Eye-Popping Statistics

Posted on July 8, 2012 | Comments Off on Eye-Popping Statistics

I often talk to people interested in improving their health or losing weight via lifestyle modification, mostly changes in diet and exercise.  Many of them are motivated by health-related facts.  Here is a smattering of facts I compiled in 2008 (so some are outdated), starting out worrisome and ending hopeful: 

  • 65% of U.S. adults are overweight or obese.  Half are overweight, half are obese. 

  • 12% of deaths in the U.S. are due to lack of regular physical activity – 250,000 deaths yearly.

  • 11% of U.S. adults have diabetes mellitus.

  • 24 million in the U.S. have diabetes.  Another 57 million have pre-diabetes, a condition that increases your risk for diabetes.

  • 23% of U.S. adults over 60 have diabetes. 

  • 85% of people with type 2 diabetes are overweight.

  • 200,000 yearly deaths in the U.S. are due to obesity.

  • Excess body fat causes 14 to 20% of all cancer-related deaths in the U.S.

  • 550,000 people die yearly of cancer in the U.S. 

  • Obesity-related cancers in men: prostate and colorectal.  Obesity-related cancers in women: endometrial (uterine), cervix, ovary, breast.  Both sexes: kidney, esophageal adenocarcinoma.

  • 20% of us in the U.S. will die of cancer.

  • Lifetime risk of developing invasive cancer in the U.S. is four in 10 (a little higher in men, a little lower in women).

  • At least one-half of high blood pressure cases are caused by excess body fat.  Every 20 pounds of excess fat increases blood pressure by two to three points.

  • Peak aerobic power (a measure of physical fitness) decreases by 50% between age 20 and 65.

  • Middle-aged and older people through regular exercise can increase their aerobic power by 15 to 20%, equivalent to a 10 or 20-year reduction in biological age. 

  • Regular aerobic exercise reduces blood pressure by 8 to 11 points.  

  • Have you already had a heart attack?  If so, regular exercise reduces the odds of fatal recurrence by 25% and adds two to three years to life.

  • The Mediterranean diet is associated with lower incidence of cancer (colon, breast, prostate, uterus), cardiovascular disease (e.g., heart attacks), and dementia (both Alzheimers and vascular types). 

  • High fruit and vegetable consumption protects against cancer of the lung, stomach, colon, rectum, oral cavity, and esophagus.  The protective “dose” is five servings a day.

  • Coronary artery disease is the cause of heart attacks and many cases of sudden cardiac death.  Legume consumption lowers the risk of coronary artery disease.  The protective dose is four servings of legumes a week. 

  • Whole grain consumption is associated with reduced risk of coronary artery disease (e.g., heart attacks), lower risk of death, lower incidence of type 2 diabetes and several cancers.  The protective dose is three servings a day. 

The good news is that we can significantly reduce our risk of premature death and common illnesses such as high blood pressure, cancer, diabetes, coronary artery disease, and dementia.  How?  Weight management, diet modification, and physical activity.     

Steve Parker, M.D.

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Mediterranean Diet Reduces Cancer Risk

Posted on July 7, 2012 | Comments Off on Mediterranean Diet Reduces Cancer Risk

In 2008, the British Journal of Cancer published a report linking the traditional Mediterranean diet “…with markedly and significantly reduced overall cancer….”

Researchers from the University of Athens, the International Agency for Research on Cancer, and the Harvard School of Public Health looked at 25,623 participants of the Greek portion of the European Prospective Investigation into Cancer and nutrition (the EPIC study).  Adherence to the Mediterranean diet was assessed with a food-frequency questionnaire.

Cancer developed in 851 participants over an average follow up of 7.9 years.  Non-melanoma skin cancers were not included since they are usually not serious or life-threatening.  The common cancers in men involved the lung, prostate, colon, and stomach.  For women, common cancers were breast, colon, ovary, and uterus.

Participants’ conformity to the Mediterranean diet was graded on a 10-point scale based on consumption of vegetables, legumes, fruits and nuts, cereals, fish, meat and meat products, dairy products, ethanol (alcohol), and the monounsaturated to saturated lipid ratio.  A score of zero indicated minimal adherence; maximal adherence scored a nine.

Every two-point increase in adherence was associated with a 12% reduction in the incidence of overall cancer.  So those participants with greatest conformity to the traditional Mediterranean diet had a dramatically reduced incidence of cancer compared to those with minimal adherence.

The researchers cite three independent studies that found a similar association between the Mediterranean diet and cancer.  The study at hand was not sufficiently powered to determine reliably which specific cancers were reduced with the Mediterranean diet.  Other studies indicate that the reduced cancers are prostate, breast, colon, and uterus.

The researchers surmise that the cancer-reducing benefit of the Mediterranean diet relates to the whole diet rather than to individual components.

To move your way of eating in a Mediterranean direction, review the diet here.

Steve Parker, M.D.

Reference:  Benetou, V., et al.  Conformity to traditional Mediterranean diet and cancer incidence: the Greek EPIC cohort.  British Journal of Cancer, 99 (2008): 191-195.

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DIRECT Trial Compares Mediterranean, Low-Fat, and Low-Carb Eating for Weight Loss

Posted on July 6, 2012 | 2 comments

Today’s post is a reprint of my 2008 analysis of the DIRECT trial.

In 2008, the New England Journal of Medicine published a well-done study comparing the Mediterranean, low-carb, and low-fat weight-loss diets in an Israeli population over the course of two years.  The researchers conclude that “Mediterranean and low-carbohydrate diets may be effective alternatives to low-fat diets.  The more favorable effects on lipids (with the low-carbohydrate diet) and on glycemic control (with the Mediterranean diet) suggest that personal preferences and metabolic considerations might inform individualized tailoring of dietary interventions.”

How was the study set up?

Moderately obese participants (322) were randomly assigned to one of the three diets: 1) low-fat, calorie-restricted, 2) Mediterranean, calorie-restricted, or 3) low-carbohydrate, non-restricted.  Calories in the low-fat and Mediterranean diets were “restricted” to 1800 per day for the men, 1500 for the women.  Average age of participants was 52, and average body mass index was 31.  [A 5-foot, 10-inch man weighing 216 pounds (98.2 kg) has a BMI of 31.]  Nearly all participants – 277 or 86% of the total – were men.  So there were only 45 women.  Forty-six participants had type 2 diabetes.

The low-fat diet was based on the American Heart Association guidelines of 2000: 30% of calories from fat [this isn’t very low], 10% of calories from saturated fat, cholesterol limited to 300 mg/day.  [The AHA revised their guidelines in 2006.]  Low-fat dieters “were counseled to consume low-fat grains, vegetables, fruits, and legumes and to limit their consumption of additional fats, sweets, and high-fat snacks.”

The Mediterranean diet was based on the recommendations of Walter Willett and P.J. Skerrett as in their book, Eat, Drink, and be Healthy: The Harvard Medical School Guide to Health Eating.  Mediterranean dieters ate 2 fish meals per week, a handful of nuts daily, 30-45 grams of extra virgin olive oil per day, etc.  [One tablespoon of olive oil is 14 grams.]  The AHA states that “this diet reflects the current recommendations from the American Heart Association.”  There were no specific recommendations regarding alcohol in any of the diets.

The low-carb diet was based on  Atkins’ New Diet Revolution of 2002.  The goal was to provide 20 grams of carbohydrate per day for the 2-month induction phase, with a gradual increase to a maximum of 120 grams daily to maintain weight loss.  Total calories, protein, and fat were not limited.  “Participants were counseled to choose vegetarian sources of fat and protein….”

Whole grains were recommended for the low-fat and Mediterranean cohorts.

All participants worked at the same nuclear research facility in Dimona, Israel.  They were given careful instructions, initially and periodically, regarding the diet to which they were assigned.  Lunch is the main meal of the day in Israel, and they all ate lunch at the facility’s self-service cafeteria, which prompted them to choose the proper food items.  I assume they were told to maintain the diet when off-duty.  Adherence to the diets was assessed by a food-frequency questionnaire.

Findings

  • After 24 months, how many participants were still involved?  90% in the low-fat group, 85% in the Mediterranean, 78% in the low-carb.
  • There was little change in the usage of medications, and no significant differences among the groups.
  • Daily energy intake (calories or kcal) decreased from baseline levels significantly – about 450 calories – in all groups at 6, 12, and 24 months compared with baseline, with no significant differences among the groups in the amount of decrease.
  • All groups started with 51% of energy intake (calories) from carbohydrate.
  • At 24 months, the low-carb dieters were getting 40% of their daily calories as carbohydrates.  The other two groups were eating 50% of energy intake from carbs. [This still seems like a lot of carbs on the Atkins diet.  A gram of carbs has 4 calories.  The stated carbohydrate goal was a maximum of 120 grams of carbs daily, on a diet of 1800 calories.  So 120 grams of carbohydrate should be 27% of total daily calories.  At no point did the low-carb group reduce their average percentage of calories from carbohydrates under 40%.  OK, maybe be in the first two weeks but those data are not reported.  On an 1800 calorie diet, 40% of calories from carbs would be 180 grams.]
  • At 24 months, the low-carb dieters were getting 39% of their daily calories as fat.  The other two groups were in the 30-33% range.
  • Baseline fat intake for all groups was 31-32% of total calories, with saturated fat being 10% of the fat calories.
  • The low-fat cohort dropped their fat calories from 31 to 30% of total calories, which is essentially no change from baseline percentage.
  • At 24 months, the low-carbers were getting 22% of their daily calories from protein.  The other groups were at 19%.  [The low-carb Atkins diet is often criticized as having too much protein.]
  • Only the low-carb group made major changes in macronutrient composition of their diet.  Macronutrients are protein, fat, and carbohydrates.  This Atkins group increased saturated fat from 10 to 12% of total calories, reduced carbs from 51 to 40% of calories, increased protein from 19 to 22% of calories, and increased total fat from 32% to 39% or total calories.
  • All cohorts lost weight, but losses were greater in the low-carb and Mediterranean groups.  For the 272 participants who completed the full 24 months of intervention, the losses averaged 3.3 kg (7.3 lb) for the low-fat group, 4.6 kg (10.1 lb) for the Mediterraneans, and 5.5 kg (12.1 lb) for the low-carb group.
  • Among the 45 women, the low-fat group lost only 0.1 kg (0.22 lb), the Mediterraneans lost 6.2 kg (13.6 lb), and the low-carbers lost 2.4 kg (5.3 lb).  There were only 15, 20, and 10 women in these groups, respectively.
  • All groups had significant blood pressure reductions: about 4 mmHg systolic and 1 mmHg diastolic.
  • HDL cholesterol (the “good cholesterol”) increased in all groups, 8.4 mg/dl in the low-carb group, about 6.3 in the others.
  • LDL cholesterol (the “bad cholesterol”) fell 5.6 mg/dl in the Mediterraneans, 3.0 mg/dl in the low-carbers, and none in the low-fat group.  But these were not statistically significant differences between the groups.
  • The ratio of total to HDL cholesterol decreased for all groups, but the relative 20% decrease in the low-carb group was statistically significant compared to the 12% relative decrease in the low-fat group.  The ratio fell 16% in the Mediterranean group.  [The total/HDL ratio is thought to reflect risk of developing atherosclerotic complications.  You want it under 5 to 1, and 3.5 to 1 may be ideal.]
  • The level of high-sensitivity C-reactive protein decreased significantly only in the Mediterranean and low-carb cohorts.  [C-reactive protein is felt to be a marker of the systemic inflammation that has a role in atherosclerosis or hardening of the arteries.]
  • Thirty-six of the diabetics had adequate lab studies for analysis – about 12 in each diet group.  Only those in the Mediterranean group had a significant decrease in fasting glucose – 33 mg/dl.  The low-fat group had an increase.  Glycated hemoglobin decreased in all three groups although to a significant degree (0.9%) only in the low-carb group.  [High glycated hemoglobin levels reflect poor control of blood sugar levels in diabetics.]
  • Insulin levels decreased significantly in all three groups, diabetic or not.  [Abnormally high insulin levels are felt to have adverse health effects.]

Limitations of the study

  • Relatively few women, making it difficult to reliably generalize results to women.
  • Relatively few people with diabetes, making it difficult to reliably generalize results to people with diabetes.
  • Israeli gene pool?  Results not applicable to others?
  • No change in physical activity recommended to participants.  Increased exercise should enhance weight loss.

Take-Home Points

  • Caloric restriction leads to weight loss.
  • Mild degrees of weight loss reduce blood pressure.
  • In this study, the low-carb/Atkins and Mediterranean diets were more effective than the “low-fat” diet.
  • Atkins dieters can lose weight without counting calories, by limiting carbohydrate intake.
  • You gotta wonder if the low-carb group would have been even more successful if they had actually limited carbs to 120 grams daily, or less.
  • It’s possible a lower-fat diet may have been more efficacious than the one utilized here.
  • This study did not enroll enough women to prove that a calorie-restricted Mediterranean diet is superior to low-fat and Atkins diets.  The greater weight loss – 13.6 pounds for Mediterranean versus 5.3 with Atkins – is suggestive and requires further study.
  • The average amounts of weight loss are not much when you think about the effort expended over 24 months of intervention.
  • These dieters reportedly reduced their daily caloric intake from baseline levels by about 450 calories, over the course of two years.  Yet they lost relatively little weight.  The numbers do not jive.  Most likely there is a problem with the methodology.  I doubt the average daily calorie deficit was as high as 450.
  • The Mediterranean diet seems to have been better for the people with diabetes.  Confirmatory studies are imperative.  Insulin resistance is an important factor in type 2 diabetes.  Monounsaturated fats, which are prominent in olive oil and the Mediterranean diet, are linked to improvement in insulin resistance in other studies.
  • For people who need to lose excess fat yet refuse to consciously restrict overall caloric  intake, the low-carb Atkins diet is a reasonable option.
  • The traditional Mediterranean diet has demonstrable long-term health benefits: longer lifespan, less cancer (colon, prostate, breast, uterus), reduction of cardiovascular disease, less dementia, and prevention of type 2 diabetes.  The Atkins diet cannot make those claims in 2008.

-Steve Parker, M.D.

Reference:  Shai, Iris, et al.  Weight Loss with a Low-Carbohydrate, Mediterranean, or Low-Fat Diet.  New England Journal of Medicine, 359 (2008): 229-241.

Additional information and critical analysis:

Dr. Dean Ornish’s analysis in Newsweek online   Dr. Ornish is a leading low-fat diet advocate.

American Heart Association comments on the study in a July 19, 2008, news release

Update on August 23, 2008:

The Mediterranean diet used in this study is based on Walter Willett’s 2001 book, Eat, Drink, and Be Healthy: The Harvard Medical School Guide to Healthy Eating.  From the author:

I wrote this book to show you where the USDA Pyramid is wrong and why it is wrong.  I wanted to offer a new healthy eating guide based of the best scientific evidence, a guide that fixed the fundamental flaws of the USDA Pyramid and helps you make better choices about what you eat.  I also wanted to give you the latest information on new discoveries that shuould have profound effects on our eating patterns. 

Dr. Willett made a conscious decision not to call his new eating plan a Mediterranean diet.  Elsewhere in the book he notes that the Mediterranean diet pyramid promoted by Oldways Preservation and Exchange Trust is a good, evidence-based guide for healthy eating.  The entire book promotes Harvard’s Healthy Eating Pyramid, not the Mediterranean diet per se.

Harvard’s Healthy Eating Pyramid:

Harvard's Healthy Eating Pyramid

So were the Mediterranean dieters in the study at hand even following the Mediterranean diet?  The most glaring difference is Harvard’s lack of emphasis on olive oil.  Of lesser note is Harvard’s recommendation to eat white rice, white bread, potatoes, and refined-flour pasta only sparingly.  However, the researchers for this study directed Mediterranean diet participants to ingest 30-45 grams of olive oil per day.  After comparing the Harvard pyramid with the Oldways Mediterranean pyramid and other Mediterranean diet descriptions, it is fair to say the dieters here were indeed instructed on a Mediterranean diet.  In fact, the Mediterranean diet in this study is quite similar to the Advanced Mediterranean Diet.

Traditional healthy Mediterranean diet pyramid of Oldways Preservation and Exchange Trust:

Traditional healthy Mediterranean diet pyramid of Oldways Preservation and Exchange Trust

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Mediterraneans Fatter After Abandoning the Traditional Mediterranean Diet

Posted on July 5, 2012 | Comments Off on Mediterraneans Fatter After Abandoning the Traditional Mediterranean Diet

In 2008, the United Nation’s Food and Agriculture Organisation reported rates of overweight and obesity in various countries in the European Union.

Greece won honors as the fattest EU country – 75% of adult Greeks are overweight or obese. Way to go, Greece!  Over the 40 years preceeding 2002, the Greeks increased their average caloric intake by 30%, compared to a 20% increase in the rest of the EU.  And I’d bet they’re expending fewer calories in physical activity than did the Greeks of 40 years ago.

Although outdone by the Greeks, over half of the adult populations in Italy, Spain, and Portugal are overweight, too.

The authors of the UN report suggest reasons for Greece’s decisive capture of first place:

  • more sedentary lifestyles
  • less home cooking
  • supermarkets and fast-food restaurants offering convenient, processed foods high in sugar, animal fat, and salt.  [Salt should have nothing to do with weight gain.]
  • less fruit and vegetable consumption

In other words, they’ve been moving away from the traditional Mediterranean diet and lifestyle of the mid-20th century.  Recent observational studies in Greece and Spain showed less obesity in current residents who had higher adherence to the traditional Mediterranean diet.

How do North American adult overweight and obesity rates compare?

  • United States – 67%
  • Mexico – 63%
  • Canada – 59%

If the Mediterraneans have forgotten their dietary heritage, I can help.

Steve Parker, M.D.

References:

Mendez, M.A., et al.  Adherence to a Mediterranean diet is associated with reduced 3-year incidence of obesity.  Journal of Nutrition, vol. 136 (2006): 2,934-2,938.

Panagiotakos, D.B., et al.  Association between the prevalence of obesity and adherence to the Mediterranean diet: the ATTICA study.  Nutrition, vol 22 (2006): 449-456.

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Mediterranean Diet Improves Asthma

Posted on July 4, 2012 | 2 comments

Researchers in Portugal found that high adherence to the Mediterranean diet reduced by 78% the risk of out-of-control asthma.

Other recent studies have associated the Mediterranean diet with 1) lesser incidence of asthma-like symptoms and allergies in children of women who followed the Mediterranean diet while pregnant, and 2) reduced risk of chronic obstructive pulmonary disease in men who eat Mediterranean-style.

The Mediterranean diet is famous for prolonging life and reducing rates of cardiovascular disease, cancer, and dementia.  Type 2 diabetes mellitus was recently added to the list of diseases prevented by the Mediterranean diet.  We have to consider adding lung disease to the list next.

In my capacity as a hospitalist, I see lots of poorly-controlled asthmatics.  The standard therapeutic approach is avoidance of allergens when possible, and administration of multiple drugs with multiple potential adverse effects.  So the following study involving diet and asthma caught my eye.

Scientists in Portugal studied 174 asthmatics with an average age of 40.  They administered an Asthma Control Questionnaire and measured lung function and exhaled nitric oxide.  Food intake was determined with a food frequency questionnaire, and a diet score was used to determine conformity to the Mediterranean diet.

Asthmatics felt to be under good control comprised 23% of the participants.  Were there dietary factors associated with good control?

I’m glad you asked.  The answer is , “Yes”:

  • high adherence to the Mediterranean diet
  • higher intake of fresh fruit
  • lower intake of ethanol (alcohol)

The researchers note that “the traditional Mediterranean diet is claimed to possess antioxidant and immune-regulatory properties in several chonic diseases.  Typical Mediterranean foods have recently been associated with improvement of symptoms of asthma and rhinitis [runny nose, often allergy-related] in children” in Crete and Spain.

This study is good news for people with asthma.  But association of well-controlled asthma with the Mediterranean diet does not prove that the diet is causing the improvement.  Next, we need a study that educates people with asthma on the Mediterranean diet, monitors adherence, and follows them over time while checking for improvement in asthma and comparing to a control group on a standard diet.

Steve Parker, M.D.

Reference:  Barros, R., et al.  Adherence to the Mediterranean diet and fresh fruit intake are associated with improved asthma control.  Allergy, vol. 63 (2008): 917-923.

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Does Food Affect Lung Disease?

Posted on July 3, 2012 | 1 comment

In another blog post, I provided evidence that diet may indeed affect lung function and disease, specifically asthma.  Another common lung condition is chronic obstructive pulmonary disease (COPD), which includes chronic bronchitis and emphysema.  COPD is usually associated with smoking.

By the way, a couple years ago “chronic lower respiratory tract disease” finally surpassed stroke to become the third leading cause of death in the U.S.  These lung diseases are mostly emphysema, COPD, and asthma.

In 2007, scientists with the Harvard School of Public Health, Harvard Medical School, and Simmons College concluded that “in men, a diet rich in fruits, vegetables, and fish may reduce the risk of COPD whereas a diet rich in refined grains, cured and red meats, desserts and French fries may increase the risk of COPD.”

The Boston, MA, researchers included academic heavyweights such as Teresa Fung, Walter Willett, and Frank Hu.  They studied 42,917 men in the Health Professionals Follow-up Study via detailed periodic questionnaires.  The men at baseline had never had asthma or COPD.  Onset of COPD between  1986 and 1998 was evaluated by questionnaire and was defined as an “affirmative response to physician-diagnosed chronic bronchitis or emphysema and by the report of a diagnostic test at diagnosis (pulmonary function testing, chest [x-ray] or chest CT scanning).”  Participants reported 111 new cases of COPD.

Investigators identified two distinct major dietary patterns at baseline:

  1. “Prudent” pattern:  high intake of vegetables, fruits, fish, poultry and whole grains.
  2. “Western” pattern:  high consumption of cured and red meats, refined grains, desserts and sweets, French fries, eggs and high-fat dairy products.

The prudent dietary pattern was inversely associatied with the risk of newly diagnosed COPD, regardless of smoking status.  In other words, the higher an individual’s conformity to the prudent pattern, the lower the risk of new COPD.

On the other hand, the Western pattern was positively associated with the risk of newly diagnosed COPD, again regardless of smoking status.

They did not note any association between either dietary pattern and the risk of developing asthma.

Clearly, there are similarities between the prudent dietary pattern and the traditional Mediterranean diet.  The main differences are that the Mediterranean diet includes significant amounts of olive oil, limited red meat and eggs, and judicious amounts of wine.  The Mediterranean diet incorporates the prudent pattern.  But the Mediterranean diet is not the “prudent dietary pattern” studied at Harvard.  Whether the Mediterranean diet would match or supercede the prudent diet in prevention of COPD is a matter of speculation.  The smart money would bet in favor of the Mediterranean diet reducing rates of COPD to at least some degree.

In view of a study associating improved asthma control with the Mediterranean diet, you gotta wonder if the researchers would have confirmed it, if they had been looking.  Are there substances in olive oil, or other aspects of the Mediterranean diet, that  improve lung function?

Many people are aware that dietary patterns have an effect on heart disease, overweight and obesity, high blood pressure, diabetes, dementia, cancer, and strokes.  We can add chronic lung disease to the list now.

Steve Parker, M.D.

Reference:  Varraso, Raphaelle, et al.  Prospective study of dietary patterns and chronic obstructive pulmonary disease among US men.  Thorax, vol. 62, (2007): 786-791.

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Evidence In Favor of Healthfulness of Whole Grains

Posted on July 2, 2012 | 3 comments

I bought a sack of potatoes the other day.  The advertising on the sack proclaimed   these potatoes as “Gluten-Free!”.  As if other potatoes have gluten (they don’t).

In these days of gluten-free this and gluten-free that, the health benefits of grains—especially wheat—are being questioned.

A 2008 review article in a scientific journal confirmed the association between high whole grain intake and reduced incidence of cardiovascular disease.  Heart disease and strokes (subsets of cardiovascular disease) are the first and fourth leading causes of death, respectively, in the U.S.

The article authors, Philip Mellen, Thomas Walsh, and David Herrington, reviewed the scientific literature on the subject and found seven pertinent published observational studies.  Study participants were divided into those with high average whole grain intake (2.5 servings per day) and those with low average intake (0.2 servings a day, or 1 serving every 5 days).  Compared with low intake, participants with high intake had 21% lower risk of cardiovascular disease events, such as heart disease, stroke, and death from cardiovascular disease.

Refined grain intake, such as standard white bread, was not associated with cardiovascular disease one way or the other.

The authors conclude, “There is a consistent, inverse association between dietary whole grains and incident cardiovascular disease…and clinicians should redouble efforts to incorporate clear messages on the beneficial effects of whole grains into public health and clinical practice endeavors.”

I’ll be the first to admit that observational studies don’t prove that whole grains reduce the risk of cardiovascular disease.  They identify an association that should lead to additional testing of the hypothesis.  I don’t see any proof on the foreseeable horizon.

If heart attacks and strokes ran in my blood lines (genes), I’d try to incorporate two or three daily servings of whole grain into my diet, assuming I had no good reasons to avoid grains.

That being said, I’m also convinced that many can live long health lives without grains.

Steve Parker, M.D.

References and resources:

Mellen, Philip, et al.  Whole grain intake and cardiovascular disease: A meta-analysis.  Nutrition, Metabolism & Cardiovascular Diseases, 18, (2008): 283-290.

The Whole Grains Council.  Learn more about the benefits of various whole grains and how to find whole grain products.  Many recipes here, plus links to hundreds of recipes at other websites.

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Adverse Health Effects of Obesity

Posted on July 1, 2012 | Comments Off on Adverse Health Effects of Obesity

As a physician, I see many illnesses and conditions that are caused or aggravated by overweight and obesity.  Both terms refer to excess body fat; obesity is a greater degree of fat.

Body mass index (BMI) is used to define overweight and obesity.  Your BMI is your weight in kilograms divided by your height in meters squared.  A BMI between 18.5 and 25 is considered healthy.  BMIs between 25 and 30 are overweight.  Here’s an online BMI calculator.  For example, a 5-foot, 4-inch person enters obesity territory – BMI over 30 – when weight reaches 174 pounds (79 kilograms).  A 5-foot, 10-incher is obese starting at 208 pounds (94.5 kilograms).

People trying to lose excess fat typically have days when willpower, discipline, and commitment waver.  On those days, it can help to remember why they started this adventure in the first place.  The reasons for many involve improved health and longevity.  Even if you have just 20 pounds of excess fat to lose, it will often take twenty weeks.  Your weight-loss goal is one to one-and-a-half pounds a week.  This race is won not by the swift, but by the slow and steady.

Here’s a laundry list of obesity-related conditions to remind you why you want to avoid obesity:

  • Premature death.  It starts at BMI of 30, with a major increase in premature death at BMI over 40.  The U.S. has 200,000 yearly deaths directly attributable to obesity.
  • Arthritis, especially of the knees.
  • Type 2 diabetes melllitus.  Eight-five percent of people with type 2 diabetes are overweight.
  • Increased cardiovascular disease risk, especially with an apple-shaped fat distribution as compared to pear-shaped.  Cardiovascular disease includes heart attacks, high blood pressure, strokes, and peripheral arterial disease (poor circulation).
  • Obstructive sleep apnea.
  • Gallstones are three or four times more common in the obese.
  • High blood pressure.  At least one third of cases are caused by excess body fat.  Every 20 pounds of excess fat raises blood pressure 2-3 points (mmHg).
  • Tendency to higher total and LDL cholesterol, higher triglycerides, while lowering HDL cholesterol.  These lipid changes are associated with hardening of the arteries – atherosclerosis – which can lead to heart attacks, strokes, and peripheral arterial disease.
  • Increased cancers.  Prostate and colorectal in men.  Endometrial, gallbladder, cervix, ovary, and breast in women.  Kidney and esophageal adenocarcinoma in both sexes.  Excess fat contributes to 14-20% of all cancer -related deaths in the U.S.  Over 550,000 people die from cancer in the U.S. yearly.  Twenty percent of us will die from cancer.
  • Strokes.
  • Low back pain.
  • Gout.
  • Varicose veins.
  • Hemorrhoids.
  • Blood clots in legs and lungs.
  • Surgery complications: poor wound healing, blood clots, wound infection, breathing problems.
  • Pregnancy complications: toxemia, high blood pressure, diabetes, prolonged labor, greater need for C-section.
  • Fat build-up in liver.
  • Asthma.
  • Low sperm counts.
  • Decreased fertility.
  • Delayed or missed diagnosis due to difficult physical examination or weight exceeding the limit of diagnostic equipment.

I hope you find this information motivational rather than depressing.  For those already obese, weight loss can significantly improve, alleviate, or prevent these conditions.  Many obesity-related medical conditions and metabolic abnormalities are improved with loss of just five or 10% of total body weight.  For instance, a 240 pound man with mild diabetes and high blood pressure may be able to reduce or avoid drug therapy by losing just 12 to 24 pounds.  He’s still obese, but healthier.

Steve Parker, M.D. 

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After Heart Attack, Which Is Better Diet: Low-Fat or Mediterranean?

Posted on June 30, 2012 | Comments Off on After Heart Attack, Which Is Better Diet: Low-Fat or Mediterranean?

For the last 12 years, the answer has been “Mediterranean.”  But a new study challenges that conclusion.

By the way, “diet” in this blog post refers to “a habitual way of eating” rather than a weight-loss program.

Researchers at The Heart Institute of Spokane (Washington) set out to compare the effects of a Mediterranean-style diet and a conventional “heart-healthy” low-fat diet in people who had suffered a heart attack within the last six months.  To test whether diet intervention per se had any effect, a “usual-care” group of patients (101 participants) was also studied.

Methodology

Dietary intervention participants were randomized to either:

  1. A low-fat diet (American Heart Association Step II) (50 participants).  Main goals were to reduce cholesterol intake to under 200 mg/day and saturated fat to under 7% of total calories, or
  2. A Mediterranean-style diet (51 participants) with the same cholesterol and saturated fat goals, plus an increased intake of omega-3 fatty acids (to over 0.75% of calories) and monounsaturated fats (to 20-25% of calories).  Emphasis was on consumption of cold-water fish 3-5 times per week, and on oils from olives, soybeans, and canola.

Both diets encouraged intake of fresh fruits and vegetables – at least 5 servings a day – and whole grains.  Loss of excess weight was not a goal.

Diet intervention participants were given two individual counseling sessions with a dietitian within the first month, with additional sessions at months 3, 6, 12, 18, and 24.  Participants also attended six group sessions.  Three-day food diaries were examined periodically to assess compliance with dietary recommendations.  Various lipids and omega-3 fatty acids were measured in plasma.  I assume that judicious wine consumption was at least mentioned as part of the Mediterranean diet, but actual intake was not reported.

The “usual-care” group, also known as controls, “received dietary advice from medical center dietitians.  American Heart Association Step II guidelines were presented as a nutrition class or video and written materials.”  Just one presentation, apparently.

All participants were followed on average for almost four years.  “The primary outcome [emphasis added] was a composite of end points including all-cause and cardiac deaths, myocardial infarction, hospital admission for heart failure, unstable angina, or stroke.”  Obviously,  you want to avoid these primary outcome end points.

Results

  • Avoidance of the primary outcome end points was the same in both the low-fat and Mediterranean diet groups.  Each intervention group had eight primary outcome end points.
  •  Forty of the 101 people in the usual care group suffered one or more of the primary outcome end points.  Only 16 of the 101 dietary intervention patients suffered one or more of the primary outcome end points.  Compared to the usual care group, the dietary intervention patients were only one-third as likely to suffer cardiac death, death from any cause, heart attack, hospital admission for heart failure, unstabe angina, or stroke.  This is a significant difference.
  • Goals for cholesterol, saturated fat, and omega-3 intake were achieved, or nearly so, in the dietary intervention groups.
  • Neither diet intervention group lost weight.
  • After two years, there were no differences between low-fat and Mediterranean groups in terms of HDL cholesterol, LDL cholesterol, triglycerides, and fasting glucose.
  • Among the diabetics (10 in each intervention group), there were no differences in fasting glucose.
  • The drop-out rate was low.

Take-Home Points

In the researchers’ words:

[This study] demonstrates that low-fat and Mediterranean-style diets can be similarly effective strategies for therapeutic lifestyle change, particularly when applied with equal intensity of intervention.

[This study] highlights the importance of heart-healthy diets in patients who have recently had [heart attacks].  The 2 intervention groups had relatively low intakes of cholesterol and saturated fat, but only Mediterranean-style diet partipants increased omega-3 fat consumption.  Because neither cardiovascular events nor risk factors differed between interventions , [this study] does not substantiate claims that increased omega-3 fat intake, predominantly from eating fish, adds benefit beyond a diet emphasizing reduced cholesterol and saturated fat.

The authors admit that the small number of participants is a weakness of their study.

They also cite another study, Medi-RIVAGE, that tends to support their findings.  Yet the Medi-RIVAGE “data predicted a 9% reduction in cardiovascular disease risk with the low-fat diet and a 15% reduction with this particular Mediterranean diet.”  According to the Medi-RIVAGE study abstract, “After a 3-mo intervention, both diets [low-fat and Mediterranean] significantly reduced cardiovascular disease risk factors to an overall comparable extent.”

The seeming equality of the low-fat and Mediterranean diets is a surprise to me.  I would have predicted superiority of the Mediterranean diet.  Alcohol and nut consumption have been associated with improved cardiovascular outcomes in several observational studies.  I wonder if these two intervention groups had the same or different consumption of alcohol and nuts.

But these researchers may be on to something here.  That is,  low-fat and Mediterranean diets – with intensive dietary instruction – are equally good diet interventions for preventing future cardiac events in people who have had a recent heart attack.  Dr. Dean Ornish’s vegetarian program might also stack up well against these two diets and “usual care.”

Before I abandon my preference for the Mediterranean diet in prevention of cardiac disease, I’d like to see the findings of this study confirmed by a larger one.  In addition to cardiovascular benefits, the Mediterranean diet is associated with:

No diet other than the Mediterranean can legitimately claim all these benefits.  And it tastes good.

Steve Parker, M.D.

References:

Tuttle, Katherine R., et al.  Comparison of Low-Fat Versus Mediterranean-Style Dietary Intervention After First Myocardial Infarction (from The Heart Institute of Spokane Diet Intervention and Evaluation Trial).  American Journal of Cardiology, 101 (2008): 1,532-1,531.

Vincent-Baudry, Stephanie, et al.  The Medi-RIVAGE study: reduction of cardiovascular disease risk factors after a 3-mo intervention with a Mediterranean-type diet or a low-fat diet.  American Journal of Clinical Nutrition, 82 (2005): 964-971.

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Posted in Coronary Heart Disease, Diet Reviews

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

Posted on June 28, 2012 | 3 comments

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 from a few years ago, 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 causative healthy 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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Posted in Alcohol, Coronary Heart Disease, Stroke, Uncategorized