There's no denying that hamburgers are delicious. But according to a new study, men who ate them often were much more likely to develop prostate cancer. 
 
 Scientists have long known that foods can raise or lower a person’s risk for developing cancer. But unraveling which foods can lead to which cancers—and for what kinds of patients—has been anything but easy. The most obvious example was the World Health Organization’s recent declaration that eating processed meats can increase a person’s risk of colorectal cancer. Now it seems that some types of carbohydrates and sugars might also increase a person’s cancer risk; people who regularly consumed sugary drinks were three times more likely to develop prostate cancer, and processed carbohydrates like those found in pizza and hamburgers doubled their risk. The researchers presented their work yesterday at this year’s Experimental Biology meeting. 
 
 The researchers have tracked the diets of over 3,000 volunteers since 1991. Periodically, they gave participants questionnaires about the types of foods they usually ate, then ranked their foods based on whether the carbohydrates were “good” (legumes, non-starchy vegetables, fruit, whole grains) or “bad” (processed meats, sugary soft drinks, fruit juices). Then they compared the participants' food sources to their cancer rates, controlling for a number of factors. 
 
 They found that people who ate more “bad” carbs were 88 percent more likely to develop prostate cancer. For those who consumed a lot of processed meats and sugary beverages, that risk was even higher. On the other hand, women who ate more “good” carbs were 67 percent less likely to develop breast cancer. In particular, legumes like beans and lentils lowered patients’ overall risk of developing cancer by 32 percent. 
 
 "Our study showed very strong associations between certain foods and cancer, in particular with prostate cancer," Nour Makarem, a doctoral student at New York University and the lead author on the study, said in a press release. "There had not been very many studies on food sources and prostate cancer previously." 
 
 There are some big caveats here, though. Because of the study design, the researchers don’t know the mechanism that connects sugar and cancer development—that would require much more technical studies in the future. They also note that 99 percent of their study participants were Caucasian. That would have almost certainly thrown off their conclusions, especially since black men are much more likely to develop prostate cancer. It’s also difficult to separate patients’ eating habits from their body mass index, which is important because obesity is a known risk factor for a number of types of cancer, though its link to prostate cancer is more tenuous. What’s more, even foods that have been repeatedly shown to increase cancer risk, like processed meats, are not as carcinogenic as other factors like smoking. 
 
 At this early stage, it’s impossible to know just what this association means. Nonetheless, it’s a robust one, the researchers say. Future studies will likely look into the mechanism that might make sugars and carbohydrates increase a patient’s cancer risk. ||||| Recent years have brought more attention to the role of carbohydrates in our diets and the differences between healthy and unhealthy carbs, most often in the context of weight control. A new study highlights one more reason to avoid sugary beverages, processed foods and other energy-dense carbohydrate-containing foods -- cutting them may help reduce your risk of cancer. 
 
 In the new study, regular consumption of sugary beverages was associated with a 3 times greater risk of prostate cancer and higher intake of processed lunch foods such as pizza, burgers and meat sandwiches doubled prostate cancer risk. By contrast, healthy carbohydrate-containing foods like legumes, non-starchy vegetables, fruits and whole grains were collectively associated with a 67 percent lower risk for breast cancer. 
 
 "One of the most important findings here is that the type of carbohydrate-containing foods you consume can impact your cancer risk," said Nour Makarem, a Ph.D. student at New York University and the study's lead author. "It appears that healthy carbohydrate sources, such as legumes, tend to protect us from cancer, but non-healthy ones, such as fast foods and sugary beverages, seem to increase the risk of these cancers." 
 
 Makarem will present the research at the American Society for Nutrition Scientific Sessions and Annual Meeting during Experimental Biology 2016. 
 
 The study is based on the health records of 3,100 volunteers tracked since the early 1970s. Researchers began tracking participants' diets through detailed food frequency questionnaires starting in 1991. For the new study, Makarem and her colleagues categorized all of the study participants' food sources by glycemic index -- a measure of dietary carbohydrate quality based on an item's relative impact on blood sugar levels as compared to a reference food -- and glycemic load, a measure of both the quantity and quality of carbohydrates in a given food item. They then analyzed the results in relation to volunteers' cancer rates. 
 
 After taking into account multiple cancer risk factors, the study found that eating foods with a higher glycemic load was associated with an 88 percent higher prostate cancer risk. Prostate cancer is one of the most common types of cancer and the second leading cause of cancer-related death in men. 
 
 "Our study showed very strong associations between certain foods and cancer, in particular with prostate cancer," said Makarem. "There had not been very many studies on food sources and prostate cancer previously." 
 
 The risk increase was most pronounced for people who regularly consumed processed lunch foods or sugary beverages, a category that includes sugar-sweetened soft drinks in addition to fruit juices, which can be naturally high in sugar and often contain added sugars. 
 
 "Americans consume almost half of their added sugars in beverages," said Makarem. "Sugar-sweetened beverages have been shown to increase the risk of obesity and diabetes, and our study documents that they may also have a detrimental impact on cancer risk." 
 
 By contrast, consuming low-glycemic index foods such as legumes, non-starchy vegetables, most fruits and whole grains was associated with a 67 percent lower breast cancer risk. Breast cancer risk was also reduced among women who had a higher level of carbohydrate intake overall as a proportion of their total calories. However, in this study participants with in the highest level of carbohydrate intake also had higher intakes of fruits and vegetables, whole grains and legumes. These findings underscore the idea that the type of carbohydrates matters more than the total amount of carbohydrates, said Makarem. 
 
 Among individual foods, legumes such as beans, lentils and peas were associated with 32 percent lower risk of all overweight- and obesity-related cancers, including breast, prostate and colorectal cancers. 
 
 By nature of the study design, the results point only to associations, not necessarily to cause-and-effect. Nonetheless, the findings are in line with previous studies, which have shown that malignant cancer cells seem to feed on sugar, and that diets high in refined carbohydrates may lead to a range of adverse health effects primarily due to their impacts on body fatness and on the dysregulation of insulin and glucose, both of which are factors that may increase cancer risk. 
 
 "Current cancer prevention guidelines recommend avoiding sugary drinks and limiting the consumption of energy-dense foods, which tend to be high in refined carbohydrates," said Makarem. "I think our findings add to the body of evidence behind this recommendation and strengthen the associations between these types of food and cancer." 
 
 One caveat that Makarem noted is that the volunteers involved in the study were 99 percent Caucasian. Further study is needed to determine if these associations hold true in more ethnically-diverse groups. 
 
 Makarem will present the findings during the Experimental Biology 2016 meeting on Tuesday, April 5. ||||| A new World Health Organization study found that processed meat like bacon and hot dogs cause cancer. It is the most prominent group to declare it a cause of the disease, and the U.S. beef industry isn't happy about it. (Jenny Starrs/The Washington Post) 
 
 A research division of the World Health Organization announced Monday that bacon, sausage and other processed meats cause cancer and that red meat probably does, too. 
 
 The report by the influential group stakes out one of the most aggressive stances against meat taken by a major health organization, and it is expected to face stiff criticism in the United States. 
 
 The WHO findings were drafted by a panel of 22 international experts who reviewed decades of research on the link between red meat, processed meats and cancer. The panel reviewed animal experiments, studies of human diet and health, and cell processes that could explain how red meat might cause cancer. 
 
 But the panel’s decision was not unanimous, and by raising lethal concerns about a food that anchors countless American meals, it will be controversial. 
 
 The $95 billion U.S. beef industry has been preparing for months to mount a response, and some scientists, including some unaffiliated with the meat industry, have questioned whether the evidence is substantial enough to draw the strong conclusions that the WHO panel did. 
 
 In reaching its conclusion, the panel sought to quantify the risks, and compared to carcinogens such as cigarettes, the magnitude of the danger appears small, experts said. The WHO panel cited studies suggesting that an additional 3.5 ounces of red meat everyday raises the risk of colorectal cancer by 17 percent; eating an additional 1.8 ounces of processed meat daily raises the risk by 18 percent, according to the research cited. 
 
 “For an individual, the risk of developing colorectal cancer because of their consumption of processed meat remains small, but this risk increases with the amount of meat consumed,” says Kurt Straif, an official with the World Health Organization’s International Agency for Research on Cancer, which produced the report. “In view of the large number of people who consume processed meat, the global impact on cancer incidence is of public health importance.” 
 
 About 34,000 cancer deaths a year worldwide are attributable to diets high in processed meats, according to figures cited by the panel. 
 
 [WHO says hot dogs, bacon cause cancer. Does this mean we should all become vegetarians?] 
 
 
 
 The research into a possible link between eating red meat and cancer has been the subject of scientific debate for decades, with colorectal cancer being a long-standing area of concern. But by concluding that processed meat causes cancer, and that red meat “probably” causes cancer, the WHO findings go well beyond the tentative associations that some other groups have reported. 
 
 The American Cancer Society, for example, notes that many studies have found “a link” between eating red meat and heightened risks of colorectal cancer. But it stops short of telling people that the meats cause cancer. Some diets that have lots of vegetables and fruits and lesser amounts of red and processed meats have been associated with a lower risk of colorectal cancer, the American Cancer Society says, but “it’s not exactly clear” which factors of that diet are important. 
 
 Likewise, the Dietary Guidelines for Americans, the U.S. government’s advice compendium, encourage the consumption of protein-containing foods such as lean meats as part of a healthy diet. Regarding processed meats, though, the Dietary Guidelines offer a tentative warning: “Moderate evidence suggests an association between the increased intake of processed meats (e.g., franks, sausage, and bacon) and increased risk of colorectal cancer and cardiovascular disease.” The Dietary Guidelines do not assert that processed meats cause cancer. 
 
 Officials from the Department of Health and Human Services, which is updating the Dietary Guidelines with the USDA, have not yet reviewed the WHO report, a spokesperson said. 
 
 [95 percent of the world's people may be wrong about salt] 
 
 For consumers, the WHO announcement offers scant practical advice even while casting aspersions over a wide array of foods. Red meat includes beef, veal, pork, lamb, mutton and goat. Processed meat includes hot dogs, ham, sausages, corned beef and beef jerky — or any other meat that has been cured, smoked, salted or otherwise changed to enhance flavor or improve preservation. 
 
 How much of those is it safe to eat? The group doesn’t offer much guidance: “The data available for evaluation did not permit a conclusion about whether a safe level exists.” 
 
 Should we be vegetarians? Again, the group does not hazard an answer. 
 
 And how exactly does red meat and processed meat cause cancer? The group names a handful of chemicals involved in cooking and processing meat, most of them nearly unpronounceable, and some believed to be carcinogenic. 
 
 “But despite the knowledge it is not yet fully understood how cancer risk is increased by red meat or processed meat,” the group wrote. 
 
 Despite the voids in the science, the WHO findings might cast a pall over diners and those who serve them. 
 
 At The Pig Restaurant on 14th Street NW in Washington, where the menu includes an array of pork products - kielbasa, prosciutto, pork cheek, etc - a worker sweeping the tables outside encouraged a reporter to look elsewhere for comments about cancer and red meat. Around the corner, outside the Whole Foods grocery, shoppers evinced a weary of fatalism regarding authoritative diet advice. 
 
 “It makes some sense,” said Nassrin Farzaneh, a development consultant, carrying a bag out of the store, said of the WHO finding on processed meat. “But they say one thing and then two or three years later they something that contradicts it. It goes on and on.” 
 
 “Everything causes cancer,” said Caroline Rourke, an energy policy analyst, also on her way out of the grocery. “Life causes cancer. Who cares what food does? Life is terminal, isn’t it?" 
 
 [Another food to worry about? Honey not as healthy as we think.] 
 
 In recent years, meat consumption has been the target of multi-faceted social criticism, with debates erupting not just over its role on human health, but the impact of feedlots on the environment and on animal welfare. The public debate over the WHO’s findings will probably play out with political lobbying and in marketing messages for consumers. 
 
 An industry group, the North American Meat Institute, called the WHO report “dramatic and alarmist overreach,” and it mocked the panel’s previous work for approving a substance found in yoga pants and treating coffee, sunlight and wine as potential cancer hazards. 
 
 The WHO panel “says you can enjoy your yoga class, but don’t breathe air (Class I carcinogen), sit near a sun-filled window (Class I), apply aloe vera (Class 2B) if you get a sunburn, drink wine or coffee (Class I and Class 2B), or eat grilled food (Class 2A),” said Betsy Booren, vice president of scientific affairs for the group. 
 
 “We simply don’t think the evidence supports any causal link between any red meat and any type of cancer,” said Shalene McNeill, executive director of human nutrition at the National Cattlemen’s Beef Association. 
 
 But at its core, the issue revolves around science, and in particular the difficulty that arises whenever scientists try to link any food to a chronic disease. 
 
 Experiments to test whether a food causes cancer pose a massive logistical challenge: they require controlling the diets of thousands of test subjects over a course of many years. For example, one group might be assigned to eat lots of meat and another less, or none. But for a variety of reasons involving cost and finding test subjects, such experiments are rarely conducted, and scientists instead often use other less direct methods, known as epidemiological or observational studies, to draw their conclusions. 
 
 “I understand that people may be skeptical about this report on meat because the experimental data is not terribly strong,” said Paolo Boffetta, a professor of Tisch Cancer Institute at the Mount Sinai School of Medicine who has served on similar WHO panels. “But in this case the epidemiological evidence is very strong.” 
 
 [Why the Bureau of Prisons stripped pork from the menu for federal inmates] 
 
 Some scientists, however, have criticized the epidemiological studies for too often reaching “false positives,” that is, concluding that something causes cancer when it doesn’t. 
 
 “Is everything we eat associated with cancer?” asked a much noted 2012 paper in the American Journal of Clinical Nutrition. 
 
 That paper reviewed the academic studies conducted on common cookbook ingredients. Of the 50 ingredients considered, 40 had been studied for their relation to cancer. Individually, most of those studies found that consumption of the food was correlated with cancer. But when the research on any given ingredient was considered collectively, those effects typically shrank or disappeared. 
 
 “Many single studies highlight implausibly large effects, even though evidence is weak,” the authors concluded. 
 
 Although epidemiological studies were critical in proving the dangers of cigarettes, the magnitude of the reported meat risk is much smaller, and it is hard for scientists to rule out statistical confounding as the cause of the apparent danger. 
 
 Moreover, some skeptics noted that two experiments that tested diets with reduced meat consumption, the Polyp Prevention Trial and the Women’s Health Initiative, found that people who reduced their meat intake did not appear to have a lower cancer risk. It is possible, though, that the reductions in animal flesh were too small to have an effect. 
 
 “It might be a good idea not to be an excessive consumer of meat,” said Jonathan Schoenfeld, the co-author of the American Journal of Clinical Nutrition article and an assistant professor in radiation oncology at Harvard Medical School. “But the effects of eating meat may be minimal, if anything.” 
 
 Read more: 
 
 Was it wrong that the government steered people away from whole milk for decades? 
 
 How Coca-Cola has tricked everyone into drinking so much of it 
 
 What Americans do with fish is shocking 
 
 Why Americans are falling out of love with one of their favorite fruits 
 
 Whole milk, butter and eggs are now okay to eat. What's next?
– Meat is often the bad guy linked to higher cancer rates: The World Health Organization says bacon is carcinogenic and red meats in general "probably" are, while grilling meats is linked to higher kidney cancer rates. But researchers out of New York University report in ScienceDaily that their latest study suggests it isn't just meat but highly processed "bad" carbohydrates (think sugary soft drinks and pizza) that are linked to higher cancer rates. They've presented their findings at the American Society for Nutrition Scientific Sessions and Annual Meeting, noting that the link is strongest to prostate cancer, which is nearly twice as common among men who eat "bad" carbs over "good" ones such as legumes and whole grains. The longitudinal study follows 3,100 volunteers as far back as the 1970s, with participants regularly reporting detailed food questionnaires starting in 1991. All foods were categorized by glycemic index, which measures carbohydrate quality by looking at its impact on blood sugar compared to a reference food, as well as glycemic load, which measures both the quantity and quality of carbs in each item. Controlling for many variables, they compared these results to the participants' cancer rates. And while Popular Science notes that there are some holes in the study, including that 99% of the participants were Caucasian, the study is a "robust" one and will likely be followed up by additional investigations into the precise mechanism at play between carbs and cancers. (Bad carbs have also been linked to depression.)