Sunday, May 5, 2013

Debunking the Mediterranean Diet

The Debunking 

The Mediterranean diet is one of America’s slower growing diet fads.  The main idea behind it is that the key to longevity and optimal health is to abandon our modern diets, which make us ill, and move far back in time to the people of Crete more than 60 years ago and eat like them. 

This idea was started in 1945 by Ancel Keys and has become more popular since then (Google: ‘books on the Mediterranean diet’).  The language makes references to nutritionism, and plant-based diet.  The diet seems primarily targeted at women as there are many images of skinny women near water 

Lots of red wine! 

This idea broken down into 4 parts: 
  1. Our modern diet today makes us chronically ill and is high in saturated fat, cholesterol, salt and high GI carbs
  2. We need to abandon these modern diets and move back in time to the 1940s and eat more like the people of Crete over 60 years ago
  3. We know what these diets were like and they had a lot of red wine, they were mainly plant based and that was supplemented with fish and chicken.  But it definitely did not contain much animal fat and red meat
  4. If we emulate this diet we will improve out health and enable us to live longer 

All that red wine! 

The Mediterranean diet as it is promoted in popular books, on TV, on self-help websites, and in the overwhelming majority of popular news articles has virtually no basis in diets of the Mediterranean 

Myth 1: People in Crete consumed large quantities of red wine.  Quite the opposite, at most they consumed an average of about 30 grams (one once) per day.  (Calculated from these data: people in Crete ate about 2500 calories per day and 1% of those came from wine, beer and spirits [1], a glass of wine contains 85 calories per 103 grams [2]) 

Myth 2: Mediterranean peoples did not eat much red meat, animal fats and in some portrayals total fat.  The Cretan diet in in 1940s was higher in fat than the SAD (38% [1] vs. ~30-35%).  And it seems Mediterranean peoples may have eaten more animal foods and animal fats than what we are told* [3].  Also low fat dairy is a modern first world invention.  Many Cretans were hungry** [1], so they probably didn’t make low fat cheese then throw the fat away. 

Myth 3: Mediterraneandiet foods are what people in the Mediterranean have traditionally eaten.  This is not true.  Most food pictures in Mediterraneandiet promotional images are from non-organic and genetically modified plants or animals***.  Also in this recipe (first one I came across) the black pepper and basil came from India, not the Mediterranean (tut tut). 

Mediterranean diets were regionally and seasonally variable and they did a lot more activity than we did.  But it’s almost impossible for us now to eat this sort of diet.  Grain agriculture, as it’s currently practiced, is not sustainable 

What dietary lessons can we learn from real Mediterranean diets? 

  • Diversity is important 
  • Eat fresh foods in season, when they are ripe and most nutritious
  • Eat whole foods, not processed foods 

* Although that article may have just as much selection bias as Keyes, et al 

** If you want a diet to be sustainable why would you base it off an eating pattern where 72% were dissatisfied with their diet (which is probably mainly due to there not being enough calories) and many wanted more meat. 

*** Not that I'm an organic and anti-GMO zealot.  I'm just applying the same stupid criteria that is used to say that: 'since Paleo isn't 100% perfect reenactment, therefore it is a completely invalid approach to diet'

Not Debunked 

Just so everyone knows, this isn’t a real criticism of the Mediterranean diet, but rather a tongue in cheek post on Christina Warriner’s ‘Debunking the Paleo Diet’.  I don’t consider this post or her talk to debunk any diet as neither has used biological mechanisms or data from clinical trials.  Robb Wolf has commented on the talk (here and here) so I won’t add much, just a few things: 

3:10: “Humans have no known anatomical, physiological, or genetic adaptations to meat consumption”.  What about our requirement for vitamin B12, K2 and LCO3s 

10:30: She discusses how we have selectively bred plants to increase their size and calories and reduce their toxins, seeds and fibrous bits as if that’s a bad thing.  But also the idea that plants were toxic and fibrous kind of contradicts her earlier assertion that we didn’t eat much meat.  If plants were too difficult for ancient humans to extract calories from they would have turned to something else, animal foods perhaps...

14:20: ‘To look at a Paleo diet lets go 7,000 years back in time’…Really? 

Throughout the talk she made references that allude to Paleolithic peoples having a harder time finding calories, which is true, but is a popular idea often taken to extremes beyond the boundaries of common sense.  I compiled the list below from various sources.  While not all of these were said by Christina Warriner, how could hunter-gatherers have possibly survived assuming: 

  • They maintained a high level of activity and muscle mass (comparatively)
  • Meat was scarce and lean and getting it required a lot of effort
  • Plants were more toxic, more fibrous, had more seeds and less sweet
  • They often went hungry (thrifty gene hypothesis) and missed meals (the intermittent fasting idea)
  • They lacked central healing (therefore used more energy to warm up)
  • They had (more) parasites that stole calories
  • Food was blander so people ate less
  • Amylase activity was lower
  • There was less food processing, therefore food was more difficult to digest 

Something has to give 

* By the way, I have bought Marlene Zuk’s ‘Paleofantasy’ and plan to read it after my exams in June. 

** Some credit for this post should go to Jamie Scott who inspired this post with the following tweets

5 comments:

  1. http://realbalance.com/icaria-long-lived-people-and-no-dimentia

    In all, we found 13 likely contributors to Ikarian longevity. The formula below may be the closest you’ll get to the fountain of youth:

    Graze on greens More than 150 varieties of wild greens grow on Ikaria. Some have more than ten times the level of antioxidants in red wine.

    Sip herbal teas Steeping wild mint, chamomile, or other herbs in hot water is a lifelong, daily ritual. Many teas lower blood pressure, which decreases the risk of heart disease and dementia.

    Throw out your watch Ikarians don’t worry about time. Work gets done when it gets done. This attitude lowers stress, which reduces the risk of everything from arthritis to wrinkles.

    Nap daily Ikarian villages are ghost towns during the afternoon siesta, and science shows that a regular 30-minute nap decreases the risk of heart attack.

    Walk where you’re going Mountainous terrain and a practice of walking for transport mean that every trip out of the house is a mini workout.

    Phone a friend With the island’s rugged terrain, family and village support have been key to survival. Strong social connections are proven to lower depression, mortality, and even weight.

    Drink goat’s milk Most Ikarians over 90 have drunk goat’s milk their whole lives. It is rich in a blood-pressure-lowering hormone called tryptophan as well as antibacterial compounds.

    Maintain a Mediterranean diet Around the world, people who most faithfully stick to this region’s diet—a regimen high in whole grains, fruits, vegetables, olive oil, and fish—outlive people who don’t by about six years. The Ikarian version features more potatoes than grains (because they grew better in the mountains) and more meat than fish (because the sea was a day’s journey away).

    Enjoy some Greek honey The local honey contains antibacterial, anticancer and anti-inflammatory properties. (Unfortunately, the health benefits of Ikarian honey do not extend to American honey, as far as we know.)

    Open the olive oil Ikaria’s consumption of olive oil is among the world’s highest. Residents drizzle antioxidant-rich extra-virgin oil over food after cooking, which preserves healthful properties in the oil that heat destroys.

    Grow your own garden (or find farmers’ markets) Fruits and vegetables eaten soon after picking are higher in compounds that decrease the risk of cancer and heart disease.

    Get religion Ikarians observe Greek Orthodox rituals, and regular attendance at religious services (of any kind ) has been linked to longer life spans.

    Bake bread The island’s sourdough bread is high in complex carbohydrates and may improve glucose metabolism and stave off diabetes.

    ReplyDelete
  2. http://www.motherjones.com/tom-philpott/2012/10/ikarian-greek-island-diet-health-benefit

    The Ikarians down two to 3.5 glasses of wine each day—including, apparently, the occasional glass with breakfast. Coffee is indulged at the rate of two to three cups daily. And the afternoon nap, apparently, is observed near universally. "People stay up late here," a local doctor tells Buettner. "We wake up late and always take naps. I don't even open my office until 11 a.m. because no one comes before then."

    Other lessons will seem austere to many Americans. Per capita US meat consumption averages to a little more than half a pound a day. Ikarians, by contrast, eat meat on average just five times per month. And Ikarians eat about a quarter as much sugar as Americans do, and very little processed food (although that is beginning to change.) The overall diet is classic Mediterranean. Buettner describes a typical couple's daily food routine:

    [A] breakfast of goat's milk, wine, sage tea or coffee, honey and bread. Lunch was almost always beans (lentils, garbanzos), potatoes, greens (fennel, dandelion or a spinachlike green called horta) and whatever seasonal vegetables their garden produced; dinner was bread and goat’s milk. At Christmas and Easter, they would slaughter the family pig and enjoy small portions of larded pork for the next several months.

    So they're eating a low-meat, relatively seafood-rich, nutrient-dense diet with plenty of greens and (he emphasizes elsewhere) olive oil. Buettner also mentions a warm beverage they drink which he translates as "mountain tea," "made from dried herbs endemic to the island," a rotating, seasonal list that includes wild marjoram, sage, mint, and dandelion leaves. Buetnner had samples of the greens tested in a lab, and they proved to be "rich sources of polyphenols" with "strong antioxidant properties."

    ReplyDelete
  3. http://www.businessinsider.com/ikaria-greece-longevity-secrets-2012-7?op=1

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3051199/

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3051199/table/tab2/


    http://www.nytimes.com/2012/10/28/magazine/the-island-where-people-forget-to-die.html?_r=0

    ReplyDelete
    Replies
    1. Hi Charles, thanks for those links. I'm not sure they are all that relevant as this post didn't debunk the Mediterranean diet and (just like Christina Warriner's talk) I haven't actually said anything bad about it

      "Just so everyone knows, this isn’t a real criticism of the Mediterranean diet..."
      "I don’t consider this post...to debunk any diet"

      Delete
  4. Or perhaps the diet gave you constant hunger pangs? Determining the reasons of past diet failures will help you understand your dieting strengths and weaknesses, and will help you make a better, more effective diet program.
    biogenetic laboratories hcg activator amazon

    ReplyDelete