Should People with CVD Take Omega-3s?

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Last time, I talked about some research that hasn’t been done to definitively know whether DHA contributes to arrhythmias or not, but I implied that there may be one issue that may have contributed to this latest study. Let’s talk about research bias.

Research Bias

Some of the researchers who examined the data from the longitudinal study I talked about on Tuesday were also involved in at least one of the clinical trials on Vascepa, the pharmaceutical form of EPA-only omega-3s. I know what you’re thinking: somehow they intentionally manipulated data so that it seemed DHA was bad. I wouldn’t assume that, because these are good scientists. However, there has to be an inherent bias—beliefs that set up space in your brain and affect your actions without you realizing it. Another way of stating this would be that you find what you look for. It would be very difficult to examine any data involving EPA, DHA, and cardiovascular disease and withhold bias. I don’t believe it was intentional, but I also believe that it could have influenced the results to some degree.

The INtermountain Healthcare Biological Samples Collection Project and Investigational Registry (INSPIRE for short) is not a randomized clinical trial; it’s an observational study. I’ve already talked about the data that are missing on diet, supplementation, and exercise. In addition, it’s a big stretch to suggest that 10 years after samples were taken during an angiographic procedure that the same distribution of EPA-DHA was maintained.

Prior Research

Let’s think about the studies from last week: they were test-tube studies. Those are the foundation you must build before you start doing animal testing; only after that do you get to human testing. One research group also did a study on rodents which demonstrated proof of possible benefit. Have we had that type of research on EPA and DHA as it relates to cardiovascular disease? I did find some.

There have been studies examining how omega-3s may positively affect heart rhythms. In studies on rodents and dogs, DHA but not EPA showed clear benefits on reducing atrial fibrillation and other forms of cardiovascular disease.

But when you examine research on humans, the data are conflicting. By that I mean that some studies show that higher DHA intake and/or levels are associated with the reduction of arrhythmias. Other more recent research shows that it may not. There’s simply not enough information to make a decision.

The Bottom Line

At this point, you have to be thinking “What the heck am I supposed to do?” I think that we stand in an area of research where we have to “reserve judgment,” or maybe it would be better to say to “reserve condemnation.” We just don’t have enough data to make an informed decision either way. I’ve illustrated some of the things that need to be answered as it relates to omega-3 intake, but there are many more questions.

So I’ll leave you with this. If you have had no signs or symptoms of cardiovascular disease, no matter your age, you can most likely continue taking the same omega-3 supplements you always have been. If you have had a heart attack with damage to the muscle tissue, that seems to be where the problem lies, but it isn’t the same for every person. I would have a discussion with your cardiologist before deciding whether to take just EPA or to continue taking combinations of EPA and DHA; that’s the prudent thing to do.

But as you make that decision, consider all the other benefits of omega-3s. A search for “omega-3” at drchet.com yields several pages of results. Very rarely in life do we have simple decisions to make; it’s always a balancing act between competing objectives and imperfect information, and this is another one of those situations.

What are you prepared to do today?

        Dr. Chet

References:
1. J Am Coll Cardiol. 2021 May, 77 (18_Supplement_1) 1453.
2. Vascul Pharmacol. 2016 Jul;82:11-9. doi: 10.1016/j.vph.2016.03.007.
3. Can J Physiol Pharmacol. 2016 Mar;94(3):309-23. doi: 10.1139/cjpp-2015-0300.
4. Circulation: Arrhythmia and Electrophysiology. 2012;5:978–983.

Omega-3s and Heart Disease

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In addition to the research papers on omega-3s I talked about last week, another paper was presented at the American College of Cardiology in May that suggests EPA seems to reduce cardiovascular disease (CVD), while DHA seems to neutralize the benefits. Let’s take a look at this recent study to see what they found.

I haven’t seen the data, just press releases of varying lengths; I’ve written the authors but haven’t heard back yet. The problem with this recent study is that it’s a retrospective examination of a large group of people. The data are part of an ongoing study (much like the All Of Us study in which I’m a volunteer) that secured blood and tissue samples of volunteers; the researchers use that data as well as access to the volunteers’ medical records. In this case, they assessed the EPA and DHA levels of the blood samples and the CVD events that occurred in a random sample of the volunteers over the years. That’s how they determined that the EPA was beneficial in reducing CVD and as DHA levels rose, the benefits were negated.

The primary problem is that the blood samples are a snapshot of one day in the life of the volunteers. We have no idea if they took dietary supplements or if they happened to eat a lot of fish or a lot of nuts and other foods with omega-3s. No other dietary data, no supplement data, no exercise data—all things that we know are related to the development of cardiovascular disease. I think there’s a significant factor at play in this data analysis, and I’ll give you that observation in Saturday’s memo.

What are you prepared to do today?

        Dr. Chet

Reference: Press Release: Warning: Combination of Omega-3s in Popular Supplements May Blunt Heart Benefits. Intermountain Medical Center May 17, 2021

Omega-3s May Kill Tumors

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As exciting as Tuesday’s Memo might have been on omega-3s and superbugs, today’s Memo probably tops that. Before we get too excited, it’s important to remember that this was another test-tube study. That’s fine; that’s how research into any topic begins, but it still has to be proven in human trials.

Researchers in Belgium exposed tumors to various types of polyunsaturated fatty acids including omega-3s and omega-6s. This is the important part: as they made the medium more acidic, the tumors preferentially used fatty acids as fuel. The tumor cells started to implode via a process called ferroptosis. Literally, it means “iron cell death.” What seems to happen is that as the tumor becomes more acidic, it can’t store the fat as well. That creates free radicals, and the tumor cells are destroyed from the inside out. The fish-oil DHA was the most effective at killing tumor cells.

What does this mean for us? Nothing yet, but in another study, when mice were given DHA, their tumors developed more slowly. Remember, what happens in tumors may not happen in the body because actual tumors may have developed a more sophisticated defense system. Then there’s the matter of causing acidity—not necessarily easy to do systemically or targeting just the cancer. But just as with the superbugs, it gives us a reason to take our fish oil with EPA and DHA. And of course, there are other potential benefits to the body as well. Fish burps seem a small price to pay for all this protection, right?

How about the recent research on DHA and atrial fibrillation? I’ll tackle that issue in next week’s Memos. It comes down to scientists asking the correct question.

What are you prepared to do today?

        Dr. Chet

Reference: Cell Metabolism. https://doi.org/10.1016/j.cmet.2021.05.016.

Omega-3s: New Weapon Against Superbugs?

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One of the biggest concerns with hospitalization is catching an antibiotic-resistant bacterial infection. It happened to my father-in-law about 15 years ago, and it was a serious infection requiring over a week in the hospital. He survived, but more superbugs are still around and have gotten worse.

Researchers in Australia examined one such superbug to see how it responds to exposure to omega-3 fatty acids from fish oil. This was a test-tube study and the paper isn’t published online yet, so I can’t check the methodology. What they have reported is that one such superbug, Acinetobacter baumannii, doesn’t seem to discriminate between the fats that it consumes in the hosts’ body. The omega-3s seem to make the bacteria susceptible to a greater variety of antibiotics.

Remember, this is a test-tube study; not everything that works in a test tube works in a human body. Human trials will take some time if those scientists and others can replicate this research. What it means to us right now is that the fish oil we’ve been taking all these years may have benefits we never even considered. I’ll cover another such benefit on Saturday.

Wednesday night at 9 E.T. is the Insider Conference Call. Topics on the docket are more info on omega-3s and cardiovascular disease, plus collagen and skin health. You can still participate by becoming an Insider before 8 p.m. Wednesday.

What are you prepared to do today?

        Dr. Chet

Reference: mBio. DOI: 10.1128/mBio.01070-21

High-Intensity Walking Is Better for Peripheral Artery Disease

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As I said in Tuesday’s memo, high-intensity walking was better than low-intensity walking in terms of physical measurements after one year; subjects were able to cover more distance in a six-minute walk and they were able to walk for a longer period of time on a treadmill. Another important outcome was that there was no damage to muscle fibers in response to the high-intensity walking as was found in other studies.

There are a couple of other factors I think were significant about this study. Let’s take a look.

High-Intensity Walking Saved Time

High-intensity walkers performed better on the physical tests in spite of the fact that they actually exercised half the time as the low-intensity walkers. I think that that’s a solid positive for people who really dislike exercise because they will save time: more benefit in a shorter period of time.

Even though there was a similar improvement in subjective quality of life assessments, what we don’t know is whether each individual session was more painful for the higher-intensity walkers.

Subjects Were Coached the Entire Year

The primary difference between high-intensity and low-intensity walkers was pain. Both the high-intensity and low-intensity walkers had assigned coaches who could track progress through the subjects’ accelerometer readings. Having done a similar type of study myself, it’s important that people can get answers to their questions, especially related to the significance of pain versus discomfort, and therefore push on. I believe subjects also feel obligated to a person, their coach, more strongly than to the study itself.

While it would be very difficult as a public health initiative, I think the approach would work for any type of physical-limiting condition whether it was cardiac rehabilitation, type 2 diabetes, or as in this case, PAD.

The Bottom Line

This analysis of high-intensity versus low-intensity walking for PAD might seem to be narrow in focus; after all, most of you probably don’t have PAD. But the greater question to me is determining what will be more effective to help recovery or even prevent disease from occurring. If high-intensity exercise can be beneficial for people with severe PAD, then there’s no question that it can be beneficial for just about everyone. And the key is coaching: having someone available to encourage you when you need it and to answer questions when they become important to you.

What are you prepared to do today?

        Dr. Chet

Reference: JAMA. 2021;325(13):1266-1276. doi:10.1001/jama.2021.2536.

Exercise for Peripheral Artery Disease

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Peripheral arterial disease (PAD) is a narrowing of the arteries in the arms or legs, usually caused by the build-up of plaque similar to what can happen in the arteries of the heart or the neck. The result is pain in the muscles of the legs, sometimes mild, other times severe. As you might expect, the harder you exercise, the more potential for pain. Termed “intermittent claudication,” it can reduce mobility, or rather, the desire to be mobile.

Higher-intensity exercise such as fast walking is typically avoided due to the resulting pain. The prevailing recommendation is slow walking. But as several studies have determined, people won’t do it because it hurts. So why recommend it?

Researchers from several universities across the U.S. recruited over 300 subjects with a mean age of 69 to participate in a yearlong study on the effects of low-intensity versus high-intensity walking. This was a massive undertaking due to the extensive training and coaching for all subjects. I won’t keep you hanging until Saturday: the high-intensity walkers did better on physical tests than the low-intensity walkers or the control group. But there was one other critical point, and I’ll talk about that on Saturday.

What are you prepared to do today?

        Dr. Chet

Reference: JAMA. 2021;325(13):1266-1276. doi:10.1001/jama.2021.2536.

Fasting: Another Piece of the Puzzle

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Fasting is gaining popularity. Actually, periods of complete abstinence from food within a 24-hour cycle is what really seems to be gaining in popularity, but this study doesn’t address intermittent fasting. It examines fasting for a specific period of time before a dietary change—in this case, to the DASH diet. We don’t know if the results would be the same if someone were switching to a ketogenic diet or a paleolithic diet. These are the major results of the study we began examining on Tuesday.

The Results

  • The five-day fast prior to beginning the DASH diet appeared to have positive effects on blood pressure. There was an average drop of eight points in systolic BP and a reduction in the use of medication to lower blood pressure.
  • Subjects adhering to the DASH diet lost weight as well. However, it was not the reduction in weight loss that caused the drop in systolic blood pressure based on their analysis.
  • The immunome, a portion of the total proteome I talked about a few weeks ago, improved. While the exact mechanism is not known, the positive changes in immune proteins appeared to have a positive effect on lowering blood pressure.
  • Researchers also discovered genetic differences between those who responded to the fast and the subsequent DASH diet by lowering their blood pressure and those who did not. The key seems to be in the bacteria that produce short-chain fatty acids. Fasting was identified as a way to increase the bacteria producing those SCFAs.

What Does It Mean?

What are we to conclude? With only 71 total subjects, there’s not a lot of data to generalize to entire populations, but here’s what I think is important.

First, fasting does have a role to play in the health of our microbiome; it also has role to play in our immune function. It’s not completely clear why these changes can occur, but research shows that they do. It may be that eliminating food for a period of time helps the naturally occurring bacteria to function better.

Second, it doesn’t seem to have anything to do with intermittent fasting. It very well may be that complete abstinence from food could get you similar benefits if you were to withhold food for 18 or 20 hours a day and only eat in a very small block of time. But until fasting for a specific amount of days is compared with hourly intermittent fasting, we just don’t have the best answers yet.

The Bottom Line

Fasting, however you define it, appears to have some beneficial effects. If you find a way that fits into your lifestyle, there doesn’t seem to be any reason that you shouldn’t do it unless you have a metabolic disorder and must eat. For example, if you have problems with your blood sugar or take meds that must be accompanied by food, fasting may not be for you.

Here’s my plan: now and then, I’m going to try a reduction to 500 to 800 hundred calories per day for one to three days. That seems to be supported by the most science. It also appears to benefit immune function the most.

Anticipating questions from those doing a ketogenic or paleolithic diet, is the diet after the fast important? Maybe if you select the right foods, such as going vegan during those fasting days, you may get the positive changes in your microbiome. What would happen if you then went on a ketogenic or paleo diet after that? We just don’t know whether the changes would last. This study provided a few pieces of the puzzle, but there’s much we still need to know.

What are you prepared to do today?

        Dr. Chet

Reference: Nat Comm (2021)12:1970. https://doi.org/10.1038/s41467-021-22097-0

How Fasting Affects the Microbiome

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How did you do? I asked you to reduce your caloric intake to fewer than 1,200 calories and keep it vegan if you can. Paula and I did okay, but not completely vegan.

Before I describe the study, you need to know that wasn’t the actual fasting part of the study—that was the fasting preparation phase. The actual fast was 300 to 350 calories per day of vegetable juice and vegetable broths. If you’ve ever done a detox just drinking tea and broths, that’s very similar.

There were multiple parts of the study, but we’ll focus on just two. The purpose of the two portions of the study was to examine changes in the microbiome and immunome as well as blood pressure after 12 weeks on the Dietary Approach to Stop Hypertension (DASH) diet. Before the dietary changes were begun, researchers randomly assigned 71 subjects to either the fasting-plus-DASH diet or just the DASH diet alone. All the subjects had diagnosed hypertension as well as metabolic syndrome.

This was one of the most complicated analyses I’ve ever seen because there were so many genes examined related to the bacterial composition of the gut as well as the immune system. The first question is simply this: were there changes in the microbiome after the initial fast? Yes, but the changes were reversed once normal eating resumed.

I’ll cover the post-DASH diet changes in Saturday’s Memo. Until then, unless you have metabolic issues or must eat at specific times of the day with medications, give the fast, the real fast as described above, a try for just one day.

What are you prepared to do today?

        Dr. Chet

Reference: Nat Comm (2021)12:1970. https://doi.org/10.1038/s41467-021-22097-0

Summer Body Prep Time

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This week culminates with the first outdoor holiday of the summer season, and for many of us, the first family cook-out in over a year. Next week I’m going to review a study on the benefits of intermittent fasting, but I want to challenge you to mimic part of the study before the weekend to see how you do. Here’s the task.

For any two consecutive days, cap your eating at 1,200 calories. If you can get by on 1,000 calories, great, but no more than 1,200 and no fewer than 800. The second part is to make them vegan days as well. Don’t think only salads and carrot sticks: beans, legumes, nuts, root vegetables, and every other vegetable and fruit you can think of as well as whole grains. Two days—that’s all. Then you can resume your normal eating if you want. That will give you at least part of experience of the subjects in the intermittent fasting study I’ll review.

The irises in the photo are from our yard. Two years ago, we dug up entire iris beds and replanted them until we ran out of space. This year, they produced more flowers than ever, and they’re just beginning; the ones pictured are hand-me-down yellow ones we got from Paula’s dad and another called “Red at Night.” There are more colors to come, including an electric blue called “Blue Suede Shoes.”

All those flowers don’t happen by accident; neither does a healthier and fitter body. It takes work and it may take a while to see the benefits, just like the irises. Take the vegan-fast challenge and see how you do. Just remember: no lower than 800 calories and no more than 1,200. It will give you a sense of how the subjects initially felt in the study on fasting, the microbiome, and blood pressure.

Paula and I are going to spend this week putting flowers in containers, so this is the only Memo this week. Enjoy the outdoors and if you’re traveling, be safe. See you next week.

What are you prepared to do today?

        Dr. Chet

Vision Health: Never Too Young

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Continuing with what I asked Dr. Laura Kenyon during my interview with her, the question is still “What are the mistakes people make related to retaining their vision?” Here are the rest of her answers as well as a program every parent needs to know about.

Eye Protection

The third mistake we make is not wearing eye protection when we should. Obviously you’ll want safety glasses if you’re working with a chainsaw. When you’re working with liquids such as paint, oil, and gasoline, protecting your eyes is critical then as well.

But let’s move beyond the obvious: wear safety glasses anytime you’re working in the yard. True, when you’re mowing the lawn or using the weed-whacker, eye protection makes a lot of sense. But when you bend over to pull weeds or prune trees or bushes, you might not focus on that tiny little branch that’s sticking out from the rosebush. That kind of stab or scratch can severely damage the eye.

The other is when you’re cooking. When you’re cutting foods such as onions and hot peppers, a squirt into your eye can certainly make your life miserable for a long time, even though probably not causing permanent damage. And you’ve probably heard that you shouldn’t cook bacon naked. I can tell you that you shouldn’t be without eye protection then as well. I can remember putting a piece of fish into a fryer, and in a perfect splatter, it came right from the tail end of that fish directly into my right eye. You’ll find out whether you can dance or not when that happens to you! So be sure to wear eye protection even for tasks that do not seem as obviously dangerous.

Eat Vegetables and Fruit

I was a little surprised that Dr. Kenyon said then another mistake that we all make in relation to our eyes is that we don’t eat enough vegetables with carotenoids in them such as lutein, alpha-carotene, zeaxanthin, and, of course, you probably know beta-carotene already. Those are all critical to eye health and we need some every day.

One little piece that I contributed was to mention that chopped or cooked vegetables with carotenoids will release more carotenoids than if you eat them raw. So those baby carrots (that we know really aren’t baby carrots at all), would serve you better if they were cooked and put in soup.

Never Too Young: InfantSEE™

When I said that it’s never too early to start with regular checkups, I meant it: if you’ve got a baby, it’s time to start. The InfantSEE program was started in 2005 with the support of former President Jimmy Carter. He had a grandson who was diagnosed with amblyopia, a condition that could have been easily treated had they been aware of it. The result of his effort, as well as the American Optometric Association efforts, has resulted in a free program for children six to twelve months old. The examination can identify conditions such as astigmatism, which in a single eye, can result in what we typically call lazy eye—easy to treat if you know the child has it at an early age but very difficult to treat later. You can search for a participating optometrist on the home page of InfantSEE; let’s all help spread the word to new parents.

The Bottom Line

There you have it, right from the optometrist’s mouth: the biggest mistakes we make when taking care of our eyes. Use this info to put together a list of actions you should take to keep your eyes healthy throughout your life.

If you live in the Grand Rapids area, Dr. Kenyon and her practice is taking new patients. The contact information is below (2). Also, for all Members and Insiders, I’ll be posting parts of the interview in the members section after it plays in Grand Rapids.

What are you prepared to do today?

        Dr. Chet

References:
1. www.infantsee.org
2. West Michigan Eyecare Associates. https://wmeyecare.com 616-949-8500.