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Cancer has many faces − 5 counterintuitive ways scientists are approaching cancer research to improve treatment and prevention

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Cancer has many faces − 5 counterintuitive ways scientists are approaching cancer research to improve treatment and prevention

Cancer cells don’t follow the typical rules that allow a multicellular collective to function.
Dr. Cecil Fox/National Cancer Institute

Vivian Lam, The Conversation

How researchers conceptualize a disease informs how they treat it. Cancer is often described as uncontrollable cell growth triggered by genetic . But cancer can also be seen from angles that emphasize mathematics, evolutionary game theory and physics, among others.

Molecular biology has brought significant advances in making it possible to with cancer as a chronic illness rather than a fatal disease. Alternative frameworks, however, can offer scientists additional insights on how to prevent tumors from spreading throughout the body and becoming resistant to treatment.

Here are a few unconventional lenses through which researchers are viewing cancer with fresh eyes, drawn from The Conversation’s archives.

1. Evolution and natural selection of cancer

The body is far from a wonderland for cells. Each individual cell competes against trillions of others for finite space and nutrients. If they’re able to cooperate in an orderly enough fashion, sharing resources and dividing labor, the collective functions effectively. Cancer cells, however, cheat the system: They hog resources, take up as much space as possible and refuse to die.

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In this way, cancer can be thought of as an evolutionary disease – these are cells that have developed the genetic mutations to outcompete their neighbors, and subsequent cell generations inherit this survival advantage. Cancer cells benefit at the expense of the collective until the entire organism collapses.

Microscopy image of pancreas tumor with multicolored cell subgroups
Most tumors are made of many different kinds of cancer cells, as shown in this pancreatic cancer sample from a mouse.
Ravikanth Maddipati/Abramson Cancer Center at the University of Pennsylvania via National Cancer Institute

Oncologist Monika Joshi and pathologists Joshua Warrick and David DeGraff believe that understanding evolution is key to understanding cancer. Screening programs are effective, for example, because removing a nascent tumor is easier than treating one that has evolved the ability to spread. Cancer cells likewise become resistant to treatments because they’re pushed to further evolve to survive.

Some researchers are applying the principles of evolutionary game theory to reduce treatment resistance and optimize therapies for children.

“The fight against cancer is a fight against evolution, the fundamental that has driven on Earth since time immemorial,” they wrote. “This is not an easy fight, but medicine has made tremendous progress.”

2. Fluid mechanics of cancer

As much as cancer is a disease that respects no boundaries, tumor cells are still shaped by their environment. Unlike healthy cells that take the hint when their presence isn’t wanted, however, tumor cells not only survive but thrive in stressful conditions. Isolated cancer cells able to adapt to harsh settings are the ones that establish metastatic colonies and become resistant to treatment.

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While researchers have focused on how biochemical signals direct cells to move from one location to another, a cell’s physical environment also affects where it migrates. Mechanical engineer Yizeng Li found that a cell’s “solid” and “fluid” surroundings influence its movement.

Cancer cells encounter varying degrees of fluid viscosity, or thickness, as they travel through the body. Li and her team found that breast cancer cells counterintuitively move faster in high viscosity environments by changing their structure. This meant that fluid viscosity serves as a mechanobiological cue for cancer cells to metastasize.

Animation comparing two fluids with lower and higher viscosity.
The blue fluid on the left has a lower viscosity relative to the orange fluid on the right.
Synapticrelay/Wikimedia Commons, CC BY-SA

“Cancer usually don’t die from the original source of the tumor but from its spread to other parts of the body,” Li wrote. “Understanding how fluid viscosity affects the movement of tumor cells could researchers figure out ways to better treat and detect cancer before it metastasizes.”

3. Inflammation link to cardiovascular disease

Apart from being leading causes of death around the world, cardiovascular disease and cancer may not initially seem to have much in common. The many risk factors they share, however – like poor diet, smoking and chronic stress – coalesce with chronic inflammation: persistent, low-grade activation of the immune system can damage cells in ways that encourage either disease to develop.

For biomedical engineer Bryan Smith, the developmental parallels between these diseases signal they could be treated at the same time.

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Nanoparticles can ‘eat’ the plaques that cause heart disease.

Drugs can be repurposed to target diseases for which they weren’t originally designed. Certain , for example, can direct immune cells called macrophages to consume both cancer cells and the cellular debris that contribute to cardiovascular plaques.

“As basic science discovers other molecular parallels between these diseases, patients will be the beneficiaries of better therapies that can treat both,” wrote Smith.

4. Mathematics of cancer

In certain contexts, math has unique strengths in describing the natural world. For instance, epigenetics – where and when genes are turned on or off – plays as much a role in cancer progression as direct changes to the genetic code. Epigenetic changes can alter healthy cells to the point of losing their normal form and function. But the randomness of these changes makes it difficult to tease out pathological from normal genetic activity.

A mathematical concept called stochasticity – or how the randomness of the steps of a process influences how predictable its outcome will be – lends a logical framework to the epigenetic changes contributing to cancer, clarifying when healthy cells rapidly develop into tumor cells.

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Twins sharing the exact same genome can develop in completely different ways because of epigenetics.

Stochasticity is commonly used to study stock market behavior and epidemic disease spread, and researchers quantify it by examining the degree of uncertainty, or entropy, of a particular outcome. Identifying high entropy areas in the genome could offer another approach to cancer detection and drug design.

Cancer geneticist Andrew Feinberg has been using entropy to quantitatively describe the epigenetics of cancer. He and his colleagues found that high entropy regions of the genome in the skin become even more entropic with sun damage, increasing the of developing cancer. This offers a potential explanation for why cancer risk significantly increases with age.

“Epigenetic entropy shows that you can’t fully understand cancer without mathematics,” Feinberg wrote. “Biology is catching up with other hard sciences in incorporating mathematical methods with biological experimentation.”

5. A public health issue

Cancer is a disease that develops in an individual, but its socially derived causes and societal-wide effects are hardly limited to a single person.

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Take the case of lung cancer. It is stigmatized as a disease brought on by poor lifestyle choices – a consequence of a personal decision to use tobacco products. But as thoracic oncologist Estelamari Rodriguez noted, the face of lung cancer has changed.

“Over the past 15 years, more women, never-smokers and younger people are being diagnosed with lung cancer,” she wrote. While lung cancer rates have significantly decreased for , they have substantially risen for women around the world. Despite being the leading cause of cancer death among women, screening rates remain low compared with other cancers.

More broadly, cancer symptoms are often unrecognized or misdiagnosed, not only for women but also for many marginalized populations, people of color, transgender patients and the uninsured.

An increasing number of lung cancer diagnoses are among people who never smoked.

These disparities are due in part to biases in medical education and clinical research that fail to prepare clinicians to care for the diversity of patients they’ll encounter. Tenuous access to preventive care and disproportionate exposure to carcinogens among certain populations compound these inequities.

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The purview of cancer goes far beyond a single discipline. It takes a village of researchers, policymakers and patient advocates to achieve effective and accessible cancer care for all.The Conversation

Vivian Lam, Associate Health and Biomedicine Editor, The Conversation

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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The Conversation

Why can’t it always be summer? It’s all about the Earth’s tilt

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theconversation.com – Stephanie Spera, Assistant Professor of Geography and the , of Richmond – 2024-09-20 10:34:02

One hemisphere has summer, while the opposite has winter.

Prasit photo/Moment via Getty Images

Stephanie Spera, University of Richmond

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Curious Kids is a series for of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com.


Why can’t it always be summer? – Amanda, age 5, Chile


With its long days just itching to be spent by doing nothing, summer really can be an enchanting season. As Jenny Han wrote in the young adult novel “The Summer I Turned Pretty”: “Everything good, everything magical happens between the months of June and August.”

But all good things must to an end, and summer cannot last forever. There’s both a simple reason and a more complicated one. The simple reason is that it can’t always be summer because the Earth is tilted. The more complicated answer requires some geometry.

I’m a professor of geography and the environment who has studied seasonal changes on the landscape. Here’s what seasons have to do with our planet’s position as it moves through the solar system.

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This animation shows why the Earth has seasons.

Closeness to the Sun doesn’t explain seasons

First, you need to know that the Earth is a sphere – technically, an oblate spheroid. That means Earth has a round shape a little wider than it is tall.

Every year, Earth travels in its orbit to make one revolution around the Sun. The Earth’s orbit is an ellipse, which is more like an oval than a circle. So there are times when Earth is closer to the Sun and times when it’s farther away.

A lot of people assume this distance is why we have seasons. But these people would be wrong. In the United States, the Earth is 3 million miles closer to the Sun during winter than in the summer.

An artistic diagram shows the Earth revolving around the Sun.

Our distance from the Sun is not why we have seasons.

NASA

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Spinning like a top

Now picture an imaginary line across Earth, right in the middle, at 0° latitude. This line is called the equator. If you drew it on a globe, the equator would pass through countries Brazil, Kenya, Indonesia and Ecuador.

Everything north of the equator, including the United States, is considered the Northern Hemisphere, and everything south of the equator is the Southern Hemisphere.

Now think of the Earth’s axis as another imaginary line that runs vertically through the middle of the Earth, going from the North Pole to the South Pole.

As it orbits, or revolves, around the Sun, the Earth also rotates. That means it spins on its axis, like a top. The Earth takes one full year to revolve around the Sun and takes 24 hours, or one day, to do one full rotation on its axis.

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This axis is why we have day and night; during the day, we’re facing the Sun, and at night, we’re facing away.

But the Earth’s axis does not go directly up and down. Instead, its axis is always tilted at 23.5 degrees in the exact same direction, toward the North Star.

The Earth’s axis is tilted due to a giant object – perhaps an ancient planet – smashing into it billions of years ago. And it’s this tilt that causes seasons.

A series of diagrams showing the Earth's equator, axis and tilt.

Because of the tilt of the Earth, we are able to experience the seasons.

Stephanie Spera

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It’s all about the tilt

So that means in June, the Northern Hemisphere is tilted toward the Sun. That tilt means more sunlight, more solar energy, longer days – all the things that make summer, well, summer.

At the same time, the Southern Hemisphere is tilted away from the Sun. So countries such as Australia, Chile and Argentina are experiencing winter then.

To say it another way: As the Earth moves around the Sun throughout the year, the parts of the Earth getting the most sunlight are always changing.

Fast-forward to December, and Earth is on the exact opposite side of its orbit as where it was in June. It’s the Southern Hemisphere’s turn to be tilted toward the Sun, which means its summer happens in December, January and February.

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If Earth were not tilted at all, there would be no seasons. If it were tilted more than it is, there would be even more extreme seasons and drastic swings in temperature. Summers would be hotter and winters would be colder.

A diagram showing the Earth, its tilt and the Northern and Southern Hemispheres.

The Earth’s axis is always tilted at 23.5 degrees.

Stephanie Spera

Defining summer

to a meteorologist, climate scientist or author Jenny Han, and they’ll tell you that for those of us in the Northern Hemisphere, summer is June, July and August, the warmest months of the year.

But there’s another way to define summer. Talk to astronomers, and they’ll tell you the first day of summer is the summer solstice – the day of the year with the longest amount of daylight and shortest amount of darkness.

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The summer solstice occurs every year sometime between June 20 and June 22. And every day after, until the winter solstice in December, the Northern Hemisphere receives a little less daylight.

Summer officially ends on the autumnal equinox, the fall day when everywhere on Earth has an equal amount of daylight and night. The autumnal equinox happens every year on either September 22 or 23.

But whether you view summer like Jenny Han or like an astronomer, one thing is certain: Either way, summer must come to an end. But the season and the magic it brings with it will be back before you know it.


Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to CuriousKidsUS@theconversation.com. Please tell us your name, age and the where you .

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And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.The Conversation

Stephanie Spera, Assistant Professor of Geography and the Environment, University of Richmond

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Invasive caterpillars can make aspen forests more toxic for native insects – a team of ecologists explains how

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theconversation.com – Richard L. Lindroth, Vilas Distinguished Achievement & Sorenson Professor Emeritus, of Wisconsin- – 2024-09-19 07:27:59

The aspen forest where our team conducted our recent study.
Mark R. Zierden

Richard L. Lindroth, University of Wisconsin-Madison and Patricia C. Fernandez, Universidad de Buenos Aires

When we walked with a colleague into an aspen forest near Madison, Wisconsin, in the early spring of 2021, we expected to finalize our plans for a research on several species of insects that and feed on the trees. Instead, we found a forest laden with fuzzy, brown egg masses.

These masses, belonging to an invasive species known as the spongy moth, brought our plans to a screeching stop. We knew that within weeks, hungry spongy moth caterpillars would strip the forest bare.

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A tree with two female spongy moths laying brown egg masses.
Female spongy moths lay individual egg masses, each of which contains 100 to 600 eggs.
Richard L. Lindroth

We are chemical ecologists interested in how plant chemistry influences the interactions between plants and plant-feeding insects. As seasoned scientists, we’ve seen that good science stories sometimes end up nowhere near where the researchers first anticipated. This is one of those stories. And like many good stories, it incorporates villains, beauty, poison and .

After an initial period of distressed hand-wringing about the fate of our aspen forest, we pivoted our research plans. We decided to address how defoliation – another word for leaf consumption – by an invasive species might alter the chemical composition of plants, to the detriment of native species.

All plants produce defense compounds to fend off herbivores, like insects, that try to eat them. These defenses include well-known chemicals like tannins, caffeine and cyanide. In turn, insects have evolved adaptations to these chemical defenses tailored to the particular species that they feed on.

The results from this study surprised even us and were published in September 2023 in the journal Ecology and Evolution.

The ecological players

Quaking aspen (Populus tremuloides) is the most widespread tree species in North America.

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Aspen trees with no leaves.
Caterpillars completely defoliated our aspen forest in June 2021.
Richard L. Lindroth

As a keystone species, aspen provides food and shelter for many forest organisms. Without these trees, forests across much of North America would look very different. Aspen has been ecologically successful in part because of its unique chemistry. It produces a class of defense compounds called salicinoids. Under most conditions, these defenses keep herbivores from fully defoliating the trees.

Invasive spongy moths (Lymantria dispar) are the most destructive defoliators of broadleaf forests in North America. Aspen is a favored food plant of spongy moths, which feed on expanding leaves in early summer. At high population densities, spongy moths can defoliate extensive of forest.

This spongy moth-induced carnage does not bode well for other insects that depend on aspen for food, such as the native silk moth Anthereae polyphemus, which feeds on aspen from mid- to late summer.

A moth with big spots on its wings.
An adult polyphemus silk moth.
Richard L. Lindroth

A natural experiment

From May through June 2021, spongy moth caterpillars ate nearly every green leaf in our aspen forest.

By early July, however, the trees grew another full set of leaves. A second aspen forest of the same age, located 4 miles (6 kilometers) away, experienced no defoliation.

A large cluster of hairy spongy moth caterpillars on the trunk of an aspen tree.
A congregation of spongy moth caterpillars gathered on an aspen tree in June 2021.
Mark R. Zierden

This combination of damaged and undamaged forests provided the perfect conditions for what scientists call a natural experiment. The undamaged forests served as an experimental control that we could compare with the damaged forest to evaluate the consequences of spongy moth defoliation for insects that feed in late summer.

We collected leaves from both forests in late summer and analyzed them for levels of salicinoids.

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We also fed the native polyphemus caterpillars leaves from either the defoliated or control forest to see how the defense compounds might influence their ability to live and grow.

We found that after defoliation by spongy moths, aspen trees grew a second set of leaves with much higher levels of salicinoids – an average of 8.4 times higher. In contrast, the control forest had leaves with far lower salicinoid levels, typical of aspen in late summer.

The high levels of defense compounds in the defoliated forest caused serious to the native silk moth caterpillars. Few caterpillars survived when fed leaves from the previously defoliated forest. Those that did survive had stunted growth.

Two petri dishes with a leaf and a caterpillar in each. The leaf on the left has more pieces missing.
Polyphemus caterpillars fed previously undefoliated (control) leaves ate more and were healthier than caterpillars fed the defoliated (reflush) aspen leaves.
Richard L. Lindroth

Ecological implications

Our research showed for the first time how an invasive species can harm a native species by making their shared food resource far more toxic. And this type of ecological dynamic is likely not restricted to just aspen and silk moth caterpillars.

Over 100 different species of insects and mammals feed on aspen, and our earlier research has shown that high levels of salicinoids are harmful to many of them. Other tree species, like oaks, also produce more defense compounds after spongy moth defoliation, which could affect native herbivores.

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A caterpillar on a young tree.
A polyphemus caterpillar climbing on aspen.
Richard L. Lindroth

Insects are critically important for the functioning and flourishing of all terrestrial ecosystems. But scientists have seen their numbers and diversity decline worldwide, a phenomenon called the insect apocalypse.

The causes of these declines are many, varied and far from completely known. Research like this is helping to fill that gap. Plant toxin-mediated indirect effects of invasive species appear to be yet one more cut in the death by a thousand cuts experienced by insects worldwide.

Finally, our story is one of science in action. Scientists cannot fully anticipate how natural may disrupt the best-laid research plans, especially for field projects. Floods, droughts, tornadoes, lightning strikes, insect outbreaks – our research groups have experienced them all.

Occasionally, though, researchers can counter these challenges with creative ingenuity and scientific adaptability. And those can to surprising breakthroughs in our understanding of this extraordinary world.The Conversation

Richard L. LindrothUniversity of Wisconsin-Madison and Patricia C. Fernandez, Professor of Agronomy and CONICET Scientist, Universidad de Buenos Aires

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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TRUTH in Labeling Act would heighten the warning for shoppers looking to cut sugar, salt and saturated fat intake

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theconversation.com – Kimberly Baker, Food and Safety Program Team Director, Clemson – 2024-09-19 07:26:40

Only about 40% of consumers frequently read the nutrition label.
demaerre/iStock via Getty Images Plus

Kimberly Baker, Clemson University

With rising rates of obesity in the U.S. and increasing attention being paid to the health harms of processed foods, it’s clear that far more could be done to help consumers make healthy food choices.

A bill known as the TRUTH in Labeling Act has been sitting before since late 2023. If passed, it would require U.S. food manufacturers to add a second nutrition label to the front of product packages, in addition to the ones currently found on the back or side panel. It would also require the label to highlight any potentially unhealthy ingredients in the product, such as the amount of sugar, sodium and saturated fat it contains.

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The proposed legislation would provide consumers with a standardized, easy-to-read and quick way to decide whether a product is a healthy choice. Should the bill, which is still in committee, become , the front-of-package label would be regulated by the U.S. Food and Drug Administration.

The current nutrition facts label, typically featuring more detailed nutritional information and found on a product’s side panel, would remain unchanged.

Consuming more vitamin D, calcium, iron and potassium can reduce the risks of osteoporosis, anemia and hypertension.

As a food safety extension specialist who works with farmers, entrepreneurs, manufacturers and the government to help bring healthy food to shoppers, I believe that consistent front-of-package labeling would greatly benefit consumers by offering a straightforward way to compare multiple products, helping them make more informed choices.

Even if passed, it will take time for the FDA to interpret the law and standardize the design and format. And it might be years before all food manufacturers are required to use the new label. In the meantime, more than 175 million Americans are overweight or obese, and with each passing day, that number grows.

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Why the change?

The newly proposed legislation is the latest effort by lawmakers to educate the public about smart food choices. Congress began requiring standardized nutrition labels on food packages through the Nutrition Labeling and Education Act of 1990.

A black-and-white nutritional graphic that shows the sodium, saturated fat and added sugar content of a product is
The FDA has not made a final on the front-of-product label’s content and look, but it is testing a variety of designs, this one.
FDA

But in the 34 years since that first label appeared, the obesity rate has more than tripled; 40% of Americans are now obese. Another 31% are overweight, and diet-related chronic illnesses, including heart disease, stroke, cancer, hypertension and Type 2 diabetes are rampant. About 60% of U.S. adults – 130 million people – have at least one of these chronic illnesses.

All of these diseases are associated with consuming too much sugar, sodium or saturated fat – three key ingredients the front label will focus on.

Labels help shoppers make better choices

There’s another reason to require a second, easy-to-notice, easy-to-comprehend label. Only about 40% of Americans frequently read the existing nutrition facts label; some shoppers say they don’t understand it. A simpler label with a more direct message might help those consumers. In fact, some studies suggest front-of-package labels do assist shoppers in making smart choices.

Research shows that those who frequently read the current label tend to have healthier diets than those who don’t. For example, frequent readers are almost four times more likely than rare readers to meet the recommended daily fiber intake.

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Now the bad : Even the frequent readers met their fiber goals only about 13% of the time. That isn’t good, but it’s an improvement over the rare readers, who meet their goals a paltry 3.7% of the time.

For the record, the recommendation for fiber is 25 grams for women and 38 for men under 50; its slightly less for those over 50.

The existing nutrition facts label.
This is what the current nutrition facts label looks like. Note the serving size for this particular product is two-thirds of a cup. So if you have a 1-cup serving, you need to add 50% more to all the values listed below the serving size, including calories, fat and saturated fat.
FDA

Some foods still exempt

It’s possible you’ve already seen some front-of-package nutritional labels on food products. But these labels are not regulated by the government. Known as the “facts-up-front” labeling system, it’s strictly voluntary and a choice of the individual food manufacturer, with label designs and formats provided by the Consumer Brands Association, a trade association representing the food industry. Only a small number of manufacturers have chosen to put these labels on their products.

That said, more research is needed to know how long-term behavior may change due to front-of-package labeling. But at least one food safety advocacy organization, while supportive of front-of-package labels, says the trade association’s facts-up-front system is less than optimal.

Even if the TRUTH in Labeling Act passes as currently written, some foods could remain exempt from the nutritional label requirement, including fish, coffee, tea and spices.

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There is one caveat, however. If any product makes a nutritional or claim on its package – including those that are normally exempt – then a nutrition facts label must be on it.The Conversation

Kimberly Baker, Food Systems and Safety Program Team Director, Clemson University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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