Nutritional Pearls: Mediterranean Diet: When 2 + 2 Is More Than 4
Your patient is a 42-year-old man who has been treated with a statin for several years. When you ask about his diet, he answers that he regularly enjoys steak and other red meat. He assumes that this is okay, because of his statin.
How would you advise your patient?
(Answer and discussion on next page)
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Timothy S. Harlan, MD, is a board-certified internist and professional chef who translates the Mediterranean diet for the American kitchen with familiar, healthy recipes. He is an assistant dean for clinical services, executive director of The Goldring Center for Culinary Medicine, associate professor of medicine at Tulane University in New Orleans, and faculty chair of the all-new Certified Culinary Medicine Specialist program.
Answer: The effects of combining a Mediterranean-style diet with statin treatment are greater than the sum of its part.
In medical school I had a teacher who liked to say that instead of giving up his thick, juicy steaks, he would just continue to take his statins. What he obviously didn't know at the time (although I'm not sure any of us did), is that you don't have to choose between taking a statin and improving your diet. In fact, you might actually see better results from a statin combined with a Mediterranean-style diet than you would with a statin alone.
The Research
Utilizing data from the Moli-sani Study, a long-term cohort study, researchers in Italy identified 1320 persons who reported a previous diagnosis of cardiovascular disease (CVD) from an initial group of over 24,000. All participants responded to a detailed dietary and medical questionnaire at the start of the study, and the authors further excluded from their analysis those with unreliable or unbelievable dietary or medical histories. This left the authors with 1180 men and women at least 35 years old who had been diagnosed with CVD and had submitted complete dietary and medical questionnaires.
The dietary histories allowed the researchers to assign the participants a Mediterranean Diet score ranging from 0 to 9. Participants who had been prescribed statins were identified not only through the participants' self-report but also through linking to the Italian National drug index.
The authors broke the participants out into 4 groups for analysis:
1. Low Mediterranean Diet score (4 or less out of 9) + no statin use
2. Low Mediterranean Diet score + statin use
3. Average-high Mediterranean Diet score (5 or more out of 9) + no statin use
4. Average-high Mediterranean Diet score + statin use
The authors kept track of the participants over the course of an average of almost 8 years, and at the endpoint of their study they compared the Mediterranean Diet score and statin use of those who died with those who did not. When looking at the Mediterranean Diet score alone, the authors noted that a 2-point increase in the score reduced the risk of death from any cause by 16%, reduced the risk of death from cardiovascular disease by 23%, and reduced the risk of death from cerebrovascular mortality by 30%.
When compared with a lower Mediterranean Diet score and no statins, however, combining a higher Mediterranean Diet score with statin use cut the risk of all-cause mortality by 48%, cardiovascular mortality by 50%, and cerebrovascular mortality by 62%.
By comparison, those taking statins but with a lower Mediterranean Diet score cut their risk of all-cause mortality by only 10%, while their risks of cardiovascular and cerebrovascular mortality were actually higher than if they were not taking statins, (29% and 81% greater, respectively).
What’s the “Take-Home”?
I've said before that medicine is not like math: if A = B and B = C, that does not necessarily mean that A = C.
A Mediterranean Diet plus cholesterol medications is synergistic: rather than the effects simply being additive (2+2=4), the effects of both treatments together are greater than the sum of their parts (2+2=5).
If you have a cholesterol problem and your physician suggests that you take a statin, that doesn't mean that you shouldn't also improve your diet. Doing both together seems to be more than the sum of its parts.
Reference:
Bonaccio M, Castelnuovo A, Costanzo S, et al. Interaction between Mediterranean diet and statins on mortality risk in patients with cardiovascular disease: Findings from the Moli-sani Study. International Journal of Cardiology. 2019;276(2):248-254.