You may want to leave the bacon off that cheeseburger. That's the message from a large new study looking at meat consumption.
Red meat, particularly when grilled, has been linked to certain forms of cancer, heart disease, and to a shorter life expectancy.
The study also found some reduction of life expectancy associated with eating lots of red meat. But far worse effects from processed meat like hotdogs, bologna, and sausage. These typically contain additives and preservatives, and are high in salt, nitrates, cholesterol, and fat.
The more processed meat a person ate, the more their risk of death from any cause increased.
Eating small amounts of non-processed red meat did have its benefits, the researchers found, which they suggest may stem from the fact that red meat provides certain nutrients, like essential vitamins and protein.
Part of the difficulty in designing studies to test the connections between the foods we eat and our health outcomes is that so many factors can affect the results. For example, people who eat red meat are also more likely to smoke and less likely to eat vegetables and to exercise.
Any of these other factors could contribute to health status and death risk, and researchers are well aware of their potential to confuse or confound study results. Therefore, the question is always how these variables overlap, and how they may be teased apart to reveal the effect of one vs. the other on long-term health.
The enormous size and scope of the new study helps address some of these concerns. It looked at half a million people in 10 countries for 12 years, analyzing their dietary habits, lifestyle, and health problems, like heart disease and cancer. They also tracked how many people died over the course of the study and adjusted their findings to take into account these confounding factors.
"Risks of dying earlier from cancer and cardiovascular disease also increased with the amount of processed meat eaten,” said study author Sabine Rohrmann in a statement. “Overall, we estimate that 3% of premature deaths each year could be prevented if people ate less than 20g processed meat per day."
The research confirms what more and more studies are showing: Processed foods should generally be avoided, or eaten only on occasion. The Mediterranean diet continues to be one of the healthiest diets around, with good evidence that it contributes to heart health, longevity, and even to brain health.
An occasional hotdog or sausage link may not shorten your lifespan by much – but, as we’re finding, they probably shouldn’t be an everyday part of the diet. Diets rich in whole grains, fruits, vegetables and good fats are the way to go, together with healthy protein sources like fish, chicken, and low-fat dairy.
The study was carried out by a team at the University of Zurich, and published in the journal BMC Medicine.