How Canada Can Help Protect Canadians from Obesity and Chronic disease

University of Toronto nutritional scientists are leading a study with national experts calling on the Canadian government to outlaw junk food marketing to children, impose stricter limits on unhealthy nutrients added to foods, and impose a “sugary drink tax.”

Professor Mary L’Abbé, chair of the Department of Nutritional Sciences and Banting postdoctoral fellow Lana Vanderlee, made the recommendations in a newly released report, called the Food-EPI Study, funded by the Canadian Institutes of Health Research. In it, they examined Canada’s progress on obesity-curbing measures compared with other countries.

They found that Canada performed well on some important measures, such as political leadership to support healthy eating, and transparency in developing food policies (which if secretive can lead to undue influence by the food industry).

For some important areas where Canada trails its peers, Health Canada has recently announced new policies to address these issues. However, the authors say Canada still has work to do: there are a number of areas where there are almost no policies or programs at any level of government.

Despite the good news, there were notable disparities between provinces, with Quebec having the most progressive food policies, including a restriction of junk-food marketing to children, and some other provinces failing to do as much to protect residents. Even the foods and drinks that can be sold in schools varied across provinces and territories. Overall, Ontario fared roughly in the middle of the pack.

“Even if we’re meeting best practices in some areas, we shouldn’t get complacent,” says Vanderlee. “Canada doesn’t have taxes on unhealthy foods, such as sugary drinks, even though the evidence from other countries suggests these work. If we don’t move on this front, we’re going to fall behind.”

Mexico, which has some of the world’s highest child obesity rates, is seeing success with a soda tax, and other countries are following suit, she says. The UK is on the verge of implementing such a tax, and South Africa just announced one.

“Most of the evidence indicates that sugary drinks are among the biggest contributors to sugar consumption and play an important role in weight gain,” she says. “You don’t get as full when you’re drinking your calories and it’s easy to consume a lot of sugar in a short time.”

The federal government also currently imposes no restrictions on marketing junk food to children, L’Abbe says, although they have announced impending regulations as part of the Healthy Eating Strategy.

“We know that marketing to kids changes what they want to eat and what they’re asking their parents to buy. And we know that it is the unhealthy foods that are the most heavily marketed to children,” she says.

Asking for voluntary industry cooperation to make foods healthier, with less sodium, hasn’t worked well in the past for all foods, she says. The Canadian government hasn’t made any voluntary or mandatory restrictions on the amount of sugar or saturated fat in foods either, nor have officials set any targets for levels in restaurant foods.

“The evidence is mounting that these kinds of government interventions work,” says Vanderlee. “But we know no individual policy is a silver bullet. That’s why Canada needs a comprehensive and coordinated strategy if we want to move the dial on obesity and diet-related diseases like diabetes, heart disease and cancer and keep up with international leaders.”

Source: EurekAlert!

Advertisements

Link between Obesity and Cancer is not Widely Recognized

A new study published in the Journal of Public Health has shown that the majority of people in the United Kingdom do not understand the connection between weight issues and cancer. Obesity is associated with thirteen types of cancer, including those of the breast, kidney, bowel, and womb. However, after surveying 3293 adults, taken as representative of the UK population, researchers found that only a quarter of respondents were aware of the link between obesity and cancer.

Obesity is the second biggest preventable cause of cancer after smoking, leading to approximately 3.4 million deaths worldwide. Despite the fact that 63% of the English and 67% of the Scottish adult population is overweight, only 25.4% of this population listed cancer as a health issue related to being overweight when asked an unprompted question.

There were also several misconceptions about cancer types linked to obesity. Researchers found greater levels of awareness about cancers of the digestive system organs, such as bowel and kidney, than for those of the reproductive organs, such as womb or breast.

The study’s authors also examined the impact of respondents’ socio-economic background and found that those in a lower income group were more likely to be overweight or obese and were less aware of the link between weight issues and cancer. Modelled projections show obesity trends will increase by 2035 and the gap between the highest and lowest income groups will widen further.

Although there are currently several healthcare initiatives to address obesity issues, the study found that not all participants had seen a healthcare professional in the last 12 months. Of those who had, only 17.4% had received advice about their weight, despite 48.4% being overweight.

Those who received advice were mainly instructed on how to lose weight, rather than given information about the range of health issues associated with being overweight or obese.

Dr Jyotsna Vohra, from Cancer Research UK and study co-author, said: “We’re very concerned that most people simply don’t connect cancer with obesity. This study shows that only one in four know that excess weight increases the risk of cancer so we need to make the link very clear. This may go some way towards tackling the obesity epidemic which all too often begins in childhood.”

“Our study also showed that GPs aren’t discussing weight with patients who are too heavy as often as they might, Dr Vohra said “GPs have very little time during their appointments and should have more support to introduce sensitive issues such as obesity, with patients.”

Source: EurekAlert!


Today’s Comic

Science Weighs in On How Fat Raises Cancer Risk

Scientists have known for years that obesity can rise cancer risk, but how? Now, new research offers clues to how fat cells encourage tumors.

The issue is an important one, the study author said.

“Obesity is increasing dramatically worldwide, and is now also recognized as one of the major risk factors for cancer, with 16 different types of cancer linked to obesity,” explained Cornelia Ulrich, of the Huntsman Cancer Institute in Salt Lake City.

To help prevent the disease, “we urgently need to identify the specific mechanisms that link obesity to cancer,” she said.

Prior studies have already outlined several ways fat could play a role in cancer. For example, obesity increases inflammation in the body, which has long been associated with the disease.

Obesity can also affect cancer cell metabolism and undermine the immune system’s natural defenses, which may help tumors to grow and spread.

Ulrich’s team noted that the link between fat and cancer also hinges on cellular “crosstalk” — changes in complex chemical signaling within cells. Finding ways to interrupt this “crosstalk” could lead to new ways to help prevent cancer, the researchers theorized.

In the new review, to be published Sept. 5 in Cancer Prevention Research, an international team of researchers looked at data from 20 existing studies. The studies were published over the past seven decades, and each focused on cellular crosstalk between fat cells and malignant tumors.

In several of these studies, certain fat cells — known as “adipose stromal cells” — were able to invade cancer lesions and then help spur the growth of tumors. The data also showed that obese people with prostate or breast cancer appeared to have more of these cells than thinner people.

Some types of fat cells are also more “metabolically active,” releasing more substances that promote tumor growth, the review found.

Also, fat may be white, brown or beige, Ulrich’s team noted. And these different types of fat each behave differently, depending on quantity and location in the body. For example, the review found that white fat tissue is linked with inflammation and worse outcomes for women with breast cancer.

The location of fat in the body also influences how it affects certain types of cancer, the review found. Fat tissue is usually adjacent to colon and rectal cancers, the research team noted, and it is part of the direct environment of breast tumors.

According to the team, future studies might help doctors figure out if it’s possible to disrupt the processes that promote the growth of tumors by affecting nearby fat.

“We are just beginning to unravel the ways crosstalk occurs and the substances involved,” Ulrich said in a journal news release. “The more we understand this process, the better we can identify targets and strategies for decreasing the burden of obesity-related cancer.”

Two experts in obesity agreed that this type of research is important.

“Obesity is going to surpass cigarette smoking as the leading cause of cancer deaths,” said Dr. Mitchell Roslin, chief of obesity surgery at Lenox Hill Hospital in New York City.

“The take-home message here is that proper nutrition and maintaining a proper weight is essential for successful preventative health,” he said. “Obesity is not inert and impacts virtually every aspect of your body, and not in a positive manner.”

Dr. Raymond Lau is an endocrinologist at NYU Winthrop Hospital in Mineola, N.Y. He said that “there has long been an association between obesity and cancer risk. There is growing evidence that inflammation is the common link between these two disease states, and this review article helps to strengthen this relationship.”

Source : HealthDay


Today’s Comic

Study Shows How Food Preservatives May Disrupt Human Hormones and Promote Obesity

Can chemicals that are added to breakfast cereals and other everyday products make you obese? Growing evidence from animal experiments suggests the answer may be “yes.” But confirming these findings in humans has faced formidable obstacles — until now.

A new study published today in Nature Communications details how Cedars-Sinai investigators developed a novel platform and protocol for testing the effects of chemicals known as endocrine disruptors on humans.

The three chemicals tested in this study are abundant in modern life. Butylhydroxytoluene (BHT) is an antioxidant commonly added to breakfast cereals and other foods to protect nutrients and keep fats from turning rancid; perfluorooctanoic acid (PFOA) is a polymer found in some cookware, carpeting and other products; and tributyltin (TBT) is a compound in paints that can make its way into water and accumulate in seafood.

The investigators used hormone-producing tissues grown from human stem cells to demonstrate how chronic exposure to these chemicals can interfere with signals sent from the digestive system to the brain that let people know when they are “full” during meals. When this signaling system breaks down, people often may continue eating, causing them to gain weight.

“We discovered that each of these chemicals damaged hormones that communicate between the gut and the brain,” said Dhruv Sareen, PhD, assistant professor of Biomedical Sciences and director of the Induced Pluripotent Stem Cell Core Facility at the Cedars-Sinai Board of Governors Regenerative Medicine Institute. “When we tested the three together, the combined stress was more robust.”

Of the three chemicals tested, BHT produced some of the strongest detrimental effects, Sareen said.

While other scientists have shown these compounds can disrupt hormone systems in laboratory animals, the new study is the first to use human pluripotent stem cells and tissues to document how the compounds may disrupt hormones that are critical to gut-to-brain signaling and preventing obesity in people, Sareen said.

“This is a landmark study that substantially improves our understanding of how endocrine disruptors may damage human hormonal systems and contribute to the obesity epidemic in the U.S.,” said Clive Svendsen, PhD, director of the institute and the Kerry and Simone Vickar Family Foundation Distinguished Chair in Regenerative Medicine.

More than one-third of U.S. adults are considered to be obese, according to federal statistics.

The new testing system developed for the study has the potential to provide a much-needed, safe and cost-effective method that can be used to evaluate the health effects of thousands of existing and new chemicals in the environment, the investigators say.

For their experiments, Sareen and his team first obtained blood samples from adults, and then, by introducing reprogramming genes, converted the cells into induced pluripotent stem cells. Then, using these stem cells, the investigators grew human epithelium tissue, which lines the gut, and neuronal tissues of the brain’s hypothalamus region, which regulates appetite and metabolism.

The investigators then exposed the tissues to BHT, PFOA and TBT, one by one and also in combination, and observed what happened inside the cells. They found that the chemicals disrupted networks that prepare signaling hormones to maintain their structure and be transported out of the cells, thus making them ineffective. The chemicals also damaged mitochondria — cellular structures that convert food and oxygen into energy and drive the body’s metabolism.

Because the chemical damage occurred in early-stage “young” cells, the findings suggest that a defective hormone system could impact a pregnant woman as well as her fetus in the womb, Sareen said. While other scientists have found, in animal studies, that effects of endocrine disruptors can be passed down to future generations, this process has not been proved to occur in humans, he explained.

More than 80,000 chemicals are registered for use in the U.S. in everyday items such as foods, personal care products, household cleaners and lawn-care products, according to the National Toxicology Program of the U.S. Department of Health and Human Services. While the program states on its website that relatively few chemicals are thought to pose a significant risk to human health, it also states: “We do not know the effects of many of these chemicals on our health.”

Cost and ethical issues, including the health risk of exposing human subjects to possibly harmful substances, are among the barriers to testing the safety of many chemicals. As a result, numerous widely used compounds remain unevaluated in humans for their health effects, especially to the hormone system.

“By testing these chemicals on actual human tissues in the lab, we potentially could make these evaluations easier to conduct and more cost-effective,” Sareen said.

Source : Cedars-Sinai


Today’s Comic

Where Body Fat Is Carried Can Predict Obesity-related Cancer Risk

Scientists have found that carrying fat around your middle could be as good an indicator of cancer risk as body mass index (BMI), according to research published in the British Journal of Cancer.

It shows that adding about 11 cm to the waistline increased the risk of obesity related cancers by 13 per cent.

For bowel cancer, adding around 8 cm to the hips is linked to an increased risk of 15 per cent.

Carrying excess body fat can change the levels of sex hormones, such as oestrogen and testosterone, can cause levels of insulin to rise, and lead to inflammation, all of which are factors that have been associated with increased cancer risk.

This is the first study comparing adult body measurements in such a standardised way for obesity-related cancers.

Using a novel approach, scientists at the International Agency for Research on Cancer (IARC-WHO) showed that three different measurements of body size, BMI, waist circumference, and waist to hip ratio all predicted similar obesity-related cancer risk in older adults.

The study combined data from around 43,000 participants who had been followed for an average of 12 years and more than 1,600 people were diagnosed with an obesity-related cancer.

Dr Heinz Freisling, lead study author and scientist at the International Agency for Research on Cancer (IARC-WHO), said: “Our findings show that both BMI and where body fat is carried on the body can be good indicators of obesity-related cancer risk. Specifically, fat carried around the waist may be important for certain cancers, but requires further investigation.”

“To better reflect the underlying biology at play, we think it’s important to study more than just BMI when looking at cancer risk. And our research adds further understanding to how people’s body shape could increase their risk.”

Being overweight or obese is the single biggest preventable cause of cancer after smoking and is linked to 13 types of cancer including bowel, breast, and pancreatic.

Dr Julie Sharp, Cancer Research UK’s head of health information, said: “This study further highlights that however you measure it being overweight or obese can increase the risk of developing certain cancers, including breast and bowel.

“It’s important that people are informed about ways to reduce their risk of cancer. And while there are no guarantees against the disease, keeping a healthy weight can help you stack the odds in your favour and has lots of other benefits too. Making small changes in eating, drinking and keeping physically active that you can stick with in the long term can help you get to a healthy weight – and stay there.”

Source: Cancer Research UK


Today’s Comic