Michael Greger M.D. FACLM December 14th, 2018
Preventing and treating chronic diseases such as heart disease, diabetes, and stroke with diet and lifestyle changes is not just safer but may be dramatically more effective.
Medical myths and dogmas die hard. Researchers creating a new body of knowledge for prevention and control of heart disease had to disprove and displace a bunch of doozies, like we used to think that heart disease was just an inevitable consequence of aging, or that cholesterol and blood pressure just naturally go up as we age. All these are now bygone notions, refuted by massive data. But other long-standing myths and dogmas about our #1 killer epidemic persist. For example, this notion that major risk factors, like cholesterol, account for a minority of risk and that many people have heart attacks with no risk factors; so, it’s just kind of a crap shoot – not much you can do about it.
There are rare genetic conditions that give people high cholesterol no matter what they eat, but such genetic defects occur in no more than 1 in 200 people. This means, of course, that most persons with atherosclerosis acquire it by what they put in their mouth.
The INTERHEART study showed that for men and women, old and young, and in all areas of the world, 9 potentially modifiable factors like diet, exercise, and smoking, accounted for >90% of the proportion of the risk of having a heart attack. And this has been confirmed in prospective studies.
Follow men over time and those making healthy lifestyle choices are associated with a 90% drop in risk. Same with women, 92% of the risk gone. Same with diabetes—91% of cases could be contributed to bad habits and behaviors. And the same healthy lifestyle, which includes not smoking, eating a healthy diet, exercising, and maintaining an optimal body weight, may reduce the risk of multiple chronic diseases—not just heart disease and diabetes but stroke as well. Up to 80% of strokes avoidable with simple lifestyle changes.
How does this all compare to drugs? Why change our diet, lose weight, and start exercising if we can just pop some pills? Pharmacological therapies, including cholesterol lowering statin drugs and blood pressure pills typically only reduce cardiovascular disease risk not by 90% but only by 20% to 30%. So, even on drugs, 70 to 80% of heart attacks still occur.
One of the great things about this study, the Harvard Health Professionals Follow-Up, is that they also looked at the effect of lifestyle changes on people already on medications. Even those on cholesterol and blood pressure lowering drugs may be able to get a further 78% drop in risk by eating and living healthfully. So, the choice isn’t diet or drugs. Cardiovascular medications should be used as an adjunct to, not just a replacement for, healthy lifestyle practices.
It takes time for new science to trickle down into mainstream medical practice. The practice of cardiology and medicine in general may correspond, on average, to what was being published 10 or 20 years before. So, it’s important to know if our doctors are still stuck back practicing 20th century medicine.