Meat and cheese may be as bad for you as smoking

“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.”

 

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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.”

 

Source: http://www.sciencedaily.com/releases/2014/03/140304125639.htm

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A Vegan Diet (Hugely) Helpful Against Cancer

If you’re anything like me, the “C” word leaves you trembling. But today there is very good news to report: Research suggests you can improve your odds of never getting cancer and/or improve your chances of recovering from it. Not with a drug or surgery, although those methods might be quite effective. This is all about the power on your plate, and it’s seriously powerful.

A 2012 analysis of all the best studies done to date concluded vegetarians have significantly lower cancer rates. For example, the largest forward-looking study on diet and cancer ever performed concluded that “the incidence of all cancers combined is lower among vegetarians.”

That’s good news, yes. But what if we’re looking for great news? If vegetarians fare so much better than meat-eaters, what about vegans? Is that an even better way to eat? We didn’t know for sure until now.

A new study just out of Loma Linda University funded by the National Cancer Institute reported that vegans have lower rates of cancer than both meat-eaters and vegetarians. Vegan women, for example, had 34 percent lower rates of female-specific cancers such as breast, cervical, and ovarian cancer. And this was compared to a group of healthy omnivores who ate substantially less meat than the general population (two servings a week or more), as well as after controlling for non-dietary factors such as smoking, alcohol, and a family history of cancer.

Why do vegans have such lower cancer risk? This is fascinating stuff: An elegant series of experiments was performed in which people were placed on different diets and their blood was then dripped on human cancer cells growing in a petri dish to see whose diet kicked more cancer butt. Women placed on plant-based diets for just two weeks, for example, were found to suppress the growth of three different types of breast cancer (see images of the cancer clearance). The same blood coursing through these womens’ bodies gained the power to significantly slow down and stop breast cancer cell growth thanks to just two weeks of eating a healthy plant-based diet! (Two weeks! Imagine what’s going on in your body after a year!) Similar results were found for men against prostate cancer (as well as against prostate enlargement).

How may a simple dietary change make one’s bloodstream so inhospitable to cancer in just a matter of days? The dramatic improvement in cancer defenses after two weeks of eating healthier is thought to be due to changes in the level of a cancer-promoting growth hormone in the body called IGF-1. Animal protein intake increases the levels of IGF-1 in our body, but within two weeks of switching to a plant-based diet, IGF-1 levels in the bloodstream drop sufficiently to help slow the growth of cancer cells.

How plant-based do we need to eat? Studies comparing levels of IGF-1 in meat-eaters vs. vegetarians vs. vegans suggest that we should lean toward eliminating animal products from our diets altogether. This is supported by the new study in which the thousands of American vegans studied not only had lower rates of obesity, diabetes, and hypertension, but significantly lower cancer risk as well.

This makes sense when you consider the research done by Drs. Dean Ornish and Nobel Prize winner Elizabeth Blackburn; they found that a vegan diet caused more than 500 genes to change in only three months, turning on genes that prevent disease and turning off genes that cause breast cancer, heart disease, prostate cancer, and other illnesses. This is empowering news, given that most people think they are a victim of their genes, helpless to stave off some of the most dreaded diseases. We aren’t helpless at all; in fact, the power is largely in our hands. It’s on our forks, actually.

Source: http://www.huffingtonpost.com/kathy-freston/vegan-diet-cancer_b_2250052.html