Advanced Mediterranean Diet

One of the very first users of insulin injections lived to be 73.  That amazes me since most of her life was lived before we could keep close track of blood sugar levels with home glucose monitoring.  She died of pneumonia in 1981.  She was a type 1 diabetic since age 11.

Insulin was discovered in Canada

Her name was Elizabeth Hughes, daughter of a New York governor.  She was started in insulin around 1922. 

I read about her in Nutrition Journal earlier this year.  Most of the article was about the use of starvation diets for diabetics in the pre-insulin era .  Ever heard of the Joslin Clinic, a preeminent U.S. diabetes center?  Elliott Joslin was once an advocate of these starvation diets.  Insulin changed that.

The article notes that before insulin therapy was available, the standard diabetic diet was low-carbohydrate, avoiding sugars and starches, sometimes called the “animal diet.”

I also learned that urine became easily testable for sugar in the early part of the 20th century, if not earlier.  Before this, many cases of diabetes (mostly type 2) were undetectable or misdiagnosed.

Even today, type 1 diabetes is a hard row to hoe.  Before 1922, it was even worse.  As bad as it can get.

Steve Parker, M.D.

I’ve found that nearly everbody’s eyes glaze over if I try to explain how, physiologically, the Mediterranean diet promotes health and longevity.  Below are some of the boring details, for posterity’s sake, from my 2007 book, The Advanced Mediterranean Diet: Lose Weight, Feel Better, Live Longer.

Many of the nutrient-disease associations I mention below are just that: associations, linkages, not hard proof of a benefit.  Available studies are often contradictory.  For instance, there may be 10 observational studies linking whole grain consumption with reduced deaths from heart disease, while three other studies find no association, or even suggest  higher death rates. (I’m making these numbers up.)  If you want hard proof, you’ll have to wait.  A long time.  Such is nutrition science.  Take it all with a grain of salt. 

Also note that the studies supporting my claims below are nearly all done in non-diabetic populations.

Coronary Heart Disease

Coronary heart disease, also known as coronary artery disease, is the No.1 cause of death in the world. It’s responsible for 40% of deaths in the United States and other industrialized Western countries. The Mediterranean diet is particularly suited to mitigating the ravages of coronary heart disease. Mediterranean diet cardiac benefits may be related to its high content of monounsaturated fat (in olive oil), folate, and antioxidants.

The predominant source of fat in the traditional Mediterranean diet is olive oil, which is rich in monounsaturated fatty acids. High intake of olive oil reduces blood levels of triglycerides, total cholesterol, and LDL (”bad”) cholesterol. HDL or “good” cho-lesterol is unaffected. Olive oil tends to lower blood pressure in hypertensive people. Monounsaturated fatty acids reduce cardiovascular risk substantially, particularly when they replace simple sugars and easily digestible starches. Monounsaturated fatty acids and olive oil may also reduce breast cancer risk. The cardioprotective (good for the heart) and cancer-reducing effects of olive oil may be partially explained by the oil’s polyphenolic compounds.
    
Nuts are another good source of monounsaturated fatty acids and polyunsaturated fatty acids, including some omega-3 polyunsaturated fatty acids. Nuts have been proven to be cardioprotective. They lower LDL and total cholesterol levels, while providing substantial fiber and numerous micronutrients, such as vitamin E, potassium, magnesium, and folic acid. Compared with those who never or rarely eat nuts, people who eat nuts five or more times per week have 30 to 50% less risk of a fatal heart attack. Lesser amounts of nuts are also cardioprotective, perhaps by reducing lethal heart rhythm dis-turbances. 
    
Another key component of the Mediterranean diet is fish. Fish are excellent sources of protein and are low in cholesterol. Fatty, cold-water fish are particularly good for us because of their omega-3 polyunsaturated fatty acids: eicosapentaenoic acid (EPA) and docosahexanaenoic acid (DHA). The other important omega-3 polyunsaturated fatty acid is alpha-linolenic acid (ALA), available in certain plants. Our bodies can convert ALA into EPA and DHA, but not very efficiently. Fish oil supplements, which are rich in EPA, lead to lower total cholesterol and triglyce-ride levels. Fish oil supplements have several properties that fight atherosclerosis (hardening of the arteries). In people who have already had a heart attack, the omega-3 polyunsaturated fatty acids have proven to dramatically reduce cardiac deaths, especially sudden death, and nonfatal heart attacks. So omega-3 polyunsaturated fatty acids are “cardioprotective.”

The first sign of underlying coronary heart disease in many people is simply sudden death from a heart attack (myocardial infarction) or heart rhythm disturbance. These unfortunate souls had hearts that were ticking time bombs. I have little doubt that a significant number of such deaths can be prevented by adequate intake of cold-water fatty fish. As a substitute for fish, fish oil supplements might be just at beneficial. The American Heart Association also recommends fish twice weekly for the general population, or fish oil supplements if whole fish isn’t feasible. Compared with fish oil capsules, whole fish are loaded with vitamins, minerals, and protein. The richest fish sources of omega-3 polyunsaturated fatty acids are albacore (white) tuna, salmon, sar-dines, trout, sea bass, sword-fish, herring, mackerel, anchovy, halibut, and pompano.
    
Cardioprotective omega-3 polyunsaturated fatty acids (mainly ALA) are also provided by plants, such as nuts and seeds, legumes, and vegetables. Rich sources of ALA include walnuts, butternuts, soy-beans, flaxseed, almonds, leeks, purslane, pinto beans, and wheat germ. Purslane is also one of the few plant sources of EPA. Several oils are also very high in ALA: flaxseed, canola, and soybean. Look for them in salad dressings, or try cooking with them.

Macular Degeneration

Omega-3 fatty acid and fish consumption may also be “eye-protective.” Eating fish one to three times per week apparently helps prevent age-related macular degeneration (AMD), the leading cause of blindness in people over 50 in the United States. While AMD has a significant hereditary component, onset and progression of AMD are affected by diet and lifestyle choices. For instance, smoking cigarettes definitely increases your risk of developing AMD. Other foods associated with lower risk of AMD are dark green leafy vegetables, orange and yellow vegetables and fruits: spinach, kale, collard greens, yellow corn, broccoli, sweet potatoes, squash, orange bell peppers, oranges, mangoes, apricots, peaches, honeydew melon, and papaya. Two unifying phytochemicals in this food list are lutein and zeaxanthin, which are also found in red grapes, kiwi fruit, lima beans, green beans, and green bell peppers. Increasing your intake of these foods as part of the Advanced Mediterranean Diet may well help preserve your vision as you age.      
    
Alzheimer’s Dementia
    
Another exciting potential benefit of fish consumption is prevention or delay of Alzheimer’s dementia. Several recent epidemiologic studies have suggested that intake of fish once or twice per week significantly reduces the risk of Alzheimer’s. Types of fish eaten were not specified. No one knows if fish oil capsules are equivalent. For now, I’m sticking with fatty cold-water fish, which I call my “brain food.”
    
Vitamin E supplements may slow the progression of established Alzheimer’s disease; clinical studies show either modest slowing of progression or no benefit. As a way to prevent Alzheimer’s, however, vitamin E supplements have been disappointing. On the other hand, high dietary vitamin E is associated with reduced risk of developing Alzheimer’s. Good sources of vitamin E include vegetable oils (especially sunflower and soybean), sunflower seeds, nuts, shrimp, fruits, and certain vegetables: sweet potatoes, asparagus, beans, broccoli, Brussels sprouts, carrots, okra, green peas, sweet peppers, spinach, and tomatoes. All of these are on your new diet. 

Wine

For centuries, the healthier populations in the Mediterranean region have enjoyed wine in light to moderate amounts, usually with meals. Epidemiologic studies there and in other parts of the world have associated reasonable alcohol consumption with prolonged lifespan, reduced coronary artery disease, diminished Alzheimer’s and other dementias, and possibly fewer strokes. Alcohol tends to increase HDL cholesterol, have an antiplatelet effect, and may reduce C-reactive protein, a marker of arterial inflammation. These effects would tend to reduce cardiovascular disease. Wine taken with meals provides antioxidant phytochemicals (polyphenols, procyanidins) which may protect against atherosclerosis and some cancers. 

What’s a “reasonable” amount of alcohol? An old medical school joke is that a “heavy drinker” is anyone who drinks more than the doctor does. Light to moderate alcohol consumption is generally consi-dered to be one or fewer drinks per day for a woman, two or fewer drinks per day for a man. One drink is 5 ounces of wine, 12 ounces of beer, or 1.5 ounces of 80 proof distilled spirits (e.g., vodka, whiskey, gin). The optimal health-promoting type of alcohol is unclear. I tend to favor wine, a time-honored component of the Mediterranean diet. Red wine in particular is a rich source of resveratrol, which is thought to be a major contributor to the cardioprotective benefits associated with light to moderate alcohol consumption. Grape juice may be just as good—it’s too soon to tell.
    
I have no intention of overselling the benefits of alcohol. If you are considering habitual alcohol as a food, be aware that the health benefits are still somewhat debatable. Consumption of three or more alcoholic drinks per day is clearly associated with a higher risk of breast cancer in women. Even one or two drinks daily may slightly increase the risk. Folic acid supplementation might mitigate the risk. If you are a woman and breast cancer runs in your family, strongly consider abstinence. Be cautious if there are alcoholics in your family; you may have inherited the predisposition. If you take any medications or have chronic medical conditions, check with your personal physician first. For those drinking above light to mod-erate levels, alcohol is clearly perilous. Higher dosages can cause hypertension, liver disease, heart failure, certain cancers, and other medical problems. And psychosocial problems. And legal problems. And death. Heavy drinkers have higher rates of violent and accidental death. Alcoholism is often fatal. You should not drink alcohol if you:
            ■  have a history of alcohol abuse
                or alcoholism
            ■  have liver or pancreas disease
            ■  are pregnant or trying to become
                pregnant
            ■  may have the need to operate
                dangerous equipment or machinery,
                such as an automobile, while under
                the influence of alcohol
            ■  have a demonstrated inability to
                limit yourself to acceptable
                intake levels
            ■  have personal prohibitions due
                to religious, ethical, or other
                reasons. 
    
Cancer

Do you ever worry about cancer? You should. It’s the second leading cause of death. Over 500,000 people die from cancer each year in the United States. One third of people in the United States will develop cancer. Twenty percent of us will die from cancer. About half the deaths are from cancer of the lung, breast, and colon/rectum. Are you worried yet?

According to the American Cancer Society, one third of all cancer deaths can be attributed to diet and inadequate physical activity. So we have some control over our risk of developing cancer. High consumption of fruits and vegetables seems to protect against cancer of the lung, stomach, colon, rectum, oral cavity, and esophagus, although other studies dispute the protective linkage. Data on other cancers is limited or inconsistent. If you typically eat little or no fruits and vegetables, you can start today to cut your cancer risk by up to one half. Five servings of fresh fruits and vegetables a day seems to be the protective dose against cancer. Make it a life-long habit. The benefits accrue over time. Fruits and vegetables contain numerous phytochemicals thought to improve or maintain health, such as carotenoids (e.g., lycopene), lignans, phytosterols, sulfides, isothyocyanates, phenolic compounds (including flavonoids, resveratrol, phytoestrogens, antho-cyanins, and tannins), protease inhibitors, capsaicin, vitamins, and minerals. 
   
In addition to cancer prevention properties, fruits and vegetables provide fiber, which is the part of plants resistant to digestion by our enzymes. The other source of fiber is grain products, especially whole grains. Liberal intake of fiber helps prevent constipation, diverticular disease, hemorrhoids, irritable bowel syndrome, and perhaps colon polyps. Soluble fiber helps control blood sugar levels in diabetics. It also reduces LDL cholesterol levels, thereby reducing risks of coronary heart disease. Whether or not related to fiber, high fruit and vegetable intake may reduce the risks of coronary heart disease and stroke. Legume consumption in particular has been associated with a 10 to 20% lower risk of coronary heart disease, with the effective dose being around four servings per week. 

Fiber and Whole Grains

Processed, refined grain products have much less fiber than do whole grains. For instance, white all-purpose enriched flour has only about one fourth the fiber of whole wheat flour. The milling process removes the bran, germ, and husk (chaff), leaving only the endosperm as the refined product, flour. Endosperm is mostly starch and 10–15% protein. Many nutrients are lost during processing. The germ is particularly rich in vitamins (especially B vitamins), polyunsaturated fatty acids, antioxidants, trace minerals, and phytochemicals. Phytochemicals protect us against certain chronic diseases. Bran is high in fiber and nutrients: B vitamins, iron, magnesium, copper, and zinc, to name a few. Enriched grain products are refined grains that have had some, but certainly not all, nutrients added back, typically iron, thiamin, niacin, riboflavin, and folate. Why not just eat the whole grain? Whole grain products retain nearly all the nutrients found in the original grain. Hence, they are more nutritious than refined and enriched grain products.
    
Liberal intake of high-fiber whole grain foods, as contrasted with refined grains, is linked to lower risk of death and lower incidence of coronary heart disease and type 2 diabetes mellitus. For existing diabetics, whole grain consumption can help im-prove blood sugar levels. Three servings of whole grains per day cut the risk of coronary heart disease by about 25 percent compared with those who rarely eat whole grains. Regular consumption of whole grains may also substantially reduce the risk of sev-eral forms of cancer.

Average adult fiber intake in the United States is 12 to 15 grams daily. Expert nutrition panels and the American Heart Association recommend 25 to 30 grams daily from whole grains, fruits, and vegetables.

The health benefits of the Mediterranean diet likely spring from synergy among multiple Mediteranean diet components, rather than from a single food group or one or a few food items. 

Steve Parker, M.D.

Intentional weight loss didn’t have any effect either way on risk of death, according to recent research out of Baltimore.  Surprising, huh?

Obesity tends to shorten lifespan, mostly due to higher rates of cancer and cardiovascular disease like heart attacks and strokes.  Doctors and dietitians recommend loss of excess weight all day long, figuring it will reduce the risk of obesity-related death and disease.  That’s not necessarily the case, however.  It’s called the “obesity paradox“: some types of overweight and obese patients actually seem to do better (e.g., live longer) if they’re above the so-called healthy body mass index of 18.5 to 24.9.  For instance: those with heart failure, coronary artery disease, and advanced kidney disease.

It’s never really been clear whether the average obese person (body mass index over 30) improves his longevity by losing some excess weight.  That’s what the study at hand is about.

Methodology

Baltimore-based investigators followed the health status of 585 overweight or obese older adults over the course of 12 years.  Half of them were randomized to an intentional weight loss intervention.  All of them had a high blood pressure diagnosis.  Average age was 66.  Average body mass index was 31.  Details of the weight-loss intervention are unclear, but it was probably along the lines of “eat less, exercise more.”

What Did They Find?

The weight-loss group lost and maintained an average of 4.4 kg (9.7 lb) over the 12 years of the study.  This is about 5% of initial body weight, the minimal amount thought to be helpful for improvement in weight-related medical problems.  Most of the weight loss was over the first three years.

The men assigned to the weight-loss program had about half the risk of dying over the course of the study, compared to the men not assigned to weight loss.  The authors don’t seem to put much stock in it, however, stating that “…no significant difference overall was found in all-cause mortality between older overweight and obese adults who were randomly assigned to an intentional weight-loss intervention and those who were not.” 

Comments

With regards to the men losing weight, we’re only talking about 100-150 test subjects, a relatively small number.  So I understand why the researchers didn’t make a big deal of the lower mortality: it may not be reproducible.

This same research group did a similar study of 318 arthritis patients and intentional weight loss, finding a 50% lower death rate over eight years.

The authors reviewed many similar studies done by other teams, noting increased death rates from weight loss in some studies, and lesser death rates in others. 

When the studies are all over the place like this, it usually means there’s no strong association either way.  Nearly all the pertinent studies were done on relatively healthy, middle-aged and older folks.  The most reliable thing you can say about the issue is that loss of excess fat weight doesn’t increase your odds of premature death. 

 Remember that patients with coronary heart disease, congestive heart failure, or advanced kidney disease tend to live longer if they’re overweight or at least mildly obese.  It’s the obesity paradox.  Will they live longer or die earlier if they go on a weight-loss program?  We don’t know.

We do know that intentional weight loss helps:

• prevent type 2 diabetes
• maintain reasonable blood pressures (avoiding high blood pressure)
• improves lower limb functional ability

Maybe that’s enough.

Steve Parker, M.D.

Reference: Shea MK, Nicklas BJ, Houston DK, Miller ME, Davis CC, Kitzman DW, Espeland MA, Appel LJ, & Kritchevsky SB (2011). The effect of intentional weight loss on all-cause mortality in older adults: results of a randomized controlled weight-loss trial. The American journal of clinical nutrition, 94 (3), 839-46 PMID: 21775558

Folks with celiac disease won’t be able to thrive on the traditional Mediterranean diet.  What are the odds you have it?

Celiac disease, aka gluten enteropathy, affects one of every 133 Americans, according to the National Digestive Diseases Information Clearinghouse.  That’s much more common than we thought a couple decades ago.  Read about celiac disease symptoms and physical signs at About.com or the NDDIC link.

I read a few paleo diet/lifestyle blogs regularly.  In case you didn’t know, paleo diet advocates shun wheat and other grains.  Recent paleo converts often report how this or that symptom or physical condition improved when the dieter “went paleo,” often attributing the improvement to cutting out wheat products.   Wheat contains a protein—gluten—that causes disease in people who have celiac disease.  Other sources of gluten are barley and rye.

Visit WebMD for details about celiac disease: http://www.webmd.com/digestive-disorders/celiac-disease/default.htm

Click to see one definition of the paleo diet: http://paleodiet.com/definition.htm

An article in the Wall Street Journal implies that star tennis player Novak Djokovic’s recent winning streak is attributable to a gluten-free (and low-carb) diet.  Click for details: http://online.wsj.com/article/SB10001424052748703509104576327624238594818.html 

Here are Dr. Barbara Berkeley’s thoughts on Djokovic: http://refusetoregain.com/refusetoregain/2011/08/novak-djokovic-the-diet-that-conquered-tennis.html

Or is Djokovic playing so well because of the CVAC pod?: http://online.wsj.com/article/SB10001424053111904787404576532854267519860.html

If cutting out wheat from your diet improves or resolves bothersome medical symptoms, it makes me wonder if you have celiac disease.  Other possible explanations include placebo effect and coincidence.  And if you switch from a standard American diet to paleo, you’re doing more than just eliminating gluten.

I reviewed several sources for the prevalence of celiac disease in the U.S.  The best figure is one of every 133 residents. 

Most countries have a prevalence of roughly one of every 350 citizens.  Prevalence varies by country and ancestry; celiac disease is at least twice as common in whites of northern European lineage.

Full-blown classic celiac disease is relatively easy for doctors to recognize, but that’s only the tip of the iceberg.  Adults more commonly have one or two milder, nonspecific manifestations such as fatigue, malaise, depression, malnutrition (especially low iron, folate, or vitamin D), neuropathy, belly pain, headaches, thin bones, diarrhea, or a rash.  I’m glad to see increasing physician and public awareness of gluten intolerance.  If it’s not considered as a cause of these symptoms, it’ll never be diagnosed and treated appropriately.

Tom Naughton reviewed Dr. William Davis’ new book, Wheat Belly, August 31, 2011.  In the book, Dr. Davis notes that modern wheat varieties are vastly different from their ancient ancestors, different even than wheat of 50 years ago.  The modern varieties apparently contain much more of the gluten proteins that trigger immunologic celiac symptoms.  Maybe that’s why I see more celiac disease now than I did 30 years ago.

Celiac disease is being diagnosed more often because of the availability of blood tests that help us screen for it.  If you think you have celiac disease, consider getting one of two blood tests: IgA antibodies to tissue transglutaminase, or IgA endomysial antibodies.  If that test is positive and symptoms or physical signs suggest celiac disease, the next step is usually a small bowel biopsy.

Steve Parker, M.D.

References: WebMD.com (about one in a hundred US residents affected), University of Chicago Celiac Disease Center (one in 133 Americans affected), and MedicineNet.com (one in 3000 (sic) North Americans affected), UpToDate.com (in most countries, one in 350 have celiac disease), National Digestive Diseases Information Clearinghouse (one in 133 in U.S.).

“It is easier to change a man’s religion than to change his diet.”

-Margaret Mead

Daily work-related energy expenditure over the last half-century in the U.S. has decreased by over 100 calories.  This may well explain the increase in body weights we’ve seen, according to a 2011 article in PLoS ONE.

I sorta hate to open this can o’ worms, but it’s important.  As a population, are we fat because we eat too much or because we burn too few calories in physical activity?  Or is it a combination?  The correct answer may help us learn how to reverse the trend.

Methodology

Authors of the study at hand estimated the amount of energy (calories) necessary to perform various jobs, then noted changes in numbers of people employed in those jobs over time.  In the early 196os, for example, nearly half of U.S. jobs required at least moderate intensity physical activity, compared to less than 20% demanding that degree of energy now.  The authors note the dramatic shift from manufacturing to service-type jobs over the last 50 years.  Service jobs, like mine, often entail a lot of sitting and standing around. 

They chose to ignore how much energy we expend in exercise, figuring what we do in a 40-hour work week overwhelms the 1-2 hours of  exercise we may do.

Researchers’ Findings and Conclusions

They found that work-related daily energy expenditure has decreased by over 100 calories over the last half-century, which (in the authors’ view) would account for a significant portion of the increased body weight we’ve seen.  Since physically demanding jobs are unlikely to see a resurgence, the authors advocate physically active lifestyles away from workplace. 

Discussion

Surveys indicate that only one in four of us fulfill the federal physical activity guidelines: 150 minutes a week of moderate intensity activity or 75 minutes a week of vigorous intensity activity.  When activity is actually measured with an accelerometer, only one in 20 achieve that lofty goal.  We over-estimate how much we exercise, and under-estimate how much we eat.

The researchers cite studies showing significantly increased average per capita calorie consumption in the U.S. over the last several decades.  Some experts estimate the caloric increase is in the range of 500 a day for adults; the authors here think that’s too high but don’t offer a specific alternative. Looking at one of their references (Hall et al), they must think the increase is closer to 200 calories a day, comparing 2005 to 1975.

Several studies suggest that average daily energy expenditure has not decreased in developed countries, at least from the 1980s to the present.   A strength of the current study at hand is that it spans about 50 years, up to 2008.

My sense is that both calorie consumption (too much) and physical activity (too little) contribute to our overweight problem that started 40 or 50 years ago.  Excessive consumption is the predominant factor.  To ”exercise off”  the calories in a Snickers candy bar, you’d have to jog for an hour.  If you’re watching your weight, you’ll have more success if you just skip the Snickers.

In case you couldn’t tell,  I still believe in the “calories in/calories out” model of overweight and obesity, aka “the energy balance equation.”  At the same time, I believe certain calories are more fattening than others: concentrated sugars and refined starches.

Steve Parker, M.D.

References:

Church, T., Thomas, D., Tudor-Locke, C., Katzmarzyk, P., Earnest, C., Rodarte, R., Martin, C., Blair, S., & Bouchard, C. (2011). Trends over 5 Decades in U.S. Occupation-Related Physical Activity and Their Associations with Obesity PLoS ONE, 6 (5) DOI: 10.1371/journal.pone.0019657
 

Swinburn, B., et al.  Increased food energy supply is more than sufficient to explain the U.S. epidemic of obesity.  American Journal of Clinical Nutrition, 2009 (90): 1,453-1,456.  

Hall, K.D., et al.  The progressive increase of food waste in America and its environmental impact.  PLoS ONE, 2009, 4(11): e7940.  doi: 10.1371/journal.pone.0007940

I have a soft spot for cannibal jokes.

At the hospital last night, I admitted an elderly heart patient with chest pain.  I asked if he’d ever heard of the Mediterranean diet.  He answered, “What’s that? Does it mean you only eat those kinds of people?”

Steve Parker, M.D.

PS: In the course of our conversation, he worked in five other one-line jokes. What a blessing.

PSS:  Q: Why did the cannibal eat the trapeze artist?

A: He wanted a balanced meal.