A recent article published in the July 2021 issue of Critical Reviews in Food Science and Nutrition reviewed 13 studies that combined followed more than 1.4 million people for up to 25 years. The results tracked the consumption of unprocessed red meat (beef and pork), processed red meat (beef and pork), and poultry consumption with heart disease.
These researchers showed a substantial increased risk for heart disease from eating unprocessed red meat, double the risk with processed meat consumption, yet no increased risk from eating poultry. This is yet another scientific study in a very long sequence that has noted problems with red meat intake.
How Much Read Meat Does It Take to Cause an Increased Risk?
This study showed that if you eat about 2 ounces (50 grams) of “unprocessed” red meat per day, you increase your risk for a cardiovascular event by 9%. Yet the average American eats more red meat than this and 10% of people eat a much larger serving at least twice per day.
When “processed” red meat intake was evaluated, it was found to double the risk, meaning an 18% increased risk from eating less than 2 ounces per day. Processed meats include hot dogs, bacon, sausage, bologna, deli meats, and hamburger—making processed meat twice as harmful as eating a steak.
In contrast in this same study, poultry consumption did not cause any increased risk for heart disease.
And although this study did not analyze seafood intake, nearly all previous studies have shown that eating seafood lowers your risk for heart disease.
Why Does Processed Red Meat Have Twice the Risk of Unprocessed Red Meat?
Processed meat contains far more sodium (salt), which may increase blood pressure levels, and it also contains chemicals called nitrosamines to extend the shelf life of ground and thinly sliced meat. Even modest nitrosamine intake can cause an increased risk for cancer, Alzheimer’s disease, and insulin resistance—the #1 cause for heart disease.
Why Does Unprocessed Red Meat Consumption Increase the Risk for Heart Disease?
There have been several theories as to why eating unprocessed red meat might cause this risk:
- Saturated Fat
- Pesticides and Hormones
- A change in the gut microbiome, producing a compound called TMAO.
Cholesterol Intake? For decades health officials said that eating cholesterol increased the risk for heart disease, but nearly all the recent data shows that cholesterol by itself does not cause heart disease, and that eating cholesterol does not even raise your cholesterol levels by a significant degree.
The truth is that your liver will produce plenty of cholesterol whether you consume it or not. It is likely the other factors that come with cholesterol in animal protein are causing an increased risk, not the cholesterol itself.
Saturated Fat Intake? Health officials continue to condemn saturated fat intake (because eating saturated fat does increase blood cholesterol levels), even though the most definitive study on saturated fat intake and heart disease did not show a significantly increased risk for heart disease. It may be again that the factors that come with saturated fat increase the risk, not the saturated fat itself. The cautious thing to do would be to keep your saturated fat intake in the moderate range, although you do not need to avoid it entirely.
Pesticide and Hormone Intake? For me, this is a much greater concern than saturated fat intake, as by far the largest source of pesticides and hormones in our diets comes from eating animal products, especially red meat. Pesticides and hormones also increase our risk for cancer and Alzheimer’s disease, not just heart disease.
The desire to avoid pesticides and hormones is why many health experts advocate that if you eat red meat, it should be either wild or pasture and organically raised (and while I wholeheartedly agree with them, this may not remove your risk for heart disease entirely).
So, if you do eat red meat, make sure that you select a cut of real meat and that it is organically and pasture-raised.
A change in the gut microbiome? This is the most compelling reason as to why eating red meat truly increases your risk for heart disease, as red meat consumption leads to an increase in abnormal bacteria in the intestinal tract that will increase the production of TMAO (trimethyl-amine-oxide), which circulates in the bloodstream.
Elevated TMAO levels have been shown to increase the risk for heart disease by a whopping 62%, which is triple the risk from having high versus low cholesterol levels.
Eating poultry and seafood can also increase TMAO levels, but not nearly to the same degree as from eating red meat.
Unfortunately, eating grass-fed, organically raised red meat will not reduce your risk for excess TMAO production, hence the healthiest recommendation is to limit eating red meat to at most an occasional basis, meaning not more than 6 ounces per week.
If You Avoid or at least Limit Red Meat, What Should You Be Eating?
I hope that you can see that these findings support following a Mediterranean Diet, an eating plan that focuses on consuming vegetables, fruits, beans nuts, extra-virgin olive oil, red wine, spices and herbs, seafood, poultry, and dairy products.
Following a Mediterranean Diet has been proven to reduce TMAO levels, will keep your saturated fat intake modest, and help eliminate pesticide and hormone intake. Plus, it has been rated the healthiest and easiest diet to follow on the planet, and the meals are delicious!
A Mediterranean diet limits red meat consumption to only occasional intake (1-3 times per month or less), it focuses on locally produced food that avoids pesticides and hormones, as well as avoiding processed foods with chemicals and sweeteners.
If you would like to learn more about a Mediterranean, heart-healthy eating plan and discover delicious recipes that you can make in your own home, check out my books, The Mediterranean Method and The 30-Day Heart Tune-Up.
I hope this information has been helpful to you and I wish you the best of health!
Steven Masley, MD, FAHA, FACN, CNS
- Papier K, Knuppel A, Syam N, Jebb SA, Key TJ. Meat consumption and risk of ischemic heart disease: A systematic review and meta-analysis, Critical Reviews in Food Science and Nutrition 2021 DOI: 10.1080/10408398.2021.1949575
- Katz DL, Meller S. Can We Say What Diet Is Best? Annu. Rev. Public Health 2014. 35:83–103
- Chowdhury R, et al. Association of dietary, circulating and supplement fatty acids with coronary risk. Ann Intern Med 2014;160.398-406.
- Trichopoulou A, Bamia C, Trichopoulos D. Anatomy of health effects of Mediterranean diet: Greek EPIC prospective cohort study. BMJ 2009;338:b2337 doi:10.1136/bmj.b2337
- Estruch R, Ros E, Salas-Salvado J, Covas MI, Corella D, et al. for the PREDIMED Study Investigators. Primary Prevention of Cardiovascular Disease with a Mediterranean Diet. N Engl J Med 2018;378(25):2441-2.
- Masley SC, Weaver W, Peri G, Phillips S. Efficacy of exercise and diet to modify markers of fitness and wellness. Alternative Therapies in Health and Medicine, 2008;14:24-29.
- Masley SC, Roetzheim R, Masley LV, McNamara T, Schocken DD. Emerging Risk Factors as Markers for Carotid Intima Media Thickness Scores. Journal of the American College of Nutrition 2015; 34: 100-107
- Jennifer Abbasi. TMAO and heart disease: the new red meat risk? JAMA 2019;321:2149.
Please share these blogs with your friends and family!
Send them this link to sign-up to receive my blog posts: www.drmasley.com/
I started following your diet and experienced the best bloodwork results ever. I’m 59yrs old, 150lbs, exercise and have never had an HDL level in the normal range. After being on your diet for 8 months, I had my first HDL level in the normal range since being tested for 15 years. Does this red meat study indicate any HDL results? Also, should I stay away from chicken and turkey deli meat too, or just red meat deli meat?
I am very happy to hear that you have had such good results!
This recent study on red meat consumption did not address HDL levels. Prior studies have shown that the impact of red meat on HDL is fairly neutral. More red meat intake makes the total; HDL, and LDL cholesterol levels go up, but the size of the LDL and HDL particles also increases, so the cholesterol level response to eating red meat seems overall neutral, not harmful.
This recent study showed that poultry intake was neutral for heart disease, although eating processed red meat had twice the risk of regular red meat. To me that suggests that you should avoid processed poultry meats (like sausage), and especially avoid any processed poultry products if they contain nitrosamines (nitrate like compounds). Although from this study, sliced turkey and chicken deli meats would be fine if they were unprocessed and were nitrate free)–It is always better to eat organically and pasture raised cut of meat or poultry than to eat processed animal protein.
From previous studies, we know that cutting out sugar and refined carbs, plus adding more intense aerobic activity, are the best ways to improve the level and size of your HDL. Eating more healthy fiber from vegetables, fruits, beans, and nuts, plus eating healthy fats like avocado and extra-virgin olive oil improve HDL levels as well. It was likely the combination of these healthy changes that made the difference–so keep up the great work.
Steven Masley, MD