For years, nutrition guidance has recommended diets relatively low in red meat in order to prevent chronic diseases, including cardiovascular disease (CVD). Recently, however, systematic reviews and meta-analyses from the Burden of Proof Study and the Nutritional Recommendations (NutriRECS) consortium showed no association between red meat intake and the risk of CVD.

Because those meta-analyses had flawed methodologies and included low-grade studies, researchers at Brigham and Women’s Hospital and colleagues applied rigorous analytical approaches to study the issue in a very large U.S. prospective cohort.

Dong Wang, ScD, an epidemiologist in the Channing Division of Network Medicine in the Department of Medicine, Luc Djoussé, DSc, MD, an epidemiologist in the Department’s Division of Aging, and colleagues report in The Journal of Nutrition that higher intake of red meat, either processed or unprocessed, was associated with higher risk of CVD.

Moreover, statistical modeling showed replacing red meat with alternative major protein sources, especially plant-based protein sources such as nuts, was associated with lower risk of CVD.

Methods

The data source for the study was the Million Veteran Program, a socioeconomically and racially/ethnically diverse prospective U.S. cohort that reached an enrollment of 790,116 veterans in 2020. By that time, 351,892 participants had completed a baseline semiquantitative food frequency questionnaire.

The questionnaire divided red meat into unprocessed (beef, pork and lamb) and processed (e.g., bacon, hot dogs, sausage, salami and bologna). 148,506 participants who completed the questionnaire were free from diabetes, cancer, and CVD at baseline and were included in this analysis.

Red Meat Intake and CVD

The multivariate-adjusted relative risk of CVD comparing the highest vs. the lowest categories of red meat intake was:

• Total red meat—1.18 (P for trend < 0.0001)
• Unprocessed red meat—1.14 (P-trend = 0.01)
• Processed red meat—1.29 (P-trend = 0.003)

When examining specific CVD endpoints, each one-serving/day increment in total red meat intake was associated with:

• 12% higher risk of fatal CVD (P-trend = 0.003)
• 14% higher risk of nonfatal myocardial infarction (P-trend < 0.002)
• 11% higher risk of nonfatal acute ischemic stroke (P-trend = 0.03)

Red meat was consistently associated with greater CVD risk across subgroups defined by sex, race, ethnicity, smoking status, body weight, family income, and baseline health conditions.

Substitution Analyses

Statistical modeling showed that a hypothetical replacement of 0.5 serving/day of red meat with 0.5 serving/day of another food group reduced the estimated risk of CVD by:

• 14% for nuts
• 7% for whole grains
• 3% for skimmed milk
• 3% for legumes
• 4% for vegetables

All reductions were statistically significant.

In real life, of course, food substitutions are rarely isolated, and the model couldn’t capture the complex potential combinations. Still, this study contributes robust evidence supporting the cardioprotective benefits associated with reducing red meat intake.