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Ultra-processed foods linked to increased cancer risk

By Jen Christensen, CNN

Updated 1924 GMT (0324 HKT) February 28, 2018

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Not eating enough fruit led to to an estimated 7.5% diet-related "cardiometabolic deaths" in 2012, the researchers said in <a href="http://jamanetwork.com/journals/jama/fullarticle/2608221" target="_blank">a recent study in JAMA</a>. Two servings of fruit are recommended each day. A serving would equal one whole fruit, such as an entire banana, or one cup equivalent.
Photos: Which of your food habits is most dangerous?
Not eating enough fruit led to to an estimated 7.5% diet-related "cardiometabolic deaths" in 2012, the researchers said in a recent study in JAMA. Two servings of fruit are recommended each day. A serving would equal one whole fruit, such as an entire banana, or one cup equivalent.
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Vegetables are another necessary part of a healthy diet, with a recommendation of 2½ cups each day. Not eating enough vegetables led to to an estimated 7.6% of diet-related deaths, such as heart disease, stroke and type 2 diabetes, in 2012. Overall, a larger proportion of men than women died early due to diet-related causes, which researchers say is consistent with generally unhealthier eating habits of men.
Photos: Which of your food habits is most dangerous?
Vegetables are another necessary part of a healthy diet, with a recommendation of 2½ cups each day. Not eating enough vegetables led to to an estimated 7.6% of diet-related deaths, such as heart disease, stroke and type 2 diabetes, in 2012. Overall, a larger proportion of men than women died early due to diet-related causes, which researchers say is consistent with generally unhealthier eating habits of men.
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Nuts and seeds are high-protein foods that naturally come in nutrient-dense forms. The recommendation for healthy eating includes 5.5 ounces of protein-rich foods, such as walnuts, each day. Not eating enough nuts and seeds led to an estimated 8.5% of diet-related cardiometabolic deaths in 2012.
Photos: Which of your food habits is most dangerous?
Nuts and seeds are high-protein foods that naturally come in nutrient-dense forms. The recommendation for healthy eating includes 5.5 ounces of protein-rich foods, such as walnuts, each day. Not eating enough nuts and seeds led to an estimated 8.5% of diet-related cardiometabolic deaths in 2012.
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A healthy diet includes eating whole grains (such as brown rice, quinoa, buckwheat and oats) while limiting your intake of refined grains (white rice and white flour) and products made with refined grains, such as bread and pasta. Too few whole grains (and too many refined grains) led to to an estimated 5.9% of all diet-related deaths due to heart problems, stroke and diabetes during 2012.
Photos: Which of your food habits is most dangerous?
A healthy diet includes eating whole grains (such as brown rice, quinoa, buckwheat and oats) while limiting your intake of refined grains (white rice and white flour) and products made with refined grains, such as bread and pasta. Too few whole grains (and too many refined grains) led to to an estimated 5.9% of all diet-related deaths due to heart problems, stroke and diabetes during 2012.
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Oils provide essential fatty acids and vitamin E. Oils, which are liquid at room temperature, should replace solid fats, such as butter, rather than being added to the diet. Not replacing solid fats with oils led to to an estimated 2.3% of all diet-related deaths caused by heart disease, stroke and type 2 diabetes during 2012.
Photos: Which of your food habits is most dangerous?
Oils provide essential fatty acids and vitamin E. Oils, which are liquid at room temperature, should replace solid fats, such as butter, rather than being added to the diet. Not replacing solid fats with oils led to to an estimated 2.3% of all diet-related deaths caused by heart disease, stroke and type 2 diabetes during 2012.
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Seafood is rich in omega-3 fats, which are good for your heart and brain. Not eating enough seafood led to to an estimated 7.8% of diet-related deaths due to cardiometabolic factors during 2012. For the general population, dietary guidelines recommend 8 ounces a week of a variety of seafood.
Photos: Which of your food habits is most dangerous?
Seafood is rich in omega-3 fats, which are good for your heart and brain. Not eating enough seafood led to to an estimated 7.8% of diet-related deaths due to cardiometabolic factors during 2012. For the general population, dietary guidelines recommend 8 ounces a week of a variety of seafood.
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The leading diet-related factor linked to a death caused by heart disease, stroke or type 2 diabetes was high sodium. Eating too much salty food led to an estimated 9.5% of all diet-related deaths in 2012. People over the age of 65, in particular, were most likely to be victims this tiny yet mighty killer.
Photos: Which of your food habits is most dangerous?
The leading diet-related factor linked to a death caused by heart disease, stroke or type 2 diabetes was high sodium. Eating too much salty food led to an estimated 9.5% of all diet-related deaths in 2012. People over the age of 65, in particular, were most likely to be victims this tiny yet mighty killer.
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Too much red meat led to to an estimated 4.2% of diabetes-related deaths during 2012. It's included in the recommended 5.5 daily ounces of protein-rich foods. In addition to protein, meat provides important nutrients such as iron, copper, zinc, selenium, choline, phosphorous, B vitamins (including niacin and riboflavin), vitamin D and vitamin E.
Photos: Which of your food habits is most dangerous?
Too much red meat led to to an estimated 4.2% of diabetes-related deaths during 2012. It's included in the recommended 5.5 daily ounces of protein-rich foods. In addition to protein, meat provides important nutrients such as iron, copper, zinc, selenium, choline, phosphorous, B vitamins (including niacin and riboflavin), vitamin D and vitamin E.
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Deaths related to processed meats were higher among men than women. Too much processed meat, including bacon, led to to an estimated 8.2% of all diet-related deaths, primarily heart disease and diabetes, during 2012.
Photos: Which of your food habits is most dangerous?
Deaths related to processed meats were higher among men than women. Too much processed meat, including bacon, led to to an estimated 8.2% of all diet-related deaths, primarily heart disease and diabetes, during 2012.
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More men than women contributed to the total deaths associated with drinking too many sugar-sweetened beverages. Too many sugary beverages led to to an estimated 7.4% of all early, diet-related deaths during 2012. For people between the ages of 25 and 64, sodas and other sugary drinks were associated with early deaths more than any other single dietary factor.
Photos: Which of your food habits is most dangerous?
More men than women contributed to the total deaths associated with drinking too many sugar-sweetened beverages. Too many sugary beverages led to to an estimated 7.4% of all early, diet-related deaths during 2012. For people between the ages of 25 and 64, sodas and other sugary drinks were associated with early deaths more than any other single dietary factor.
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Story highlights

  • Increase in ultra-processed foods linked to heightened cancer risk
  • Ultra-processed food makes up 60% of the US diet and more than 50% in the UK

(CNN)Ultra-processed foods are not known for their health qualities. We know this, yet it's hard to resist the doughnuts your kind colleague brought into the office. Now, research published Wednesday in the BMJ may give you at least a longer pause before you pick the pink one with sprinkles.

Researchers discovered that people who eat more ultra-processed foods have a higher risk of cancer. Such foods are the ones with unrecognizable and unpronounceable words on the list of ingredients -- anything from the candy that turns your tongue blue to healthier-sounding canned soups packed with artificial flavors, additives or emulsifiers. Most food is processed to some degree, but ultra-processed foods are typically much more calorie-, sodium- and sugar-packed.
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    Research has long showed that people who live on ultra-processed food tend to be more obese and overweight. They're also more likely to have heart and circulation problems or diabetes, studies have found. Eating a lot of processed meat like hot dogs has also been tied to an increased risk of colorectal cancer.
    Researchers saw this new cancer link when they analyzed 24-hour dietary records of nearly 105,000 adults in the NutriNet-Sante cohort, a general population group in France. The individuals recorded what they ate from a list of 3,300 food items that were then categorized by how processed they were, using a system called NOVA.
    What the scientists found was that a 10% increase in the proportion of ultra-processed foods in the diet was associated with a significant increase of greater than 10% in risks for overall cancer and breast cancer.
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    "Ultra-processed fats and sauces, sugary products and drinks were associated with an increased risk of overall cancer," the study says. "Ultra-processed sugary products were associated with an increased risk of breast cancer."
    People who tended to eat more ultra-processed food also tended to smoke more and exercise less than the others, but the authors controlled for these issues and still found the elevated cancer risk.
    "It was quite surprising, the strength of the results. They were really strongly associated, and we did many sensitive analysis and adjusted the findings for many co-factors, and still, the results here were quite concerning," study co-author Mathilde Touvier said.
    "What people eat is an expression of their lifestyle in general and may not be causatively linked to the risk of cancer. So it is necessary to rule out what are called cofounding factors," said Tom Sanders, scientific governor of the British Nutrition Foundation and an emeritus professor at King's College London.
    Sanders, who was not involved in the study, said the authors made statistical adjustments to accommodate for some of that, but he cautions that "the approach of categorizing dietary patterns that depend on industrially processed food in relation to disease risk is novel but probably needs refining before it can be translated into practical dietary advice."
    The nonprofit trade group Association of Food Industries did not respond to requests for comment.
    Marji McCullough, strategic director of nutritional epidemiology at the American Cancer Society, suggests caution about interpreting what is responsible for the cancer risk associated with ultra-processed food.
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    "This study doesn't mean that people should think 'if I eat this cracker, I'm going to get cancer,' " McCullough said. "The overriding message of this study was really to look at an overall diet pattern rather than a specific ingredient, and it supports a lot of what we already know."
    For example, she said, people eating more highly processed foods are probably eating fewer healthy foods, which may help prevent cancer. Nutritionists recommend a diet rich in whole grains, whole fruits and vegetables instead of foods that have little nutritional value.
    Touvier also noted that it's an observational study, meaning scientists don't know what exactly is causing the increased cancer risk, but her group at the Sorbonne Paris Cité Epidemiology and Statistics Research Center plans to look closer at what the connection may be. "The challenge now is to disentangle the different foods and understand this relationship to see what specifically is having this effect."
    Animal studies have shown that some additives are "quite good candidates" for being carcinogenic, Touvier said, "but that would need to be seen if they are also carcinogenic in the human population."
    If you are starting to worry about what you've brought for lunch, Touvier cautions not to be "too alarmist" about this research.
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    However, ultra-processed foods occupy a growing part of the world's diet. A 2016 study found that 60% of the calories in the average American diet come from this kind of food. A 2017 study found that they make up 50% of the Canadian diet, and they make up more than 50% of the UK diet. And more of the developing world is starting to eat this way.
    A balanced and diversified diet should be considered one of the most important public health priorities, the authors advise. "Eat real food and try to limit ultra processed items," Touvier said. "At least until we know more."