Low-Carb Research Update

Grapes are an iconic Mediterranean fruit

Grapes are an iconic Mediterranean fruit

As much as possible, I base my nutrition and medical recommendations on science-based research published in the medical literature.

In the early 2000s, a flurry of research reports demonstrated that very-low-carb eating (such as the Atkins diet) was safe and effective for short-term weight management and control of diabetes.  Eighty hours of literature review in 2009 allowed me to embrace low-carbohydrate eating as a logical and viable option for many of my patients. The evidence convinced me that the relatively high fat content of many low-carb diets was nothing to worry about long-term.

By the way, have you noticed some of the celebrities jumping on the low-carb weight-management bandwagon lately?  Sharon Osbourne, Drew Carey, and Alec Baldwin, to name a few.

My primary nutrition interests are low-carb eating, the Mediterranean diet, and the paleo diet.  I’m stay up-to-date with the pertinent scientific research.  I’d like to share with you some of the pertinent research findings of the last few years.

Low-Carb Diets

  • Low-carb diets reduce weight, reduce blood pressure, lower triglyceride levels (a healtlhy move), and raise HDL cholesterol (another good trend).  These improvements should help reduce your risk of heart disease.  (In the journal Obesity Reviews, 2012.)
  • Dietary fat, including saturated fat, is not a cause of vascular disease such as heart attacks and atherosclerosis (hardening of the arteries).  (Multiple research reports.)
  • If you’re overweight and replace two sugary drinks a day with diet soda or water, you’ll lose about four pounds over the next six months.  (American Journal of Clinical Nutrition, 2012.)
  • United States citizens obtain 40% of total calories from grains and added sugars.  Most developed countries are similar.  Dr. Stephan Guyenet notes that U.S. sugar consumption increased steadily “…from 6.3 pounds [2.9 kg] per person per year in 1822 to 107.7 pounds [50 kg] per person in 1999.  Wrap your brain around this: in 1822 we ate the amount of added sugar in one 12-ounce can of soda every five days, while today we eat that much sugar every seven hours.”
  • A very-low-carb diet improves the memory of those with age-related mild cognitive impairment. Mild cognitive impairment is a precursor to dementia.  (University of Cincinnati, 2012.)
  • High-carbohydrate and sugar-rich diets greatly raise the risk of mild cognitive impairment in the elderly. (Mayo Clinic study published in the Journal of Alzheimers’ Disease, 2012.)
  • Compared to obese low-fat dieters, low-carb dieters lose twice as much fat weight.  (University of Cincinnati, 2011.)
  • Diets low in sugar and refined starches are linked to lower risk of age-related macular degeneration in women.  Macular degeneration is a major cause of blindness.  (University of Wisconsin, 2011.)
  • A ketogenic (very-low-carb) Mediterranean diet cures metabolic syndrome (Journal of Medicinal Food, 2011.)
  • For type 2 diabetics, replacing a daily muffin (high-carb) with two ounces (60 g) of nuts (low-carb) improves blood sugar control and reduces LDL cholesterol (the “bad” cholesterol). (Diabetes Care, 2011.)
  • For those afflicted with fatty liver, a low-carb diet beats a low-fat diet for management. (American Journal of Clinical Nutrition, 2011.)
  • For weight loss, the American Diabetes Association has endorsed low-carb (under 130 g/day) and Mediterranean diets, for use up to two years. (Diabetes Care, 2011.)
  • High-carbohydrate eating doubles the risk of heart disease (coronary artery disease) in women.  (Archives of Internal Medicine, 2010.)
  • One criticism of low-carb diets is that they may be high in protein, which in turn may cause bone thinning (osteoporosis).  A 2010 study shows this is not a problem, at least in women.  Men were not studied.  (American Journal of Clinical Nutrition.)
  • High-carbohydrate eating increases the risk of developing type 2 diabetes (American Journal of Clinical Nutrition, 2010.)
  • Obesity in U.S. children tripled from 1980 to 2000, rising to 17% of all children.  A low-carb, high-protein diet is safe and effective for obese adolescents.  (American Journal of Clinical Nutrition, 2010.)

Mediterranean Diet

The traditional Mediterranean diet is well established as a healthy way of eating despite being relatively high in carbohydrate: 50 to 60% of total calories.  It’s known to prolong life span while reducing rates of heart disease, cancer, strokes, diabetes, and dementia.  The Mediterranean diet is rich in fresh fruits, vegetables, nuts and seeds, olive oil, whole grain bread, fish, and judicious amounts of wine, while incorporating relatively little meat.  It deserves your serious consideration.  Here’s the latest scientific literature on this diet.

  • Olive oil is linked to longer life span and reduced heart disease.  (American Journal of Clinical Nutrition, 2012.)
  • Olive oil is associated with reduced stroke risk.  (Neurology, 2012).
  • The Mediterranean diet reduces risk of sudden cardiac death in women.  (Journal of the American Medical Association, 2011.)
  • The Mediterranean diet is linked to fewer strokes visible by MRI scanning.  (Annals of Neurology, 2011.)
  • It reduces the symptoms of asthma in children.  (Journal of the American Dietetic Association, 2011.)
  • Compared to low-fat eating, it reduces the incidence of type 2 diabetes by 50% in middle-aged and older folks.  (Diabetes Care, 2010.)
  •  A review of all available well-done studies on the Mediterranean diet confirms that it reduces risk of death, decreases heart disease, and reduces rates of cancer, dementia, Parkinson’s disease, stroke, and mild cognitive impairment.  (American Journal of Clinical Nutrition, 2010.)
  • It reduces the risk of breast cancer.  (American Journal of Clinical Nutrition, 2010.)
  • The Mediterranean diet reduces Alzheimer’s disease.   (New York residents, Archives of Neurology, 2010).
  • It slowes the rate of age-related mental decline.  (Chicago residents, American Journal of Clinical Nutrition, 2010.)
  • In patients already diagnosed with heart disease, the Mediterranean diet prevents future heart-related events and preserves heart function.  (American Journal of Clinical Nutrition, 2010.)

Clearly, low-carb and Mediterranean-style eating have much to recommend them.  Low-carb eating is particularly useful for weight loss and management, and control of diabetes, prediabetes, and metabolic syndrome.  Long-term health effects of low-carb eating are less well established.  That’s where the Mediterranean diet shines.

That’s why I ask many of my patients to combine both approaches: low-carb and Mediterranean.  Note that several components of the Mediterranean diet are inherently low-carb: olive oil, nuts and seeds, fish, some wines, and many fruits and vegetables.  These items easily fit into a low-carb lifestyle and may yield the long-term health benefits of the Mediterranean diet.  I’ve posted on the Internet a Low-Carb Mediterranean Diet that will get you started, if interested.

Is a carbohydrate-restricted Mediterranean diet healthier than the traditional Mediterranean diet?  Nobody knows.

Steve Parker, M.D.

Which Are the Low-Carb Veggies?

A half cup of sliced bell pepper has about 2 grams of digestible carbohydrate

Laura Dolson over at About.com has a helpful list of low-carb veggies.  Helpful if you experience excessive blood sugar spikes from high-carb items, or if you’re restricting carbs for weight management.

-Steve

What Do Dietitians Think About Ketogenic Diets?

You get it?

Registered Dietitian Franziska Spritzler recently reviewed the concept of low-carb ketogenic diets.  She thinks they are a valid approach to certain clinical situations.  Among dietitians, this puts her in a small but growing minority.

One of your weight-loss choices in my Advanced Mediterranean Diet (2nd Edition) is a ketogenic diet.  Here’s the basic program.

I hesitate to mention this, but I will anyway.  Many, if not most, dietitians too easily just go along with the standard party line on low-carb eating: it’s rarely necessary and quite possibly unhealthy.  Going along is much easier than doing independent literature review and analysis.  I see the same mindset among physicians.

Franziska breaks the mold.

Steve Parker, M.D.

QOTD: Joshua Brown On Email

Email is totally out of control and needs to be made illegal effective immediately. It is the worst thing that’s ever happened to humanity. Unless you consider the alternative – phone calls – which I view as an act of violence. “Why is he calling me? What emergency necessitated his dialing my number and waiting for it to ring, what utter atrocity required the disruptively instantaneous back-and-forth of a voice conversation?” But I digress…

Here’s the thing you have to know about emails in 2012: It’s okay to ignore them. Even the ones from people you know. I started doing that this fall and you know what’s gone wrong? Nothing. No lost friendships, no hard feelings, no missed business opportunities, no miscommunications. It’s all good. So which emails do you respond to and which do you ignore? Simple! When you see an email, ask yourself “is ignoring this going to keep me up at night and make me feel as though I’ve been careless or sloppy or cruel?”  If the answer is yes, then deal with the email! If not, ignore it. It’s okay, if the person sending it knows you, then they’ll accept that you’re busy or think maybe you never got it (the spam folder ate my homework). This frees you up to respond to clients, vendors, business partners and close friends and acquaintances with whom you’re actively dialoging or making plans.

So don’t make all these dumbass folders and files you’re never going to use, just start blowing emails off as they come in. A wise man once said that your inbox is like a To Do list that someone else makes for you. To which I say, no thanks. I make my own To Do list, the needs and wants and tasks of others come after the tasks that are important to my clients and my practice.

As for what should replace the email, I vote for the Twitter direct message. No one will DM you annoying or wasteful communiques if you’re following each other on Twitter. PR people can be blocked, never mind any “safe unsubscribe” email spam ritual – you can get rid of a PR sea-creature whom you’ve accidentally followed forever with a Twitter unfollow.  As soon as they start allowing attachments on Twitter and slightly longer messaging, I’m going to start replacing as many email convo’s as possible with it.

—Joshua M. Brown

U.S. Life Expectancy: Overall Versus 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 earlier, 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.

QOTD: Rule of Lawyers

Americans could once boast proudly that their system set the benchmark for the world; the United States was the rule of law. But now what we see is the rule of lawyers, which is something different.

—Niall Ferguson

Study Finds Low-Carb Diet Reduces Heart Disease Risk Factors

Obesity Reviews just published details of a recent meta-analyis of low-carbohydrate diet effects on cardiovascular risk factors.

A systematic review and meta-analysis were carried out to study the effects of low-carbohydrate diet (LCD) on weight loss and cardiovascular risk factors (search performed on PubMed, Cochrane Central Register of Controlled Trials and Scopus databases). A total of 23 reports, corresponding to 17 clinical investigations, were identified as meeting the pre-specified criteria.

Over a thousand obese patients were involved.  By eating low-carb, blood pressure dropped by 3–4 mmHg, average body weight decreased by 7 kg (15 lb), body mass index dropped by 2, triglycerides decreased by 30 mg/dl, hemoglobin A1c dropped by 0.21% (absolute decrease), insulin levels fell by 2.23 micro IU/ml, while HDL cholesterol rose by 1.73 mg/dl.  LDL cholesterol didn’t change.

The authors conclusion:

Low-carboydrate diet was shown to have favourable effects on body weight and major cardiovascular risk factors; however the effects on long-term health are unknown.

I haven’t see the full text of the article yet, so I don’t know the carbohydrate level under review.  I bet it’s under 50 g of digestible carb daily.  My Low-Carb Mediterranean Diet starts at 20-30 grams a day.

Steve Parker, M.D.

Reference:  Santos, F.L., et al. Systematic review and meta-analysis of clinical trials of the effects of low carbohydrate diets on cardiovascular risk factors. Obesity Reviews. Article first published online: 20 AUG 2012. DOI: 10.1111/j.1467-789X.2012.01021.x

Book Review: The Oldways 4-Week Mediterranean Diet Menu Plan

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I’ve been an admirer of Oldways for many years. They tirelessly advocate for a way of eating that demonstrably lengthens lifespan while reducing rates of heart disease, stroke, cancer, diabetes, and dementia. Especially when compared to the standard American diet.

I’m very pleased to see Oldways present a four-week plan that helps the average person incorporate Mediterranean diet principles into daily life. These recipes are simple, practical, and delicious. No need for exotic ingredients or culinary classes!

Get started soon. You won’t regret it.

Steve Parker, M.D.

Disclosure: Olways provided me with a free pre-publication review copy of the book.

Could the Paleo Diet Prevent Tooth Decay?

The truth is that tooth decay is a relatively new phenomenon. Until the rise of agriculture roughly 10,000 years ago, THERE WAS NO TOOTH DECAY IN HUMANS.  Let that sink in for a moment. Humanity is 2,500,000 years old.  For the fist 2,490,000 years no one ever had a cavity.  If we understand that tooth decay started when people started farming instead of hunting and gathering for a living clearly you realize that tooth decay is a disease or mismatch between what you are eating and what your body expects you to eat.  If we examine the past as prologue it becomes clear that the path to proper health starts in the mouth and the answers are so simple that not only did a Cave Man do it.  They perfected it.

—John Sorrentino in a blog post August 6, 2012

PS: The paleo diet is also referred to as the Paleolithic, Cave Man, Stone Age, ancestral, primal, or hunter-gatherer diet.

Exercise Does and Doesn’t Help With Weight Loss

With regards to TV’s “The Biggest Loser” show:

The show’s 24-week regimen consists of approximately 4 hours of daily exercise, including 1 hour of intense resistance, 1 hour of intense aerobic activity, and 2 hours of moderate aerobic activity (for example, walking), along with a caloric  intake of at least 70% of estimated resting daily energy expenditure, explained Dr. [Robert] Huizenga, who is a former team physician to the L.A. Raiders football team.

exercise for weight loss and management, dumbbells

If you’re not familiar with resistance training, a personal trainer is an great idea

This is an excerpt from “The Biggest Loser Pushes Envelope on Diabetes,” in Internal Medicine News, vol. 45, No.11, page 17.

In a previous post about The Biggest Loser, I’d written that I didn’t know how much they exercised.

For purposes of discussion, let’s assume the documented major weight losses of Biggest Loser contestants is not simply due to caloric restriction.

Dr. Huizenga shared some of his experience at the recent annual meeting of the American Association of Clinical Endocrinologists.  In a study of 35 Biggest Loser participants, about half had prediabetes or type 2 diabetes.  Hemoglobin A1c, a measure of blood sugar control, fell significantly in this subset.  Three of the six with diabetes were able to stop metformin early on.  By week 29 of the study, average body mass index for the entire group had fallen from 46 to 29.

Yes, exercise helps with weight loss.  But most folks aren’t willing or able to exercise vigorously for four hours a day.  Physical activity is more important for maintenance of weight loss, when it demands much less time.

Steve Parker, M.D.