Illegally labeled diet, immune-boosting pills ‘potentially dangerous,’ report …

Dozens of weight loss and immune system supplements on the market are illegally labeled and lack the recommended scientific evidence to back up their purported health claims, government investigators warn in a new review of the $20 billion supplement industry.

The report, being released Wednesday by the Department of Health and Human Services’ inspector general, found that 20 percent of the 127 weight loss and immune-boosting supplements investigators purchased online and in retail stores across the country carried labels that made illegal claims to cure or treat disease.

Some products went so far as to state that the supplements could cure or prevent diabetes or cancer, or that they could help people with HIV or AIDS, which is strictly prohibited under federal law.

Consumers may not just be wasting their money on pills or tablets, but they could be endangering their health if they take a supplement in place of a drug thinking it will have the same effect, the report concluded.

“Consumers rely on a supplement’s claims to determine whether the product will provide a desired effect, such as weight loss or immune support,” the report said. “Supplements that make disease claims could mislead consumers into using them as replacements for prescription drugs or other treatments for medical conditions, with potentially dangerous results.”

The market for dietary supplements — which can include anything from Vitamin C tablets to capsules of Echinacea — is a huge one with hundreds of products. The inspector general’s investigation focused on one segment that officials said is booming.

Federal regulations do not require the Food Drug Administration to review supplement companies’ scientific evidence for most of their products’ purported health benefits before they hit the market.

The Office of Inspector General found that in numerous cases, when companies did submit evidence to back up their health claims, it fell far short of government recommendations.

One company submitted a 30-year-old handwritten college term paper to substantiate its claim, while others included news releases, advertisements and links to Wikipedia or an online dictionary, according to the report.

Overall, the review raises questions about whether the system is allowing companies to mislead consumers, investigators said, and recommended that FDA ramp up its oversight. The report did not name individual brands or products, and also did not estimate the total number of dietary supplements on the market.

In response, the food safety agency said it would consider asking Congress for more oversight powers to review supplement companies’ evidence proving their products’ purported health benefits. FDA agreed that the agency should expand surveillance of the market to detect spurious claims that supplements can cure or treat specific diseases.

Investigators also found that 7 percent of the weight loss and immune support supplements they surveyed lacked the required disclaimer stating that FDA had not reviewed whether the statement on the label was truthful.

More top health news:

Common herbal remedy blamed for 11 year-old girl’s hot flashes

Skull in stomach: Woman makes remarkable recovery after procedure

Fewer babies in the US? Blame the economy

Diet Chef comments on the news that junk food diets increase stroke risk

UNITED KINGDOM, Oct. 3, 2012 /PRNewswire-iReach/ — Diet Chef is reminding people of the importance of a healthy diet following new research that has shown eating junk food diet could increase the risk of stroke or death at a younger age.

A study conducted by the Heart and Stroke Foundation Centre for Stroke Recovery in Canada suggested people who eat so called ‘cafeteria diets’, which are high in calories, sugar, fat and salt, are more likely to suffer a stroke or even die at a younger age.

To conduct the research, rats were given unlimited access to both nutritional food pellets and junk food items like cookies and sausages. They could also choose between water and a 30 per cent sucrose solution, similar to soft drinks.

It was discovered that the majority of rats preferred the junk food and, as a result, they suffered from high levels of cholesterol, blood sugar, obesity and blood pressure after just two months. They presented a combination of these symptoms, often referred to as metabolic syndrome, which is thought to increase the risk of suffering from a stroke.

Dr Dale Corbett, scientific director of the Heart and Stroke Foundation Centre for Stroke Recovery, said: “I think we’ll soon start to see people in their 30s or 40s having strokes, having dementia, because of this junk food diet. Young people will have major, major problems much earlier in life.”

Caron Leckie, Diet Chef nutritionist, comments: “The junk food style ‘cafeteria’ diet is one more example of excess; high calories, high sugar, high fat and high salt. With growing public health concerns such as stroke and metabolic syndrome it is important now more than ever to encourage moderation and balance in our food choices”

Diet Chef is a specially designed, delivered meal plan that helps people to lose weight, while ensuring they get all the vitamins and nutrients they need to stay fit and healthy. All meals are prepared by an expert chef, meaning they are calorie and portion controlled, allowing individuals to shed the pounds the healthy way.

[ENDS]

Diet Chef carefully counts the calories of all meals so dieters on the plan will be averaging less than 1,200 calories per day. The daily menu allows you to get delicious home delivered food, as well as offering a tasty and varied, healthy balanced plan encouraging dieters to lose weight at a healthy pace.

Those on the diet looking to check their own progress can do so using the weight loss calculator as well as sharing their weight loss success stories via the website or Diet Chef social media channels.

Visit the website: www.dietchef.co.uk
Become a fan: www.facebook.com/DietChef
Follow: www.twitter.com/dietchef

Press release submitted by online press release distribution site Submitpressrelease123.com

Media Contact: Diet Chef Three Sixty Communications Diet Chef, 0207 580 8360, dietchef@360team.co.uk

News distributed by PR Newswire iReach: https://ireach.prnewswire.com

Diet Chef: Over a Decade of Dieting

LONDON–(BUSINESS WIRE)–

A shocking 90% of British women have been on a diet with the average
woman losing her body weight over nine times during her life time and
spending over seventeen years on a diet, diet
delivery
brand, Diet Chef has found.

The average woman diets twice a year, losing 11lbs each time. Life
expectancy data* reveals that the average woman lives until 82 and
weighs on average 11 stone. If she begins dieting at the age of 18, she
will lose her body weight 9.1 times and if she spends seven weeks on a
diet twice a year she will spend 17.2 years dieting.

Kevin Dorren, Founder Head Chef, comments: ‘Deciding to lose weight
can be an easy one to make when we know we have a special occasion
coming up or aren’t feeling confident in our appearance, however as we
can see actually embarking on a diet and losing the extra pounds is more
difficult and takes real commitment. Diet Chef takes the thinking out of
dieting providing tasty yet nutritionally balanced meals direct to your
door.’

Those in the North West find it the most difficult sticking to a diet,
only able to sum up the stamina for four days on average – the shortest
amount of time in the UK (12%). Whereas those in the North East (11%)
and East Anglia (17%) have the most will power with their last diet
lasting one month. Less than 1% of women managed to stick to a diet
for a 12 month period (0.6%) and a third of all women diet for at least
six months per year.

Not fitting into any of their clothes was the top prompt (52%) to lose
weight with the same number of people saying that developing a muffin
top was the first sign that they had piled on the pounds.

Summer holidays (33%), health reasons (22%) and weddings (18%) were the
top three incentives to lose weight and 43% of the female population
said not feeling comfortable in a swimsuit was the main reason for
wanting to streamline their look.

Ultimately it is a general love of food (35%) and lack of will power
(33%) that keeps would-be dieters from achieving their dream body with
over a third saying they were their main reasons for struggling with
managing their weight
loss
. Although a fifth of women say that they find it too expensive
to buy healthy food.

One in three women will splurge on comfort purchases when feeling down
about their diet, with shoes being the top thing to splurge on (37%).

Diet Chef offers dieters the chance to lose weight at a sensible rate
and affordable cost with tasty food to help keep them on track.

-Ends-

* Office of National Statistics Male
and female life expectancy at birth and at age 65: by rank order of
local areas in the United Kingdom, 2004-06 to 2008-10
 19-Oct-2011

Diet Chef carefully counts the calories of all meals so dieters on the
plan will be averaging less than 1,200 calories per day. The daily menu
delivers a tasty and varied, healthy balanced diet allowing dieters to
lose weight at a healthy pace.

Price of £5.57 per day price is based on the Diet Chef 1200 programme on
Pay Monthly

Visit the website: www.dietchef.co.uk

Become a fan: www.facebook.com/DietChef

Follow: www.twitter.com/dietchef

Questioning the Superpowers of Omega-3 in Diets

Name the affliction—heart disease, Alzheimer’s, arthritis, depression, asthma—and omega-3 fatty acids can help prevent it.

Or not.

That is the confusion being stirred up by new research on omega-3s, fats found in cold-water fish and plant oils that have intrigued nutrition scientists ever since the 1970s discovery that Greenland Eskimos rarely die from heart disease, despite a diet of fatty fish.

Some 21% of U.S. adults report using omega-3 fish-oil supplements, according to the Council for Responsible Nutrition, an industry trade group, making it the most popular supplement after multivitamins and vitamin D.

But last month, the Journal of the American Medical Association published a meta-analysis of 20 clinical trials involving nearly 70,000 people that found that omega-3 fatty acids didn’t prevent heart attacks, strokes or deaths from heart disease. Other recent studies in the New England Journal of Medicine and the Archives of Internal Medicine found that omega-3 supplements didn’t prevent heart problems in people with Type 2 diabetes or a history of heart disease.

Experts say such studies should be viewed with caution—just like studies with positive findings.

Critics noted that the JAMA study combined clinical trials that used different doses and sources of omega-3s. Many of the subjects were also on heart medication, which may have blunted the impact. Plus, diet studies are also notoriously imprecise. “It’s impossible for five researchers to control the diet of almost 70,000 patients over several years,” says Duffy MacKay, the CRN’s vice president for scientific and regulatory affairs.

What’s more, the JAMA authors imposed an unusually strict standard for statistical significance. Using the typical standard, the analysis would have concluded that omega-3 supplements are associated with a 9% reduction in cardiac deaths.

“My colleagues are writing letters to the editor about this,” said University of Pennsylvania nutritionist Penny Kris-Etherton, a spokeswoman for the American Heart Association. She says, for now, the association will continue recommending that everyone eat omega-3 rich fish at least twice a week; people with heart disease or high triglycerides could also consider taking fish-oil supplements under a doctor’s care. The American Psychiatric Association and the World Health Organization have similar advice.

Omega-3 fatty acids are essential for building cell membranes and maintaining the connections between brain cells. They also may reduce inflammation,increasingly recognized as a cause of chronic diseases.

Humans can’t produce omega-3 fatty acids, so we must get them from outside sources. The two most important kinds—EPA and DHA—are primarily found in fish such as salmon, sardines, tuna and herring; a third kind, ALA, is found in walnuts, flaxseed, soybean oil and some green vegetables, including Brussels sprouts, spinach and kale.

The typical American diet is far higher in omega-6 fatty acids, which come from corn and safflower oil and are plentiful in processed foods and cornfed beef and poultry. Some experts believe that reducing the ratio of omega 6s to 3s is even more important than increasing omega-3s, but the evidence is mixed.

Blood tests (typically $100 to $200) can measure the amount of omega-3s in red blood cells or plasma and a growing number of doctors are ordering them. No official deficiency standard has been set, but according to one lab, OmegaQuant Analytics, having 4% or less omega-3s out of total fatty acids is “undesirable” and indicates an elevated heart risk; 8% or more is “desirable.” Most Americans score between 3% and 5% omega-3s, says William Harris, a veteran heart researcher who founded OmegaQuant. “In Japan, it’s about 10%, and they have much less cardiovascular disease and live, on average, four years longer than we do,” he says.

Thousands of studies since the 1970s have shown that people with high levels of omega-3s have lower triglycerides, lower blood pressure, lower LDL cholesterol, less inflammation and a lower risk of heart disease. Those with low levels of omega-3s are more likely to be depressed, to commit suicide and have memory loss and brain shrinkage as they age.

Many of those are observational studies that can’t prove cause-and-effect; it may be that people who eat more fish have more healthy behaviors in general. The evidence from randomized-controlled trials is more mixed—but experts say that’s not surprising in dietary studies, where researchers often have to rely on patients to accurately report what they ate over long periods.

Recent research offers a tantalizing mix of healing possibilities:

Alzheimer’s disease and dementia: Several studies show that older people who eat plenty of fish have lower levels of beta-amyloid protein, associated with Alzheimer’s, than those who eat less. But giving elderly people omega-3 fish-oil supplements didn’t help ward off cognitive decline, according to a meta-analysis published in June. (The authors conceded that the trials may not have been long enough to show much effect.) Giving omega-3s to people with Alzheimer’s did not slow the disease’s progression.

Macular degeneration: A 2011 Harvard study found that women who ate fish at least once a week were 38% less likely to develop age-related macular degeneration than women who ate it less than once a month.

Attention-Deficit Hyperactivity Disorder: Children with ADHD tend to have lower omega-3 levels than their peers, and a study in the journal PLOS One last month found that DHA can improve reading and behavior in underperforming children. Still, there is no evidence to date that omega 3s are as effective as medication.

Depression: Rates of depression, bipolar disorder and postpartum depression are all lower in fish-eating populations, writes psychiatrist Drew Ramsey in his 2011 book, “The Happiness Diet.” He also lists wild salmon and shrimp as the top foods for good mood, and encourages his patients to increase their fish intake. Supplements with a high ratio of EPA to DHA appear to be most effective.

Cancer: Animal studies suggest that omega-3s may suppress the growth of some cancers. But a 2006 review of 40 years of research concluded that omega-3 supplements are unlikely to prevent cancer in humans.

Rheumatoid arthritis: Fish oil doesn’t appear to slow the progression of rheumatoid arthritis, but small studies show that it helps reduce symptoms like joint pain and morning stiffness, and may allow people to lower their dose of anti-inflammatory drugs.

Fetal development: Omega-3s are needed for brain and vision development in unborn babies, but concerns about mercury levels have scared some pregnant women away from eating fish. Health authorities say that many good omega-3 sources, including shrimp, salmon and tuna, are relatively low in mercury. Nursing women and young children should avoid shark, swordfish and tilefish.

Many physicians are more comfortable urging patients to eat more fish than take fish-oil supplements, since fish also contain protein, vitamin B-12, zinc and iodine.

Side effects from fish-oil supplements are minor—mostly gastrointestinal upset and burping with a fishy aftertaste. (Freezing the capsules or taking them with food may help.) In doses of 3 grams and above, EPA and DHA can increase the risk of bleeding, so people on blood thinners should consult their physician before taking them. Some hospitals advise patients to discontinue taking omega-3s before surgery.

What’s the bottom line? Does it make sense to consume more omega-3s? “There is no single answer here,” says Paul Coates, director of the Office of Dietary Supplements, part of the National Institutes of Health. “Given that there is a potential for benefit, and the harm has not yet been fully explored, at reasonable levels of intake, it’s not a bad idea.”


Write to
Melinda Beck at HealthJournal@wsj.com

Diet Coke to Style One Lucky Chicagoan with Couture Refreshment

CHICAGO–(BUSINESS WIRE)–

You’re never fully dressed without a smile – or now a Diet Coke. A lucky
Chicagoan will win a new fall look and a chance to meet couture
designers from around the block and across the country at Chicago’s Art
of Fashion event on October 19 at Millennium Park – courtesy of Diet
Coke, The Shops at North Bridge and 101.9fm THE MIX.

Starting today through October 7 aspiring fashionistas and Diet Coke
fans alike can tune into 101.9fm THE MIX and listen for a chance to
text-to-win a makeover and VIP experience for two at Chicago’s Art of
Fashion event. Valued at $2,500, this prize package includes:

  • $400 gift card to The Shops at North Bridge and makeover by renowned
    FORD Artist Fashion Stylist and Photographer, Helen Berkun
  • Haircut, style, facial and make-up session at the famed Chicago
    Charles Ifergan Salon and Day Spa
  • 2 VIP tickets to the Art of Fashion Event and the After Party – limo
    included!
  • Diet Coke cosmetics bag

“Diet Coke and Chicago’s Art of Fashion Event bring together the best of
what’s possible when you push the limits of design and fashion,” said
Michael Dulin, Vice President, Commercialization, Coca-Cola
Refreshments. “This event recognizes both young and established
designers and reinforces the positive power of ambition. Supporting our
fans and their dreams is just one more way Diet Coke celebrates those
who ‘stay extraordinary.’”

Art of Fashion is the culmination of “Fashion Focus Chicago” a week-long
celebration of Chicago’s fashion industry. In partnership with Style
Chicago and presented by the City of Chicago’s Department of Cultural
Affairs and Special Events (DCASE), Fashion Focus Chicago showcases some
of the city’s top designers, and features three headlining runway shows
in Millennium Park. This is Diet Coke’s inaugural year sponsoring Art of
Fashion.

The iconic Diet Coke can is also getting a makeover this fall. Diet Coke
has re-introduced its stylish cropped logo design for its aluminum can
and launched a new, refreshed ad campaign. The campaign is the latest
evolution of Diet Coke’s iconic “Stay Extraordinary” platform and
features a modern, bold look on the Diet Coke can and a series of new
print and out-of-home ads. The refreshed packaging design features a
section of the Diet Coke logo, cropped to feature the “D” and the “k,”
set against the brand’s signature silver backdrop, creating a sleek,
modern look for the brand.

For more information on this contest please visit: www.wtmx.com
or follow on Twitter @DietCokeUS.

About The Coca-Cola Company

The
Coca-Cola Company
(KO) is the world’s largest beverage
company, refreshing consumers with more than 500 sparkling and still
brands. Led by Coca-Cola, the world’s most valuable brand, our Company’s
portfolio features 15 billion dollar brands including Diet Coke, Fanta,
Sprite, Coca-Cola Zero, vitaminwater, Powerade, Minute Maid, Simply,
Georgia and Del Valle. Globally, we are the No. 1 provider of sparkling
beverages, ready-to-drink coffees, and juices and juice drinks. Through
the world’s largest beverage distribution system, consumers in more than
200 countries enjoy our beverages at a rate of 1.8 billion servings a
day. With an enduring commitment to building sustainable communities,
our Company is focused on initiatives that reduce our environmental
footprint, support active, healthy living, create a safe, inclusive work
environment for our associates, and enhance the economic development of
the communities where we operate. Together with our bottling partners,
we rank among the world’s top 10 private employers with more than
700,000 system employees. For more information, please www.thecoca-colacompany.com
or follow us on Twitter at twitter.com/CocaColaCo.

The Coca-Cola Company
Katie Busch, 847-600-2272
kbusch@coca-cola.com

For White Sharks, Diet Is Different For Each Individual

April Flowers for redOrbit.com – Your Universe Online

White sharks are the largest predatory sharks in the ocean. They are thought of as apex predators, animals who as adults have no natural predators of their own in their natural ecosystem. Marine scientists have long known that white sharks feed on seals and sea lions, but a new study from the University of California, Santa Cruz demonstrates that there is surprising variability in the diets of individual sharks.

The research team traced variations in diet over a sharks’ entire life by analyzing composition of growth bands in shark vertebrae. Carbon and nitrogen isotopes in the shark’s tissues serve as natural tracers of dietary inputs.

“We did find that white shark diets changed with age, as expected, but we were surprised that the patterns and extent of change differed among individuals,” said Sora Kim, who led the study as a UCSC graduate student and is now at the University of Wyoming.

The study looked at the vertebrae of 15 adult white sharks caught along the west coast; fourteen were caught off the coast of California and one off Baja California. White sharks in this population eat a wide variety of animals, including dolphins, fish and squid in addition to the seals and sea lions. According to Paul Koch, professor of Earth and planetary sciences at UCSC, not every shark eats the same mix of prey animals.

“We confirmed that the diets of many individuals observed at seal and sea lion rookeries shift from fish to marine mammals as the sharks mature,” he said. “In addition, we discovered that different individual sharks may specialize on different types of prey. These two types of flexibility in feeding behavior are difficult to document using traditional methods, but may be very important for understanding how the population is supported by the eastern Pacific ecosystem and how it may respond to changes in that ecosystem.”

White sharks are found in temperate waters around the globe. They are considered an important, though not terribly common, predator in California’s coastal habitats. The National Oceanic and Atmospheric Administration (NOAA) announced that the agency is considering whether to list the west coast population on the Endangered Species Act to protect them.

The Endangered Species Act of 1973 is a law that is designed to provide for the conservation of species that are endangered or threatened. It is also geared towards the conservation of the ecosystems of those threatened species. NOAA’s National Marine Fisheries Service (NMFS) shares responsibility for implementing the ESA with the U.S. Fish and Wildlife Service.

White sharks found along the California coast cruise the coast from late summer to early winter before moving offshore in a regular migratory pattern that has been tracked by tagging studies. While their movements may be predictable, the results of this new study illuminate important dietary and behavioral differences between individual sharks.

The shark vertebrae were obtained from various collections, caught at different times and in different places along the coast from 1957 to 2000.

“Interestingly, we do see a small shift in diet as marine mammal populations increased after the passage of the Marine Mammal Protection Act in 1972,” Kim said.

The results of this new study are published online in the journal PLoS One.

Beggar the Dolphin Killed By a Diet of Hot Dogs and Beer

Turns out that a diet of beer and hot dogs—though theoretically appetizing—is just as harmful to dolphins as it is to humans, especially when it encourages bad behavior in the former.

Just like the dog who has learned to eye dinner scraps at the table, Beggar the dolphin developed an ultimately fatal habit of approaching humans in Sarasota, Florida—a habit that was reinforced and enabled by boaters feeding the bottlenose dolphin an unhealthy diet of, among other things, hot dogs, beer, fruit, shrimp, and squid. His learned unnatural behavior is believed to have contributed to his death. Beggar was recently found floating dead near Albee Road Bridge. He was about 20 years old.

Under the Marine Mammal Protection Act, feeding and petting wild dolphins is illegal, and punishable by up to $100,000 in fines and and a year in jail per violation. That didn’t stop curious humans from luring Beggar—a dolphin famous in the area for being one of the most observed and ill-fed of his kind—to their boats with food unfit for dolphins.

MORE: Ready, Set, Kill: Dolphin Hunting Season Begins

The feeding drastically altered Beggar’s behavior, leaving him more susceptible to injury from boats he tried to approach. A necropsy performed on Beggar’s body revealed multiple watercraft inflicted wounds and a stomach filled with items not normally included in a dolphin’s diet such as fishing hooks, strands of fishing line, and squid beaks, as well as several ulcers of varying severity. He also had multiple broken ribs and vertebrae and was dehydrated—probably because he wasn’t eating the normal dolphin diet that would provide him with the hydration he needed. While no single cause of death could be determined, Beggar’s necropsy suggests that humans had a hand in it.

Twenty years of age is the average lifespan of a dolphin, but steady observation of Beggar revealed that human interference may have dramatically reduced his quality of life. In 100 hours, Dr. Katie McHugh of the Sarasota Dolphin Research Program documented 3,600 interactions between Beggar and humans with up to 70 interactions an hour, 169 attempts to feed him 530 different kinds of food, which included hot dogs and beer, and 121 attempts to touch him resulting in 9 bites (probably because he thought people’s fingers looked like little Vienna sausages). Rather than spend time with other dolphins, Beggar spent his days hounding humans for food. When law enforcement was present on the water, humans were less likely to approach Beggar and, consequently, Beggar was more likely to forage for food on his own like a normal dolphin.

But while Beggar’s death is a sad reminder of how humans can have devastating effects on wildlife, more tragic is the violent demise of a dolphin shot to death in Louisiana. Conservationists are offering a $1,500 reward for information leading to the conviction of the killer of a bottlenose dolphin found dead at Elmer’s Island Wildlife Refuge. The dolphin died of a gunshot wound just behind its blowhole—the bullet was found in its lung. Similarly, another dolphin was found stabbed with a screwdriver off the coast of Alabama earlier in the summer season. No arrests have been made in either case, but once the perpetrators are found, justice is sure to be swift. Just as the Marine Mammal Protection Act outlaws the feeding and touching of dolphins, it delivers the same harsh penalties for those who harass, harm, or kill wild dolphins.

What do you think could be done to prevent dolphin deaths like Beggar’s? More education or more policing? Can we trust humans to respectfully admire dolphins on their own?

Related Stories on TakePart:

• ‘The Cove’ Still Open for Slaughter: Dolphin Hunting Season Begins in Japan

• 2012 Taiji Dolphin Slaughter: A Hunting Season in Review

• A Major Victory and a Path Forward for Saving Dolphins in the Solomon Islands

Liz Acosta is a writer, artist, and activist living in San Francisco. She likes to practice what she calls “accessible activism,” doing what she can to change the world. She loves dogs, photography, bicycles, IPAs, and Britney Spears.

Great white sharks show diversity in diet, study says

Great white sharks may munch on a wider array of sea creatures throughout their lives than previously thought, according to a new study published Friday in the journal PLoS ONE.

The great whites are well known to many as the stars of “Shark Week” and as one of the ocean’s most feared predators. Researchers have long believed that a shark’s diet evolves over its lifetime as it grows, moving from small prey like fish to larger animals like seals and, every once in a while, humans.

But in the new study, the researchers found that great whites show a remarkable diversity in their diets. Even sharks that live near each other ate differently throughout the course of their lifetimes, and some sharks never made the transition to large animals at all.

The researchers, from UC Santa Cruz, studied the vertebrae of 15 great whites that were caught off the West Coast of the U.S. between 1957 and 2000. When sharks eat, a record of their diet is stored in their vertebrae in the form of carbon and nitrogen. Over time, the elements amass as bands in their vertebrae, akin to a tree’s rings. Because animals lower on the food chain have different levels of carbon and nitrogen in their tissue than animals higher on the food chain, researchers can tell what the sharks ate over time by looking at bands from different periods in a shark’s life.

The researchers expected to find a gradual change in the levels of carbon and nitrogen over time, signifying increasing consumption of bigger animals as they got older. This would lead to a plateau in the elements’ levels once the transition to large animals was complete.

While they saw that pattern in some sharks, the diets varied a great deal between different sharks. Some sharks appeared to eat small animals, such as fish and squid, for their entire lives. Others seemed to get feisty while still young, eating bigger animals like seals virtually from the get-go.

The researchers also noticed another shift over time: In general, sharks have recently consumed more marine mammals than they used to, a change the researchers attribute to the Marine Mammal Protection Act, which passed in 1972.

You can read the full study here.

Return to the Science Now blog.