Heme Iron From Meat Tied to Higher Diabetes Risk, Research Shows

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Key Takeaways

• Consuming animal products has been linked to a higher risk of developing type 2 diabetes, according to new research.

• One study specifically links heme iron, which is commonly found in meat, to type 2 diabetes risk.

• Unlike heme iron, non-heme iron from plant sources does not show the same association with increased diabetes risk.

• While meat provides easily absorbed heme iron, experts advise against cutting it entirely from the diet without considering overall dietary patterns and the type of meat consumed.

Two new studies confirm a link between eating meat and developing type 2 diabetes. One of those studies, led by researchers at Harvard T.H. Chan School of Public Health, suggests the culprit might be the type of iron found in animal products: heme.

Iron is a vital mineral that helps support red blood cell production, energy levels, and immune health. Iron from dietary sources presents itself in two distinct forms: heme and non-heme. Heme iron, primarily found in animal products, is more readily absorbed by your body, making it a potent source of this important nutrient. Non-heme iron, on the other hand, is prevalent in plant-based foods and isn't quite as efficiently absorbed.

While both forms contribute to maintaining healthy iron levels and can help prevent deficiencies, understanding their differences—along with their unique benefits and drawbacks—can empower you to make informed food choices that best support your overall health and vitality.

Heme vs. Non-Heme Iron

Heme iron is found in animal products and is known for its high bioavailability, meaning your body can absorb it efficiently. Absorption rates of heme iron range from 15–35% versus 2–20% from non-heme iron sources. This makes heme iron sources particularly effective in quickly replenishing iron stores in the body.

Some of the best sources of heme-iron include:

• Lean beef

• Dark meat poultry

• Oysters

• Organ meats

• Game meats

In contrast, non-heme iron is primarily found in plant-based foods. While non-heme iron is more abundant in plant sources, its absorption can be influenced by other dietary components. For instance, vitamin C-rich foods, drinks, and supplements may enhance the absorption of non-heme iron when consumed together.

Some of the best sources of non-heme iron include:

• Legumes

• Tofu

• Nuts and Seeds

• Whole Grains

• Leafy Greens

Related: 17 Iron-Rich Vegetarian Meals

New Data Links Heme Iron to Diabetes Risk

The easy absorption of iron from meat is a major benefit. But new data suggests one downside: a potentially higher risk of developing type 2 diabetes.

To draw this conclusion, researchers analyzed data from 204,615 participants over 36 years, including dietary pattern reports and information from blood samples.

Results showed that heme iron intake was linked to a 26% higher risk of type 2 diabetes when comparing the highest intake group to the lowest. The same effect was not seen from non-heme iron intake, total iron intake, or iron supplement intake.

The study also linked higher heme iron intake to blood metabolic biomarkers associated with type 2 diabetes.

The researchers shared a few potential reasons for this observational effect:

• Increased heme iron intake was linked to higher levels of inflammation, unhealthy fats in blood, higher insulin levels, and metabolites that may impact type 2 diabetes development.

• Excess iron stores, particularly in the form of heme iron, may promote oxidation in the body. This can lead to tissue damage and an elevated risk of developing certain diseases, including type 2 diabetes.

• Diabetes risk may be attributed to the overall dietary pattern people who eat heme iron tend to follow compared to those who eat more non-heme iron. Those who ate more heme iron tended to follow the Western dietary pattern score, which is rich in ultra-processed foods. That in and of itself is linked to a higher diabetes risk. Those who ate more non-heme iron tended to follow dietary patterns like the Mediterranean diet and the DASH diet, which are associated with better health outcomes.

While the link between heme iron and type 2 diabetes has been reported previously, the study’s findings more clearly establish and explain the link.

"Compared to prior studies that relied solely on epidemiological data, we integrated multiple layers of information, including epidemiological data, conventional metabolic biomarkers, and cutting-edge metabolomics,” lead author Fenglei Wang, research associate in the Department of Nutrition, shared in a press release. “This allowed us to achieve a more comprehensive understanding of the association between iron intake and type 2 diabetes risk, as well as potential metabolic pathways underlying this association.”

Related: Iron Deficiency (Low Iron)

Should You Avoid Meat To Reduce Diabetes Risk?

While this current study does suggest a potential link between heme iron sources, like meat, and diabetes risk, experts say that's not a reason to cut meat from your diet.

"This study adds to a growing body of evidence suggesting that a high intake of heme iron, found in foods like red and processed meats, may be linked to an increased risk of type 2 diabetes," Vandana Sheth, RDN, registered dietitian and diabetes specialist, told Verywell. "While these findings are significant, it's important to note that since it was an observational study, we can't establish direct cause and effect."

Plus, there's not enough nuance in the findings to make a clear recommendation.

"It's not clear if [the researchers] differentiated between higher saturated fat cuts of red meat and lean cuts of red meat. After decades of research, we know there is a difference in the long-term health impact between those two categories," Mary Ellen Phipps, MPH, RDN, told Verywell.

Previous data has actually failed to show a link between some sources of heme iron and diabetes, though it's important to note that none of those sources were red or processed meats:

• A study published in the American Journal of Clinical Nutrition in 2020 showed no overall association between moderate consumption of eggs, a source of heme iron, and risk of type 2 diabetes.

• A study published in Diabetologia in 2021 suggested that intake of non-fried poultry, another source of heme iron, is not linked to type 2 diabetes risk.

• A study published in the journal Clinical Nutrition in 2021 showed that following a sardine-enriched diet may help protect against type 2 diabetes.

The Dietary Guidelines for Americans suggest eating a combination of lean animal-based protein and plant-based protein sources if you are not following a vegan lifestyle to support your overall health, being mindful of proper portion sizes and servings per week. Since 10 million people in the U.S. have an iron deficiency, it is important to consume enough iron foods to help bridge this gap.

“My takeaway: Focus on adding a variety of plant-based foods to your diet. Lean red meat sources in moderation can still be included in a balanced and healthy diet for many people,” Phipps said.

What This Means For You

If you are at-risk for developing type 2 diabetes, limiting heme-iron sources like meat may offer some benefit, but more data is needed to confirm this approach.

Read the original article on Verywell Health.