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Posts Tagged ‘Diet & Nutrition’

Researchers have found that the insulin signaling pathways in worms have a direct bearing on their lifespan. This research is particularly interesting because humans and worms share very similar insulin signaling pathways.

Over a decade ago, the first part of this research led to some positive news as researchers found that certain mutations involved in the insulin pathways can greatly extend lifespan in worms.

“In the early 90s, we discovered mutations that could double the normal life span of worms,” Kenyon said. Those mutations effected insulin signals. Specifically, a mutation in a gene known as daf-2 slowed aging and doubled life span. That longer life depended on another “FOXO transcription factor” called DAF-16 and the heat shock factor HSF-1.

Unfortunately, the recent results show that adding sugar to the worm diet has the opposite effect.

By adding just a small amount of glucose to C. elegans usual fare of straight bacteria, they found the worms lose about 20 percent of their usual life span. They trace the effect to insulin signals, which can block other life-extending molecular players.

Here is the technical aspect of the results:

In fact, glucose makes no difference to the life span of worms that lack DAF-16 or HSF-1, they show. Glucose also completely prevents the life-extending benefits that would otherwise come with mutations in the daf-2 gene.Ultimately, worms fed a steady diet containing glucose show a reduction in aquaporin channels that transport glycerol, one of the ingredients in the process by which the body produces its own glucose. “If there is not enough glucose, the body makes it with glycerol,” Kenyon explained. That glycerol has to first get where it needs to go, which it does via the aquaporin channels.

There are a few ways in which the result from studying worms affects us as humans.

A diet with a low glycemic index seems like a safe bet for now. One of the scientists was alarmed enough with the data to make serious changes to her diet:

As an aside, Kenyon says she read up on low-carb diets and changed her eating habits immediately — cutting out essentially all starches and desserts — after making the initial discovery in worms. The discovery was made several years ago, but had not been reported in a peer-reviewed journal until now.

Another area of concern is medicine. Current drugs may be offering treatment which carry as of yet unknown long term side effects. Fortunately, as is the case with anti-depressant medication, science is continually advancing to make our lives better and this research will undoubtedly result in better life saving medicines.

She says the findings may also have implications for drugs now in development for the treatment of diabetes, which are meant to block glucose production by inhibiting glycerol channels. The new findings “raise a flag” that glycerol channels might be doing something else, she says, and that drugs designed to block them might have a downside.

A long term study recently found a connection between consuming two servings of diet soda daily and a significant decline in kidney function. How do different types of artificial sugars factor into these results? Is there any connection between these two studies?

Aging in humans is far more complex than in worms.

“Although we do not fully understand the mechanism by which glucose shortens the life span of C. elegans, the fact that the two mammalian aquaporin glycerol-transporting channels are downregulated by insulin raises the possibility that glucose may have a life-span-shortening effect in humans, and, conversely, that a diet with a low glycemic index may extend human life span,” the researchers write. Kenyon also points to recent studies that have linked particular FOXO variants to longevity in several human populations, making the pathway the first with clear effects on human aging.

Glucose and the insulin signaling pathways are probably just one piece in a complex puzzle explaining the aging process. With every piece of the puzzle that gets illuminated and understood we come one step closer to allowing science an opportunity to stop aging.

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Some sobering news about diet soda has come to light which should give people pause before consuming such beverages.

Julie Lin MD, MPH, FASN and Gary Curhan, MD, ScD, FASN of Brigham and Women’s Hospital studied more than 3,000 women participating in the Nurses’ Health Study to identify the impact of sodium and sweetened drinks on kidney function.

The information from the participating women, whose median age is 67, was from 1984, 1986, and 1990 and included data about kidney function. Over the course of the years from 1989 – 2000, the shocking data revealed that over 11% of the women suffered a decline of over 30% in their kidney function.

“Thirty percent is considered significant,” says researcher Julie Lin, MD, MPH, assistant professor of medicine at Harvard Medical School and a staff physician at Brigham and Women’s Hospital in Boston. That’s especially true, she says, because most study participants had well-preserved kidney function at the start of the study.

What those women had in common was a thirst for artificially sweetened sodas which exceeded two per day. Other factors were ruled out in reaching that conclusion, including age, caloric intake, obesity, high blood pressure, diabetes, cigarette smoking, physical activity, and cardiovascular disease.

Put another way: the women who drank two or more diet sodas a day had a decline in their glomerular filtration rate, a measure of kidney function, of 3 milliliters per minute per year. ”With natural aging, kidney function declines about 1 mL per minute per year after age 40,” Lin says. No link was found with the other beverages. And less than two sodas a day didn’t seem to hurt. “We didn’t see any association up to two artificially sweetened beverages a day,” Lin says.

”A serving was reported as either a glass, a can, or a bottle of a beverage,” Lin tells WebMD. ”It was not more specific than that.”

”The mechanisms aren’t clear,” Lin says of the association she found. In another study she presented at the meeting, she found higher salt intake is also associated with faster kidney function decline.

Understanding the mechanisms are important because it can help evaluate with certainty whether these results are applicable to men as well.

Unsurprisingly, an industry group remains skeptical of these findings:

Asked to review the study findings, Maureen Storey, senior vice president of science policy for the American Beverage Association, says in a prepared statement: “It’s important to remember that this is an abstract presented at an annual meeting.” She notes that the research needs further scrutiny by researchers.

She acknowledges that kidney disease is serious but that diabetes and high blood pressure account for the majority of kidney disease cases, ”not consumption of diet soda.”

When it comes to dieting and exercise there are no short cuts. Diet soda may help satisfy a craving for a sugary beverage without the caloric penalty, but there may be unintended consequences. For example, what if the body recognizes a discrepancy between the information sent by the tongue, “sugar incoming”, and the message processed by the other parts of the metabolism, “no sugar received”? Logically, if the discrepancy is processed, the body will increase the hunger drive as a way of compensating for the missing sugar, which may cause the person to consume more calories than they would have otherwise.

Even for those people who take the excellent first step towards getting healthy by exercising need to be keenly aware of the law of unintended consequences, because exercise can make you fatter.

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The New York Times has a lengthy article which begins with the story of Stephanie Smith, who became paralyzed after contracting a deadly E. coli O157:H7 infection, and continues by detailing the flaws in the way ground beef is processed which allows contaminants to spread.

Meat companies and grocers have been barred from selling ground beef tainted by the virulent strain of E. coli known as O157:H7 since 1994, after an outbreak at Jack in the Box restaurants left four children dead. Yet tens of thousands of people are still sickened annually by this pathogen, federal health officials estimate, with hamburger being the biggest culprit. Ground beef has been blamed for 16 outbreaks in the last three years alone, including the one that left Ms. Smith paralyzed from the waist down. This summer, contamination led to the recall of beef from nearly 3,000 grocers in 41 states.

Since meat preparation is supposed to be under the supervision of federal food safety inspectors, where are the potential sources of contamination?

Federal inspectors based at the plant are supposed to monitor the hide removal, but much can go wrong. Workers slicing away the hide can inadvertently spread feces to the meat, and large clamps that hold the hide during processing sometimes slip and smear the meat with feces, the workers and inspectors say.

Greater Omaha vacuums and washes carcasses with hot water and lactic acid before sending them to the cutting floor. But these safeguards are not foolproof.

“As the trimmings are going down the processing line into combos or boxes, no one is inspecting every single piece,” said one federal inspector who monitored Greater Omaha and requested anonymity because he was not authorized to speak publicly.

The E. coli risk is also present at the gutting station, where intestines are removed, the inspector said

Every five seconds or so, half of a carcass moves into the meat-cutting side of the slaughterhouse, where trimmers said they could keep up with the flow unless they spot any remaining feces.“We would step in and stop the line, and do whatever you do to take it off,” said Esley Adams, a former supervisor who said he was fired this summer after 16 years following a dispute over sick leave. “But that doesn’t mean everything was caught.”

Another problem is that processors do not want to get the individual slaughterhouses in trouble, or they will lose them as a supplier.

The food safety officer at American Foodservice, which grinds 365 million pounds of hamburger a year, said it stopped testing trimmings a decade ago because of resistance from slaughterhouses. “They would not sell to us,” said Timothy P. Biela, the officer. “If I test and it’s positive, I put them in a regulatory situation. One, I have to tell the government, and two, the government will trace it back to them. So we don’t do that.”

Although some processors may not be carrying out enough inspections, the problem is really that the final ground product is what gets inspected in most cases, not the batch of trimmings coming in from any particular supplier. Meat from different suppliers are mixed together. A contaminated batch of ground beef can therefore be traced to a processor, but not to a specific supplier.

The sad part of this whole tale is the conclusion presented by the New York Times reporter:

Dr. Petersen, the U.S.D.A. official, said the department had adopted additional procedures, including enhanced testing at slaughterhouses implicated in outbreaks and better training for investigators.

“We are not standing still when it comes to E. coli,” Dr. Petersen said.

The department has held a series of meetings since the recent outbreaks, soliciting ideas from all quarters. Dr. Samadpour, the laboratory owner, has said that “we can make hamburger safe,” but that in addition to enhanced testing, it will take an aggressive use of measures like meat rinses and safety audits by qualified experts.

At these sessions, Felicia Nestor, a senior policy analyst with the consumer group Food and Water Watch, has urged the government to redouble its effort to track outbreaks back to slaughterhouses. “They are the source of the problem,” Ms. Nestor said.

We find it curious that a major newspaper can publish a lengthy story which is clearly the result of careful research and somehow come to a conclusion which is exactly the same as it would be if Food and Water Watch wrote the entire article. Please note that no other possible solutions to the problems are written about in the article.

As we have previously revealed, the best kind of advocacy pieces masquerading as journalism or science do not commit crimes of commission, rather, they simply omit pertinent data which the average, non-expert reader would otherwise be unaware of.

In this particular case, there are two simple answers which can deal with the problems posed by the article simply and effectively without the need for more government regulation, inspectors, and taxes.

The first answer comes from Reason:

What solution? Irradiation. That is, treating foods with gamma, electron beam or X-ray radiation to kill bacteria that might be found on food before it is offered to the consumer. It is no more dangerous than pasteurization of milk and would prevent tens of thousands of food poisoning episodes if widely adopted.

According to research by the CDC, irradiation works and is safe:

Treating raw meat and poultry with irradiation at the slaughter plant could eliminate bacteria commonly found raw meat and raw poultry, such as E. coli O157:H7, Salmonella, and Campylobacter. These organisms currently cause millions of infections and thousands of hospitalizations in the United States every year. Raw meat irradiation could also eliminate Toxoplasma organisms, which can be responsible for severe eye and congenital infections. Irradiating prepared ready-to-eat meats like hot dogs and deli meats, could eliminate the risk of Listeria from such foods. Irradiation could also eliminate bacteria like Shigella and Salmonella from fresh produce. The potential benefit is also great for those dry foods that might be stored for long times and transported over great distances, such as spices and grains. Animal feeds are often contaminated with bacteria like Salmonella. Irradiation of animal feeds could prevent the spread of Salmonella and other pathogens to livestock through feeds.

Reason’s conclusion is markedly different than the one reached by the New York Times:

Why should Americans be forced to trust their health chiefly to the good will of politically well-connected corporations and a bunch of bureaucrats when applying a simple elegant inexpensive technnology can go a long way toward solving the problem?

The second solution is: get to know your butcher. Go and visit a local butcher shop that makes their ground beef on the spot. It will cost more than the premade patties you can find in major supermarkets because it is made fresh on the spot with higher quality ingredients. As we have found, making friends with the butcher can also help you snag really high quality cuts of meat which are rarely available outside of high end steakhouses.

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UPDATE: Welcome Instapundit readers. Have look around, enjoy the show.

Since the lifetime prevalence of mental disorders is lower in Mediterranean countries than in Northern European countries, a study was conducted to see if diet plays a role as a protective factor.

We have covered the Mediterranean diet previously, in the article Take It Or Leave It? The Truth About 8 Mediterranean Diet Staples, which we recommend reading to get up to speed about the particulars of this diet.

The report was published in the October issue of Archives of General Psychiatry. Over 10,000 Spanish people participated in this study. Participants had to fill out a survey detailing their dietary intake. Researchers then translated those details into a level of adherence to the Mediterranean diet using a system of nine components. For example, one such component is maintaining a high ratio of monounsaturated fatty acids to saturated fatty acids in the diet.

After a median (midpoint) of 4.4 years of follow-up, 480 new cases of depression were identified, including 156 in men and 324 in women. Individuals who followed the Mediterranean diet most closely had a greater than 30 percent reduction in the risk of depression than whose who had the lowest Mediterranean diet scores. The association did not change when the results were adjusted for other markers of a healthy lifestyle, including marital status and use of seatbelts.

The scale of the study seems to clearly show some correlation between following the Mediterranean diet and better mental health. However, as long time readers are undoubtedly aware, correlation is not causation.

“The specific mechanisms by which a better adherence to the Mediterranean dietary pattern could help to prevent the occurrence of depression are not well known,” the authors write. Components of the diet may improve blood vessel function, fight inflammation, reduce risk for heart disease and repair oxygen-related cell damage, all of which may decrease the chances of developing depression.

“However, the role of the overall dietary pattern may be more important than the effect of single components. It is plausible that the synergistic combination of a sufficient provision of omega-three fatty acids together with other natural unsaturated fatty acids and antioxidants from olive oil and nuts, flavonoids and other phytochemicals from fruit and other plant foods and large amounts of natural folates and other B vitamins in the overall Mediterranean dietary pattern may exert a fair degree of protection against depression,” the authors write.

There may be a combination of factors at play here. Perhaps living in Spain is less depressing than living in Northern Europe regardless of diet. We need scientists to unravel the specific mechanisms which are responsible for these results. Until then, we can only speculate.

Vitamin D is called the “sunshine vitamin” for a reason, and people in Northern Europe may simply not be getting enough.

Dairy is a good source of Vitamin D, but most people do not eat enough dairy to meet their daily requirements without sun exposure. Aside from the fact that eating so much dairy may be unhealthy and counterproductive, 60% of adults cannot digest lactose.

An important component of the Mediterranean diet is fish, and fish are rich in Docosahexaenoic acid (DHA). A recent study determined that feeding infants formula enriched with DHA is worth the cost premium because it can enhance IQ.

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A characterization of cancerous cells is their ability to metastasize and show up in areas where they do not belong. When a normal cell becomes detached from its environment, a process called apoptosis (cellular self destruction) is triggered.

The genes which would be activated in a normal cell to trigger apoptosis may be damaged and non-functional in a cancerous cell, thereby allowing it to survive the initial detachment from its environment. However, even if apoptosis is not triggered, the cell should die of starvation because it is cut off from its supply of nutrients.

A group at Harvard published a study examining cellular detachment and found some surprising results. From Derek Lowe:

So far, so good – this all fits in well with what we already know about tumor cells. But this study found that there was another way to keep detached cells from dying: give them antioxidants. (They used either N-acetylcysteine or a water-soluble Vitamin E derivative). It appears that oxidative stress is one thing that’s helping to kill off wandering cells. On top of this effect, reactive oxygen species also seem to be inhibiting another possible energy source, fatty acid oxidation. Take away the reactive oxygen species, and the cells are suddenly under less pressure and have access to a new food source.

Clearly, there are serious implications to this research. Right now all we have are more questions and not enough answers.

This looks like a very strong paper to me; there’s a lot of work in it and a lot of information. Taken together, these results suggest a number of immediate questions. Is there something that shuts down normal glucose uptake when a cell is detached, and is this another general cell-suicide mechanism? How exactly does oxidative stress keep these cells from using their fatty acid oxidation pathway? (And how does that relate to normally positioned cells, in which fatty acid oxidation is actually supposed to kick in when glucose supplies go down?)

The biggest questions, though, are the most immediate: first, does it make any sense at all to give antioxidants to cancer patients? Right now, I’d very much have to wonder. And second, could taking antioxidants actually have a long-term cancer-promoting effect under normal conditions? I’d very much like to know that one, and so would a lot of other people.

After this and that exercise study, I’m honestly starting to think that oxidative stress has been getting an undeserved bad press over the years. Have we had things totally turned around?

The exercise study referred to examines whether antioxidants combined with exercise is a formula for failure. After exercising, the body tries to increase the number of mitochondria and it does so by signaling with reactive oxygen species (ROS).

Of course, ROS are also implicated in many theories of aging and cellular damage, which is why cells have several systems to try to soak these things up. That’s exactly why people take antioxidants, vitamin C and vitamin E especially. So. . .what if you take those while you’re exercising?

Once again, the law of unintended consequences rears its ugly head.

And as it turns out, antioxidant supplements appear to cancel out many of the beneficial effects of exercise. Soaking up those transient bursts of reactive oxygen species keeps them from signaling. Looked at the other way, oxidative stress could be a key to preventing type II diabetes. Glucose uptake and insulin sensitivity aren’t affected by exercise if you’re taking supplementary amounts of vitamins C and E, and this effect is seen all the way down to molecular markers such as the PPAR coactivator proteins PGC1 alpha and beta. In fact, this paper seems to constitute strong evidence that ROS are the key mediators for the effects of exercise, and that this process is mediated through PGC1 and PPAR-gamma.

Taking supplemental antioxidants may unnecessary because the body produces enough of its own.

Interestingly, exercise also increases the body’s endogenous antioxidant systems – superoxide dismutase and so on. These are some of the gene targets of PPAR-gamma, suggesting that these are downstream effects. Taking antioxidant supplements kept these from going up, too.

In conclusion, antioxidant supplements will hinder the some of the benefits gained from exercise and likely helps cancerous cells survive and spread around.

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Boost Your Baby’s IQ

Breastfeeding has been shown to be beneficial to babies because of the immune system boost they get from mom. Breast milk also has an essential fatty acid called docosahexaenoic acid (DHA) which may provide infants with a cognitive boost.

Researchers decided to test if supplementing regular formula with DHA would have the same effect that came naturally from breastfeeding.

The researchers studied 229 infants, who received either formula supplemented with DHA or traditional infant formula. The babies were given the different formulas either shortly after birth, after 6 weeks of breastfeeding, or after 4 to 6 months of breastfeeding. When they were 9 months old, they were given a problem-solving test in which they had to complete a sequence of steps to get a rattle.

Babies who were fed formula supplemented with DHA were more likely to get the rattle and showed more intentional behaviors that allowed them to get the rattle.

More studies need to be conducted to confirm these effects.

“Currently, there is no clear consensus on whether infant formula should be supplemented with DHA,” notes lead author James R. Drover, a former postdoctoral fellow at the Retina Foundation of the Southwest who is now assistant professor of psychology at Memorial University in Canada.

“However, our results clearly suggest that feeding infants formula supplemented with high concentrations of DHA provides beneficial effects on cognitive development. Furthermore, because infants who display superior performance on the means-end problem-solving task tend to have superior IQ and vocabulary later in childhood, it’s possible that the beneficial effects of DHA extend well beyond infancy.”

This is not the first time DHA has been in the news. A news report from 2002 showed that the FDA approved its inclusion in formula, although evidence that it had a positive effect was scant at the time. Other factors, including the average age of a breastfeeding mother and socioeconomic status could have influenced results.

No doubt all this is why experts at the American Council on Science and Health, including the former chairman of the American Academy of Pediatrics Committee on Nutrition, concluded in a recent report that, “the addition of DHA and AA to infant formulas is not warranted at this time.”

In light of this new study, is paying a premium for enhanced baby formula worth it?

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Drunk + Gassy = Long Life?

Although you wouldn’t necessarily need to be drunk, enjoying red wine has some benefits because it contains resveratrol. Feel free to stop when you feel tipsy.

The gassy part of the formula comes from the chemical sulforaphane.

Dr Paul Evans, from the National Heart and Lung Institute at Imperial College London, who led the research team, said: “We found that the innermost layer of cells at branches and bends of arteries lack the active form of Nrf2, which may explain why they are prone to inflammation and disease. Treatment with the natural compound sulforaphane reduced inflammation at the high-risk areas by ‘switching on’ Nrf2.

Nrf2 is a protective protein which reduces inflammation, normally found in arteries.

Arteries don’t clog up in a uniform way. Bends and branches of blood vessels – where blood flow is disrupted and can be sluggish – are much more prone to the build-up of fatty plaques known as atherosclerosis. Atherosclerosis can lead to angina, heart attack and stroke.

Actually, the gassy part does not come from sulforaphane directly. It comes from the fact that sulforaphane is naturally present in broccoli. However, the research done here was with the pure form of sulforaphane.

“Sulforaphane is found naturally in broccoli, so our next steps include testing whether simply eating broccoli, or other vegetables in their ‘family’, has the same protective effect. We also need to see if the compound can reduce the progression of disease in affected arteries.”

Brassicas – also called ‘cruciferous’ vegetables – include broccoli (which has the highest levels of sulforaphane), cabbage, kale, Brussels sprouts, cauliflower, bok choy and rocket.

Professor Peter Weissberg, Medical Director at the BHF, said: “These fascinating findings provide a possible mechanism by which eating vegetables protects against heart disease.

In conclusion, to live a long and healthy life, you should probably bend an elbow, lift a leg, and proudly announce to the world… you know what, we’re very happy for you – but leave the room if you need to do that. Seriously.

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