Turns out it might not be the fat and cholesterol in red meat that most harm your heart. It could be how bacteria in your gut interact with the food.
Cleveland Clinic researchers surprised everyone with that news years ago. This month they revealed another surprise: It could be possible to treat or prevent diet-induced heart disease by tweaking your gut bacteria. So far, it has worked in lab mice.
The same method may one day treat chronic kidney disease and diabetes. Those diseases are linked to gut microbes too.
“The concept that gut bacteria contribute not only to atherosclerosis, but also to heart failure and chronic kidney disease, opens up exciting new nutritional and interventional prospects,” says Stanley Hazen, MD, PhD, Head of Preventive Cardiology and Rehabilitation at Cleveland Clinic.
Your digestive tract is full of bacteria. Some of them feed on choline and carnitine, nutrients in red meat, egg yolks and high-fat dairy products. As they feed, they give off a chemical called TMA (trimethylamine). Your liver turns TMA into TMAO (trimethylamine-N-oxide).
TMAO in your blood affects the inner wall of your blood vessels, causing cholesterol buildup. If you have chronically high TMAO, you have double the risk of heart attack, stroke and death. Studies show that levels of TMAO in your blood can help predict your risk of heart disease.
So, if TMAO is harmful, how do we get rid of it? One way is to stop gut bacteria from making TMA in the first place.
The new study by Dr. Hazen and his team found that a natural substance called DMB (3,3-dimethyl-1-butanol) could do this in mice. The result was lower TMAO levels and fewer clogged arteries.
“We were able to show that drugging the microbiome is an effective way to block diet-induced heart disease,” says Dr. Hazen. “It’s much like how we use statins to stop cholesterol from forming in a body’s cells.”
DMB is found in some olive and grapeseed oils. Because it’s not an antibiotic, DMB doesn’t kill “good bacteria.” And, unlike antibiotics, there’s little risk of overusing it or building resistance to it.
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There’s a long way to go before treatments are fully tested and approved for humans.
“My hope is that, down the road, this type of approach to lowering TMAO can be used to augment other approaches for reducing risk of cardiovascular events,” says Dr. Hazen.
In the meantime, should you stop eating meat and other animal products? Dr. Hazen says moderation is key.
“Omnivores usually do have higher levels of TMAO than vegetarians and vegans, but not always,” he says. “TMAO level is determined more by your gut microbes than your diet. Other factors also play a role, such as the microbes you’re exposed to and other aspects of your health, like kidney function and genetics.”
A test to measure TMAO levels is now available at Cleveland HeartLab.