Will Fat Kill You, or Make You Live Forever?

As you might expect, it depends on the kind of fat.  As I wrote about a few weeks ago, the standard advice from the 1970s and 80s about following a low-fat diet turned out to be less healthy than including "good" fats from foods like nuts and olive oil.  Another recent scientific paper from Australia, published in the British Medical Journal, further blows to top off the old dietary fats advice, showing that saturated fat may not be as bad as we thought it was.

A few decades ago, researchers started noticing a correlation between intake of saturated fats (from foods like meat, dairy products, and shortening) and cardiovascular disease.  The recommendation, therefore, was to replace these fats with healthier polyunsaturated fats from vegetable sources.  In this study, researchers examined data about 458 men, half of whom received advice to replace saturated fats with omega-6 oils from vegetable sources.  The other half (the control group) received no specific dietary advice.  After about seven years, it turned out that the death rate in the omega-6 group was 17.6%, versus 11.8% in the control group.  Heart disease rates were also 60% higher in the vegetable oil group.

Wait.  Take a look at those numbers.  Don't we all know that a saturated fat laden cheeseburger will just clog up our arteries as we're sitting there?  Isn't this why all the lard and shortening have been replaced with "healthy" vegetable oil for frying?

It turns out that not all polyunsaturated fats are created equal.  There are two major categories of PUFAs:  omega-6 and omega-3.  Ideally, the ratio of our intake of omega-6 to omega-3 should be about 2 to 1.  A higher intake of omega-3 fatty acids has been shown over and over again to decrease cardiovascular disease risk, and lower mortality rates.  However, the current ratio in America is about 20 to 1, omega-6 to omega-3.  This is a major reason why chronic degenerative diseases continue to escalate in this country.  Maybe it's those french fries that are killing us, not the burgers.

So what are we to do with this information?  No, this is not carte blanche to go and scarf down as much meat as you want; we still know that a plant-based eating pattern such as the Mediterranean diet is highly protective overall.  For cooking, use smaller amounts of healthy saturated fat, such as extra-virgin coconut oil.  Extra-virgin olive oil is also a good choice, as a source of monounsaturated fats (and yes, contrary to popular belief, you absolutely can cook with it).  A fish oil supplement is a must for most people, to ensure adequate omega-3 intake.  Skip deep-fried foods altogether, since the omega-6 fats in the vegetable oils may actually increase our mortality risk (either by themselves, or by transformation into trans fats).

The more we learn, the more we'll untangle which fats are good for us!

Use of dietary linoleic acid for secondary prevention of coronary heart disease and death: evaluation of recovered data from the Sydney Diet Heart Study and updated meta-analysis.  BMJ 2013; 346 doi: http://dx.doi.org/10.1136/bmj.e8707 (Published 5 February 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.

1.  n–3 Fatty Acids in Patients with Multiple Cardiovascular Risk Factors.  N Engl J Med 2013; 368:1800-1808May 9, 2013DOI: 10.1056/NEJMoa1205409