Showing posts with label cardiac risk. Show all posts
Showing posts with label cardiac risk. Show all posts

Monday, June 10, 2013

Fish Oil is Dead... or Is It?

If you're a patient or a regular reader of my articles, you know that one supplement that I often recommend is fish oil -- a good source of omega-3 fatty acids.  These fats are essential to our health, because our bodies cannot make them from any other type of fat.  The many benefits of omega-3 fats include:

  • Cardiovascular health benefits
  • Immunomodulation
  • Anti-inflammatory effects
  • Psychological and behavioral health improvement
  • Improved bone density
A large study published recently in the New England Journal of Medicine (1) has called into serious question the well-established cardiovascular benefits of fish oil.  Italian researchers divided a group of over 12,000 subjects into two groups:  one received 1 gram of omega-3 fats from fish oil per day, the other 1 gram of placebo (olive oil).  These were high-risk patients:  people with multiple cardiovascular risk factors such as high cholesterol, type 2 diabetes, or even established atherosclerosis.  The outcome?  After 1 year, there was no difference in the rates of death, non-fatal heart attack, or stroke between the two groups.

What are we to conclude from this?  The sound-bite headlines trumpet "Fish Oil is Worthless!"  Some eminent cardiologists agree.  But let's peel back the layers, and examine the flaws in this otherwise large and impressive study.
  1.  Dose.  1 gram of omega-3 fats is not a high dose at all, especially in this population of high-risk patients.  For my patients with any cardiovascular risk factors, I recommend 1.5-2.5 grams of omega-3 fats per day.  And remember, a 1 gram (1000 mg) fish oil softgel only contains about 300 mg of omega-3s.  For cardiovascular health, 5-8 softgels per day are required.  An alternative would be to take a concentrated form of fish oil, or to use liquid cod liver oil.  I take about 2 teaspoons of cod liver oil daily, which supplies around 2.5 grams (2500 mg) of omega-3s.
  2. Quality.  There is a wide variability in the quality of fish oil products.  A pharmaceutical-grade form is best, which is screened for impurities, and has less chance of being rancid.  The form used in the study is not specified.
  3. Lab Values.  One of the main ways that omega-3 fats benefit the cardiovascular system is by lowering triglyceride levels -- data about patients' triglyceride levels were not included in the study.  Also, how well were the diabetic patients maintaining blood sugar control?  Poorly controlled blood sugar is a major risk factor that a little fish oil won't overcome.
  4. Choice of "Placebo."  A placebo (inactive pill) is necessary in research studies to compare to the active intervention, to account for the fact that people's expectations about receiving care can have a strong therapeutic effect.  This is know as the placebo effect.  But is olive oil a good choice as an inert comparison?  There is a mountain of research about the cardiovascular benefits of the Mediterranean Diet, whose foundation is daily olive oil use.  Just a few weeks ago, I wrote about the PREDIMED study, which found that an olive oil-supplemented Mediterranean diet resulted in a 30 percent decreased risk of cardiovascular disease
  5. Other Benefits of Omega-3 Fats.  Now granted, the list of other benefits was not being looked at in this study, but some commentators really threw the baby out with the bathwater on this point.  Cardiologist Eric Topol, MD, called fish oil a "no-go," a "nada effect," and even "implores" his patients to stop taking it.  Really?  That's quite an exercise in ignoring the large body of research on fish oil for multiple body systems.
As always, I urge you to look past the headlines, and consider the whole research picture.  Don't throw out your fish oil on the basis of this one flawed study.

Wednesday, May 15, 2013

More Good News for the Mediterranean Diet

For years, the standard nutritional advice for cardiovascular disease prevention has been to follow a low-fat diet.  This is still the official recommendation of the American Heart Association.  However, more and more evidence is pointing to the fact that it may be the quality, not quantity, of the fats we consume that is good for our hearts.

A few weeks ago, I wrote about a new study showing that detrimental effects of red meat consumption on our gut bacteria.  This could be one of the keys that links higher risk of cardiovascular disease to hiding meat intake.  The Mediterranean diet, which is low in meat, has just gotten some new support for its effectiveness in primary prevention of cardiovascular disease.  The Mediterranean diet is definitely not low in fat; it just relies more on different types of fat than the standard American diet (S.A.D.).  Instead of high levels of animal-based saturated fats from meat and dairy, the Mediterranean approach relies more on the healthful unsaturated fats in nuts and olive oil.

This new study from Spain, called PREDIMED (1), differs from previous research, in that it was a randomized controlled trial, involving over 7000 older men and women without any established cardiovascular disease.  This means that the investigators assigned a different diet to different groups of subjects -- either Mediterranean, or the AHA low-fat diet.  Most previous research was a retrospective -- that is, it looked at people's dietary habits in the past, based on recall or diet diaries.

The exciting finding from PREDIMED is that the Mediterranean diet, with a special focus on either olive oil or nuts, resulted in about a 30% lower risk of heart attack, stroke, or cardiovascular death compared to the low-fat approach.  Perhaps surprisingly, there are no studies of similar quality to support the benefits of a low-fat diet.  This recommendation of the AHA could be classified as a medical myth.

Dr Ramón Estruch, one of the lead researchers in this study, summarized his recommendations this way:
"People should know that the Mediterranean diet is a diet healthier than others and should know the key components of this food pattern. The plan should be to increase the intake of the key foods (vegetables, fruit, nuts, fish, legumes, extra virgin olive oil, and red wine in moderation), also increase the intake of white meat, and decrease the intake of red and processed meat, soda drinks, whole dairy products, commercial bakery goods, and sweets and pastries."
He continued: "To achieve a score of 14 in the 14-item adherence scale to traditional Mediterranean diet [laid out in a supplemental appendix in the paper] is more or less impossible, but to upgrade two to three points in this score is enough to reduce your cardiovascular risk by 30%."

 1.  Estruch R, Ros E, Salas-Salvadó J, et al. Primary prevention of cardiovascular disease with a Mediterranean diet. N Engl J Med 2013; DOI:10.1056/NEJMoa200303. 

Monday, October 29, 2012

Is Vitamin D Good for the Heart or Not?

Based on much recent research linking low levels of vitamin D to increased risk of heart disease, this is something I measure in all of my older patients.  If low, supplementation is simple, cheap, and can effectively raise those levels back up.  This is especially important at this time of year, since the sun is not strong enough to produce any vitamin D from skin exposure at our latitude.

A recent study in the Journal of Clinical Endocrinology & Metabolism (1) looked at the question of whether or not supplementing with vitamin D can change cardiovascular risk.  This was one of the first actual placebo-controlled clinical trials to examine the question.  Half the participants got vitamin D3 (a good quality form of vitamin D), and the other half got placebo.  At the end of the study, they examined cardiovascular risk markers, such as blood cholesterol, blood pressure, and C-reactive protein, and found no significant difference between the groups.  The conclusion?  Quoting from the New York Times:
“The study actually shows that vitamin D does not protect you against heart disease,” said Helen M. Macdonald, a senior lecturer at the University of Aberdeen in Scotland, who led the study. “That’s not what people want to hear, but it’s true.”
Now hold on a minute.  The researchers are making a huge assumption:  that the risk markers of cholesterol, C-reactive protein, etc., are synonymous with heart disease.  The thinking is that if something (in this case vitamin D) does not affect those traditional risk markers directly, there is no impact on heart disease.   However, it is well known that a significant percentage of heart disease and heart attacks occur in people with normal cholesterol levels and blood pressure.  Perhaps vitamin D is an independent risk factor -- that is, it could protect against heart disease without changing those other parameters.

The way to  really tell this for sure experimentally would be to use actual cases of heart disease as the end point of vitamin D supplementation.  This study was a good first step, but the error in logic on the part of the researchers is glaring.  In the meantime, I'll keep checking blood levels of vitamin D on my patients over age 40 as part of an overall cardiovascular risk assessment, using the naturopathic principle of "Treat the whole person."

1.  Vitamin D3 Supplementation Has No Effect on Conventional Cardiovascular Risk Factors: A Parallel-Group, Double-Blind, Placebo-Controlled RCT.  Published online before printAugust 3, 2012, doi:10.1210/jc.2012-2126
The Journal of Clinical Endocrinology & Metabolism, vol. 97 no. 103557-3568

Monday, October 1, 2012

Top 5 "Myths" in Natural Medicine

As a doctor of naturopathic medicine, I have years of experience and training to respect the vis medicatrix naturae, or healing power of nature.  This is foundational to our approach to health.  I also have a background in science, and know that it is important to examine natural methods of health care to see if they are valid and effective.

That is why (though it might be dangerous to step on some toes) I like to clarify common misperceptions:  My goal is to help patients be as healthy as possible, not to be wedded to a particular idea.  Therefore, over the next few articles, I will present five common myths I often encounter, in no particular order.

Myth #1: Policosanol is a good alternative to cholesterol-lowering medication.
Policosanol is an extract of the sugar cane plant that made big news about ten years ago, with studies showing it was very effective at lowering blood cholesterol levels (1).  The nutritional supplement industry responded with a deluge of policosanol products.  However, much of that early research was conducted in Cuba, the source of the sugar cane--the raw material for policosanol production.  Follow-up studies conducted on larger populations, showed little to no clinically significant cholesterol-lowering effects of policosanol (2, 3).  Even though this well-designed research was published in 2006, policosanol sales continue to this day.  More recent research from 2011 (4) found that even a form of policosanol modified to make it better absorbed from the gastrointestinal tract failed to make a significant dent in cholesterol levels.  Some recent studies showing benefits used policosanol in combination with red yeast rice and berberine, two natural compounds that have been proven time and again to be effective in lowering cholesterol.  It's highly likely in these studies that the policosanol could have been left out, without affecting the results.

With all this evidence against policosanol, why are sales still so brisk today?  Well, in the midst of bashing the evil of Big Pharma companies, we sometimes forget that supplement companies are businesses, too, driven by market forces.  As long as there's a demand for policosanol (based on those biased studies from 10-15 years ago), they'll keep selling it.  Sorry, folks--supplement companies are not selfless crusaders for health; they're driven by the profit motive.  It's the American way.

I stopped recommending policosanol in 2006, in favor of much more effective treatments.  I also like to remind patients that high cholesterol is not a disease; it's a risk factor for cardiovascular disease (CVD).  I put the emphasis on lifestyle factors for CVD prevention, and look at modifying other risk factors too (such as high-sensitivity C-reactive protein and blood levels of vitamin D).

Next Time:  Cinnamon for blood sugar control

1.  Policosanol: a new treatment for cardiovascular disease?   2002 Jun;7(3):203-17.
2.  Effect of policosanol on lipid levels among patients with hypercholesterolemia or combined hyperlipidemia: a randomized controlled trial.   2006 May 17;295(19):2262-9.
3.  Comparative lipid-lowering effects of policosanol and atorvastatin: a randomized, parallel, double-blind, placebo-controlled trial.   2006 Nov;152(5):982.e1-5.
4.  Modified-policosanol does not reduce plasma lipoproteins in hyperlipidemic patients when used alone or in combination with statin therapy.   2011 Oct;46(10):923-9. Epub 2011 Jul 8.

Thursday, August 30, 2012

Great Science on What We Should Eat

In recent years, medical researchers have recognized some common denominators in chronic degenerative diseases:  insulin resistance, long-term inflammation, high blood pressure, and cholesterol imbalance (to name a few).  In fact, several of these factors have been grouped together to form metabolic syndrome, a constellation of symptoms including at least 3 of the following 5 conditions:

  • Fasting blood sugar (glucose) ≥100 mg/dL
  • Blood pressure ≥130/85 mm Hg
  • Triglycerides ≥150 mg/dL
  • HDL-C ("good cholesterol") < 40 mg/dL in men or < 50 mg/dL in women
  • Waist circumference ≥40 inches in men or ≥35 inches in women

I often talk to patients about dietary factors to reduce these risk factors, mainly focused on low glycemic index foods -- healthy foods that stabilize blood sugar and insulin levels throughout the day.  In a recent study (1), researchers used a dietary intervention for overweight middle-aged adults that significantly improved many of these markers for cardiometabolic risk.  Key components of the diet included the following:
  • Antioxidant-rich fruits and veggies
  • Omega-3 fatty acids (from fish oil)
  • A focus on low glycemic index meals
  • Viscous dietary fiber and plant sterols/stanols
  • Whole grains, soybeans, and almonds
  • Probiotic bacteria supplement
Sound familiar?  If you've been through FirstLine Therapy with me, this sounds an awful lot like that diet plan.  Most of these factors are available through sensible consumption of whole foods.  Some are more easily obtained through supplements (probiotic bacteria) or medical food meal replacements (viscous fiber, plant sterols/stanols).  And the results for good adherence to this diet?
  • Total cholesterol decreased by 26%
  • LDL ("bad cholesterol") decreased by 34%
  • hs-CRP (a marker of systemic inflammation) decreased by 29%
  • Systolic blood pressure dropped by 8%
Once again, science is showing that a common-sense, supplemented Mediterranean diet is as good as pharmaceuticals for improving cardiometabolic health -- without the side effects.

1.  Juscelino Tovar; Anne Nilsson; Maria Johansson; Rickard Ekesbo; Ann-Margreth Åberg; Ulla Johansson; Inger Björck.  A Diet Based on Multiple Functional Concepts Improves Cardiometabolic Risk Parameters in Healthy Subjects.  Nutr Metab. 2012;9(29).  Accessed August 29, 2012 at http://www.medscape.com/viewarticle/766177