Wednesday, December 12, 2012

The Mediterranean Diet Secret: Olive Oil or Low Fat Plant-Based 200 Days A Year?

In the early 1950s, the population of Greece had a very low incidence of cardiovascular disease, particularly on the island of Crete, compared to the incidence in the U.S..  In 1948 the Rockefeller Foundation did a majory epidemiological study on the island of Crete, part of which included investigation of the food habits on Crete. 1

The following table shows the results of that investigation by a seven day food record. 

 The table shows the following:

    •    Cereals, pulses, potatoes, nuts, vegetables, and fruits supplied 61 percent of the total energy in the diet of Crete, compared to only 37 percent of energy in the U.S. food supply.
    •    Items of animal origin provided only 7 percent of the total energy in the Cretan diet, compared to 29 percent of the energy in the U.S. food supply.
    •    Table oils and fats, primarily olive oil, supplied 29 percent of the energy in the Cretan diet.

Cereals provided thirty-nine percent of the 2500 kcal of energy supplied by the Cretan diet, or 975 kcal.  Since cereals supply about 70 percent of energy as carbohydrate, cereals alone supplied 170 g of carbohydrate in the Cretan diet.

Since 28 g (1 ounce) of bread supplies about 60 kcal, the typical diet of someone living in Crete about 1950 may have included up to 16 ounces of wheat bread daily. 

Regardless of relative proportion of bread and pasta in the Cretan diet, a very low rate of heart disease occurred in Crete in conjunction with a high intake of wheat.

Meat, fish, eggs, and dairy products provided only seven percent of energy of the Cretan diet, about 178 kcal per day.

Dairy products such as feta cheese and yogurt supplied only three percent of energy, or about 75 kcal per day.  Since one cup of Greek yogurt (10% milkfat) supplies 290 kcal, and one ounce of feta cheese supplies only 75 kcal (6 g fat, 4 g saturated, 25 mg cholesterol), apparently in 1950 the people of Crete consumed no more than one ounce of cheese or about one-quarter of a cup of yogurt (6 g fat, 4 g saturated fat, 19 mg cholesterol) daily, far less than the three servings daily currently recommended by the USDA food guide. 

Meat, fish, and eggs supplied about four percent of calories or 103 kcal per day.  One egg supplies about 80 kcal, and one ounce of roasted goat flesh or grilled sardine (items consumed historically in Crete) supplies about 40 kcal, so the Cretan diet of 1950 contained an average of no more than 2.5 ounces of meat or fish daily for individuals expending 2500 kcal per day, or about one ounce of animal flesh per thousand kcal consumed (i.e. someone consuming only 2000 kcal would consume only two ounces daily).

Two and one-half ounces of roasted goat meat supplies only 19 g protein, 2 g of total fat, 0.5 g saturated fat, and 52 mg cholesterol, and 2.5 ounces of grilled sardines supplies about 12 g protein, 7 g of total fat, about 2 g saturated fat (yes, 29 percent of the fat in sardines consists of saturated fatty acids, a higher proportion than in the goat flesh). and 100 mg cholesterol (yes, the sardines supply more cholesterol than the goat meat).

Thus, from meat, fish, and dairy products, the Cretan diet circa 1950 would have on average supplied  8 to 13 g total fat, 5 to 6 g saturated fat, and 70 to 125 mg cholesterol per day.   In comparison, NHANES found that the average U.S. male consumes 307 mg cholesterol daily, and the average U.S. female 225 mg, two to four times the amount consumed by individuals in Crete 62 years ago. 2

Evidently, in 1950, people in Crete ate a starch-based diet with quite limited amounts of animal flesh, eggs, and milk.

Seven Countries Study Links Olive Oil To Health

In 1986, Keys et al reported the results of a 15-year follow-up on 15 cohorts in the prospective ecological Seven Countries Study  (which by the way involved original data collection from the 15 cohorts, not sorting through and arbitrarily selecting previously collected data, as so often incorrectly claimed):
"Death rates were related positively to average percentage of dietary energy from saturated fatty acids, negatively to dietary energy percentage from monounsaturated fatty acids, and were unrelated to dietary energy percentage from polyunsaturated fatty acids, proteins, carbohydrates, and alcohol. All death rates were negatively related to the ratio of monounsaturated to saturated fatty acids. Inclusion of that ratio with age, blood pressure, serum cholesterol, and smoking habits as independent variables accounted for 85% of variance in rates of deaths from all causes, 96% coronary heart disease, 55% cancer, and 66% stroke. Oleic acid accounted for almost all differences in monounsaturates among cohorts. All-cause and coronary heart disease death rates were low in cohorts with olive oil as the main fat. Causal relationships are not claimed but consideration of characteristics of populations as well as of individuals within populations is urged in evaluating risks."3
Notice that Keys et al specifically disclaimed assertion of causal relationships based on their data.  However, the team found a strong positive relationship between saturated (i.e. animal) fat intake and coronary heart diseaes, cancer, and stroke; and a negative relationship with olive oil. 

However, of the seven countries involved in the study (Japan, Italy, Greece, USA, Yugoslavia, Finland, and Netherlands), only two (Italy and Greece) had significant olive oil consumption.  Of these two, one had a significant brake on olive oil consumption for many days of the year, and this may have given olive oil an undeserved good reputation.

The Orthodox Mediterranean Diet Secret:  Avoid Olive Oil 180 Days A Year

Few popular or scientific accounts of the Mediterranean diet mention the fact that at least 95 percent of Greeks belong the the Eastern Orthodox Church, and a high proportion of Greeks follow the dietary directions of the Church which involve avoiding olive oil, meat, fish, milk, and dairy products on as many as 200 days every year:

"Orthodox Christian holy books recommend a total of 180–200 days of fasting per year. The faithful are advised to avoid olive oil, meat, fish, milk and dairy products every Wednesday and Friday throughout the year. Additionally, there are three principal fasting periods per year: i) a total of 40 days preceding Christmas (meat, dairy products and eggs are not allowed, while fish and olive oil are allowed except on Wednesdays and Fridays), ii) a period of 48 days preceding Easter (Lent). During Lent fish is allowed only two days whereas meat, dairy products and eggs are not allowed. Olive oil consumption is allowed only at weekends, iii) a total of 15 days in August (the Assumption) when the same dietary rules apply as for Lent with the exception of fish consumption which is allowed only on August 6th. Seafood such as shrimps, squid, cuttlefish, octopus, lobsters, crabs as well as snails are allowed on all fasting days throughout the year. The Greek Orthodox fasting practices can therefore be characterized as requiring a periodic vegetarian diet including fish and seafood." 4

Thus, on many days of the year, many Greeks eat a primarily plant-based diet without the olive oil so often identified as the secret to health and longevity.  Apparently, the Seven Countries Study did not account for this.  In fact, up until the year 2000, no scientific study, including the Seven Countries Study (SCS), had evaluated the impact of Greek Orthodox Christian fasting on serum lipoproteins or risk of cardiovascular disease or cancer.

At the ten-year follow-up of the SCS, Greece had the lowest CHD mortality of all seven countries: a remarkable 0/1000, compared to the next lowest in Japan, 7/1000. 5  This means that the Greek data would most strongly influence the appearance that a diet high in olive oil protects against CHD, when as a matter of fact, some significant portion of Greeks actually avoided eating olive oil on many days of the year. 

In 2000-2001, scientists from the University of Crete School of Medicine compared the blood lipids of Greeks who adhered to the fasting periods to those of Greeks who did not adhere during that year. They found that by the end of the year the fasters had significantly lower total cholesterol, LDL, and body mass index.  They also found that "when fasters returned to their usual dietary habits (non-fasting periods) total cholesterol and LDL cholesterol were increased by 6% and 9% respectively."4

Therefore, considering that the olive oil users of Roman Catholic Italy did not have the very low incidence of CHD and other diseases of civilization found in Greece in the 1950s, it seems possible that the Greeks enjoyed better health than the Italians because they avoided olive oil more often than the Italians, resulting in lower total cholesterol, LDL, and body fat levels.  

Greek Data Supports The Lipid Hypothesis

In 1997, an earlier team from the University of Crete School of Medicine reported that between 1962 and 1991, individuals participating in the Crete cohort of the Seven Countries Study had increased their intake of saturated fats and decreased their intake of monounsaturated fats, with corresponding increases in body mass index, adipose palmitic acid, diastolic and blood pressure, and by 1991,  "all age groups were characterized by central obesity."6
“Over time, the diet of Crete has changed remarkably and is now characterized by higher intake of saturated fat and cholesterol, and reduced intake of monounsaturated fat.  At the same time, total fat consumption has fallen.  These trends have been accompanied by a stead rise in CHD risk during 25 years of follow-up of the Cretan cohort (Menotti et al. 1999). Hence, as the Cretan diet increasingly resembles a Western diet, there has been a concurrent rise in CHD risk.”5


George Henderson said...

A good read on the Mediterranean diet is "Sea and Sardinia" by D.H. Lawrence. Sardinia was one of the other med. longevity examples that started this fad. He details what is and isn't available at the markets. For example, bread is somewhat scarce and expensive, eggs are dirt cheap.
There's pages of documentation about what people really ate.

Peter said...
This comment has been removed by the author.
Peter said...

^Keys actually studied Sardinia in the 1950s, mean intake of eggs was about 5 per week. Other than that, it was the typical high-pasta and high wheat-bread fare. The consumption of butter, ice cream and cream was very modest.

"Only small portions of meat are taken few times a week, milk is consumed only in the morning coffee, the bread and pasta (spaghetti, etc) is made without shortening and olive oil is the sole cooking fat"

New York Times covered an article about other European blue-zone, the Greek Ikaria island. Dietary staples: potatoes, beans, wheat-bread. Gary Taubes is appearing in the article with rather interesting views (given his overall standpoint on these issues)

Peter said...

Esselstyn used, inter alia, this one in his slides:

Olive, soybean and palm oils intake have a similar acute detrimental effect over the endothelial function in healthy young subjects

Esselstyns presentation:

Kushal Pandit said...

Thanx for ur post and giving us a hugefull information, i also read somewhere The omega-3 fatty acids found in Fish Oil possesses many health benefits.and recomended by many Health Autorities as a part of Balanced Diet. Fish Oil contains Omega-3 Fatty Acids, specifically Docosahexaenoic Acid (DHA) and Eicosapentaenoic Acid (EPA). One of the Health Benefits linked to Fish Oil is a low risk of Heart Attack. very healpfull for Blood Circulations. is this true..????

Healthy Longevity said...
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Rex said...

Keep posting Don! I really enjoy reading your posts...There are so many people out there who believe, quite fervently, that a high-fat, low carb diet is the "ideal" human diet for everyone. Having tried such a diet, I can say with 100% certainty it does not work for me. I had a recent conversation online with a diabetic working to help other diabetics in India...The guy kept telling me that a high-fat diet improved all his patients' biomarkers, and that therefore, a high-fat diet is the ideal diet for reversing the aging process. What kind of diet would you recommend for managing/treating diabetes in your experience? (I am not a diabetic, just curious)

Evangelista Nick said...

Great overview, thanks a lot for posting!

Healthy Longevity said...

Keys also noted in regards to the Greek vital statistics between 1941-47 that Athens and Piraeus experienced a decline in consumption of fat and a decline in mortality from CHD during the war period but did not specify what fats these were.

19thnervousbreakdown said...

Dear Don,

Are you eating a completely vegan diet now? Is it unhealthy to eat wild caught fish? How much do you eat per day or week? What is your opinion on Durianrider, Doug Graham and the 80/10/10 diet?


Charles Grashow said...

Will you be willing to follow this diet?

Salad days
Saturday, Sunday, Tuesday and Thursday

Breakfast Hard bread, tea
Lunch Pasta or rice,vegetables, olive oil
Dinner Lentils, fruit and salad, olive oil. Red wine

Monday, Wednesday and Friday no olive oil

Holidays and feast days Fish and seafood

Meals on the peninsula, which the Prince of Wales has visited regularly and which can only be reached by boat, are ascetic and repetitive affairs that have changed little over the centuries, although there are variations between the 20 monasteries.

The monks sit in silence while, from a pulpit, passages from the Bible are read in Greek. They eat at speed – as soon as the Bible passage is over, the meal is officially completed.

The staples are fruit and vegetables, pasta, rice and soya dishes, and bread and olives. They grow much of what they eat themselves.

Agioritiko red wine is made locally from mountain grapes. Dairy products are rare – female animals are banned from the autonomous semi-state.

Life on Athos has changed little over the past 1,043 years. Breakfast is hard bread and tea. Much of the day is taken up with chores – cleaning, cooking, tending to crops – followed by a supper, typically of lentils, fruit and salad, and evening prayers.

What say you Don??

Charles Grashow said...

How prevalent is vitamin B12 deficiency among vegetarians?

Roman Pawlak1,*, Scott James Parrott2, Sudha Raj3, Diana Cullum-Dugan4, Debbie Lucus5
Article first published online: 2 JAN 2013

DOI: 10.1111/nure.12001

Author Information
1Department of Nutrition Science, East Carolina University, North Carolina, USA
2Department of Nutritional Sciences, School of Health Related Professions, University of Medicine and Dentistry of New Jersey, Newark, New Jersey, USA
3Department of Public Health, Food Studies and Nutrition, Syracuse University, Syracuse, New York, USA
4Namaste Nutrition, Watertown, Massachusetts, USA
5Sutter Medical Foundation, Roseville, California, USA
*Correspondence: R Pawlak, Department of Nutrition Science, East Carolina University, Rivers West 337, Greenville, NC 27858, USA. E-mail: Phone: +1-252-328-2350.

Affiliations: R Pawlak is with the Department of Nutrition Science, East Carolina University, North Carolina, USA. SJ Parrott is with the Department of Nutritional Sciences, School of Health Related Professions, University of Medicine and Dentistry of New Jersey, Newark, New Jersey, USA. S Raj is with the Department of Public Health, Food Studies and Nutrition, Syracuse University, Syracuse, New York, USA. D Cullum-Dugan is with Namaste Nutrition, Watertown, Massachusetts, USA. D Lucus is with the Sutter Medical Foundation, Roseville, California, USA.

"Vegetarians are at risk for vitamin B12 (B12) deficiency due to suboptimal intake. The goal of the present literature review was to assess the rate of B12 depletion and deficiency among vegetarians and vegans. Using a PubMed search to identify relevant publications, 18 articles were found that reported B12 deficiency rates from studies that identified deficiency by measuring methylmalonic acid, holo-transcobalamin II, or both. The deficiency rates reported for specific populations were as follows: 62% among pregnant women, between 25% and almost 86% among children, 21–41% among adolescents, and 11–90% among the elderly. Higher rates of deficiency were reported among vegans compared with vegetarians and among individuals who had adhered to a vegetarian diet since birth compared with those who had adopted such a diet later in life. The main finding of this review is that vegetarians develop B12 depletion or deficiency regardless of demographic characteristics, place of residency, age, or type of vegetarian diet. Vegetarians should thus take preventive measures to ensure adequate intake of this vitamin, including regular consumption of supplements containing B12."

Charles Grashow said...

The scientists also point out that the vegan myth that your body a great ability to store B12 and it would take years if not decades for them to be depleted:
"Studies do not support the position that it takes up to 20 or 30 years to develop a deficiency.7 According to Donaldson, 47% of the sample developed a deficiency, and most of these individuals had adhered to a raw vegan diet for between 23 and 49 months or about 2–4 years. In a study conducted by Herrmann et al.66% of German participants who had adhered to a vegetarian diet for at least 2 years were found to be B12 deficient." (Pawlak. 2013)
Since the whole problem is further increased by the lack of hydrochloric acid (low-to-no intrinsic factor production, which is necessary for the absorption of B12), low iron induced damage to the gut mucosa and subsequent nutrient malabsorptions, I'd suggest that all of you who insist on following a vegetarian life-style go, have their levels checked and get some B12 injections if you are where Pawlak et al. believe you are: Rock bottom.

Rex said...

Charles Grashow, what's your point? Veganism can and does work...Look at the Seventh Day Adventists...Lots of people, omnivores, vegetarians, and vegans are deficient in various vitamins and minerals due to soil depletion, pollution, a diet that is not varied enough or of poor quality and lacking in nutritional factors, etc. Everyone, regardless of diet, should probably be taking 1000 mcg of B12 everyday...I also need to take supplemental Vitamin D3 because where I live there is not enough UVB radiation. Most people in the US are deficient in Vitamin D. I take a high quality whole food multi-vitamin as well for insurance. I eat meat...No pun intended, but what's your beef?

Ivor Goodbody said...

Don, Unless I've missed it in your references somewhere, you may not have seen this, which rather tends to support your case in this blog:

Public Health Nutrition, 8(6),666

Letter to the Editor

"The Seven Countries Study in Crete: olive oil, Mediterranean diet or fasting?"

Wishing you enduring health