 2 and Dr. McDougall have fantastic ones) to family and friends as presents. Sign up with a friend for a 21-day Vegan Kickstart or do a 28-Day Engine 2 Challenge (providing support is so important!). Organize events in your community such as documentary viewings or bringing in plant-based nutrition speakers. You can also volunteer with local organizations or write to public officials. I’m sure that there are lots of other things that you can do to share this information and help the plant-based movement gain momentum, but this is just a list to get you started and give you some ideas 🙂
They say that someone needs to see something about seven times before it sinks in and sticks with them. So the more we can get the word out and expose people to this information, the better a chance we have of making a lasting influence. This is a message worth sharing, so let’s get to it! 🙂