Advanced Mediterranean Diet

I just read ”Low-Carbing Among Friends, Volume 1″ by Jennifer Eloff, Maria Emmerich, Carolyn Ketchum, Lisa Marshall, and Kent Altena.

♦   ♦   ♦

If you’re serious about low-carb eating, you’ll want this book.  Five well-known low-carb cooks and chefs present many of their best recipes in a straightforward format.  All 300+ recipes are gluten-free, wheat-free, and sugar-free.  I read through over half of the recipes and understood all the instructions; I’m confident I could make anything in this book.

Some of of the recipe ingredients will be a little hard to find. You may have to order a few of them online, and the authors tell you where to order. Unless you’re just dabbling in low-carb eating, you’ll want to stock up on some of these anyway. 

I have an incurable sweet tooth.  I like to share my cooking with my wife, but she has, um, (ahem)… ”gastrointestinal problems” with my usual non-caloric sweetener, Splenda.  That’s not very common, but is a well-known phenomenon.  I was glad to learn herein that erythritol is a trouble-free alternative, GI-wise.

One thing I miss about standard high-carb eating is baked sugary items like cakes and muffins.  Sure, I’ve read that if you stay away from those for four to six months, you’ll lose your desire.  Not me.  And I tried.  In my next stretch of days off, I’m making a batch of Jennifer Eloff’s Splendid Gluten-Free Bake Mix and spending some time in the kitchen!

Not being previously familiar with him, I was particularly impressed with Kent Altena’s background.  Starting at over 400 pounds (182+ kg), he lost over 200 pounds (91+ kg) and reenlisted in the U.S. National Guard and started running marathons (26.2 miles)!  Thank you for your service to our country, Mr. Altena.

The book is laced with commentary from low-carb proponents, including Dana Carpender, Jimmy Moore, Dr. John Briffa, Dr. Andreas Eenfeldt, Dr. Robert Su, and me.  I am honored to have been invited.

By the way, recipe measurements are given in both U.S. customary and metric units, which non-U.S. residents will appreciate.  Serving size nutrient analysis includes digestible carb grams (aka net carbs).  All recipe carb counts are under 10 g; most are under 5 g.  All of these would jibe with my KMD: Ketogenic Mediterranean Diet.  

If you’re tired of eating the same old things, I’m sure you’ll find many new dishes here that will become time-honored classics in your household.

Steve Parker, M.D.

Disclosure: As a supporter of low-carb eating, I contributed two pages to the book.  I did not and will not recieve any remuneration, and I purchased my own copy of the book.

PS: Recipes I want to try: Cinnamon Swirl Cookies, Green Bean and Bacon Salasd, Gingerbread Biscotti, Tuan Burgers, Blueberry Muffins, Pecan Sun-Dried Tomato and Bacon Cauli-Rice, Spicy Shrimp with Avocado Dressing, 24-Hour Chili, Harvest Pancakes, Breakfast Casserole, Bacon Wrapped Jalapeno Poppers, Stuffed Mushrooms, Broccoli Bacon Salad, Seven Layer Salad, Sausage Quiche, Low-Carb Pancakes, Stuffed Hamburgers, Eggplant Parmeson, Flax Bread, Splendid Gluten-Free Bake Mix, and Mock Danish.

U.S. obesity rate over last 40 years

Beth Mazur over at Weight Maven has posted a lecture by Dr. Stephan Guyenet in which he outlines the changes in American diet over the last 100 years.  It’s only 16 minutes long.  You may  find an explanation for our excess weight problem. 

Steve Parker, M.D.

Laura Dolson over at About.com explains the differences and briefly discusses olive processing in a recent post.

Olives, of course, are time-honored components of the Mediterranean diet.  I’ve had a few good crops in my backyard here in Arizona.

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.

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.).

Olives and olive oil are iconic components of the the Mediterranean diet.  Nutrition Diva Monica Reinagel has a wonderful post about olives and olive oil.  What are the best olives to eat?  How are olives processed?  Are olives more heathful than olive oil?  Click through for the answers.

Steve Parker, M.D.

Michael Pollan is credited with the aphorism, “Eat food.  Not too much.  Mostly plants.”  Tag lines are just good marketing; nothing wrong with that as long as it’s honest.

Bill Gottlieb interviewed me recently on the topic of prediabetes for his upcoming book (Bottom Line’s Breakthroughs in Natural Healing 2012).  Bill had given me a preparatory list of questions, one of which was,”What are the best dietary recommendations? I’m looking for fun, fresh specificity here—along the lines of your book!”  Also, “What’s the best way for a person to implement it—specific, practical, small-step actions that would lead to actually changing the diet?”

We didn’t have a chance to get to those in the interview, but here are some of my thoughts:

• Give up all man-made food*
• Give up all sugar-sweetened sodas and “sports drinks”
• Give up all flour products
• Give up all flours, starches, and added sugars
• Give up deserts

But “giving up” is not a message  people want to hear when contemplating a diet change, even if it’s for their own good.  Nor do they want to hear, “Don’t eat . . .”  “Avoid” and “cut back on” are not specific.  “Forego” works, but is just a euphemism for “give up.” 

“Eat only God-made foods” works for me but might turn off the atheists and agnostics.

Here’s a more marketable catch-phrase that I rather like and claim as my own:

Eat natural food.*

By “natural,” I mean “present in or produced by nature.”  This would not include candy bars, potato and corn chips, soda pop, sports drinks, apple pie, bread and other flour products, cookies, etc.  That still leaves a lot of different foods to eat, including most  of the items on the Low-Carb Mediterranean Diet and Advanced Mediterranean Diet. 

 Whether modern, mass-produced versions of fruits and vegetables are natural is a debate for another day.  I suspect modern corn, for example, is nothing close to the maize cultivated by Native Americans 400  years ago. 

Why the asterisk?  The exceptions to the “eat natural food” rule are red wine, olive oil, and vinegar.  Those are partly natural, partly man-made.  (Where do we get vinegar?)  The red wine and olive oil are potentially healthful, and many of us like vinegar on our  natural salad vegetables.

Eat natural food.

I bet the average person eating the standard American diet would tend to lose excess weight and be healthier by making the switch.

Steve Parker, M.D.

* Exceptions: red wine, olive oil, vinegar

Darya Pino over at Summer Tomato recently wrote about eating fish:  health aspects, which are best to eat, shopping, and sustainability.  I recommend it to you, even though I don’t agree with everything.  For instance, I think in general the risk of mercury contamination is overblown.  [I know that’s little consolation for those few who have suffered mercury poisoning from fish.]

Steve Parker, M.D.

Red meat and processed meat consumption are associated with “modest” increases in overall mortality and deaths from cancer and cardiovascular disease, according to National Institutes of Health researchers.  This goes for both sexes.

Data are from the huge NIH-AARP Diet and Heart Study, a prospective cohort trial involving  over 550,000 U.S. men and women aged 50-71 at the time of enrollment.  Food consumption was determined by questionnaire.  Over the course of 10 years’ follow-up, over 65,000 people died.  Investigators looked to see if causes of death were related to meat consumption.

What do they mean by red meat, processed meat, and white meat?

Red meat:  all types of beef and pork [wasn’t there a U.S. ad campaign calling pork “the other white meat”?]

White meat:  chicken, turkey, fish

Processed meat:  bacon, red meat sausage, poultry sausage, luncheon meats (red and white), cold cuts (red and white), ham, regular hotdogs, low-fat poultry hotdogs, etc.

What did they find?

See the first paragraph above.

Studies like this typically look at the folks who ate the very most of a given type of food, those who ate the very least, then compare differences in deaths between the two groups.  That’s what they did here, too.  For instance, the people who ate the very most red meat ate 63 grams per 1000 caories of food daily.  Those who ate the least ate 10 grams per 1000 cal of food daily.  That’s about a six-fold difference.  Many folks eat 2000 calories a day.  The high red meat eaters on 2000 cals a day would eat 123 grams, or 4.4 ounces of red meat.  The low red meat eaters on 2000 cals/day ate 20 grams, or 0.7 ounces.

The heavy consumers of processed meats ate 23 grams per 1000 cal of food daily.  The lowest consumers ate 1.6 grams per 1000 cal.

Comparing these two quintiles of high and low consumption of red and processed meats, overall mortality was 31-36% higher for the heavy red meat eaters, and 16-25% higher for the heavy processed meat eaters.  [The higher numbers in the ranges are for women.]  Similar numbers were found when looking at cancer deaths and cardiovascular deaths (heart attacks, strokes, ruptured aneurysms, etc).

It’s not proof that heavy consumption of red and processed meats is detrimental to longevity, but it’s suggestive.  The “Discussion” section of the article reviews potential physiological mechanisms for premature death.

The researchers called these differences “modest.”  I guess they use “modest” since most people eat somewhere between these extreme quintiles.  The numbers incline me  to stay out of that “highest red and processed meat consumer” category, and lean more towards white meat and fish.

The traditional Mediterranean diet and Advanced Mediterranean Diet are naturally low in red and processed meats.

Steve Parker, M.D. 

Reference:  Sinha, Rashmi, et al.  Meat intake and mortality: a prospective study of over half a million people.  Archives of Internal Medicine, 169 (2009): 562-571.

How many times have you heard how important it is to eat fruits  and vegetables?  Now, is it five or nine servings a day?  Why are fruits and veggies always lumped together?  What does a watermelon have in common with spinach?

The author of a 2004 article in the Journal of Postgraduate Medicine answered some of these questions.  Here are a few quotes from from the summary:

The intake of 400-600 g/d of fruits and vegetables is associated with reduced incidence of many common forms of cancer, and diets rich in plant foods are also associated with a reduced risk of heart disease and many chronic diseases of ageing.

These foods contain phytochemicals that have anti-cancer and anti-inflammatory properties which confer many health benefits. Many phytochemicals are colourful, and recommending a wide array of colourful fruits and vegetables is an easy way to communicate increased diversity of intake to the consumer. For example, red foods contain lycopene, the pigment in tomatoes, which is localized in the prostate gland and may be involved in maintaining prostate health, and which has also been linked with a decreased risk of cardiovascular disease. Green foods, including broccoli, Brussels sprouts and kale, contain glucosinolates which have also been associated with a decreased risk of cancer. Garlic and other white-green foods in the onion family contain allyl sulphides which may inhibit cancer cell growth. Other bioactive substances in green tea and soybeans have health benefits as well.

Consumers are advised to ingest one serving of each of the seven colour groups daily, putting this recommendation within the United States National Cancer Institute and American Institute for Cancer Research guidelines of five to nine servings per day. Grouping plant foods by colour provides simplification, but it is also important as a method to help consumers make wise food choices and promote health.

Asking U.S. consumers to eat one serving from each of seven fruit and vegetable color groups daily is a bit much.  I don’t see that happening.  But the suggestion is a start.  Darya Pino (Summer Tomato blog) probably does it every day, but I don’t know any others.  My simplified message: Eat a variety of colorful fruits and veggies daily.

Note that the very low-carb Ketogenic Mediterranean Diet provides 400 grams of vegetables and fruits daily, and I count seven colors (assuming you allow me to include black olives).  On the KMD document I list avocado, cucumber, and tomato under “vegetables,” but they are indeed fruits.  Heck, I guess olives are fruit, too.

“So, what’s your point, Parker,” you might well ask.  I don’t expect anyone to follow the Ketogenic Mediterranean Diet for life.  When it’s time to move on to a “Diabetic Mediterranean Diet,” I’m considering adding more options: traditional fruits and some colorful vegetables like purple beets, yellow corn, and orange carrots and sweet potatoes.

I still don’t know why “fruits and vegetables” are joined at the hip.  Legumes, grains, and dairy products all rate their very own category.  It’s just not fair.

Steve Parker, M.D.

Reference:  Heber, D.  Vegetables, fruits and phytoestrogens in the prevention of diseases.  Journal of  Postgraduate Medicine, 50 (2004): 145-9.

Update: March 8, 2010

Beth at Weight Maven blog put together a colorful graphic showing the major foods and phytonutrients associated with particular colors, based on Dr. Heber’s work.