Advanced Mediterranean Diet

I started Mark Verstegen’s “Core Performance” at-home work out program today.  He’s a local guy who trains lots of pro athletes.  The program was recommended to me by a physician colleague who had a good experience with it.

Why do it? 

I’d slacked off on exercise dramatically over the last six months while writing another book.  The family went bowling three months ago, and my right arm was sore after just three “lines” (games).  That’s just not right!  Five months ago I developed some left shoulder aching without a clear precipitant.  I was able to cure it recently with a rehab program involving weight training.

So I’m starting to feel like an injury-prone, old weakling.  I wish to stay in good enough shape to keep up with my active young teenage kids, even though I’m 56.  I’m also well aware of the myriad health benefits of regular physical activity, including postponement of death.

Does this have anything to do with the Mediterranean diet?  Yes, indirectly.  It’s possible that some of the healthful aspects of the traditional Mediterranean diet are instead attributable to an active lifestyle.

Core Performance is a serious, vigorous program.  At my age, I have to be very careful not to injure myself. 

I spent $350 (US) getting the necessary equipment, such as free weights (pre-owned, from Craigslist), physioball, exercise matt, elastic bands, and a weight bench.  That’s a lot of dough, but I consider it a long-term investment in myself and my family. 

I spent two hours doing my first session today, but should be able to get the time down to 45-60 minutes after I’m more familiar with the specific exercises.  Verstegen asks for exercise six days a week for the first 15 weeks.  After that, I’m not sure.  I hope that maintenance of fitness will only require three days a week.

My initial impression is that the program may be too hard-core for the average sedentary middle-aged person with little athletic background.  I’m not confident I’ll be able to do it.  I’m excited about it and see the potential for much good.  We’ll see. 

How could I recommend regular physical activity to my patients if I didn’t do it myself?

Steve Parker, M.D.

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: Jönsson T, Granfeldt Y, Erlanson-Albertsson C, Ahrén B, & Lindeberg S (2010). A paleolithic diet is more satiating per calorie than a mediterranean-like diet in individuals with ischemic heart disease. Nutrition & metabolism, 7 PMID: 21118562

I’ve written elsewhere about the death-defying aspect of exercise and myriad other health benefits of regular physical activity. 

Very heavy folks potentially have more to gain in terms of health and longevity compared to skinny people. So it’s a cruel irony that the heavier you are, the harder it is exercise. At some point even light exercise becomes impossible.

Average-height women tipping the scales at about 280 pounds (127 kg) and men at 360 pounds (164 kg) aren’t going to be able to jog around the block, much less run a marathon. These weights are 100 percent over ideal or healthy levels. An actual “exercise program” probably won’t be possible until some weight is lost simply through very-low-carb eating, calorie restriction, or bariatric surgery. The initial exercise goal for you may just be to get moving through activities of daily living and perhaps brief walks and calisthenics while sitting in a chair.

“I’ll get started after I finish this cigarette.”

Markedly obese people who aren’t up to the aforementioned extreme weights can usually tolerate a low-intensity physical activity program. At 50 percent over ideal weight, an average-height woman of 210 pounds (95 kg) is carrying 70 excess pounds (32 kg) of fat. Her male counter-part lugs around 90 pounds (41 kg) of unnecessary fat. This weight burden causes dramatic breathlessness and fatigue upon exertion, and makes the joints and muscles more susceptible to aching and injury.

If you’re skinny, just imagine trying to walk or run a mile carrying a standard five-gallon (19 liter) water cooler bottle, which weighs only 43 pounds (19.5 kg) when full. The burden of excess fat makes it quite difficult to exercise.    

If you’re markedly obese, several tricks will enhance your exercise success. I want you to avoid injury, frustration, and burn out. Start with light activity for only 10 or 15 minutes, gradually increase session length (e.g., by two to four minutes every two to four weeks) and increase exercise intensity only after several months. Your joints and muscles may appreciate easy, low-impact exercises such as stationary cycling, walking, swimming, and pool calisthenics/water aerobics.

You may also benefit from the advice of a personal fitness trainer arranged through a health club, gym, or YMCA/YWCA. Check out several health clubs before you join. Some of them are primarily meat markets for beautiful slender yuppies. You may feel more comfortable in a gym that welcomes and caters to overweight people. Hospitals are increasingly developing fitness centers with obese orthopedic, heart, and diabetic patients in mind.

Steve Parker, M.D.

Animal-based low-carb diets are linked to higher death rates, according to a recent study in the Annals of Internal Medicine.  On the other hand, a vegetable-based low-carb diet was associated with a lower mortality rate, especially from cardiovascular disease.

As always, “association is not causation.”

Since I created the Low-Carb Mediterranean Diet, it’s just a matter of time before someone asks me, “Haven’t you heard that low-carb diets cause premature death?”  So I figured I’d better take a close look at the new research by Fung and associates.

It’s pretty weak and unconvincing.  I have little to add to the cautious editorial by William Yancy, Matthew Maciejewski, and Kevin Schulman published in the same issue of Annals.

The study at hand was observational over many years, using data from the massive Nurses’ Health Study and Health Professionals’ Follow-up Study.  To find the putative differences in mortality, the researchers had to compare the participants eating the most extreme diets.  The 80% of study participants eating in between the extremes  were neutral in terms of death rates.

They report that “…the overall low-carbohydrate diet score was only weakly associated with all-cause mortality.”  Furthermore,

These results suggest that the health effects of a low-carbohydrate diet may depend on the type of protein and fat, and a diet that includes mostly vegetable sources of protein and fat is preferable to a diet with mostly animal sources of protein and fat.

In case you’re wondering, all these low-carb diets derived between 35 and 42% of energy (total calories) from carbohydrate, with an average of 37%.  Anecdotally, many committed low-carbers chronically derive 20% of calories from carbohydrate (100 g of carb out of 2,000 calories/day).  The average American eats 250 g of carb daily, 50-60% of total calories.

Yancy et al point out that “Fung and coworkers did not show a clear dose-response relationship in that there was not a clear progression of risk moving up or down the diet deciles.”  If animal proteins and fats are lethal, you’d expect to see some dose-response relationship, with more deaths as animal consumption gradually increases over the deciles.

The Fung study is suggestive but certainly not definitive.  Anyone predisposed to dietary caution who wants to eat lower-carb might benefit from eating fewer animal sources of protein and fat, and more vegetable sources. Fung leaves it entirely up to you to figure out how to do that. Compared to an animal-based low-carb diet, the healthier low-carb diet must subsitute more low-carb vegetables and higher-fat plants like nuts, seeds, seed oils and olive oil, and avocadoes, for example.  What are higher-protein plants?  Legumes?

You can see how much protein and fat are in your favorite vegetables at the USDA Nutrient Database.

The gist of Fung’s study dovetails with the health benefits linked to low-meat diets such as traditional Mediterranean and DASH.  On the other hand, if an animal-based low-carb diet helps keep a bad excess weight problem under control, it too may by healthier than the standard American diet.

See the Yancy editorial for a much more detailed and cogent analysis.  As is so often the case, “additional studies are needed.”

Steve Parker, M.D.

Reference:  Fung, Teresa, et al.  Low-carbohydrate diets and all-cause and cause specific mortality: Two cohort studies.  Annals of Internal Medicine, 153 (2010): 289-298.

Judging from improvement in hemoglobin A1c, the combination of aerobic and strength training is needed to improve diabetic blood sugar levels.  Both types of exercise—when considered alone—did not improve diabetes control, according to the latest research in the Journal of the American Medical Association.

One type of resistance training

Why is this important?  While the most popular way to control diabetes is drug therapy, we don’t have very little information about the long-term adverse effects of many of these drugs.  Some of my diabetic patients will remember Rezulin (troglitazone), which was pulled from the U.S. market after it was linked to deaths from liver failure.

One of the things that impressed me about Dr. Richard Bernstein’s book, Diabetes Solution, was his strong advocacy of weight training, also known as resistance training and strength training.  Weight lifting is a typical example.

Prior studies had shown exercise-induced  improvements (reductions)  in hemoglobin A1c, a great test for overall diabetes control, in the range of o.66% to 1.0% (absolute change, not relative).  That’s comparable to what we see with many drugs.  Much easier to pop a pill though, huh?

One earlier study showed hemoglobin A1c lowered by 0.4% with resistance training, 0.5% with aerobic training, and 1.0% with combined resistance/aerobic.  But folks doing both aerobic and resistance were exercising 270 minutes a week—39 minutes a day—which was significantly more than the people just doing one type of exercise. [This was the DARE study: Diabetes Aerobic and Resistance Exercise.] 

Investigators at the Pennington Biomedical Research Center in Louisiana wondered which type of exercise would be more effective, comparing the same minutes per week of activity.

Methodology

They randomized 262 sedentary type 2 diabetics to one of four groups: control, aerobic exercise, resistance training 3 days a week, or combined aerobic and resistance training (resistance twice weekly).  All three groups exercised for about 140 minutes a week—just 20 minutes a day, on average—for nine months.  Exercise intensity was 50 to 80% of maximum oxygen consumption (determined by a baseline treadmill stress test).  Nearly all participants were on diabetic drugs; 18% were on insulin.  I think the aerobic group exercised on treadmills.

Participant characteristics:  Women were 64% of the total.  Average age 56. Forty-seven percent were non-white (114 black, 10 Hispanic/other).  Average body mass index was 35.  Average hemoglobin A1c was 7.7%.  Not too many people dropped out of the study before it was over.

Results

No serious adverse event occurred during exercise.  The authors didn’t mention the occurence of hypoglycemia.

The combination training group dropped their hemoglobin A1c average by 0.34% (p = 0.03). The pure resistance and aerobic exercisers didn’t show any improvement over the control group.

The combination group lost 1.6 kg body weight on average compared to the control group.  Pure resistance and aerobic exercisers’ weights didn’t differ from the control group. [Remember, this was not a weight-loss study.]

Comments

The authors write:

The failure of the aerobic group to lose a substantial amount of weight (or fat) has been reported in numerous aerobic exercise trials, which may be due to aerobic training resulting in [higher] energy intake, expenditure compensation, or both.

If you’re trying to lose excess fat weight, resistance training appears to win over aerobic exercise.

Doing either aerobic execise or resistance exercise for an average of 20 minutes a day will not improve hemoglobin A1c levels in most type 2 diabetics.  We can assume blood sugars aren’t lower either.  It takes a combination of both types of exercise to lower hemoglobin A1c.

A hundred and forty minutes of exercise weekly—just 20 minutes a day—is not too much to ask for, if improved health and weight management are the goals.  More would be better.

Over nine months, the control group ended up needing more diabetic drugs.  The combination training group decreased its drug use.

Dr. Bernstein may still by right to stress resistance training over aerobic.  I bet he’d say these folks weren’t exercising enough.  The study at hand suggests that it’s important to do both types of exercise, especially if you’re not going to put much time into it.

The details of the resistance training program are probably important.  You can read the study yourself and decide if participants were on a good regimen.  I’ve little expertise in that area. 

Diabetics taking insulin, sulfonylureas, and meglitinides are at risk for hypoglycemia during exercise. The study authors made little mention of this, so it may be safe to assume it wasn’t a problem. Certified diabetes educators saw participants monthly, which may have nipped the problem in the bud.

Steve Parker, M.D.

Church, Timothy, et al.  Effects of aerobic and resistance training on hemoglobin A1c levels in patients with type 2 diabetes.  Journal of the American Medical Association, 304 (2010): 2,253-2,262.  doi:10.1001/jama.2010.1710

A new scientific truth is not usually presented in a way to convince its opponents.  Rather, they die off, and a rising generation is familiarized with the truth from the start.

                         —Max Planck

I wanted to share a link with you that’s a review of a documentary called “Simply Raw: Reversing Diabetes in 30 Days.”  It’s at Science-Based Medicine, a blog.

Steve Parker, M.D. 

A cocktail of three common B vitamins slowed the rate of brain shrinkage over two years  in elderly patients with mild cognitive impairment, according to researchers at the University of Oxford.

As a hospitalist, I see 10 or 20 brain scans every week.  A healthy 40-year-old brain nicely fills out the allotted space in the skull.  Most 70-year-old brains have an obvious degree of shrinkage.  Those with the most shrinkage typically have worse mental functioning, often diagnosed clinically as dementia, or its precursor, mild cognitive impairment (MCI).

The medical term for brain shrinkage is brain atrophy.  It reflects loss of brain cells or decrease in brain cell size.  I see A LOT of atrophied brains and impaired mental functioning—aka cognition—in the elderly. 

Not everybody with atrophy has mental impairment; healthy brains slowly atrophy with age.  Alzheimer’s disease patients atrophy quickly; MCI patients atrophy at an intermediate rate.  MCI patients converting over the years to Alzheimer’s show a faster rate of atrophy.

Mild cognitive impairment affects 14 to 18% of those over age 70 (five million in the U.S.).  Half of these convert to Alzheimer’s disease or another dementia within five years.  We desperately need a way to prevent or slow that conversion.

That’s why I was excited to see a research report in which brain atrophy was slowed with three simple daily vitamins: folic acid 0.8 mg, B12 0.5 mg, and B6 20 mg.  The investigators will report later on whether the vitamins helped prevent mental decline.

These three vitamins are involved in homocysteine metabolism; they decrease blood levels of homocysteine.  Read elsewhere if you want the boring details. 

Methodology

Oxford area participants were at least 70 years of age and had mild cognitive impairment but not dementia.  Blood homocysteine levels were drawn periodically.  Participants were randomized to take either placebo (83 subjects) or the daily vitamins (85 subjects) for two years.  MRI scans were done periodically to determine brain volume.  Tests of mental functioning were done periodically.  More subjects were in the study at the outset but some dropped out and others didn’t have technically adequate MRI scans.

Results

After adjustment for age, the annual rate of brain atrophy was 30% less in the vitamin group compared to placebo.

For the placebo group, the rate of brain atrophy was clearly related to baseline homocysteine levels: higher homocysteine, faster atrophy.

Although the study was not powered to detect an effect of treatment on cognition (findings to be reported separately), in a post hoc analysis, we noted that final cognitive test scores were correlated to the rate of atrophy.

Atrophy appears to be a major determinant of cognitive decline in this population.

There were no significant safety issues and no differences in adverse events between the groups.

The vitamin group lowered homocysteine levels by 32% compared to placebo.

Reduction in brain shrinkage rate was best in those with a higher baseline homocysteine level (over 13 micromol/L); those with the lowest baseline levels (<9.5 micromol/L) showed no effect of vitamin therapy.  [In the U.S., 13% of those over 60 have concentrations over 13 micromol/L, whereas the median is 10 micromol/L.]

Comments

Although this is small study, I’m excited about the future clinical implications.  The results need to be replicated.  I can’t wait to hear from this group regarding the details of mental functioning tests.  If preservation of brain function or other practical benefits don’t accompany a slower rate of atrophy , it’s no use taking the vitamins.

A 2008 study found no clinical benefit with a similar vitamin mix in Alzheimer’s patients with mild to moderate disease.  In other words, the rate of mental decline was no different than the placebo group.  Average homocysteine level was 9.16 micromole/L and fell by 30% during the 18-month-long study.  Even those with the highest homocysteine levels showed no benefit.  Perhaps B vitamins need to be started much earlier in the disease process to be effective.

The time may come where we screen all 60-year-olds for above-average homocysteine levels, starting them on the vitamin cocktail.

One caveat, however.  Ten years ago doctors were quite excited about preventing heart disease events (e.g., heart attacks, cardiac deaths) and strokes in people with high homocysteine levels.  We knew that high levels were associated with cardiac events and strokes, and we knew the B vitamins would lower the blood levels.  We learned a couple years ago that B vitamin therapy actually didn’t help heart patients or those at high risk for heart disease.  Nor do the vitamins prevent strokes.  [If you’re a heart patient still taking Foltx, ask your cardiologist if it’s OK to stop it now.]

Steve Parker, M.D.

References: 
Smith, A., Smith, S., de Jager, C., Whitbread, P., Johnston, C., Agacinski, G., Oulhaj, A., Bradley, K., Jacoby, R., & Refsum, H. (2010). Homocysteine-Lowering by B Vitamins Slows the Rate of Accelerated Brain Atrophy in Mild Cognitive Impairment: A Randomized Controlled Trial PLoS ONE, 5 (9) DOI: 10.1371/journal.pone.0012244

Aisen, P.S., et al.  High-dose B vitamin supplementation and cognitive decline in Alzheimer disease: A randomized controlled trial.  Journal of the American Medical Association, 300 (2008): 1,774-1,783.