Tag Archives: longevity

“Doc, How Long Will I Live With My Type 1 Diabetes?”

Type 1 diabetics diagnosed in childhood and born between 1965 and 1980 have an average life expectancy of 68.8 years.  That compares to a lifespan average of 53.4 years for those born between 1950 and 1964.  The figures are based on Pittsburgh, PA, residents and published in a recent issue of Diabetes.

Elizabeth Hughes, one of the very first users of insulin injections, lived to be 73.  She started on insulin around 1922.

Average overall life expectancy in the U.S. is 78.2 years—roughly 76 for men and 81 for women.

Don’t be too discouraged if you have diabetes: you have roughly a 50:50 chance of beating the averages, and medical advances will continue to lengthen lifespan.

Steve Parker, M.D.

1 Comment

Filed under Diabetes Complications

Is It More Important To Be Fit, Or Healthy Weight?

Men live longer if they maintain or improve their fitness level over time, according to research out of the Cooper Clinic in Dallas, Texas.  Part of that improved longevity stems from reduced risk of death from cardiovascular disease (e.g., heart attack and stroke). 

Compared with men who lose fitness with aging, those who maintained their fitness had a 30% lower risk of death; those who improved their fitness had a 40% lower risk of death.  Fitness was judged by performance on a maximal treadmill exercise stress test.

Body mass index over time didn’t have any effect on all-cause mortality but was linked to higher risk of cardiovascular death.  The researchers, however, figured that losses in fitness were the more likely explanation for higher cardiovascular deaths.  In other words, as men age, it’s more important to maintain or improve fitness than to lose excess body fat or avoid overweight.

Steve Parker, M.D.

Reference: Lee, Duck-chul, et al.  Long-term effects of changes in cardiorespiratory fitness and bodly mass index on all-cause and cardiovascular disease mortality in menCirculation, 124 (2011): 2,483-2,490

2 Comments

Filed under Exercise, Longevity, Overweight and Obesity

Does Loss of Excess Weight Improve Longevity?

High WHR

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

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

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

Methodology

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

What Did They Find?

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

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

Comments

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

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

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

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

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

We do know that intentional weight loss helps:

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

Maybe that’s enough.

Steve Parker, M.D.

Reference: Shea, M.K., et al.  The effect of intentional weight loss on all-cause mortality in older adults: results of a randomized controlled weight-loss trial.  American Journal of Clinical Nutrition, 94 (2011): 839-846.

11 Comments

Filed under Weight Loss

Documented Health Benefits of the Mediterranean Diet

The enduring popularity of the Mediterranean diet is attributable to three things:

  1. Taste
  2. Variety
  3. Health benefits

 For our purposes today, I use “diet” to refer to the usual food and drink of a person, not a weight-loss program.

The scientist most responsible for the popularity of the diet, Ancel Keys, thought the heart-healthy aspects of the diet related to low saturated fat consumption.  He also thought the lower blood cholesterol levels in Mediterranean populations (at least Italy and Greece) had something to do with it, too.  Dietary saturated fat does tend to raise cholesterol levels, both LDL and HDL.

Even if Keys was wrong about saturated fat and cholesterol levels being positively associated with heart disease, numerous studies (involving eight countries on three continents) strongly suggest that the Mediterranean diet is one of the healthiest around.  See References below for the most recent studies.

Relatively strong evidence supports the Mediterranean diet’s association with:

■ increased lifespan

■ lower rates of cardiovascular disease such as heart attacks and strokes

■ lower rates of cancer (prostate, breast, uterus, colon)

■ lower rates of dementia

■ lower incidence of type 2 diabetes

 

Weaker supporting evidence links the Mediterranean diet with:

■ slowed progression of dementia

■ prevention of cutaneous melanoma

■ lower severity of type 2 diabetes, as judged by diabetic drug usage and fasting blood sugars

■ less risk of developing obesity

■ better blood pressure control in the elderly

■ improved weight loss and weight control in type 2 diabetics

■ improved control of asthma

■  reduced risk of developing diabetes after a heart attack

■ reduced risk of mild cognitive impairment

■  prolonged life of Alzheimer disease patients

■ lower rates and severity of chronic obstructive pulmonary disease

■ lower risk of gastric (stomach) cancer

■ less risk of macular degeneration

■ less Parkinsons disease

■ increased chance of pregnancy in women undergoing fertility treatment

■  reduced prevalence of metabolic syndrome (when supplemented with nuts)

■ lower incidence of asthma and allergy-like symptoms in children of women who followed the Mediterranean diet while pregnant

Did you notice that I used the word “association” in relating the Mediterranean diet to health outcomes?  Association, of course, is not causation. 

The way to prove that a particular diet is healthier is to take 20,000 similar young adults, randomize the individuals  in an interventional study to eat one of two test diets for the next 60 years, monitoring them for the development of various diseases and death.  Make sure they stay on the assigned test diet.  Then you’d have an answer for that population and those two diets.  Then you have to compare the winning diet to yet other diets.  And a study done in Caucasians would not necessarily apply to Asians, Native Americans, Blacks, or Hispanics.

Now you begin to see why scientists tend to rely on observational  rather than interventional diet studies.

I became quite interested in nutrition around the turn of the century as my patients asked me for dietary advice to help them lose weight and control or prevent various diseases.  At that time, the Atkins diet, Mediterranean diet, and Dr. Dean Ornish’s vegetarian program for heart patients were all prevalent.  And you couldn’t pick three programs with more differences!  So I had my work cut out for me. 

After much scientific literature review, I find the Mediterranean diet to be the healthiest for the general population.  People with particular medical problems or ethnicities may do better on another diet.  A low-carb Mediterranean diet should be healthier for type 2 diabetics.  Dan Buettner makes a good argument for plant-based diets in his longevity book, The Blue Zones.  The traditional Mediterranean diet qualifies as plant-based.

What do you consider the overall healthiest diet, and why?

Steve Parker, M.D.

References:

Buckland, Genevieve, et al.  Adherence to a Mediterranean diet and risk of gastric adenocarcinoma within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort studyAmerican Journal of Clinical Nutrition, December 9, 2009, epub ahead of print.  doi: 10.3945/ajcn.2009.28209

Fortes, C., et al.  A protective effect of the Mediterraenan diet for cutaneous melanoma.  International Journal of Epidmiology, 37 (2008): 1,018-1,029.

Sofi, Francesco, et al.  Adherence to Mediterranean diet and health status: Meta-analysis.  British Medical Journal, 337; a1344.  Published online September 11, 2008.  doi:10.1136/bmj.a1344

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

Mitrou, Panagiota N., et al.  Mediterranean Dietary Pattern and Prediction of All-Cause Mortality in a US Population,  Archives of Internal Medicine, 167 (2007): 2461-2468.

Feart, Catherine, et al.  Adherence to a Mediterranean diet, cognitive decline, and risk of dementia.  Journal of the American Medical Association, 302 (2009): 638-648.

Scarmeas, Nikolaos, et al.  Physical activity, diet, and risk of Alzheimer Disease.  Journal of the American Medical Association, 302 (2009): 627-637.

Scarmeas, Nikolaos, et al.  Mediterranean Diet and Mild Cognitive Impairment.  Archives of Neurology, 66 (2009): 216-225.

Scarmeas, N., et al.  Mediterranean diet and Alzheimer disease mortality.  Neurology, 69 (2007):1,084-1,093.

Fung, Teresa, et al.  Mediterranean diet and incidence of and mortality from coronary heart disease and stroke in women.  Circulation, 119 (2009): 1,093-1,100.

Mente, Andrew, et al.  A Systematic Review of the Evidence Supporting a Causal Link Between Dietary Factors and Coronary Heart DiseaseArchives of Internal Medicine, 169 (2009): 659-669.

Salas-Salvado, Jordi, et al.  Effect of a Mediterranean Diet Supplemented With Nuts on Metabolic Syndrome Status: One-Year Results of the PREDIMED Randomized Trial.  Archives of Internal Medicine, 168 (2008): 2,449-2,458.

Mozaffarian, Dariush, et al.  Incidence of new-onset diabetes and impaired fasting glucose in patients with recent myocardial infarction and the effect of clinical and lifestyle risk factors.  Lancet, 370 (2007) 667-675.

Esposito, Katherine, et al.  Effects of a Mediterranean-style diet on the need for antihyperglycemic drug therapy in patients with newly diagnosed type 2 diabetesAnnals of Internal Medicine, 151 (2009): 306-314.

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

Martinez-Gonzalez, M.A., et al.  Adherence to Mediterranean diet and risk of developing diabetes: prospective cohort study.  British Medical Journal, BMJ,doi:10.1136/bmj.39561.501007.BE (published online May 29, 2008).

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

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.

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

Comments Off on Documented Health Benefits of the Mediterranean Diet

Filed under Health Benefits, Mediterranean Diet

Longevity Components of the Mediterranean Diet

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

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

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

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

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

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

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

My Comments

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

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

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

Steve Parker, M.D. 

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

8 Comments

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

How Well Should Diabetes Be Controlled?

Researchers in the U.K. suggest that a hemoglobin A1c of 7.5% may be optimal in terms of longevity for type 2 diabetics treated with drugs, according to a study published recently in The Lancet.

Hemoglobin A1c (HgbA1c) is a blood test widely used as a gauge of blood sugar control, reflecting average blood sugars over the previous three months.  The American Diabetes Association recommends a HgbA1c goal of 7% or less.  The American Association of Clinical Endocrinologists recommends 6.5% or less.  Dr. Richard K. Bernstein, a diabetologist and himself a type 1 diabetic, recommends HgbA1c’s as near normal as possible (about 5%). 

Many physicians believe that keeping blood sugar levels as close to normal as possible—often referred to as “tight control”— will help prevent certain diabetes complications such as blindness, kidney failure, and nerve damage.  We have good supportive evidence.

We assume tight control would also help prevent premature death from heart attacks and strokes, too.  Several recent studies—the ACCORD and ADVANCE trials—call this into question, however.  The ACCORD trial, for example, achieved near-normal glucose control with multiple medication options, yet found that the effort was linked to increased death rates from cardiovascular disease and from any cause (all-cause mortality).

The scariest thing about tight control is hypoglycemia, which can kill you quickly, for example,  if you’re operating dangerous machinery (e.g., driving), scuba-diving, or rock-climbing.

U.K. researchers recently reviewed records of diabetics treated either with 1) two oral medications (usually metformin and a sulfonylurea), or 2) a regimen containing insulin.  Each group had over 20,000 subjects.  They found that risk of death for those with an average HgbA1c of 6.4% (the lowest blood sugar levels in this study) was 52% higher than those with HgbA1c of 7.5%.  Those with the highest blood sugar levels over time—HgbA1c over 10% if I recall correctly—had the highest risk of death.  In general, those taking insulin had higher rates of death than those on pills.

It’s extremely difficult to interpret studies like this.  There are myriad ways to treat diabetes.  We have 10 classes of drugs for treatment of diabetes: this study looked at three.  There are at least three types of “diabetic diet” in common use: low-fat/high-carb, low-carb, and just regular eating, which depends on where you live.  Exercise, too, plays a role in treatment and longevity. 

With all these variables, should we put much stock in a study that looks at longevity from the perspective of just two therapeutic regimens?  How well would a football team do with just two plays in its play-book?

You’d think we would have a definite answer to the “tight versus loose control” issue by 2010.  We don’t.  It’s still very appealing to me to think that, if done right, tight control would yield the better outcomes.  Problem is, we don’t always know what’s right. 

One thing is clear: Having a HgbA1c of 7.5% is better than 10% in terms of health and longevity. 

But is 7.5% really better than 6.5 or 5.5 or 5.0% for a particular individual on a particular treatment program?  Probably not.  That’s why the ADA and AACE emphasize that treatment programs be tailored to the individual patient.        

Maybe controlling blood sugar levels is like controlling high blood pressure.  The ideal may be 120/80, but you gain very little, if any, by reducing high blood pressure below 140/90 (130/85 for diabetics).  HgbA1c of 5.0% may be ideal, but not necessary.

Steve Parker, M.D. 

References:

Currie, Craig, et al.  Survival as a function of HgA1c in people with type 2 diabetes: a retrospective cohort study.  The Lancet, January 27, 2010.  Early online publication   doi: 10.1016/S0140-6736(09)61969-3

Dluhy, Robert and McMahon, Graham.  Intensive glycemic control in the ACCORD and ADVANCE trials.  New England Journal of Medicine, 358 (2008):2630-2633.

1 Comment

Filed under Diabetes Complications, Drugs for Diabetes

Book Review: The Blue Zones

Here’s my review of  The Blue Zones: Lessons for Living Longer From the People Who’ve Lived the Longest, a 2008 book by Dan Buettner.  I give the book four stars on Amazon.com’s five-star system (“I like it”). 

♦   ♦   ♦

The lifestyle principles advocated in The Blue Zones would indeed help the average person in the developed world live a longer and healthier life.  The book is a much-needed antidote to rampant longevity quackery.  Dan Buettner’s idea behind the book was “discovering the world’s best practices in health and longevity and putting them to work in our lives.”  He succeeds. 

Mr. Buettner assembled a multidisciplinary team of advisors and researchers to help him with a very difficult subject.  Do people living to 100, scattered over several continents, share any characteristics?  Do those commonalities lead to health and longevity? 

They studied four longevity hot spots (Blue Zones):

  • Okinawa islands (Japan)
  • Barbagia region of Sardinia (an island off the Italian mainland)
  • Loma Linda, California (a large cluster of Seventh Day Adventists)
  • and the Nicoya Peninsula (Costa Rica). 

Research focused on people who lived to be 100. 

Until recently, two of the Blue Zones—the Nicoyan Peninsula and Sardinia—were quite isolated, with relatively little influence from the outside world. 

Mr. Buettner et al identify nine key traits that are associated with longevity and health in these cultures.  Of course, association is not causation, which Mr. Buettner readily admits.  He draws more conclusions from the data than would many (most?) longevity scientists.  Scientists can wait for more data, but the rest of us have to decide and act based on what we know today.  Here are the “Power Nine”:

  1. regular low-intensity physical activity
  2. hari hachi bu (eat until only 80% full—from Okinawa)
  3. eat more plants and less meat than typical Western cultures
  4. judicious alcohol, favoring dark red wine
  5. have a clear purpose for being alive (a reason to get up in the morning, that makes a difference)
  6. keep stress under control
  7. participate in a spiritual community
  8. make family a priority
  9. be part of a tribe (social support system) that “shares Blue Zone values”

Of these, I would say the available research best supports numbers 1, 4, 7, 8, and the social support system.

I doubt that hari hachi bu (eat until you’re only 80% full) will work for us in the U.S.  It’s never been tested rigorously.  The idea is to avoid obesity.  

The author believes that average lifespan could be increased by a decade via compliance with the Power Nine.  And these would be good, relatively healthy years.  Not an extra 10 years living in a nursing home.

Appropriately and early on, Mr. Buettner addresses the issue of genetics by mentioning a single study of Danish twins that convinces him longevity is only 25% deterimined by genetic heritage.  Environment and lifestyle choices determine the other 75%.  I believe he underestimates the effect of genetics. 

Over half the population of the Nicoya Peninsula Blue Zone are of Chorotega Indian descent, not from Spanish Conquistadores.  Would a Danish twin study have much tosay about Chorotega Indians’ longevity?  We don’t know, but I’m skeptical.  Also, the Sardinians and Okinawans would seem to have centuries of a degree of inbreeding, too, according to Buettner’s own documentation. 
 
Do the Adventists tend to marry and breed with each other (like Mormons), thereby concentrating longevity genes?  You won’t find the question addressed in the book.

Because I think genetics plays a larger role in longevity than 25%, I’d estimate that the healthy lifestyle choices in this book might prolong life by six or seven years instead of 10.  But I’m splitting hairs.  I don’t have any better evidence than Mr. Buettner, just a hunch plus years of experience treating diseased and dying patients.

These four Blue Zones do share a mostly plant-based diet of natural foods with minimal processing.  Two of the populations—the Okinawans and Costa Ricans—didn’t seem to have any choice.  Heavy meat consumption just wasn’t an option available to them.  Rather than promoting a low-meat plant-based diet, it might be more accurate to conclude that “you don’t have to eat a lot of meat, chicken, or fish to live a long healthy life.”

In other words, it may not matter how much meat you eat as long as you eat the healthy optimal level of fruits, vegetables, and whole grains.  It’s a critical difference not addressed in this book except among the Adventists.

Even if you could live an extra two years as a vegan, I’m sure many people would choose to eat meat anyway.  By the way, this book conflates vegan, lacto-vegetarian, lacto-ovo vegetarian, near-vegetarian, and vegetarian into one: vegetarian.  It’s a common problem when considering the health aspects of vegetarianism.  They are not necessarily the same.   

By the same token, plenty of my patients have told me they don’t like any kind of exercise and they won’t do it, even if it would give them an extra two years of life.  What many don’t realize is that from a functional standpoint, regular exercise makes their bodies perform as if they were ten years younger.  There’s a huge difference between the age of 80 and 70 in terms of functional abilities.

Why read the book now that you have the Power Nine?  To convince you to change your unhealthy ways, and indispensible instruction on how to do so.

Steve Parker, M.D.

Disclosure:  The publisher’s representative did not pay me for this review, nor ask for a favorable review.  They offered me a review copy and three give-aways, and I accepted.  I figure the cost of the books to the publisher was $16 USD total.  I gave away the books through my Advanced Mediterranean Diet Blog.  Cost of shipping the books to the winners came out of my pocket.

3 Comments

Filed under Book Reviews, Vegetarian Diet