Category Archives: Mediterranean Diet

Whole Grains Reduce Heart Attacks and Strokes

Whole grain consumption is associated with a 21% reduction in cardiovascular disease when compared to minimal whole grain intake, according to a 2008 review article in Nutrition, Metabolism, and Cardiovascular Disease.   

Coronary heart disease is the No. 1 killer in the developed world.  Stroke is No. 3.  The term “cardiovascular disease” lumps together heart attacks, strokes, high blood pressure,  and generalized atherosclerosis (hardening of the arteries). 

Investigators at Wake Forest University reviewed seven pertinent studies looking at whole grains and cardiovascular disease.  The studies looked at groups of people, determining their baseline food consumption via questionnaire, and noted disease development over time.  These are called “prospective cohort studies.” 

None of these cohorts was composed purely of diabetics.

The people eating greater amounts of whole grain (average of 2.5 servings a day) had 21% lower risk of cardiovascular disease events compared to those who ate an average of 0.2 servings a day.  Disease events included heart disease, strokes, and fatal cardiovascular disease.  The lower risk was similar in degree whether the focus was on heart disease, stroke, or cardiovascular death.

Note that refined grain consumption was not associated with cardiovascular disease events. 

Why does this matter?

The traditional Mediterranean diet is rich in whole grains, which may help explain why the diet is associated with lower rates of cardiovascular disease.  If we look simply at longevity, however, a recent study found no benefit to the cereal grain component of the Mediterranean diet.  Go figure . . . doesn’t add up. 

Readers here know that over the last four months I’ve been reviewing the nutritional science literature that supports the disease-suppression claims for consumption of fruits, vegetables, and legumes.  I’ve been disappointed.  Fruit and vegetable consumption does not lower risk of cancer overall, nor does it prevent heart disease.  I haven’t found any strong evidence that legumes prevent or treat any disease, or have an effect on longevity.  Why all the literature review?  I’ve been deciding which healthy carbohydrates diabetics and prediabetics should add back into their diets after 8–12 weeks of the Ketogenic Mediterranean Diet.

The study at hand is fairly persuasive that whole grain consumption suppresses heart attacks and strokes and cardiovascular death.  [The paleo diet advocates and anti-gluten folks must be disappointed.]  I nominate whole grains as additional healthy carbs, perhaps the healthiest.

But . . .

. . .  for diabetics, there’s a fly in the ointment: the high carbohydrate content of grains often lead to high spikes in blood sugar.  It’s a pity, since diabetics are prone to develop cardiovascular disease and whole grains could counteract that.  We need a prospective cohort study of whole grain consumption in diabetics.  It’ll be done eventually, but I’m not holding my breath.

[Update June 12, 2010: The aforementioned study has been done in white women with type 2 diabetes.  Whole grain and bran consumption do seem to protect them against overall death and cardiovascular death.  The effect is not strong.]

What’s a guy or gal to do with this information now?

Non-diabetics:  Aim to incorporate two or three servings of whole grain daily into your diet if you want to lower your risk of heart disease and stroke. 

Diabetics:  Several options come to mind:

  1. Eat whatever you want and forget about it [not recommended].
  2. Does coronary heart disease runs in your family?  If so, try to incorporate one or two servings of whole grains daily, noting and addressing effects on your blood sugar one and two hours after consumption.  Eating whole grains alone will generally spike blood sugars higher than if you eat them with fats and protein.  Review acceptable blood sugar levels here.
  3. Regardless of family history, try to eat one or two servings of whole grains a day, noting and addressing effects on your blood sugar.  Then decide if it’s worth it.  Do you have to increase your diabetic drug dosages or add a new drug?  Are you tolerating the drugs?  Can you afford them?    
  4. Assess all your risk factors for developing heart disease: smoking, sedentary lifestyle, high blood pressure, age, high LDL cholesterol, family history, etc.  If you have multiple risk factors, see Option #3.  And modify the risk factors under your control.   
  5. Get your personal physician’s advice.    

Steve Parker, M.D.

Extra Credit:  The study authors suggest a number of reasons—and cite pertinent scientific references—how whole grains might reduce heart disease:

  • improved glucose homeostasis (protection against insulin resistance, less rise in blood sugar after ingestion [compared to refined grains], improved insulin sensitivity or beta-cell function)
  • advantageous blood lipid effects (soluble fiber from whole grains [especially oats] reduces LDL cholesterol, lower amounts of the small LDL particles thought to be particularly damaging to arteries, tendency to raise HDL cholesterol and trigylcerides [seen with insulin resistance in the metabolic syndrome])
  • improved function of the endothelial cells lining the arteries (improved vascular reactivity)

Disclaimer:  All matters regarding your health require supervision by a personal physician or other appropriate health professional familiar with your current health status.  Always consult your personal physician before making any dietary or exercise changes.

Reference: Mellen, P.B, Walsh, T.F., and Herrington, D.M.  Whole grain intake and cardiovascular disease: a meta-analysisNutrition, Metabolism and Cardiovascular Disease, 18 (2008): 283-290.

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Filed under Carbohydrate, coronary heart disease, Diabetes Complications, Grains, ketogenic diet, legumes, Mediterranean Diet, Stroke

Red Wine Improves Circulation

Red wine’s beneficial health effects may be related to improved circulation, according to a recent study by Israeli researchers.

Red wine is a time-honored component of the healthy Mediterranean diet.  Consumption is associated with longer lifespan and less cardiovascular disease such as heart attacks. 

Israeli investigators had 14 young healthy volunteers drink 250 cc of red wine daily for 21 days, while monitoring markers of circulatory function.  Endothelial progenitor cells may be particularly important in maintenance, repair, and formation of the arterial circulatory system.

Here’s their conclusion:

The results of the present study indicate that red wine exerts its effect through the up-regulation of CXCR4 expression and activation of the SDF1/CXCR4/Pi3K/Akt/eNOS signaling pathway, which results in increased [endothelial progenitor cell] migration and proliferation and decreased extent of apoptosis. Our findings suggest that these effects could be linked to the mechanism of cardiovascular protection that is associated with the regular consumption of red wine.

I’m not going to tell you I understand all that.  Don’t feel bad if you don’t, either.  My point is to illustrate one way that Science makes progress.  An observant person notices, “Hey, people who drink judicious amounts of red wine seem to live longer and have fewer heart attacks.  I wonder how that works.”  Perhaps a plausible mechanism is identified.  That might lead to isolation of a specific component in red wine that yields the benefit.  Then that component is produced and disseminated, leading to the health benefits, without the risks of alcohol consumption.

It’s an expensive, time-consuming enterprise with many blind alleys.

Steve Parker, M.D.

Reference:  Hamed, Saher, et al.  Red wine consumption improves the in vitro migration of endothelial progenitor cells in young, healthy individuals.  American Journal of Clinical Nutrition, April 14, 2010.    doi:10.3945/ajcn.2009.28408

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Filed under Alcohol, coronary heart disease, Health Benefits, Mediterranean Diet

Longevity Components of the Mediterranean Diet

According to Greek researchers, the components of the Mediterranean diet that contribute to longer lifespan are:

  • moderate alcohol consumption
  • low consumption of meat
  • high consumption of vegetables, fruits, nuts, olive oil, and legumes

The following didn’t seem to contribute much, if any:

  • cereals (the grain of a grass such as wheat, corn, oats)
  • dairy products
  • fish and seafood

Investigators at the University of Athens examined the Greek portion of the European Prospective Investigation into Cancer (EPIC) and Nutrition, which included 23,349 men and women free of diabetes, cancer, and coronary heart disease at the outset.  Food habits were documented by questionnaire. 

The focus of this particular study was death rates over an average follow-up of 8.5 years.  Adherence to the traditional Mediterranean diet ranged from minimal to high, as would be expected. 

As with numerous other studies of the Mediterranean diet, higher adherence to the Mediterranean diet was associated with lower chance of death. 

My Comments

The lack of benefit from fish is unexpected.  I have no explanation.  A preponderance of evidence elsewhere suggests fish consumption helps prolong life via lowered rates of heart disease.

Alcohol can be dangerous, of course.  Some people should not partake, ever.     

For people with diabetes who wish to avoid the carbohydrate load in cereals and dairy products, you don’t need to worry much about cutting those out of an otherwise Mediterranean-style diet.

Steve Parker, M.D. 

Reference:  Trichopoulou, Antonia, et al.  Anatomy of health effects of the Mediterranean diet: Greek EPIC prospective cohort studyBritish Medical Journal, 338 (2009): b2337.  DOI: 10.1136/bmj.b2337.

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Filed under Alcohol, Dairy Products, Fish, Fruits, Grains, Health Benefits, legumes, Mediterranean Diet, nuts, olive oil, Vegetables

MORE Health Benefits of the Mediterranean Diet

I ran across a good summary of the health benefits of Mediterranean-style eating at Medical News Today, published online May 6, 2009.  An excerpt:

The following health benefits have been observed by people who have a Mediterranean diet:

  • Longer lifespan
  • Lower risk of dying at any age
  • Lower risk of dying from heart disease
  • Lower risk of dying from cancer
  • Lower risk of developing Type 2 diabetes
  • Lower risk of hypertension (high blood pressure)
  • Lower risk of raised cholesterol levels
  • Lower risk of becoming obese
  • Lower risk of developing Alzheimer’s disease

Not mentioned above is the lower risk of Parkinson’s Disease and chronic obstructive pulmonary disease.  You’ll also find a fair description of the traditional Mediterranean diet.

Steve Parker, M.D.

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Hello, World! Announcing the Low-Carb Mediterranean Diet

It’s here.  It’s online.  It’s free.  It’s…

The Low-Carb Mediterranean Diet

Many folks—diabetic or not—following the Ketogenic Mediterranean Diet are interested in expanding their carbohydrate options and consumption.  The Low-Carb Mediterranean Diet (LCMD) does that while aiming to control both excess weight and high blood sugar levels in diabetics, prediabetics, metabolic syndrome.  

Non-diabetics on the KMD can continue with it or move on to the Low-Carb Mediterranean Diet if they wish.  If eating a “diabetic diet” seems weird, just think of the LCMD as a low-carb Mediterranean diet—the world’s first published low-carb Mediterranean Diet, by the way.  How low-carb?  The KMD supplies about 5% of energy (calories) as carbohydrate; the LCMD goes to the 10–20% range.  [By way of reference, most people eat around 55% of caloric intake as carbs.] 

I started this whole project with the goal of helping my personal patients with type 2 diabetes gain the health benefits of the traditional Mediterranean diet: longer lifespan and lower rates of heart attack, stroke, cancer, and dementia, for example.  It’s my sincere hope that it benefits others as well.

Steve Parker, M.D.  

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Alcohol Habit (Especially Wine) Started in Middle-Age Reduces Heart Attack and Stroke

Jesus turned water into wine at a wedding.  His mother asked him to do it.  Of all the miracles he performed and could have performed, I wonder why this is the first one recorded in the Holy Bible.

We have known for years that low or moderate alcohol consumption tends to lower the risk of cardiovascular disease such as heart attack and stroke, and prolongs life span.  Physicians have been hesitant to suggest that nondrinkers take up the habit.  We don’t want to be responsible for, or even accused of, turning someone into an alcoholic.  We don’t want to be held accountable for someone else’s drunken acts.  Every well-trained physician is quite aware of the ravages of alcohol use and abuse.  We see them up close and personal in our patients.

A scientific study published in 2008, however, lends support to a middle-aged individual’s decision to start consuming moderate amounts of alcohol on a regular basis.  It even provides a positive defense if a doctor recommends it to carefully selected patients.

This research, by the way, was supported by a grant from the National Heart, Lung, and Blood Institute, not the wine/alcohol industry.

Methodology

Researchers at the Medical University of South Carolina examined data on 15,637 participants in the Atherosclerosis Risk in Communities (ARIC) study over a 10-year period.  These men and women were 45 to 64 years old at the time of enrollment, living in four communities across the U.S.  Of the participants, 27% were black, 73% nonblack, 28% were smokers, and 80% of them had high blood pressure, high cholesterol, or diabetes.

Out of 15,637 participants at the time of enrollment, 7,359 indicated that they didn’t drink alcohol.  At baseline, these 7,359 had no cardiovascular disease except for some with high blood pressure.    Subsequent interviews with them found that six percent of the nondrinkers – 442 people – decided independently to become moderate alcohol drinkers.  Or at least they identified themselves as such.

“Moderate” intake was defined as 1-14 drinks per week for men, and 1-7 drinks a week for women.  Incidentally, 0.4% of the initial non-drinking cohort – 21 people – became self-identified heavy drinkers.

93.6% of the 7,359 non-drinkers said that they continued to be non-drinkers.  These 6,917 people are the “persistent nondrinkers.”

Type of alcohol consumed was also surveyed and broken down into 1) wine-only drinkers, or 2) mixed drinkers: beer, liquor, wine.

Researchers then monitored health outcomes for an average of 4 years, comparing the “new moderate drinkers” with the “persistent nondrinkers.”

Results

  •  Over 4 years, 6.9% of the new moderate drinkers suffered a cardiovascular event, defined as a heart attack, stroke, a coronary heart disease procedure (e.g, angioplasty), or death from cardiovascular disease.
  • Over 4 years, 10% of the persistent nondrinkers suffered a cardiovascular event.
  • The new moderate drinkers were 38% less likely than persistent nondrinkers to suffer a new cardiovascular event (P = 0.008, which is a very strong association).  The difference persisted even after adjustment for demographic and cardiovascular risk factors.
  • There was no difference in all-cause mortality (death rate) between the new moderate drinkers and the persistent nondrinkers.
  • New  drinkers had modest but statistically significant improvements in HDL and LDL cholesterol and mean blood pressure compared with persistent nondrinkers.
  • 133 new moderate drinkers consumed only wine
  • 234 new moderate drinkers consumed mixed types of alcohol
  • Wine-only drinkers were 68% less likely than nondrinkers to suffer a cardiovascular event.
  • “Consumers of moderate amounts of beer/liquor/mixed (which includes some wine) tended to also be less likely to have had a subsequent cardiovascular event than nondrinkers…but the difference was not significant.”

A Few Study Limitations

  • Four years is a relatively brief follow-up, especially for cancer outcomes.  Alcohol consumption is associated with certain types of cancer.
  • If moderate alcohol consumption indeed lowers death rates as suggested by several other studies, this study may not have lasted long enough to see it.
  • The alcohol data depended on self-reports.

Take-Home Points

The study authors cite four other studies that support a slight advantage to wine over other alcohol types.  It’s a mystery to me why they fail to stress the apparent superiority of wine in the current study.  Several other studies that found improved longevity or cardiovascular outcomes in low-to-moderate drinkers suggest that the type of alcohol does not matter.  Perhaps “the jury is still out.”  In the study at hand, however, it is clear that the reduced cardiovascular disease rate in new moderate drinkers is associated with wine.

In all fairness, other studies show no beneficial health or longevity benefit to alcohol consumption.  But at this point, the majority of published studies support a beneficial effect.

Wine is a component of the traditional healthy Mediterranean diet.  The Mediterranean diet is associated with prolonged life span and reduced cardiovascular disease.  This study strongly suggests that wine is one of the health-promoting components of the Mediterranean diet.

Starting a judicious wine habit in middle age is relatively safe for selected people and may, in fact, improve cardiovascular health, if not longevity.

Now the question is, red or white.  Or grape juice?

Steve Parker, M.D.

Reference:  King, Dana E., et al.  Adopting Moderate Alchohol Consumption in Middle Age: Subsequent Cardiovascular Events.  American Journal of Medicine, 121 (2008): 201-206.

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Filed under Alcohol, coronary heart disease, Mediterranean Diet, Stroke

Another Sacred Cow Slaughtered: Fruits and Vegetables DON’T Prevent Cancer

We’ve been told by the authorities repetitively that eating plenty of fruits and vegetables will lower our risk of cancer.  However, a recent study in the American Journal of Clinical Nutrition says that ain’t so.

Fire up the grill—we’re havin’ steak tonight!

Researchers looked at data from over 450,000 participants (men and women over 50) in the National Institutes of Health—AARP Diet and Health Study.  Diet data was collected by self-administered questionnaire.  State-level cancer registries identified the cancers that developed during the average follow-up of seven years.

Their conclusions and selected comments:

Intake of fruit and vegetables was generally unrelated to total cancer incidence in this cohort.

However, on the basis of animal studies, human case control and cohort studies, and randomized controlled trials, there is likely no harm associated with the consumption of fruit and vegetables and their consumption may prevent cardiovascular disease.

Indeed, analyses in this cohort and in others that have investigated dietary patterns rich in fruit and vegetables have found reduced risks of colorectal cancer [three references cited] and mortality, including death from cardiovascular disease and all cancers [one reference was cited supporting reduced deaths from CVD and all cancers—a Mediterranean diet study].

As in all good science reports, the researchers compare and contrast their findings with similar published research.  They note that theirs is one of only four large cohort studies that have examined this issue.  Two of the other three (see references below) also found no association between total cancers and fruit and vegetable consumption.  The one that did find a beneficial linkage was the smallest of the four, so not as compelling.

Before this research was published, some experts suggested that adequate fruit and vegetable intake could prevent between 5 and 12% of cancers.

Eat your fruits and vegetables because they taste good, provide myriad nutrients, and may have some other healthful properties.  But not to lower overall cancer risk.  

Steve Parker, M.D.

References:

George, Stephanie, et al.   Fruit and vegetable intake and risk of cancer: a prospective cohort studyAmerican Journal of Clinical Nutrition, 89 (2009): 347-353. 

Hung, H.C., et al.  Fruit and vegetable intake and risk of major chronic disease.  Journal of the National Cancer Institute, 96 (2004): 1,577-1,584.

Takachi, R., et al.  Fruit and vegetable intake and risk of total cancer and cardiovascular disease [in Japan].  American Journal of Epidemiology, 167 (2008): 59-70.

Benetou, V., et al.  Vegetables and fruit in relation to cancer risk: evidence from the Greek EPIC Cohort Study.  Cancer Epidemiology, Biomarkers, and Prevention, 17 (2008): 387-392.

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Filed under cancer, Fruits, Mediterranean Diet, Vegetables

Red Wine With Meaty Meals Possibly Healthier Than Wine and Meat Alone

Meaty meal in the making
Meaty meal in the making

 Wine is a time-honored component of the healthy Mediterranean diet and, traditionally, is consumed with meals.

For science and food geeks, Bix at the Fanatic Cook blog has a post outlining how red wine consumption with meals might be healthy: it reduces blood levels of cytotoxic lipid peroxidation products like malondialdehyde.

By no means is Fanatic Cook always this esoteric.  Check out some of the other topics there.

Steve Parker, M.D.

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Does Diet Influence Risk of Stroke?

Harvard researchers suggest that our food consumption does indeed influence our risk of suffering a stroke.  This matters since stroke is the third leading cause of death in the U.S.

Scientists looked carefully at 121 different studies—published between 1979 and 2004—on the relationship between dietary factors and stroke.  High blood pressure is a major modifiable risk factor for stroke, so it also was considered.  Dietary factors included fats, minerals, animal protein, cholesterol, fish, whole grains, fiber, carbohydrate quality, fruits and vegetables, antioxidants, B vitamins, and dietary patterns.

I quote their conclusions:

Diets low in sodium and high in potassium lower blood pressure which will likely reduce stroke risk.

Consumption of fruits and vegetables, whole grains, folate, and fatty fish are each likely to reduce stroke risk.

A prudent or traditional Mediterranean dietary pattern, which incorporates these individual dietary components as well as intake of legumes and olive oil, may also prevent stroke.

Evidence is limited or inconsistent regarding optimal levels of dietary magnesium, calcium, antioxidants, total fat, other fat subtypes, cholesterol, carbohydrate quality, or animal protein for stroke prevention.

A diet low in sodium, high in potassium, and rich in fruits, vegetables, whole grains, cereal fiber, and fatty fish will likely reduce the incidence of stroke.

Take Home Points

The article abstract does not address the optimal intake amount of these various foods, vitamins, and minerals.  That’s probably not known with any certainty.

The traditional Mediterranean diet incorporates many of these stroke-preventing foods.  The Advanced Mediterranean Diet helps people lose weight while teaching how to eat Mediterranean-style.

The very low-carb Ketogenic Mediterranean Diet includes these stroke-preventing foods and minerals, except for whole grains and a tendency to be low in potassium.  The KMD is high in total fat and animal protien, and potentially high in cholesterol; this study indicates those issues are nothing to worry about in terms of future strokes.

I’ll use articles such as this to recommend long-term food consumption for followers of any future Diabetic Mediterranean Diet.

Steve Parker, M.D.

Reference:  Ding, E.L, and Mozaffarian, D.  Optimal dietary habits for the prevention of stroke. Seminars in Neurology, 26 (2006): 11-23.

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Filed under Fish, Fruits, Grains, Health Benefits, legumes, Mediterranean Diet, olive oil, Stroke, Vegetables

What Are Phytonutrients and What Have They Done For Me Lately?

Nutrition scientists think that plants have small amounts of numerous “bioactive compounds,” sometimes referred to as phytonutrients, that protect us against disease.

Many scientific studies have looked at groups of people over time, noting the various foods they eat as well as the diseases they develop.  These are called epidemiologic, ecological, or observational studies.  One finding is that lower rates of heart disease, vascular disease, and cancer are seen in people consuming plant-based diets.  “Plant-based” isn’t necessarily vegetarian or vegan.  The traditional Mediterranean diet, for example, is considered by many to be plant-based because meat, fish, and poultry are not prominent compared to plants. 

In contemplating what source of carbohydrates a person with diabetes should eat, I’ve been reviewing the scientific literature to see which sources of carbs might provide the biggest bang for the buck in terms of health and longevity benefits.

Here are some quotes from a 2002 review article in the American Journal of Medicine:

Phenolic compounds, including their subcategory, flavonoids, are present in all plants and have been studied extensively in cereals, legumes, nuts, olive oil, vegetables, fruits, tea, and red wine. Many phenolic compounds have antioxidant properties, and some studies have demonstrated favorable effects on [blood clotting] and [growth of tumors]. Although some epidemiologic studies have reported protective associations between flavonoids or other phenolics and cardiovascular disease and cancer, other studies have not found these associations.

Hydroxytyrosol, one of many phenolics in olives and olive oil, is a potent antioxidant.

Resveratrol, found in nuts and red wine, has antioxidant, [anti-blood-clotting], and anti-inflammatory properties, and inhibits [malignant tumor onset and growth].

Lycopene, a potent antioxidant carotenoid in tomatoes and other fruits, is thought to protect against prostate and other cancers, and inhibits tumor cell growth in animals.

Organosulfur compounds in garlic and onions, isothiocyanates in cruciferous vegetables, and monoterpenes in citrus fruits, cherries, and herbs have [anti-cancer] actions in experimental models, as well as [heart-healthy effects].

In summary, numerous bioactive compounds appear to have beneficial health effects. Much scientific research needs to be conducted before we can begin to make science-based dietary recommendations. Despite this, there is sufficient evidence to recommend consuming food sources rich in bioactive compounds. From a practical perspective, this translates to recommending a diet rich in a variety of fruits, vegetables, whole grains, legumes, oils, and nuts.

The article discusses phytoestrogens—plant chemicals that act in us like the female hormone estrogen—but effects are complex and I suspect we know much more now than we did in 2002 .  Soy products are the most well-known source of phytoestrogens.

The traditional Mediterranean diet is rich in all of the foods mentioned above, except for tea.  Even the Ketogenic Mediterranean Diet includes the aforementioned foods except for tea (I need to add tea and coffee), cereals, and cherries.

Steve Parker, M.D.

Reference:  Kris-Etherton, P.M., et al.  Bioactive compounds in foods: their role in the prevention of cardiovascular disease and cancer.  American Journal of Medicine, 113 (2002. Supplement 9B): 71S-88S.

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Filed under cancer, coronary heart disease, Fruits, Grains, Health Benefits, legumes, Mediterranean Diet, nuts, olive oil