The low-down on meat: What’s good for you, what’s not

Watch out, meat-eaters! You might want to put down your steak knife after reading the results from this recent meta-analysis published in JAMA Internal Medicine.

Researchers found that higher intakes of processed meat, unprocessed red meat, and poultry were all significantly associated with a slight 3% to 7% increase in the risk of incident cardiovascular disease (CVD). Intake of fish was not, however. Further, higher intakes of processed meat or unprocessed red meat were also significantly associated with a 3% increase in the risk of all-cause mortality.

This is bad news all around for Americans, because a big part of the US adult diet includes processed meat, unprocessed red meat, poultry, and fish. They make up over 40% of our total protein intake, 42% of our dietary cholesterol intake, and 26% of our total energy intake.

Meat is murder—on your heart

For this study, researchers took data from 29,682 adult participants (mean age at baseline: 53.7 years; 44.4% men; 30.7% non-white) enrolled in 6 prospective cohort studies. These were major studies, including the Atherosclerosis Risk in Communities (ARIC) study, the Coronary Artery Risk Development in Young Adults (CARDIA) study, the Cardiovascular Health Study (CHS), the Framingham Heart Study (FHS), the Framingham Offspring Study (FOS), and the Multi-Ethnic Study of Atherosclerosis (MESA). Researchers obtained baseline diet data from 1985 to 2002 for all participants, and followed them through mid-2016.

Incident CVD included all fatal and nonfatal coronary heart disease, fatal and nonfatal stroke, fatal and nonfatal heart failure, and other CVD deaths.

When their analyses were completed, the researchers found that participants ate a median of 1.5 servings of processed meat per week, 3.0 servings of unprocessed red meat, 2.0 servings of poultry, and 1.6 servings of fish. Those who ate more of these four foods tended to be younger, male, non-Hispanic black, and current smokers. They also tended to have diabetes, higher BMI, higher non-HDL cholesterol levels, higher energy intake, and higher alcohol intake. In addition, they had lower HDL cholesterol levels, lower diet quality, were less likely to use lipid-lowering agents and hormone therapy. Finally, they had a higher incidence of CVD and all-cause mortality.

When researchers compared two servings/week to no servings/week, they found a statistically significant association between processed meat intake and incident cardiovascular disease (HR: 1.07; 95% CI: 1.04-1.11; 30-year adjusted relative difference [ARD]: 1.74%; 95% CI: 0.85%-2.63%). For each additional 2 servings of unprocessed red meat eaten per week, they found a significant association with incident CVD (HR: 1.03; 95% CI: 1.01-1.06; 30-year ARD: 0.62%; 95% CI: 0.07%-1.16%).

Crying fowl

A surprising finding was that each additional two servings of poultry eaten per week was also significantly associated with incident CVD (HR: 1.04; 95% CI: 1.01-1.06; 30-year ARD: 1.03%; 95% CI: 0.36%-1.70%).

“The present study identified a significant positive association between poultry intake and incident CVD, which also remained in multiple sensitivity analyses. This association may be related to the poultry intake including fried chicken. Fried food consumption has been significantly positively associated with adverse outcomes,” noted these researchers, led by Victor W. Zhong, PhD, assistant professor, Division of Nutritional Sciences, Cornell University, Ithaca, NY.  

The outlier was fish, for which researchers found no significant association with incident CVD with each additional two servings eaten per week (HR: 1.00; 95% CI: 0.98-1.02; 30-year ARD: 0.12%; 95% CI: -0.40%-0.65%). Findings were similar for associations with all-cause mortality.

Some surprising findings

But researchers also found that the strength of the association between the intake of processed meat and incident CVD decreased with age, according to whether participants were younger than 45 years old, 45-64 years old, and 65 years or older.

In addition, the association between intake of unprocessed red meat and incident CVD was also stronger in those who had a higher-quality diet compared with those who did not! It was also stronger in those who ate a non-high-fat diet compared with those who did not.

“This subgroup finding suggests that participants also benefited from reducing their unprocessed red meat intake even if the overall quality of their diet was high,” noted researchers.

And surprisingly, the association between poultry intake and CVD was stronger in participants with a non-high-fat diet compared with those without. Finally, the association between fish intake and incident CVD was stronger in those who consumed a high-protein diet compared with those who didn’t.

“The findings of this study appear to have critical public health implications given that dietary behaviors are modifiable and most people consume these four food types on a daily or weekly basis,” concluded Dr. Zhong and fellow researchers.

The researchers acknowledged their study had some limitations. First, the effect sizes of these associations were small. Second, a major limitation of the study was the lack of detail about food preparation.

Smarter meat options

Meat is a good source of protein and certain vitamins when eaten in moderation. Certain meat choices are healthier than others. For example, it would be wise to watch your intake of processed meats and unprocessed red meats. Chicken is low in saturated fats, which makes it a better protein choice than red meat. Chicken also contains healthy B vitamins, as does turkey, another lean meat. One meat option that might not be too apparent is bison. Because bison roam free, you can be sure their meat is not replete with hormones or unhealthy feed. Finally, lamb is an excellent source of zinc and iron, and is rich in B vitamins as well. 

Although fish is not considered a meat, it is one of the healthiest options you have. Rich in calcium and phosphorus, fish is an excellent source of minerals such as iron, zinc, iodine, magnesium, and potassium. Plus, it’s filled with omega-3 fatty acids and vitamins including D and B2. Studies have shown that fish can slow cognitive decline, reduce your risks of autoimmune diseases such as type 1 diabetes, and lower the risk of CVD, CVD mortality, and stroke. The American Heart Association recommends eating fish at least twice per week as part of a healthy diet. 

Bottom line: Try focusing more on eating poultry and fish, and—of course—more fruits and vegetables! If you can, try working “Meatless Monday” or “Fish Friday” into your weekly dietary planning.