A recent paper adds to the body of evidence linking type 2 diabetes (T2D) to increased heme iron intake. Heme iron occurs naturally in some animal products and is added to some meat substitutes to enhance flavor.
write in natural metabolism In August, Frank Hu, MD, PhD, of the Harvard T. H. Chan School of Public Health in Boston, and co-authors found that people with the highest heme iron intakes were more likely to be in the study than those with the lowest intakes, as measured by a multivariate variable. The risk of developing T2D was 26% higher among those who had Adjusted hazard ratio (95% CI, 1.20-1.33; P trend < .001).
“Eating a more plant-based diet and reducing heme iron intake from red meat should be considered as strategies to lower the risk of diabetes and prevent chronic diseases,” Hu said. Medscape Medical News In an interview.
“Excess heme iron intake is also associated with an increased risk of cardiovascular disease and some cancers, including colorectal cancer,” he added.
The paper builds on findings published last year by Hu et al. American Journal of Clinical Nutrition Possible association between red meat intake and T2D risk.
questioner Medscape Medical News To comment on the new paper by Dr. Hu and his co-authors, Marilyn Tan, MD, clinical director of the Endocrinology Clinic at Stanford University School of Medicine in Palo Alto, California, spoke about how dietary choices affect health. He pointed out that there are limits to research in general that aims to study such things.
“Many studies have pointed to associations between various dietary factors and certain disease states, but in studies that rely only on epidemiological data, associations cannot prove causation,” Tan said. . Medscape Medical News By email. “Furthermore, apart from the specific dietary components that have been studied, the rest of the diet can be highly heterogeneous.”
She also said that studies on general diet cannot fully control for other important lifestyle factors, such as exercise, sitting time and sleep quality.
But Tan also noted that Hu and his co-authors took additional steps when looking at heme iron and diabetes risk, including controlling for certain health and lifestyle factors.
They also used metabolic biomarkers, including small molecule metabolites from food and chemical breakdown, to further elucidate some of the possible mechanisms for the association between heme intake and diabetes risk, Tan wrote. are.
“The diabetes risk associated with heme iron calculated in the study appears to be significant and dose-dependent,” she wrote.
research design
For this study, Hu and her coauthors examined 36 years of dietary report data from 204,615 adults enrolled in the Nurses' Health Studies I and II and the Health Professionals Follow-up Study. They divided these results into five groups based on heme iron intake.
Hu said. Medscape Medical News In the lowest quintile of T2D cases per person-year of follow-up, there were 2554 of 1,052,982 (approximately 2.4 per 1000 person-years). In the highest quintile, it was 5881/1,047,447 (approximately 5.6 per 1000 person-years).
Hu et al. reported that in various studies, people in the high heme iron group ate about 8 to 10 servings of unprocessed red meat each week, whereas people in the low heme iron group ate about 2 to 3 servings of unprocessed red meat each week. The patient reported that he/she is taking in the amount of food consumed.
Combining results across studies resulted in a high heme iron quintile with a median estimated heme iron consumption of 1.5 mg/day and a low heme iron group with a median estimated heme iron consumption of 0.7 mg/day. Intake standards for heme iron have not been established.
Hu and co-authors found that people with higher intakes of total iron and nonheme iron were more physically active, more likely to use multivitamins, and smoked less than those with lower intakes. The report said the possibility of this happening is low. They also ate more grain fiber, magnesium, fruits, and vegetables. People with increased heme iron intake generally have lower physical activity, are more likely to smoke, consume less cereal fiber, magnesium, fruit, and whole grains, while eating less red meat, poultry, and fish. Intake increased.
Hu said he and his co-authors took these factors into account in their statistical analysis.
Turkey sausage vs sometimes steak
Asked to comment on Dr. Hu's paper, Dr. Dariush Mozaffarian, a cardiologist and director of the Food is Medicine Institute at Tufts University in Medford, Massachusetts, offered a different take on the study's findings. Mozaffarian focused on analyzing papers on processed meat and T2D.
In their paper, Hu and his co-authors found that although heme iron intake accounts for more than half of the association between unprocessed red meat and diabetes risk, “the association between processed red meat and “It only partially explains it,” he said. They said, “The deleterious association between processed red meat and T2D risk may be due to its high content of other compounds such as nitrates and nitrites.”
Although the medical community's dietary recommendations focus on saturated fat, Fu et al.'s paper and other studies suggest other factors are involved, such as inflammatory compounds, Mozaffarian said. said.
With that in mind, it would be a good idea to reconsider focusing on fat content, as it can mislead people into thinking highly processed foods are healthy options, he says. said.
Turkey sausage or low-fat deli meat may not be a better choice than a steak or burger made with fresh meat, he said. He disagrees with the views of both the many proponents of the Paleo diet approach, who believe that red meat is essential, and the views of its critics, who consider it extremely harmful.
“The main message for patients is that red meat is not deserving of health glories as something to be sought after, but it is the devil's horns because it is the worst thing in the food supply.'' “It's not worth it,” he said.
Hu and his co-authors reported they have received support from an American Heart Association Postdoctoral Fellowship, the Canadian Institutes of Health Research, the Novo Nordisk Foundation, and the National Institutes of Health.
Tan and Mozaffarian do not report any relevant financial disclosures.
Kelly Dooley Young is a freelance journalist based in Washington, DC.