Tag Archives: heart disease

December 26, 2011 · 8:15 AM

Got Spare Time?: Track Your Omega-3 and Omega-6 Fatty Acid Consumption

One of the major changes in the Western diet over the last century has been the increase in our consumption of omega-6 fatty acids, primarily in the form of industrial seed oils.  Examples include oils derived from soybeens, corn, and rapeseed (canola oil).  Omega-6 fatty acid consumption in the U.S. increased by 213% since 2009.  This may have important implications for development of certain chronic diseases like cancer and heart disease.  Excessive omega-6 consumption may be harmful.  On the other hand, omega-3 fatty acid consumption may prevent or mitigate the damages.  Hence, the omega-6/omega-3 ratio becomes important.

This’ll improve your omega-6/omega-3 ratio!

I haven’t studied this issue in great detail but hope to do so at some point.  Evelyn Tribole has strong opinions on it; I may get one of her books.

I saw an online video of William E.M.Lands, Ph.D., discussing the omega-6/omega-3 ratio.  He mentioned free software available from the National Insitutes of Health that would help you monitor and adjust your ratio.

You can see the video here.  Dr. Lands’ talk starts around minute 12 and lasts about 45 minutes.  He says it’s just as important (if not more so) to reduce your omega-6 consumption as to increase your omega-3.  And don’t overeat.

Steve Parker, M.D.

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September 24, 2011 · 2:00 AM

Is Grape Seed Extract as Healthful as Wine?

Patients ask me periodically if grape seed extract provides the same health benefit as judicious red wine.  Nobody knows with certainty.  The health benefits of red wine may be due to resveratrol.  Grape seed extract contains potentially healthy antioxidants called proanthocyanidins,

Many people don’t enjoy wine or other alcohol-containing drinks, and others just shouldn’t drink any alcohol.  Should they take a grape seed extract supplement or drink grape juice as a subsitute?  Again, it’s still unclear.  In 2009 I wrote a about a review article looking at the effect of various non-wine grape products and effects on heart disease risk.

A recent meta-analysis out of the University of Connecticut found improvement in two heart disease risk factors in those who take a grape seed extract supplement:

  • systolic blood pressure lower by 1.54 mmHg
  • heart rate lower by 1.42 beats per minute

No effect was seen on lipids (cholesterol and triglycerides), diastolic blood pressure, and C-reactive protein (a test of systemic inflammation).

Granted, these are tiny effects.  It’s unknown whether they, or other unknown effects of grape seed extract, would translate into clinical benefits such as fewer heart attacks and strokes, and longer lifespans.

Bottom Line

Grape seed extract and other non-wine grape products may be as beneficial as red wine in prolonging lifespan and preventing heart disease.  But we have much stronger evidence in favor of red wine and other alcohol-containing drinks.

Steve Parker, M.D.

 Reference:  Feringa, H.H.H, et al. The Effect of Grape Seed Extract on Cardiovascular Risk Markers: A Meta-Analysis of Randomized Controlled Trials.  Journal of the American Dietetic Association, 111 (2011): 1,173-1,181.

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September 2, 2011 · 5:56 AM

WHY Is the Mediterranean Diet So Healthy?

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, mostly 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 (includ-ing flavonoids, resveratrol, phytoestrogens, anthocyanins, 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.

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July 24, 2011 · 2:00 AM

Research Round-Up

 

I have a stack of scientific articles I’ve been meaning to review in depth and blog about.  But I have to finally admit I don’t have the time.  Here they are.  Click through for details.

  1. Long-term calorie restriction in humans appears highly effective in reducing atherosclerosis risk factors (lab tests) and actual carotid artery atherosclerosis. Only 18 study subjects, however.
  2. A very-low-carbohydrate diet improved memory in older adults with mild cognitive impairment over six weeks.  Twenty-three subjects were randomized to either high-carb or very-low-carbohydrate diet.  The low-carbers improved verbal memory performance, lost weight, reduced fasting blood sugar and fasting insulin levels.  Ketone levels were positively correlated with memory performance.
  3. A high-fat diet impairs cognitive function and heart energy metabolism in young men.  Sixteen test subjects.  Crossover study design with a five-day high-fat diet deriving 75% of energy from fat, compared to a low-fat diet deriving 23% of energy from fat.  High-fat diet led to impaired attention, speed, and mood.  I’m sure low-carb bloggers have been all over this.  At first blush, it appears they were testing during “induction flu” phase of very-low-carb eating, between days 2 to 7 of a new ketogenic diet.  It takes several weeks to adapt metabolism to running almost entirely on fat rather than standard carbohydrates.  Suspect results would have been different if given time to adapt.
  4. Weight-loss with the laparoscopic gastric banding procedure has poor long-term outcome, according to Belgian surgeons reporting on 82 patients.  Four in 10 patients had major complications.  Nearly half of the 82 patients needed to have the bands removed, and six of every 10 required some kind of re-operation.
  5. Trust me, you DON’T want age-related macular degeneration.  Women, reduce your risk of ARMD with a healthy lifestyle, including regular exercise, avoidance of smoking,  and by eating abundant plant foods (vegetables [including orange and dark leafy green ones], fruits, and whole grains) and limit foods high in fat, refined starches, sugar, alcohol, and oils.  At least according to these researchers. 
  6. Leafy green vegetables and olive oil are linked to reduced heart disease (CHD) in Italian women.  Fruit consumption had no effect.  This is from a subset of the huge EPIC study, following 30,000 women over almost eight years.
  7. The Mediterranean diet protects against metabolic syndrome, reducing risk by about a third according to a huge meta-analysis from Greek and Italian investigators.  It works best in Mediterranean countries. 
  8. The Mediterranean diet was linked to slower rates of cognitive decline in Chicago residents over the course of almost eight years.  The comparison diet was the Healthy Eating Index-2005.  Of the 3,800 participants, about two-thirds were black.  A Manhattan population showed lower risk of dementia when eating Mediterranean-style.

There ya’ go.  This is better than letting the articles just sit in my briefcase for months on end, eventually to be thrown out.

Steve Parker, M.D.

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July 18, 2011 · 2:17 AM

Waist-Hip Ratio: How to Determine, and What It Means

High WHR

A comment left under my recent post on healthy weight ranges reminded me about the waist-hip ratio.

The risk of heart and vascular disease is more closely linked to distribution of excess fat than with degree of obesity as measured by overall weight or body mass index. Waist-hip ratio (WHR) is a measure of abdominal or central obesity, the type of fat distribution associated with coronary artery disease. A high ratio indicates the android body habitus.  The Journal of the American College of Cardiology two months ago reported that heart patients (coronary artery disease) with “central obesity” had a greater risk of death.  A high WHR is one measure of central obesity.

To determine your waist-hip ratio:

1.   While standing, relax your stomach—don’t
      pull it in. Measure around your waist mid-
      way between the bottom of the rib cage and
      the top of your pelvis bone. Usually this is at
      the level of your belly button, or an inch
      higher. Don’t go above the rib cage. Keep the
      measuring tape horizontal to the ground and
      don’t compress your skin.
2.   Then measure around your hips at the
      widest part of your buttocks. Keep the tape
      horizontal to the ground and don’t compress
      your skin.
3.   Divide the waist by the hip measurement.
      The result is your waist-hip ratio.

For example, if your waist is 44 inches (112 cm) and hips are 48 inches (122 cm): 44 divided by 48 is 0.92, which is your waist-hip ratio.

Scientists haven’t yet determined the ideal WHR, but it is probably around 0.85 or less for women, and 0.95 or less for men. Ratios above 1.0 are clearly associated with risk of cardiovascular disease such as heart attacks. The higher the ratio, the higher the risk. Compared with body mass index, WHR is a much stronger predictor of coronary artery disease. Several of the other obesity-related illnesses are also correlated with WHR, but the relationship between WHR and cardiovascular disease is particularly strong.

Steve Parker, M.D.

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June 24, 2011 · 2:00 AM

Finally Settled: Alcohol Consumption Linked to Lower Rates of Death and Heart Attack

Canadian and U.S. researchers report that moderate alcohol consumption seems to reduce 1) the incidence of coronary heart disease, 2) deaths from coronary heart disease, and 3) deaths from all causes.  Reduction of death from all causes is a good counter-argument to those who say alcohol is too dangerous because of deaths from drunk driving, alcoholic cirrhosis, and alcohol-related cancers such as many in the esophagus. 

Remember, we’re talking here about low to moderate consumption: one drink a day or less for women, two drinks or less a day for men.  That’s a max of 12.5 grams of alcohol for women, 25 g for men.  No doubt, alcohol can be extremely dangerous, even lethal.  I deal with that in my patients almost every day.  Some people should never drink alcohol.

The recent meta-analysis in the British Medical Journal, which the authors say is the most comprehensive ever done, reviewed all pertinent studies done between 1950 and 2009, finally including 84 of the best studies on this issue.  Thirty-one of these looked at deaths from all causes.

Compared with non-drinkers, drinkers had a 25% lower risk of developing coronary heart disease (CHD) and death from CHD.  CHD is the leading cause of death in develop societies.

Stroke is also considered a cardiovascular disease.  Overall, alcohol is not linked to stroke incidence or death from stroke.  The researchers did see strong trends toward fewer ischemic strokes  and more hemorrhagic strokes (bleeding in the brain) in the drinkers.  So the net effect was zero. 

Compared with non-drinkers, the lowest risk of death from any cause was seen in those consuming 2.5 to 14.9 g per day (one drink or less per day), whose risk was 17% lower.  On the other hand, heavy drinkers (>60 g/day) had 30% higher risk of death. 

In case you’re wondering, the authors didn’t try to compare the effects of beer versus wine versus distilled spirits. 

On a related note, scientists at the Medical University of South Carolina found that middle-aged people who took up the alcohol habit had a lower risk of stroke and heart attack.  Wine seemed to be more effective than other alcohol types.  They found no differences in overall death rates between new drinkers persistent non-drinkers, perhaps because the study lasted only four years and they were following only 442 new drinkers.  

This doesn’t prove that judicious alcohol consumption prevents heart attacks, cardiac deaths, and overall deaths.  But it’s kinda lookin’ that way.

Steve Parker, M.D.

 References:  Ronksley, Paul, et al.  Association of alcohol consumption with selected cardiovascular disease outcomes: a systematic review and meta-analysis.  British Medical Journal, 2011;342:d671    doi: 10.1136/bmj.d671

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May 16, 2011 · 2:00 AM

Heart Patients: Mediterranean Diet to the Rescue!

The Mediterranean diet preserves heart muscle performance and reduces future heart disease events, according to Greek researchers reporting in the American Journal of Clinical Nutrition, May 19, 2010.

Reuters and other news services have covered the story.

The Mediterranean diet is well-established as an eating pattern that reduces the risk of death or illness related to cardiovascular disease—mostly heart attacks and strokes. Most of the studies in support of the heart-healthy diet looked at development of disease in general populations. The study at hand examined whether the diet had any effect on patients with known heart disease, which has not been studied much.

How Was the Study Done?

The study population was 1,000 consecutive patients admitted with heart disease to a Greek hospital between 2006 and 2009. In this context, heart disease refers to a first or recurrent heart attack (70-80% of participants) or unstable angina pectoris. Acute heart attacks and unstable angina are “acute coronary syndromes.” Average age was 64. Sixty percent had a prior diagnosis of cardiovascular disease (coronary heart disease or stroke). Thirty percent had diabetes. At the time of hospitalization, half had diminished function of the main heart pumping chamber (the left ventricle), half had normal pump function. Men totalled 788; women 212.

On the third hospital day, participants were given a 75-item food frequency questionnaire asking about consumption over the prior year. If a potential enrollee died in the first two hospital days, he was not included in the study. A Mediterranean diet score was calculated to determine adherence to the Mediterranean diet. Mediterranean diet items were nonrefined cereals and products, fruits, nuts, vegetables, potatoes, dairy products, fish and seafood, poultry, red meats and meat products, olive oil, and alcohol.

Left ventricle function was determined by echocardiogram (ultrasound) at the time of study entry, at the time of hospital discharge, and three months after discharge. Systolic dysfunction was defined as an ejection fraction of under 40%. [Normal is 65%: when the left ventricle is full of blood, and then squeezes on that blood to pump it into the aorta, 65% of the blood squirts out.]

Participants were then divided into two groups: preserved (normal) systolic left ventricular function, or diminished left ventricular function.

They were followed over the next two years, with attention to cardiovascular disease events (not clearly defined in the article, but I assume including heart attacks, strokes, unstable angina, coronary revascularization, heart failure, arrhythmia, and death from heart disease or stroke.

Results

  • Four percent of participants died during the initial hospitalization.
  • At the three month follow-up visit, those with greater adherence to the Mediterranean diet (a high Mediterranean diet score) had higher left ventricular performance (P=0.02).
  • At the time of hospital admission, higher ejection fractions were associated with greater adherence to the Mediterranean diet (P<0.001).
  • Those who developed diminished left ventricular dysfunction had a lower Mediterranean diet score (P<0.001)
  • During the hospital stay, those in the highest third of Mediterranean diet score had lower in-hospital deaths (compared with the lower third scores) (P=0.009).
  • Among those who survived the initial hospitalization, there was no differences in fatal cardiovascular outcomes based on Mediterranean diet score.
  • Food-specific analysis tended to favor better cardiovascular health (at two-year follow-up) for those with higher “vegetable and salad” and nut consumption. No significant effect was found for other components of the Mediterranean diet score.
  • Of those in the highest third of Mediterranean adherence, 75% had avoided additional fatal and nonfatal cardiovasclar disease events as measured at two years. Of those in the lowest third of Mediterranean diet score, only 53% avoided additional cardiovascular disease events.

The Authors’ Conclusion

Greater adherence to the Mediterranean diet seems to preserve left ventricular systolic function and is associated with better long-term prognosis of patients who have had an acute coronary syndrome.

My Comments

I agree with the authors’ conclusion.

We’re assuming these patients didn’t change their way of eating after the initial hospitalization. We don’t know that. No information is given regarding dietary instruction of these patients while they were hospitalized. In the U.S., such instruction is usually given, and it varies quite a bit.

In this study, lower risk of cardiovascular death was linked to the Mediterranean diet only during the initial hospital stay. Most experts on the Mediterranean diet would have predicted lower cardiovascular death rates over the subsequent two years. Mysteriously, the authors don’t bother to discuss this finding.

For those who don’t enjoy red wine or other alcoholic beverages, this study suggests that the Mediterranean diet may be just as heart-healthy without alcohol. A 2009 study by Trichopoulou et al suggests otherwise.

Steve Parker, M.D.

Reference:  Chrysohoou, C., et al. The Mediterranean diet contributes to the preservation of left ventricular systolic function and to the long-term favorable prognosis of patients who have had an acute coronary event.  American Journal of Clinical Nutrition 2010.  DOI: 10.3945/ajcn.2009.28982

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April 1, 2011 · 2:00 AM

Origins and Definition of the Mediterranean Diet

ORIGINS

It all starts with Ancel  Keys.

Keys was the leader of the team who put together the Seven Countries Study, which seemed to demonstrate lower rates of coronary heart disease in countries consuming less saturated fat.  [Coronary heart disease is the leading cause of death in Western cultures.]  He also found that cardiovascular disease rates rose in tandem with blood cholesterol  levels.  The two countries particularly illustrative of these connections were Italy and Greece, both Mediterranean countries.

The other countries he analyzed in Seven Countries were the United States, Yugoslavia, Japan, Finland, and the Netherlands.

Keys and his wife Margaret, a biochemist, drilled deeper in to the “Mediterranean diet” that was characteristic of Italy, Greece, and other countries on or near the Mediterranean Sea in the 1950s and 1960s.  [“Diet” in this context refers to the usual  food and drink of a person, not a weight-loss program.]  Their efforts culminated in the publication of several best-selling Mediterranean diet books in the 1970s, and Keys’ photo on the cover of Time magazine in 1961.

Thus began the still-popular healthy Mediterranean diet.

Oldways Preservation Trust re-invigorated the Mediterranean diet around 1990, helping the public incorporate Mediterranean diet principals into everyday life.  Oldways founder, K. Dun Gifford, passed away within the last year.

DEFINITION

There is no monolithic, immutable, traditional Mediterranean diet.  But there are similarities among many of the regional countries that tend to unite them, gastronomically speaking.  Greece and southern Italy are particularly influential in this context.

So here are the characteristics of the traditional Mediterranean diet  of the mid-20th century:

•It maximizes natural whole foods and minimizes highly processed ones

•Small amounts of red meat

•Less than four eggs per week

•Low to moderate amounts of poultry and fish

•Daily fresh fruit

•Seasonal locally grown foods with minimal processing

•Concentrated sugars only a few times per week

•Wine in low to moderate amounts, and usually taken at mealtimes

•Milk products (mainly cheese and yogurt) in low to moderate amounts

•Olive oil as the predominant fat

•Abundance of foods from plants: vegetables, fruits, beans, potatoes, nuts, seeds, breads and other whole grain products

•Naturally low in saturated fat, trans fats, and cholesterol

•Naturally high in fiber, phytonutrients, vitamins (e.g., folate), antioxidants, and minerals (especially when compared with concentrated, refined starches and sugars in a modern Western diet)

•Naturally high in monounsaturated and polyunsaturated fats, particularly as a replacement for saturated fats

CONTROVERSIES

Keys has been criticized for “cherry-picking” the data that linked saturated fat consumption with increased heart disease.  In other words, the allegation is that he used information if it supported his theory, while ignoring data that was contrary or neutral.  Subsequent studies indicate a weak link, if any, between saturated fat consumption and heart disease.  A list of the pertinent studies de-linking heart disease and saturated fat is at my Advanced Mediterranean Diet Blog.

The Seven Countries Study included only men.  It’s practical implications, therefore, may not apply to women.

The traditional Mediterranean diet is increasingly a thing of the past as Mediterranean countries adopt the Western diet characterized by “fast food” and highly processed foods.

FUN FACTS FOR FOOD GEEKS

Ever heard of K rations used by the U.S. military in World War II?  Keys invented them.  He earned Ph.D.s in biology and physiology.  Keys lived to age 100 and was said to be intellectually active through his 97th year.

Steve Parker, M.D.

PS:  The Mediterranean diet has too many carbohydrates (55% of total energy) for for most people with diabetes.  Hence, the Low-Carb Mediterranean Diet.

References:

Keys, Ancel.  Coronary heart disease in seven countries.  Circulation, 41, (1970) supplement I: I-1 through I-211.

Keys, Ancel.  Seven Countries:  A Multivariate Analysis of Death and Coronary Artery Disease.  Harvard University Press, 1980.

Oldways website.

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March 13, 2011 · 7:46 AM

Pilot Study: Paleo Diet Is More Satiating Than Mediterranean-Style

Swedish researchers reported recently that a Paleolithic diet was more satiating than a Mediterranean-style diet, when compared on a calorie-for-calorie basis in heart patients.  Both groups of study subjects reported equal degrees of satiety, but the paleo dieters ended up eating 24% fewer calories over the 12-week study.

The main differences in the diets were that the paleo dieters had much lower consumption of cereals (grains) and dairy products, and more fruit and nuts.  The paleos derived 40% of total calories from carbohydrate compared to 52% among the Mediterraneans.

Even though it wasn’t a weight-loss study, both groups lost weight.  The paleo dieters lost a bit more than the Mediterraneans: 5 kg vs 3.8 kg (11 lb vs 8.4 lb).  That’s fantastic weight loss for people not even trying.  Average starting weight of these 29 ischemic heart patients was 93 kg (205 lb).  Each intervention group had only 13 or 14 patients (I’ll let you figure out what happened to to the other two patients).

I blogged about this study population before.  Participants supposedly had diabetes or prediabetes, although certainly very mild cases (average hemoglobin A1c of 4.7% and none were taking diabetic drugs)

As I slogged through the research report, I had to keep reminding myself that this is a very small, pilot study.  So I’ll not bore you with all the details.

Bottom Line

This study suggests that the paleo diet may be particularly helpful for weight loss in heart patients.  No one knows how results would compare a year or two after starting the diet.  The typical weight-loss pattern is to start gaining the weight back at six months, with return to baseline at one or two years out.

Greek investigators found a link between the Mediterranean diet and better clinical outcomes in known ischemic heart disease patients.  On the other hand, researchers at the Heart Institute of Spokane found the Mediterranean diet equivalent to a low-fat diet in heart patients, again in terms of clinical outcomes.  U.S. investigators in 2007 found a positive link between the Mediterranean diet and lower rates of death from cardiovascular disease and cancer. 

We don’t yet have these kinds of studies looking at the potential benefits of the paleo diet.  I’m talking about hard clinical endpoints such as heart attacks, heart failure, cardiac deaths, and overall deaths.  The paleo diet definitely shows some promise.

I also note the Swedish investigators didn’t point out that weight loss in overweight heart patients may be detrimental.  This is the “obesity paradox,” called “reverse epidemiology” at Wikipedia.  That’s a whole ‘nother can o’ worms.

Keep your eye on the paleo diet.

Steve Parker, M.D.

Reference: Jonsson, Tommy, et al.  A paleolithic diet is more satiating per calorie than a mediterranean-like diet in individuals with ischemic heart disease.  Nutrition and Metabolism, 2010, 7:85.

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December 14, 2010 · 11:07 AM

Book Review: Why We Get Fat

Gary Taubes’s new book, Why We Get Fat: And What To Do About It, comes on the market later this month.  I give it five stars per Amazon.com’s ranking system (I love it).

♦   ♦   ♦

At the start of my medical career over two decades ago, many of my overweight patients were convinced they had a hormone problem causing it.  I carefully explained that’s rarely the case.  As it turns out, I may have been wrong.  And the hormone is insulin.

Mr. Taubes wrote this long-awaited book for two reasons: 1) to make the ideas in his 2007 masterpiece (Good Calories, Bad Calories) more accessible to the public, and 2) to speed up the process of changing conventional wisdom on overweight.  GCBC was the equivalent of a college-level course on nutrition, genetics, history, politics, science, physiology, and biochemistry. Many nutrition science geeks loved it while recognizing it was too difficult for the average person to digest.

Paradigm Shift

The author hopes to convince us that “We don’t get fat because we overeat; we overeat because we’re getting fat.”  We need to think of obesity as a disorder of excess fat accumulation, then ask why the fat tissue isn’t regulated properly.  A limited number of hormones and enzymes regulate fat storage; what’s the problem with them?

Mr. Taubes makes a great effort convince you the old “energy balance equation” doesn’t apply to fat storage.  You remember the equation: eat too many calories and you get fat, or fail to burn up enough calories with metabolism and exercise, and you get fat.  To lose fat, eat less and exercise more.  He prefers to call it the “calories-in/calories-out” theory.  He admits it has at least a little validity.  Problem is, the theory seems to have an awfully high failure rate when applied to weight management over the long run.  We’ve operated under that theory for the last half century, but keep getting fatter and fatter.  So the theory must be wrong on the face of it, right?  Is there a better one?

So, Why DO We Get Fat?

Here is Taubes’s explanation.  The hormone in charge of fat strorage is insulin; it works to make us fatter, building fat tissue.  If you’ve got too much fat, you must have too much insulin action.  And what drives insulin secretion from your pancreas?  Dietary carbohydrates, especially refined carbs such as sugars, flour, cereal grains, starchy vegetables (e.g., corn, beans, rice, potatoes), liquid carbs.  These are the “fattening carbs.”  Dozens of enzymes and hormones are at play either depositing fat into tissue, or mobilizing the fat to be used as energy.  It’s an active process going on continously.  Any regulatory derangement that favors fat accumulation will CAUSE gluttony (overeating) or sloth (inactivity).  So it’s not your fault. 

What To Do About It

Cut back on carb consumption to lower your fat-producing insulin levels, and you turn fat accumulation into fat mobilization.

Before you write off Taubes as a fly-by-night crackpot, be aware that he’s received three Science-in-Society Journalism Awards from the National Association of Science Writers.  He’s a respected, professional science writer.  Having read two of his books, it’s clear to me he’s very intelligent.  If he’s got a hidden agenda, it’s well hidden.

One example  illustrates how hormones control growth of tissues, including fat tissue.  Consider the transformation of a skinny 11-year-old girl into a voluptuous woman of 18. Various hormones make her grow and accumulate fat in the places we now see curves.  The hormones make her eat more, and they control the final product.  The girl has no choice.  Same with our adult fat tissue, but with different hormones. If some derangement is making us grow fatter, it’s going to make us more sedentary (so more energy can be diverted to fat tissue) or make us overeat, or both.  We can’t fight it.  At not least very well, as you can readily appreciate if look at the people around you at any American shopping mall.

This’N’That

Taubes’s writing is clear and persuasive.  He doesn’t beat you over the head with his conclusions. He lays out a logical series of facts and potential connections and explanations, helping you eventually see things his way.  If insulin controls fat storage by building and maintaining fat tissue, and if carboydrates drive insulin secretion, then the way to reduce overweight and obesity is carbohydrate-restricted eating, especially avoiding the fattening carbohydrates.  I’m sure that’s true for many folks, perhaps even a majority.

If you’re overweight and skeptical about this approach, you could try out a very-low-carb diet for a couple weeks or a month at little expense and risk (but not zero risk).  If Mr. Taubes and I are right, there’s a good chance you’ll lose weight.  At the back of the book is a university-affiliated low-carb eating plan.

If cutting carb consumption is so critical for long-term weight control, why is it that so many different diets—with no focus on carb restriction—seem to work, if only for the short run?  Taubes suggests it’s because nearly all diets reduce carb consumption to some degree, including the fattening carbs.  If you reduce your total daily calories by 500, for example, many of those calories will be from carbs.  Simply deciding to “eat healthy” works for some people: stopping soda pop, candy bars, cookies, desserts, beer, etc.  That cuts a lot of fattening carbs right there.

Losing excess weight or controlling weight by avoiding carbohydrates was the conventional wisdom prior to 1960, as documented by Mr. Taubes.  Low-carb diets for obesity date back almost 200 years.  The author attributes many of his ideas to German internist Gustav von Bergmann (1908).   

Taubes discusses the Paleolithic diet, mentioning that the average paleo diet derived about a third of total calories from carbohdyrates (compared to the standard American diet’s 55% of calories from carb).  My prior literature review  found 40-45% of paleo diet calories from carbohydrate.  I’m not sure who’s right.

Minor Bone of Contention RE: Coronary Heart Disease

Mr. Taubes provides numerous scientific references to back his assertions.  I checked out one in particular because it didn’t sound right.  Some background first. 

Reducing our total fat and saturated fat consumption over the last 40 years was supposed to lower our LDL cholesterol, thereby reducing the burden of coronary heart disease, which causes heart attacks.  Instead, we’ve experienced the obesity epidemic as those fats were replaced by carbohydrates.  Taubes mentions a 2009 medical journal article by Kuklina et al, in which Taubes says Kuklina points out the number of heart attacks has not decreased as we’ve made these diet changes.  Kuklina et al don’t say that.  In fact, age-standardized heart attack rates have decreased in the U.S. during the last decade. 

Furthermore, autopsy data document a reduced prevalence of anatomic coronary heart disease in people aged 20-59 from 1979 to 1994, but no change in prevalence for those over 60. The incidence of coronary heart disease decreased in the U.S. from 1971 to 1998 (the latest reliable data).  Death rates from heart disease and stroke have been decreasing steadily over the last 40 years in the U.S.; coronary heart disease death rates are down by 50%.  I do agree with Taubes that we shouldn’t credit those improvements to reduced total and saturated fat consumption.  [Reduced trans fat consumption may play a role, but that’s off-topic.] 

I think Mr. Taubes would like to believe that coronary artery disease is either more severe or unchanged in the last few decades because of low-fat, high-carb eating.  That would fit nicely with some of his theories, but it’s not the case.  Coronary artery disease is better now thanks to a variety of factors, but probably not diet (setting aside the trans-fat issue).

Going Forward

Low-carb dieting was vilified over the last half century partly out of concern that the accompanying high fat consumption would cause premature heart attacks, strokes, and death.  We know now that total dietary fat and saturated fat have little to do with coronary heart disease and atherosclerosis (hardening of the arteries), which sets the stage for a resurgence of low-carb eating.  

I advocate Mediterranean-style eating as the healthiest, in general.  It’s linked with prolonged life and lower risk of heart disease, stroke, dementia, diabetes, and cancer.  On the other hand, obesity is a strong risk factor for premature death and development of heart disease, stroke, diabetes, and cancer.  If consistent low-carb eating cures the obesity, is it healthier than the Mediterranean diet?  Maybe so.  Would a combination of low-carb and Mediterranean be better?  Maybe so.  I’m certain Mr. Taubes would welcome a decades-long interventional study comparing low-carb with the Mediterranean diet.  But that’s probably not going to happen in our lifetimes. 

Gary Taubes rejects the calories-in/calories-out theory of overweight that hasn’t done a very good job for us over the last 40 years.  Taubes’s alternative ideas deserve serious consideration.

Steve Parker, M.D.

Update December 18, 2010: I found Mr. Taubes’s reference for stating that Paleolithic diets provide about a third of calories from carbohydrate (22-40%), based on modern hunter-gatherer societies).  See References below.   

References:
Coronary heart disease autopsy data:  American Journal of Medicine, 110 (2001): 267-273.
Reduced heart attacks:  Circulation, 12 (2010): 1,322-1,328.
Reduced incidence of coronary heart disease:  www.UpToDate.com, topic: “Epidemiology of Coronary Heart Disease,” accessed December 11, 2010.
Death rates for coronary heart disease:  Journal of the American Medical Association, 294 (2005): 1,255-1,259.

Cordain, L., et al.  Plant-animal subsistance ratios and macronutrient energy estimations in worldwide hunter-gatherer diets.  American Journal of Clinical Nutrition, 71 (2000): 682-692.

Disclosure:  I don’t know Gary Taubes.  I requested from the publisher and received a free advance review copy of the book.  Otherwise I received nothing of value for this review.

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.

Update April 22, 2013: 

As mentioned above, WWGF was based on Taubes’ 2007 book, Good Calories, Bad Calories. You may be interested in a highly critical review of GCBC by Seth at The Science of Nutrition.

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