A calorie-restricted diet can extend the lives of organisms from yeast to fruit flies to rodents, as well as improving their health and preventing disease. But just because cutting calories helps animals with short lifespans doesn’t mean that humans will reap similar benefits. So the 2009 discovery that calorie-restricted diets also increase the longevity of already-longer-lived rhesus monkeys was exciting news.
But don’t pull out a calorie calculator quite yet. The latest word on the subject, from a new paper in Nature, suggests that the 2009 study might not tell the whole story: this team found that caloric restriction doesn’t actually grant rhesus monkeys longer lives.
You are what you eat—that’s true even after your bones have spent 200 years buried in the dirt. A new study using old bones from 18th century British sailors confirmed the naval diet: lots of biscuits, more protein than the average landlubber, and the same damn things sailors ate for the previous 200 years.
The Victualing Board actually kept meticulous records of a sailor’s official rations: 1 lb of bread and 1 gallon of beer per day (!), plus 1 lb of pork twice a week, 2 lbs of beef twice a week, or butter and cheese the other three days. But when the going got tough out in the middle of watery nowhere, did sailors actually get their rations? Yes, it seems, based on an analysis of nitrogen isotopes extracted from the bones of 80 sailors. The elevated levels of nitrogen suggested that sailors did get as much beef and pork as the Victualing Board recorded. And despite being at sea, they didn’t seem to eat much fish.
Even when you’re trying to eat healthy foods, it can be hard to know what to buy: Few us have the time to decipher the nutrition facts on every item we’re considering at the grocery store, and the dizzying number of health claims plastered on labels make the task, if anything, more confusing. The Institute of Medicine offered a possible solution in a report released yesterday: put a simple, standardized rating—zero to three stars or checkmarks—on every food package.
What’s the News: Trouble sticking to your diet? It may not be entirely your fault. Scientists, reporting in the journal Cell Metabolism, have now learned that when you starve yourself of calories, your brain cells also starve, causing your neurons to begin eating parts of themselves for energy. The self-cannibalism, in turn, cranks up hunger signals. This mouse study may lead to better treatments for human obesity and diabetes.
What’s the News: Researchers have known for decades that what a woman eats during her pregnancy can impact her child’s weight later in life. Now, a new study shows a possible mechanism for how mom’s diet affects baby’s weight: Epigenetic changes—changes that can increase or decrease the expression of a particular gene but don’t alter the genetic sequence—to a gene involved in fat metabolism can be passed from mother to child during pregnancy.
Did Neanderthals enjoy some diversity in their diet? A study out in this week’s Proceedings of the National Academy of Sciences claims to offer more evidence that these hominids ate a wide-ranging diet including cooked grains and grasses rather than the cartoon caveman’s diet of meat, meat, and more meat.
Amanda Henry has made the case before; in April 2008 she said that micro-fossils of plant material could be found in the plaque of recovered Neanderthal teeth. Now, she says, her team has found more traces of grains and plants stuck in the teeth of Neanderthal fossils unearthed in Belgium and Iraq.
After analyzing a selection of these particles from European and Middle Eastern Neandertal dental remains, the team found “direct evidence for Neanderthal consumption of a variety of plant foods.” … Some of the Paleolithic snacks seem to have included legumes, date palms and grass seeds. The grasses were from the Triticeae group, which includes wild varieties of barley, rye and wheat relatives. [Scientific American]
Furthermore, the grains and starches present show the signature of having been cooked—probably by boiling in water—according to study author Dolores Piperno. To test this out the researchers themselves cooked similar grains, and the effects matched what they saw in the Neanderthal samples.
Humans didn’t begin major agriculture until about 10,000 years ago. But 20,000 years before that they were grinding their own flour, a new study (in press) suggests, adding more proof that our forebears were eating the beginnings of a more balanced diet while still roving as hunter-gatherers.
Anna Revedin’s team says in today’s Proceedings of the National Academy of Sciences that they found traces evidence of flour still stuck in 30,000-year-old stones the team found in Russia, Italy, and the Czech Republic.
The flour, likely suitable for making flatbread or cakes, didn’t just give stone age people some dinnertime variety. Because it could be stored in dried form, flour would have given them greater independence from environmental and seasonal circumstance. [Wired.com]
The stones themselves appear to have been shaped for grinding, like an archaic mortar and pestle.
The health detriments of a Western diet—eating foods high in fat, sugar, and animal protein—are now well known. However, according to a group of studies out in this week’s Proceedings of the National Academy of Sciences, how you eat when you’re just a kid can have a great impact, influencing the gut microbes you’ll carry your entire life.
Researchers led by Carlotta de Filippo studied the gut microbes of African children raised in Burkina Faso versus those in European children from Italy. According to the team’s findings, the kids’ diet had a dramatic effect on what bacteria they harbored in their guts to help them with digestion. The Burkina Faso children, who grew up eating a lot of fiber, had gut bacteria that help to break down that tough material. Meanwhile the Italian children, who grew up on a Western diet, had guts dominated by a kind of bacteria that’s more common in obese people, and they had less bacterial diversity overall.
Two other PNAS papers this week took on the formation and evolution of a human’s gut microbiome. One showed how a nursing infant gets its first helpful gut microbes from mother’s milk, and the other followed the same baby for two and a half years—collecting “samples” from diapers—to show how its population of gut bacteria changed and developed.
For an in-depth take on these studies and insight on how they fit together, check out Ed Yong’s post at Not Exactly Rocket Science.
Not Exactly Rocket Science: You Are What You Eat—How Your Diet Defines You in Trillions of Ways
80beats: Scientists Sequence DNA from the Teeming Microbial Universe in Your Guts
80beats: My Excrement, Myself: The Unique Genetics of a Person’s Gut Viruses
Image: Wikimedia Commons