By CNN
There is strong evidence that there is 鈥渘o safe amount鈥 of processed meat to eat, nutrition experts say in response to a new study on the connection between diet and the risk of major diseases, including cancer, type 2 diabetes and heart disease. The researchers also found elevated risks from the consumption of sugar-sweetened beverages and trans fatty acids.
Researchers analyzed data from more than 60 previous studies on the relationship between processed meats, sugar-sweetened beverages and trans fatty acids in a person鈥檚 diet and their risk of type 2 diabetes, colorectal cancer and ischemic heart disease, which reduces blood supply to the heart and cuts off oxygen and nutrients, according to the study published Monday in the journal Nature Medicine.
鈥淗abitual consumption of even small amounts of processed meat, sugary drinks, and trans fatty acids is linked to increased risk of developing type 2 diabetes, ischemic heart disease and colorectal cancer,鈥 said lead author of the study, Dr. Demewoz Haile, a research scientist at the Institute for Health Metrics and Evaluation in Seattle.
The data showed that people who ate as little as one hot dog a day when it comes to processed meats had an 11% greater risk of type 2 diabetes and a 7% increased risk of colorectal cancer than those who didn鈥檛 eat any. And drinking the equivalent of about a 12-ounce soda per day was associated with an 8% increase in type 2 diabetes risk and a 2% increased risk of ischemic heart disease.
鈥淭his current research has shown, yet again and consistent with prior research 鈥 that to achieve health gains it is best to avoid or minimize the habitual consumption of each of processed meat, sugar-sweetened beverages (SSBs) and industrially produced trans fatty acids (TFAs),鈥 said Dr. Nita Forouhi, head of nutritional epidemiology at the University of Cambridge in the United Kingdom. She was not involved in the research.
The risk increased as consumption increased; and for processed meat consumption, the data showed that there is no 鈥渟afe amount,鈥 she added in an email.
A stronger association than it may appear
At first glance, the increase in risk seems modest and might look like the association is weak, said Dr. Mingyang Song, associate professor of clinical epidemiology and nutrition at the Harvard T.H. Chan Schoo of Public Healthl. He was not involved in the research.
鈥淲hen we look at the actual data there, it鈥檚 really remarkably consistent and remarkably strong, and even in the lower dose of consumption, we can still see an increased risk of disease,鈥 he said.
The researchers examined dozens of earlier findings on diet and disease using a burden-of-proof method: a newer form of meta-analysis that not only tries to quantify an association across multiple studies but also accounts for the quality of each, Song said. 鈥淥ne caveat is it tends to give very conservative results,鈥 he added.
It鈥檚 also important to note that the studies included in the analysis were observational, meaning that the data can only show an association between eating habits and disease 鈥撯 not prove that what people ate caused the disease. They also relied on people recalling their dietary patterns, which can leave room for misremembering or misreporting, said Dr. Gunter Kuhnle, professor of nutrition and food science at the University of Reading in the United Kingdom. He was not involved in the study.
Utilizing even 鈥渢he most sophisticated techniques does not really solve the problem that the information about diet is rather limited 鈥 which is obviously a big problem in nutritional epidemiology in general,鈥 he said.
Why meats, drinks and fats are linked to disease
There are many reasons why such foods could be associated with health problems. Sugar-sweetened beverages and processed meat 鈥撯 such as sausages, bacon, salami and burgers 鈥撯 can increase inflammation, which plays a big part in a variety of chronic diseases, Song said.
Processed meats are also often cured with nitrite, which is converted to carcinogenic nitrosamines in the stomach, Kuhnle said.
The problem with sugary drinks is that they are a quick way to consume large amounts of sugar, he added. Not only can that cause weight gain, but it also influences metabolic pathways that affect heart disease and diabetes risk, Kuhnle said.
Trans fatty acids reduce levels of good cholesterol and increase the bad, which is known to increase the risk of plaque buildup in arteries and heart disease, he added.