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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Meat the hidden culprit of climate change

 

Several cows stare into the camera
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Moving to a completely meat-free diet would go a long way to tackling climate change.

PHIL WALTER: GETTY IMAGES

Most of us agree that action needs to be taken to address climate change, but when it comes to moving to a meat-free diet to drastically reduce emissions, suddenly we’re not so keen, writes Ruby Hamad.

The cultural anthropologist Margaret Mead famously said, “It is easier to change a man’s religion than his diet.” It is also, apparently, easier to change the entire world’s energy production.

Earlier this month, the Intergovernmental Panel on Climate Change (IPCC) released its latest report, “Mitigation of Climate Change”, citing fossil fuels as the biggest source of emissions, with coal, oil, and natural gas the major culprits.

However, the panel also implicates animal agriculture, noting that“changes in diet and reductions of losses in the food supply chain, have a significant, but uncertain, potential to reduce GHG emissions from food production.”

Seventy per cent of agricultural emissions come directly from livestock – and about 37 per cent of total worldwide methane emissions – and it is clear that moving away from animal products is not just potentially significant but downright necessary.

The IPCC findings come hot on the heels of another study, “The importance of reduced meat and dairy consumption for meeting stringent climate change targets”, published in the April edition of Climate Change.

The study’s lead author argues that targeting the fossil fuel industry alone is insufficient because “the agricultural emissions … may be too high. Thus we have to take action in both sectors.”

In 2010 a UN report, “Priority, Products, and Materials” concluded that, “A substantial reduction of impacts would only be possible with a substantial worldwide diet change, away from animal products.”

That report puts agriculture’s global emissions at 14 per cent, and while not giving an exact figure, the researchers warn that “animal products, both meat and dairy, in general require more resources and cause higher emissions than plant-based alternatives”. Subsequent research suggests emissions from livestock and their by-products may be much higher (even as high as 51 per cent). Even if we err on the side of conservatism and stick to the lower UN figure, it still indicates that agriculture is responsible for more emissions that all means of transport combined.

No one who cares about the threat of climate change is ignorant of the importance of renewable energy and a reduction in energy use. So why do we still have our collective head in the sand about the need to change our diet?

In an impassioned tirade against Earth Day (April 22), which he dismisses as emblematic of “the culture of progressive green denial”, The Nation’s Wen Stephenson calls for radical action, namely, “physically, non-violently disrupting the fossil-fuel industry and the institutions that support and abet it … Forcing the issue. Finally acting as though we accept what the science is telling us.”

I don’t know what Stephenson’s food habits are but, ironically, in a piece railing against denialism, he does not mention meat consumption once. It is rather extraordinary how we acknowledge the need to address climate change and then carry on with those very activities that are causing the damage in the first place.

While some media outlets do report on the link between animal agriculture and global warming, they also undermine the urgency by featuring stories on, for example, how to include bacon in every meal – including dessert. TV channels flog reality shows glorifying high levels of meat consumption, and fast food outlets compete to see who can stuff the most meat and cheese into a single, fat-laden item.

All as scientists warn of the need to move away from dependency on animals as a food source.

When those of us who are concerned by the devastating effects of animal agriculture raise the issue, somehow the focus shifts from saving the planet to respecting personal choice, as if the choice to eat certain foods is sacrosanct.

We have to compromise our personal preferences every day in the interests of public safety. Smoking prohibitions, speed limits, alcohol restrictions, even initiatives promoting recycling and “green” household products all affect our choices.

But, for some reason, requesting people reduce their consumption of meat is taken as a personal affront to their very being. Humans have been eating animals for so long, and in such large quantities, we think we are entitled to their bodies, regardless of the consequences.

Clearly, our dependence on fossil fuels has to change but it is quite remarkable that we actually consider restructuring our entire energy system as an easier and more viable undertaking than simply altering our food habits.

The Guardian’s food writer Jay Rayner unwittingly demonstrates this in his reaction to a University of Aberdeen study that found a worldwide adoption of a vegan diet would reduce CO2 emissions by a massive 7.8 gigatonnes. But, rather than take this on board, Rayner chooses instead to shrug his shoulders, declare that “the world is not going vegan any time soon” and condemn “self-righteous vegans” for “making airy proclamations about the way forward when [they] have no power whatsoever to make it happen”.

But why don’t we have the power to make it happen?

Even if we don’t all go completely vegan, surely the takeaway is that everyone should eat less meat and more plants, and not just on Meatless Mondays?

It’s easy to point the finger only at fossil fuels because this requires no major personal sacrifice. We can pin all the blame on big corporations, demand policy change, and then feel good about ourselves by declaring on Facebook that we are against dredging the Barrier Reef and we don’t support fracking.

But meat is different. Meat means we have to change. It means we have to sacrifice something we enjoy, something we believe we are entitled to. And most of us simply aren’t willing to compromise that entitlement, so we pretend that the idea of a worldwide shift to a plant-based diet is simply too ridiculous to contemplate. That’s if we even acknowledge the crisis at all.

So we sign petitions and attend demonstrations. Some of us even drive less, take shorter showers, and use eco light bulbs. But nothing it seems, not even the looming threat of environmental catastrophe, could compel a significant number of us to simply change our diet.

Ruby Hamad is a Sydney-based writer and filmmaker. View her full profile here.

 

Source: http://mobile.abc.net.au/news/2014-04-28/hamad-meat-the-hidden-culprit-of-climate-change/5414894