So-called Prudent/Mediterranean diet rich in vegetables, fish, fruits, beans, nuts, olive oil, and whole grain deters common, fatal lung disorder
by Craig Weatherby
Respiration-focused research from Harvard shows that the so-called “prudent” diet—rich in fruit, vegetables, whole grains, and fish—may reduce the risk of a common lung condition that causes one in five deaths worldwide.
Researchers also call the prudent diet the “Mediterranean” diet… even though, as we’ll explain, that label obscures dietary realities in Europe’s sunny southern regions.
A group of Harvard analysts found that men who came closest to eating the widely recommended Mediterranean/Prudent diet over a 12-year period cut their risk of chronic obstructive pulmonary disease (COPD) by 50 percent, compared with those whose diets strayed furthest from this preferred pattern.
In contrast, men whose diets fit the pattern of the sugary, starchy, fatty, greens- and fish-poor “Western diet” had a 356 percent greater risk of being diagnosed with COPD during the 12-year study period.
To public health researchers, the terms “Western diet” and “standard American diet”—are interchangeable.
Likewise, public health experts use the “Mediterranean” and “Prudent” labels interchangeably to refer to diets rich in vegetables, fruits, nuts, legumes, whole grains, fish, wine, and olive oil.
The acronym applied to the “standard American diet”—SAD—is sadly appropriate, since it means an unhealthful eating pattern low in fruits, vegetables, and fish while overabundant in white flour, omega-6-rich vegetable oils, processed/cured meats and poultry, red meats, fried foods, and sugary, fatty snacks and desserts.
In contrast, a Mediterranean/Prudent diet will not include very much white flour, omega-6-rich vegetable oils, processed/cured meats and poultry, red meats, fried foods, or sugary, fatty snacks and desserts.
Mediterranean/Prudent-style diets have been linked to longer life, less heart disease, and protection against some cancers.
Mediterranean/Prudent diet reduces lung risk
The new findings stem from an analysis of data from the Health Professionals Follow-Up Study, in which scientists started following almost 43,000 men aged 40-75 in 1986, collecting information on their diets, lifestyles, and health status every two years.
A Harvard team led by Dr. Raphaelle Varraso examined this diet-health data, and compared the rate of COPD among men whose diets resembled the Mediterranean/Prudent pattern with the rate of COPD among men whose diets were much closer to the Western/American dietary pattern.
As they wrote, “In men, a diet rich in fruits, vegetables and fish may reduce risk of COPD, whereas a diet rich in refined grains, cured and red meats, desserts and French fries may increase risk of COPD.”
Dr. Varraso’s team cite evidence suggesting that the vitamin C and polyphenol-class antioxidants abundant in plant foods—and therefore in the Mediterranean/Prudent diet—appear to provide much of the eating plan’s protective power:
The omega-3s from the leafy greens and fish abundant in a Mediterranean/Prudent-style diet would should help deter or ameliorate COPD, thanks to their generally anti-inflammatory influence. COPD, for which there is no known cure, is characterized by chronic inflammation in the small airways of the lung, and strikes smokers disproptionately.
The Harvard group explained that part of the risk of COPD associated with the standard American diet stems from its overabundance of processed meats preserved with nitrites, which promote creation of nitrogen-based free radicals that may damage lung tissues and function.
They also noted that the high sugar/starch quotient of the standard American diet is linked with worse lung performance in people with COPD.
So serve up some herbed salmon or scallops, garlicky olive-oil sautéed chard, cannelinni beans, and brown rice with currants and walnuts… it’s a prescription most of us will welcome, with pleasure.
Accuracy of diet’s popular name is arguable… but not its allure
While the “Mediterranean” diet linked to better heart and overall health, it doesn’t really reflect what people in most of Italy, Spain, and Greece eat in 2007.
Nor does the term accurately portray the diets most in the region ate 40 years ago, when the authors of the influential Seven Countries Study initiated the Mediterranean diet fad by painting a distorted, idealized picture of the region’s culinary norms.
What the media and the diet’s many advocates call the “Mediterranean diet” is a nutritionally idealized version of 1960’s era diets in the rural fishing communities of Aegean islands like Crete.
And even those gradually disappearing dietary patterns don’t fit researchers’ and health advocates’ definition of “Mediterranean diet” precisely.
Aegean islanders likely ate (and eat) fewer vegetables and fruits—but more cheese (albeit low-fat), white bread, and salty processed meats—than called for in standard descriptions of the so-called Mediterranean diet.
The main thing that’s clearly “Mediterranean” about this prudent diet is the use of olive oil in place of omega-6-heavy, pro-inflammatory alternatives like sunflower, safflower, corn, soy, and canola oils.
And recent research has revealed the importance of the super potent, tyrosol-type polyphenol antioxidants in extra virgin grade olive oil to the good reputation enjoyed, inaccurately, by all grades.
While all olive oil grades are preferable to using conventional American vegetable oils, only unrefined extra virgin grade is clearly superior for cardiovascular health, and probably for helping prevent cancer.
(See “Olive Oil Earns More Cardiovascular and Anti-Cancer Kudos.”)
Although the authors of the famous Seven Countries Study painted a distorted, idealized picture of Mediterranean dietary realities, these distortions prompted later researchers to test the idealized diet and discover that it is highly healthful.
The alternate term “prudent diet” is more accurate, in that it describes this health-promoting diet without a misleading Mediterranean association, and is now preferred by many researchers.
But let’s face it: eating a “prudent diet” sounds like a chore, whereas a “Mediterranean diet” seems sensual and alluring.
It’s a case of health-advocacy triumphing over accuracy… and that’s a compromise worth making if it improves people’s eating patterns!
- Varraso R, Fung TT, Hu FB, Willett W, Camargo CA Jr. Prospective study of dietary patterns and chronic obstructive pulmonary disease among US men. Thorax. 2007 May 15; [Epub ahead of print] doi:10.1136/thx.2006.074534
- Hu FB, Rimm EB, Stampfer MJ, Ascherio A, Spiegelman D, Willett WC. Prospective study of major dietary patterns and risk of coronary heart disease in men. Am J Clin Nutr. 2000 Oct;72(4):912-21.
- van Dam RM, Rimm EB, Willett WC, Stampfer MJ, Hu FB. Dietary patterns and risk for type 2 diabetes mellitus in U.S. men. Ann Intern Med. 2002 Feb 5;136(3):201-9. Summary for patients in: Ann Intern Med. 2002 Feb 5;136(3):I30.