New Studies Dispel Health Benefits of Coconut Oil, Favor Olive Oil

The coconut oil craze in the United States has propelled it to the forefront of health and beauty discussion. Not only promoted for its health benefit when consumed, but also its ability to soften skin, thicken hair and whiten teeth – it has become, seemingly, the single most important item in the pantry and medicine cabinet alike.1Healthy and Unhealthy oils

But, emerging new research is casting a different light on the subject.

A new meta-analysis revealed that, in contrast to popular belief, coconut oil is not linked to lower rates of inflammation, glycemia, or adiposity.  It is, in fact, responsible for increasing LDL cholesterol and considered among one of the more dangerous oils when compared to other fats.2

According to Deirdre Mattina, MD, with the Henry Ford Health Systems Women’s Heart Center in Detroit, MI, the confusion has stemmed from widespread claims that coconut oil has anti-inflammatory properties that are based on smaller studies from geographically isolated populations.  Unfortunately, there is relatively little scientific evidence to support the claims.

“A lot of that we sort of took out of context and from what other components are available in those populations’ diets. And then people are just naturally always looking for something that’s marketed as being natural or different in processing, so I think they’re flocking to those things and maybe misinterpreting what healthy really is,” Mattina added.

The study’s senior author, Rob M. van Dam, PhD from the National University of Singapore, told TCTMD, an information resource produced by the Cardiovascular Research Foundation (CRF), that he and his colleagues launched the study because of how widely coconut oil is positively promoted for health benefit in the press.

The study included 16 international trials comparing the effects of at least two weeks of coconut oil consumption with other nontropical vegetable oils or palm oil on cardiovascular risk factors. The trials reported on body weight, body fat, waist circumference, fasting plasma glucose and C-reactive protein.

Findings revealed that when compared with these oils, coconut oil significantly increased total cholesterol, LDL cholesterol, and HDL cholesterol but not triglycerides, body measurements, glycemia, or C-reactive protein.

The authors concluded that ‘the hypercholesterolemic effect of coconut oil intake is probably attributable to its high saturated fat content – consisting of about 90% saturated fat, which is higher than the proportion of saturated fat in butter or lard.’  Additionally, “about a quarter of coconut fat consists of the long-chain saturated fatty acids myristic acid and palmitic acid.”

In an accompanying editorial, Frank Sacks, MD of Harvard TH Chan School of Public Health, Boston, MA, supported the findings and resulting recommendations saying that “coconut oil may be viewed as one of the most deleterious cooking oils that increases risk for cardiovascular disease.3”

The authors further concluded in an article summary that coconut oil holds no benefits with regards to ‘body fatness, inflammation, blood sugar, or heart health – but rather in large quantities can increase blood LDL-cholesterol concentrations, potentially increasing risk of heart disease.’

For van Dam and his colleagues, ongoing research will assess whether consuming coconut oil has any link to cardiovascular disease outcomes, not just markers of disease like serum cholesterol.

Conversely, new observational data shows that higher olive oil intake is associated with a lower risk of coronary heart disease and cardiovascular disease. The study authors note that olive oil consumption, though, is generally less in the US (where saturated fats and other plant-based unsaturated fats play a larger role in the diet) compared with European and Mediterranean populations – consequently less studied in this population group.

Author Marta Guasch-Ferré presented the findings at the American Heart Association’s EPI-Lifestyle 2020 Scientific Sessions, simultaneously publishing in the Journal of the American College of Cardiology.4

Investigators found that subjects consuming more than half a tablespoon per day (>7 g/day) had a 14% lower risk of cardiovascular disease and an 18% lower risk of coronary heart disease over 24 years of follow-up. No link was seen between olive oil consumption and stroke.

Speaking with TCTMD, Guasch-Ferré pointed to additional findings for the US cohort, including important benefits to consumers if olive oil replaced approximately 5 g/day of margarine, butter, mayonnaise, or dairy fat. However, there was no difference between the benefits associated with olive oil consumption and those associated with intake of other nontropical, plant-based oils.

“The main message is that our results provide support for the recommendations to replace saturated fats and animal fat with unsaturated olive oil or other types of unsaturated fats,” said Gausch-Ferré.

When asked about controversies stemming from randomization of subjects in an earlier study on a Mediterranean diet supplemented with additional extra virgin olive oil, reducing major cardiovascular events by 31% compared with a fat restricted control diet (PREDIMED), which Gausch-Ferré co-authored several years earlier, the author underscored the important benefits found in both studies and the need for ongoing research on olive oil consumption.

According to the study summary in TCTMD, the benefits of olive oil may be partly explained by the replacement of saturated fats with unsaturated oil, a recommendation also set out in a recent scientific advisory on dietary cholesterol from the American Heart Association. Though study authors stressed that benefits specific to olive oil itself cannot be discounted, in particular, high oleic acid content, which the authors note is less susceptible to oxidation than other more unsaturated fatty acids.

“It has also been observed that olive oil can have favorable effects on endothelial dysfunction, hypertension, inflammation, insulin sensitivity, and diabetes,” the authors conclude.

The authors were also clear to state the importance in communicating olive oil benefits to the American population, as consumption habits vary greatly from those of the European population.

The benefits intrinsic to olive oil would need to be coupled with moderation and reductions in the types of fats typically consumed in higher quantities by Americans.

We at Carient Heart and Vascular have a robust diet program.  Working collaboratively with our nutrition coaches, we are helping patients change dietary habits to fit their lifestyle and achieve long-term cardiovascular health and well-being.  Learn more about structural heart disease and interventional cardiology. To schedule a consultation, please call 888-602-3339.

Reference

  1. Very Healthy Life. https://veryhealthy.life/11-benefits-coconut-oil/?utm_source=%2Bcoconut%20%2Boil&utm_medium=11BenefitsofCoconutOil&utm_campaign=adw_us .
  2. Neelakantan N, Seah JYH, van Dam RM. The effect of coconut oil consumption on cardiovascular risk factors: a systematic review and meta-analysis of clinical trials. Circulation. 2020;Epub ahead of print.
  3. Sacks FM. Coconut oil and heart health: fact or fiction? Circulation. 2020;Epub ahead of print.
  4. Guasch-Ferré M, Liu G, Li Y, et al. Olive oil consumption and cardiovascular risk in US adultsJ Am Coll Cardiol. 2020;Epub ahead of print.

 

Aortic Stenosis and the Role of Catheter Based Therapies

When Less Invasive TAVR is Preferable in the Treatment of this Serious Heart Condition

Aortic valve disease is one of the most encountered structural abnormalities of the heart.  The aortic valve is a trileaflet structure that separates the left ventricle from the aorta. In systole, during left ventricular contraction, the aortic valve opens between 3 -5 cm2 to allow blood flow.

Aortic valve disease is one of the most encountered structural abnormalities of the heart.  The aortic valve is a trileaflet structure that separates the left ventricle from the aorta. In systole, during left ventricular contraction, the aortic valve opens between 3 -5 cm2 to allow blood flow through the aorta and to the rest of the body.

The most common disease of the aortic valve is aortic stenosis. Aortic stenosis is the result of calcification and narrowing of the aortic valve. As a result, the valve does not open adequately in systole, causing strain and pressure overload on the left ventricle. Aortic stenosis is the result of active inflammation of the valve, which in many ways is similar to atherosclerosis.

Risk factors for developing aortic sclerosis include hypertension, high cholesterol, diabetes and chronic kidney disease. There is perhaps also a genetic predisposition to developing aortic stenosis. Aortic stenosis is more prevalent in the older population. It is mostly diagnosed and treated in patients in their 70’s and 80’s. It is estimated that over six percent of the population in the United States over the age of 70 suffer from aortic stenosis. However, aortic stenosis can present earlier if the patient is born with an abnormal valve such as an unicuspid or bicuspid valve. In these instances, symptoms develop earlier in the fifth and sixth decade of life.Healthy Aortic Valve

Symptoms of aortic stenosis include chest pain, shortness of breath and palpitation. If left untreated, it can ultimately cause congestive heart failure and loss of consciousness – and ultimately sudden cardiac death. The three-year prognosis in aortic stenosis is extremely poor once the patient has developed symptoms.

Diagnosis of aortic stenosis hinges on a physical examination and noninvasive diagnostic cardiac testing such as echocardiography.  Severe aortic stenosis results in a harsh systolic murmur heard best on the left sternal border. The second heart sound is also blunted or absent in this area. Echocardiography shows thickening and calcification of the valve with significantly reduced mobility in systole. The ultimate diagnosis is made by measuring pressure gradient across the aortic valve, utilizing Doppler Wave Echocardiography. A mean gradient of over 40 mmhg, or a valve area of less than 1 cm square, strongly predicts severe aortic stenosis.Aortic Valve Assessment

Treatment of aortic stenosis requires active intervention. Medical therapy alone does not resolve the severe narrowing of the valve. Traditionally, patients have required open heart surgery to replace the narrowed valve with either a bioprosthesis or a mechanical valve. This would require a sternotomy and 4-6 weeks of recovery post operation.

Over the past decade, though, a new technique utilizing transcatheter methods has been shown to be either equivalent or superior to surgical replacement in most patients regardless of their surgical risks. During this procedure commonly known as Transcatheter Aortic Valve Replacement (TAVR), a new valve is advanced from the femoral artery in the groin (in most instances) and placed inside the narrowed valve. There is no surgical incision during TAVR, therefore recovery is much faster.Transcatheter Aortic Valve Replacement

 

Patients undergoing TAVR need elaborate work up prior to their procedure. Aortic valve size needs to be determined prior to the procedure, unlike the traditional procedure when the surgeon decides on valve size during the surgery. While most valves are delivered through the femoral arteries, there are instances where femoral arteries are either too small or diseased to accommodate delivery of the valve. In these instances, alternative access should be utilized to deliver the valve.

A gated CT angiography is essential to address sizing and access before the procedure. Cardiac catheterization is also needed to define patency of the coronary arteries before the procedure. Significant coronary artery disease usually needs to be addressed prior to TAVR. There are currently three commercially available TAVR valves. Which valve to use depends on the anatomical and clinical characteristics of each individual patient for optimal outcome.

Finally, TAVR in lieu of surgical aortic valve replacement (SAVR) is determined on a case by case basis. For example, a patient with extensive multivessel coronary artery disease (CAD), who will need coronary bypass surgery, should also have SAVR at the same time. Some patients with bicuspid aortic valve also have ascending aortic dilatation and will need surgical repair of their aorta, which can be done at the time of SAVR.

Lastly, there are patients who can go either route depending on their circumstances. For example, a younger patient with a small aortic valve might undergo TAVR now. But it is conceivable that their TAVR valve will deteriorate over the next decade or two and they will need another procedure. The small size of the aortic valve might prohibit another TAVR procedure down the line. So, this patient might decide to have a TAVR now and reserve SAVR for a later time, or, alternatively, do the reverse depending on the circumstances. That is why it is important that the treatment recommendation is made after input from every member of the valve team, including an interventional cardiologist as well as a cardiac surgeon.

 

Should Patients With Stable Coronary Artery Disease Undergo Stent Placement?

Should anyone with obstructive coronary artery disease undergo angioplasty and stent placement?

The answer is, of course, no.

Like everything else in medicine, intervening in a disease process is all about risks vs benefits. The immediate risks of the procedure should be weighed against the patient’s gains from that procedure.

In considering invasive coronary intervention, the degree of symptomatic relief as well as preventing future cardiac events should be weighed against the immediate risks of the procedure. Many trials have tried to identify the patient pools where the benefits of an invasive strategy outweigh the risks.

The recently presented ISCHEMIA trial renewed this discussion regarding the utility of coronary interventions in patients with significant disease. In this trial, presented at the last American Heart Association meeting, patients with stable coronary artery disease were randomized to an invasive strategy with coronary angiography and revascularization (either via stent placement or cardiac bypass surgery) vs Optimal Medical Therapy ( OMT).

After a median of 3.3 years, there was no difference in terms of cardiovascular deaths, heart attacks, heart failure or unstable angina admissions as well as resuscitated cardiac arrests. However, quality of life was shown to be more improved in the invasive treatment arm due to better relief of anginal symptoms.

ISCHEMIA, while a landmark trial, is not the only study showing similarity between OMT and revascularization in patients with coronary artery disease. COURAGE and BARI 2D are two such trials published in the past couple of decades showing similar findings.

There were several criticisms of these trials that resulted in the need for ISCHEMIA. For example, both these trials did not include the new generation of stents.

ISCHEMIA Trial

Also, a significant number of patients enrolled had low burden of ischemia (inadequate blood supply to the heart due to the blockage). Patients with low burden of ischemia are thought to derive less benefit from invasive strategy compared to those with higher degree of ischemia.

Additionally, everyone received cardiac catheterization prior to randomization introducing operator bias in the equation. Keeping the treating physicians blind to the patient’s coronary anatomy (obtained by CT angiography in most) prior to randomization, utilizing new stent designs in the invasive arm, and enrolling only patients with moderate or higher degree of ischemia, the ISCHEMIA trial eliminated some of the concerns raised by the earlier studies.

ISCHEMIA confirmed what most interventional cardiologists already believed. In patients with stable coronary artery disease who do not have high risk features such as left main obstructive disease or very poor heart muscle function (these groups were excluded in the ISCHMIA trial), an invasive strategy alleviates symptoms much better than OMT alone, but it does not give superiority in terms of future deaths or heart attacks.

So, do we have all the answers now based on these results? Should we tell our patients that they only get better symptomatic relief via invasive strategy and nothing else?

The majority of the data available points to the validity of this statement but there remains some unanswered questions. For one, did this study use nuclear or echo imaging as the initial work up for most patients? Nuclear perfusion imaging and stress echocardiography while prevalent are hardly the best tests to define the ischemic burden. Perhaps utilizing more sensitive tests such as PET or FFRCT would better identify patients with higher burden of disease and at higher risk.

Also, as of now we know that patients were randomized based on having more than 50% luminal narrowing on CT angiography. As all interventional cardiologists know, there is a big difference between 50% narrowing and 95%. It is unclear how many patients had FFR (hemodynamic assessment of the blockage) performed at the time of revascularization in ISCHEMIA. No one intervenes on a 50% narrowing without functional data.

Studies such as FAME have shown that identifying lesions with hemodynamic significance at the time of the angiography and intervening on them only will provide patients benefit from future events.

The exact severity of coronary artery disease on CTA and its correlation to the stress imaging studies are unknown since investigators were blinded to the CT results. We also don’t know how many patients in the invasive arm had complete revascularization. Lack of complete revascularization (leaving some of the narrowing untreated at the time of the invasive procedure) could explain absence of superior benefit with the invasive arm.

Upcoming release of further data from the trial will shed light on some of these concerns.

In summary, many patients might benefit from coronary intervention and stent placement on top of OMT. However, this benefit comes from symptomatic relief. So far, there is little data to suggest coronary stent placement protects most stable patients (patients with high risk characteristics excluded) from future cardiac events.

Whether to proceed with coronary intervention or continue with OMT should be based on in-depth discussion between the patient and their treating physicians. Severity of patient symptoms, compliance with medications and understanding of the data by the patient are essential in shared decision making.

Additionally, it is essential that the patient’s work up not stop at perfusion nuclear imaging, given patients with high risk anatomical findings on the follow up CTA were excluded from ISCHEMIA. It would be catastrophic to miss a patient with left main disease (about 5% of screened patients in the trial).

Perhaps a more sensitive test to identify patients with high ischemic burden such as PET or FFRCT should be considered upfront rather than myocardial perfusion imaging when available.