CVD – Page 7 – DrChet.com

Coconut Oil Research vs. the AHA

June 29, 2017/in Memos/by Chet Zelasko

For this memo, I’ll print conclusions from the papers cited in the American Heart Association Presidential Advisory on Dietary Fats and Cardiovascular Disease and then print what the authors wrote about the research studies they used to assess coconut oil (1). I’ll confess, it’s hard to understand how they reached some of these conclusions.

The study:
The findings suggest that, in certain circumstances, coconut oil might be a useful alternative to butter and hydrogenated vegetable fats (2).

AHA:
“A carefully controlled experiment compared the effects of coconut oil, butter, and safflower oil supplying polyunsaturated linoleic acid. Both butter and coconut oil raised LDL cholesterol compared with safflower oil, butter more than coconut oil.”

The study:
In conclusion, the results of this study indicated that it may be premature to judge SFA-rich diets as contributing to CVD risk solely on the basis of their SFA (saturated fatty acid) content.

AHA:
“Another carefully controlled experiment found that coconut oil significantly increased LDL cholesterol compared with olive oil (3).”

The study:
There was no evidence that coconut oil acted consistently different from other saturated fats in terms of its effects on blood lipids and lipoproteins.

AHA:
“A recent systematic review found seven controlled trials, including the two just mentioned, that compared coconut oil with monounsaturated or polyunsaturated oils. Coconut oil raised LDL cholesterol in all seven of these trials, significantly in six of them.”

The Advisory’s conclusion: “Because coconut oil increases LDL cholesterol, a cause of CVD, and has no known offsetting favorable effects, we advise against the use of coconut oil.”

Significantly. That’s a meaningful word in statistics but how about in the real world? I’ll finish this up in Saturday’s memo.

What are you prepared to do today?

Dr. Chet

References:
1. Circulation. 2017;135:00–00. DOI: 10.1161/CIR.0000000000000510
2. J Lipid Res. 1995;36:1787–1795.
3. Am J Clin Nutr. 2011;94:1451–1457
4. Nutr Rev. 2016;74:267–280.

Coconut Oil: Healthy or Not?

June 27, 2017/in Memos/by Chet Zelasko

The headlines screamed “Coconut Oil is Alarmingly High in Saturated Fats!” News post after news post talked about how Americans have been sold a bill of goods on the health benefits of coconut oil. Now the American Heart Association says it’s harmful. They published a Presidential Advisory on Dietary Fats and Cardiovascular Disease, a review paper to examine one issue: does saturated fat contribute to cardiovascular disease? They state that both the public and healthcare professionals are confused over this issue. The reasons are complex but primarily due to recent research publications that questioned the role saturated fat plays in the development of CVD.

The paper is 19 pages long with six pages of references. I’m not going to cover the entire paper because for the most part, there’s nothing new in what they’ve said. I’m only going to address a single issue: coconut oil. They begin the section by citing a New York Times survey that looked at which foods nutritionists consider healthy and what a group of registered voters consider healthy; nutritionists say coconut oil is not healthy while the public believes it is. The authors speculate that this is the result of the marketing of coconut oil in the popular press. Evidently they don’t spend much time on the Internet, because that’s where the bulk of claims for coconut oil are made.

I’m a fan of coconut oil for one primary reason (other than the fact that I love coconut): it contains short- and medium-chain fatty acids that can by-pass the liver and be used as energy for most organs. Is it still a saturated fat? Absolutely. Does it cause an increase in your risk of CVD? I’ll review their research on Thursday.

What are you prepared to do today?

Dr. Chet

Reference: Circulation. 2017;135:00–00. DOI: 10.1161/CIR.0000000000000510

BMI, WHR, and Lifestyle

March 18, 2017/in Memos/by Chet Zelasko

The study we’ve been examining is interesting on so many levels: large numbers of subjects; new statistical techniques due in large part to progress in computing capabilities; genetic analysis that allows for rapid analysis and identification of polymorphisms. It’s all very exciting. You’re probably anticipating a “but” coming and you’d be correct.

This study demonstrated that when using genetic information, WHR is a risk for CVD and type 2 diabetes even with a normal BMI. But there’s still at least two factors to consider that are dependent on each other.

First, just because someone has a mutated gene or genes, it doesn’t mean it will ever express itself, i.e., turn on. More than likely, the second factor has a role to play and that’s the lifestyle of the individual. Some studies refer to it as environment, but they’re intertwined. Where you live may limit or provide you with easy access to healthier foods. It may be easier to exercise in the suburbs than in a large city, or just the opposite given the park systems in different areas of the countries.

Then there’s the home environment: what foods you ate growing up and what your diet is now. All these can impact whether some genes may be expressed. Others may express themselves only when you get to a specific weight or fat intake. The variables are too numerous to consider.

I’m not attempting to confuse the issue. I just want you to know that while this study provides insight that we didn’t have before, you don’t have to be overly concerned. If you keep to a normal BMI and WHR, less than 0.9 for men and less than 0.8 for women, your risk for CVD and type 2 diabetes will not be high.

When all is said and done, it still comes down to three things. Eat less. Eat better. Move more.

What are you prepared to do today?

Dr. Chet

Reference: JAMA. 2017;317(6):626-634.

Waist-Hip Ratio vs. BMI

March 16, 2017/in Memos/by Chet Zelasko

In Tuesday’s message, I said researchers used a unique approach to answering the question of whether waist-hip ratio (WHR) is associated with cardiovascular disease and type 2 diabetes regardless of BMI. They found 48 genes which were associated WHR, a unique approach using the genetic information with Mendelian randomization of epidemiological data. If that isn’t a brain-full, I don’t know what is. Let me see if I can break it down for you.

As I’ve said many times before, epidemiological data cannot show cause and effect; they’re just observations. By using the genetic information related to WHR, researchers can analyze the data by statistically removing the effect of BMI. Because the genetic traits follow some randomization based on Mendel’s genetic work, if the WHR is still associated with the increased risks of disease, that means that where you carry your body fat is important, whether your BMI says you’re overweight or not.

They found that WHR is an independent risk factor for CVD and type 2 diabetes, confirming that the location of your body fat is important regardless of your BMI. That may be why people with a high BMI but low WHR have normal blood pressure and cholesterol levels while others with a normal BMI but a high WHR may have high numbers.

What are you prepared to do today?

Dr. Chet

Reference: JAMA. 2017;317(6):626-634.

Redefining the Risks of Extra Weight

March 14, 2017/in Memos/by Chet Zelasko

Studies show that 70% of the population is overweight; by definition, that means that their body mass index (BMI) is greater than 25 or more. But are all overweight people at the same risk? Just because you’re overweight, are you automatically at greater risk for cardiovascular disease and type 2 diabetes?

That’s what a group of researchers in the U.S. attempted to find out. They had the benefit of access to the U.K. Biobank, an independently funded databank that has collected biometric data on over 500,000 subjects in the U.K. and contains accurate measures of BMI as well as the waist-hip ratio (WHR) on all subjects. They also had one more thing: the genetic information on a large sub-group of subjects. They identified 48 genes that seemed to be associated with WHR and used a unique approach to tease out the effects of WHR from BMI. I’ll cover that the rest of the week.

In the meantime, check out your BMI and measure your waist and hip to calculate your WHR. Measure your waist about an inch below your belly-button and your hips at the widest point; divide waist by hips and you have your ratio.

What are you prepared to do today?

Dr. Chet

Reference: JAMA. 2017;317(6):626-634.

Does Sitting Cancel Out Exercise?

August 30, 2016/in Memos/by Chet Zelasko

This past Friday, I ran 4.5 miles on a great running and biking trail in Grand Rapids; it was a great morning and with the canopy of trees, it was cooler than it would have been in the sun. The rest of the day, I recorded my radio show, read, wrote, and finished off the day watching some home improvement shows. I typically spend more than eight hours sitting while I do what I do.

Unfortunately, that run won’t reduce my risk of dying from cardiovascular disease—not based on the headlines for a scientific statement just released . . .