Tag Archive for: protein

The Proteome: A Cross-Sectional Study

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Every study begins with a question. A single question often leads to more questions, which leads to questions about whether the outcome can be measured, and on and on. In this case, the question was related to changes in the blood proteome over a lifetime: Is the proteome stable? Is it a series of continuous reduction or expression in some key proteins, or are there identifiable changes that occur at different points in a lifetime?

The best way to know that is to obtain serial blood draws from a group of individuals every year (or two years or five years) to track changes in the blood proteome, the entire collection of proteins in our blood cells. We live too long to make that practical. The next best thing is to select a large group of people of all ages, get blood samples from each along with other demographic and lifestyle measures, and compare the differences over the entire age-span. That’s a cross-sectional study.

Here’s what a large group of researchers choose to do. They recruited 4,263 people from 18 to 95 years old. Getting blood samples and other data from the subjects, they measured 2,925 blood proteins. Stop and think about that: they looked at over 12 million data points. The technology to measure each protein is incredible in and of itself; now add to that the sheer volume of number crunching that it takes to analyze that much data. Without high-speed supercomputers, it wouldn’t be possible in a reasonable amount of time.

The researchers found that over the years 1,329 proteins varied at different ages of the subjects; the ages where there was more variability than at other times were about 35, 60, and 78 years old. What does that mean? The first step in finding out would be to identify all the proteins and find out what they do. If some form of lifestyle change could impact aging, that would be necessary to know.

But that isn’t all they did with the data: scientists love predictive algorithms. We’ll take a look at what they discovered on Tuesday.

What are you prepared to do today?

        Dr. Chet

Reference: Nature Medicine. 2019. https://doi.org/10.1038/s41591-019-0673-2

What Is the Proteome?

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In the week we took off, I spent my time researching a couple of fascinating studies. We all have different ideas of what’s fun, don’t we? For me, getting to research topics in depth is a refreshing opportunity to learn something new. I’m going to share part of what I learned in the next several memos and it’s all about the proteome.

Obvious question: what is the proteome? A proteome is the complete set of proteins expressed by an organism—same idea as the microbiome, but with proteins instead of microbes. That includes obvious proteins such as muscle, hormones such as insulin, or many of the thousands of enzymes and other proteins the body makes. Those proteins may be produced only during specific circumstances and in response to events within and outside the body. The proteins can be systemic or they can occur in individual tissues and cells.

More than what, why is the proteome important? Research has demonstrated that there’s variability in the proteome at specific times during life. The idea is to identify which proteins change and which ones are associated with a healthier life. That’s the first step and I’ll cover a study that did just that on Saturday.

Tomorrow is the monthly Insider conference call. Check out the membership and if you become an Insider before 8 p.m. Wednesday, you can take part.

What are you prepared to do today?

        Dr. Chet

Reference: Aging Cell. 2018;17:e12799. https://doi.org/10.1111/acel.12799

Should You Take Essential Amino Acids Before Surgery?

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Tuesday’s study left us with a question: what could explain essential amino acids (EAAs) increasing, or at least preventing, muscle loss after total knee replacement surgery? Fortunately, another study examined those factors by obtaining muscle biopsies and blood before and after surgery.

Researchers recruited 41 patients who were having total knee replacement. After randomly assigning them to placebo or experimental group, the experimental group received 20 grams of EAAs twice daily, beginning seven days prior to surgery, until six weeks after surgery. Those in the placebo group were given nonessential amino acids. Muscle biopsies were collected from all subjects the day of the surgery and again either one or two weeks post-surgery with the determination made randomly. Blood was also collected for analysis at the same times as the biopsies.

The researchers found that the subjects taking the EAAs had a significantly increased amount of satellite cells, also known as muscle stem cells that can develop into muscle cells, compared to the placebo group; the ability to build muscle faster could help the recovery process. IL-6 and TNF-alpha were elevated post-surgery in both groups; however TNF-alpha declined by two weeks post-surgery in the EAAs group, which meant inflammation decreased. Based on the changes in cytokine production, inflammation after surgery decreased faster with EAAs than it did in the placebo group.

The researchers concluded that taking the EAAs seven days before surgery increased satellite cells on the day of surgery and promoted a more favorable inflammatory environment post-surgery. That could mean a quicker recovery from surgery and benefits during post-surgical rehabilitation.

The Bottom Line

While there’s more research necessary, I think the use of EAAs before and after knee replacement surgery is helpful. I would extend that even further; I think that EAAs may ultimately prove to be beneficial before and after any type of surgery. In almost every case, muscle tissue is going to be cut and thus will need to repair itself. We don’t know the benefits of EAAs on other connective tissue such as skin and ligaments, but because we’re targeting the key elements of protein with the EAAs, there’s little to no chance of any harm.

Based on these two studies, I think that 10 to 20 grams, spread out in two doses per day, would be the best approach. One important point: take the EAAs 15 to 30 minutes before eating anything or before working out. Those were the protocols used, and it’s the same that I recommend in Aging with a Vengeance for increasing muscle mass as we age.

I’ll be honest: it tastes weird. But I made sure Paula took EAAs before and after her recent carpal tunnel surgery, so you know I think it’s worth the effort.

What are you prepared to do today?

        Dr. Chet

Reference: J Appl Physiol (1985). 2019 Aug 1; 127(2): 531–545.

Making Burgers Leaner

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The series of Memos on meatless burgers generated many interesting comments. With the major holiday for grilling just two days away, I want to show you how to reduce calories in beef burgers.

First, use a leaner cut of meat for your burgers. Ground sirloin is often designated 90/10, ground round 85/15, ground chuck as 80/20, and hamburger meat as 70/30. The first number is the percentage of protein while the second is the percentage of fat by weight, but the grams of fat are vastly difference. A 4-ounce burger made of ground sirloin has eight grams of fat while the most commonly used cut for burgers at 80/20 has 21 grams of fat. That’s a difference of close to 120 calories, and those calories come from fat.

Second, you can consider the amount of fat lost while grilling. For 80/20 it can be up to seven grams of fat or about 60 calories while 90/10 only loses about one gram of fat or just 10 calories. However, the difference in shrinkage would be significant. The four ounces can drop to 2.6 ounces with the 80/20, but you lose just under one ounce in the 90/10. That means the ground sirloin will give you a bigger burger with a lot less fat.

How do you decide? It depends on whether burgers are a staple of your diet. If you have a burger or two only on outdoor-grilling holidays, who cares? If you grill burgers a couple times of week, the fat and calories begin to add up. Add lots of veggies——tomato, lettuce, onion, pickle—and use a whole wheat bun; check the calories in the buns because they can vary greatly.

You can have your burger, meatless or beef, and enjoy it, too. Of course, there are a whole lot more options for grilling, but to me there’s nothing like a good burger grilled outdoors.

Have a Happy 4th of July and enjoy your Independence Day celebration. I’ll be back next week with another health topic to discuss in detail. If you’re not in the U.S., I hope you’ll grill along with us.

What are you prepared to do today?

        Dr. Chet

The Bottom Line on Meatless Burgers

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There are a couple more differences between the meatless burgers and beef burgers. To get the red color, the Impossible Burger uses soy leghemoglobin from the roots of soy plants, while the Beyond Burger uses beet juice. Both are vegan and give the burgers their red color. The Impossible Burger also adds some B vitamins and minerals. The Beyond Burger seems to add only some iron.

Are the meatless burgers healthy or not? From a strict look at fat content, no. Cholesterol level, yes. Sodium content, no, depending on how much salt you add to your beef burger; if you add more than one-sixth teaspoon of salt to your burger, you’ve lost that advantage. In effect, they’re very comparable to 80-20 burgers you would cook.

The real difference is that the meatless burgers are sourced from vegetable protein. Even that may strike up a debate because one uses soy protein while the other uses pea protein. Some people try to avoid soy, although there’s no real reason for it with the exception of being allergic to soy. (Check The Bottom Line on Soy Protein in the Store).

The other difference is that they both have carbohydrates and fiber because they’re sourced from plants. While there’s not a lot of fiber, that’s an advantage over beef.

The critical factor is how the burgers are prepared and presented. The final fat count will depend on how long the burgers are cooked: the longer any burger cooks, the more fat it loses to the grill. The presentation also matters. Buns, mayonnaise, cheese (for vegetarians who eat dairy), ketchup, and other condiments can take a 250 calorie burger and explode it to 700 calories or more.

There’s no information available about the environmental effects of meatless burgers, but usually vegan foods are environmentally friendlier than animal products even with the shipping and processing necessary for faux foods.

Beyond Patties

You can find Beyond Meat burger patties in some grocery stores in addition to their brand of plant-based bratwurst sausage, Italian sausage, and meat crumbles. Would your chili or meatloaf taste different with faux beef? We’ve tried cooking with other brands of vegan “beef” and noticed only a lack of fat, although if we use beef, we usually rinse it after browning it to remove most of the fat. The lower cholesterol in the meatless beef would be a big nutritional plus, but of course all this scientifically created food comes at a price: expect to pay two or three times as much as for plain old ground beef.

The Bottom Line

On paper, the meatless burgers could potentially be healthier than beef burgers. Whether they’re healthy or not is a different story. I haven’t seen research on how the meatless burgers respond to flames and whether they may produce undesirable chemicals. On top of that, the presentation mentioned earlier also matters.

Most likely whether they’re successful or not depends on the taste. I haven’t tasted either yet but I’ve planned a tasting barbecue soon, and I’ll let you know what I find out. Until then, it’s beef burgers for me. It would be exciting to have a plant-based burger that meets the taste test. Let me know how you feel if you try them.

What are you prepared to do today?

        Dr. Chet

Defining Healthier Burgers

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Other than being plant-based, how do these burgers compare for being healthy? In order to know that, we must define “healthy.” Beef is criticized, no matter how it’s raised and processed, for having too much unhealthy fat. How about the Impossible and Beyond Meat burgers?

A burger generally uses 80/20 beef, which means 80% protein to 20% fat by weight. That isn’t how it turns out in calories. A typical four-ounce beef patty has 280 calories with 20 grams of protein and 22 grams of fat. There’s also 80 mg of cholesterol.

Both faux burgers offer 20 grams of protein, but then the differences begin. The Impossible Burger has 14 grams of fat in a four-ounce burger with no cholesterol. The Beyond Burger has 18 grams of fat and no cholesterol. There’s a little less fat in the vegan burgers, but it’s fat that makes a burger a burger so they’re about tied.

One difference is in sodium levels. Beef does not have sodium added, so it starts with about 80 mg of sodium while the vegan burgers come in with close to 400 mg of sodium each—but you know you’re going to salt that burger before you eat it, so to be fair, you need to factor in whatever salt you add. What I don’t know is whether the sodium is critical to the vegan burgers or not. Because it’s a manufactured product, does the sodium have to be there as a preservative or something to that effect? Could they be manufactured with less sodium without sacrificing taste?

I’ll finish this up this weekend so you can get the menu set for the 4th of July.

What are you prepared to do today?

        Dr. Chet

Are You Ready for Meatless Burgers?

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Grilling season is here and that means all kinds of meat get char-broiled. I love a good burger, but that leaves a growing segment of the population out of luck: vegans and vegetarians. Grilled vegetables are great, from asparagus to zucchini, but some people love the sensation of chowing down on a burger. They miss out.

There are veggie burgers out there. I’ve had Boca Burgers and black bean burgers as well. They may be shaped like a burger, but the taste often leaves me feeling cheated. That may not be the case any more with two new additions: the Impossible Burger and the Beyond Meat Burger. Even before I could dig into the background of each, there have been a number of articles questioning whether these burgers are actually healthier than regular burgers. That’s what we’ll focus on this week: what’s in these burgers and whether they’re healthier than a regular burger.

In checking the labels, one difference is the protein source. The Impossible uses soy-based proteins while the Beyond uses pea protein. One thing to note is that they’re both proteins because they have all the necessary amino acids or can make them from the essential amino acids contained within. I’ll get into the rest of the ingredients on Thursday to check whether they’re healthier than beef burgers.

What are you prepared to do today?

        Dr. Chet

Keto: Clearing the Air and Your Colon

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The next keto diet issues are still related to the digestive system: excessive gas and constipation. Let’s address the issue of gas first so that maybe the next time you bend over, you won’t have to worry about challenging the strength of your anal sphincter muscles.

The protein content of the revised keto diet may be lower than prior versions, but the body still has to break it down. If you don’t make enough digestive enzymes to breakdown the protein, it produces gas as it ferments in the microbiome. A lot of it. The simplest thing to do may be take a digestive enzyme that contains proteases to breakdown proteins before every meal. Taking a probiotic may also be a good idea, but we don’t know the specific strains of bacteria that will work on protein.

On the other hand, probiotics in general may help ease the constipation that can occur while on the ketogenic diet. The problem is this: the colon doesn’t have enough to do—waste products from foods are simply not there. Fats don’t have anything left after digestion; almost all protein sources don’t have much residue either. But your digestive system still has to repair and rebuild the digestive system on a regular basis. In addition to the probiotics, soluble fiber may again be the solution for the same reason as with diarrhea: it adds bulk to the stool.

I’ll wrap this up on Saturday with the topic that seems to still be making headlines: the odors associated with going keto.

What are you prepared to do today?

        Dr. Chet

Protein and Longevity: The Unproven Relationship

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I think the best way to assess whether the study I’ve been examining this week on protein and longevity is meaningful or not is to examine the interview with the primary author Christopher Proud, PhD. I’m going to give a series of his statements and whether the research addressed the question.

“Science has shown for some time that eating too much, in particular protein, reduces lifespan; and now we know why.”

This statement isn’t exactly true. While there does seem to be a relationship between calorie restriction and longevity in fruit flies and some species of mice, it hasn’t been proven in humans. There’s evidence in longitudinal studies on relationships between animal protein intake and some diseases, but it’s not accepted that high protein intake leads to an early grave. More likely, there are genetic and environmental factors to consider, but to suggest that eating less overall increases longevity for humans is not correct at this time.

“Eating high-fiber carbohydrate, such as those found in fruit, vegetables, and unprocessed grains and seeds, will produce the healthiest benefits. This is similar to the traditional Mediterranean diet which has well-established links to longevity. We already knew that lower food intake extends lifespan.”

Same as before—it’s an overstatement. There are some studies that show a decreased rate of diseases using the Mediterranean diet, but that doesn’t mean it will result in people living longer. It may mean they live better for the time they’re alive.

“Our team demonstrated that increased [protein] nutrient levels speed up protein synthesis within cells. The faster this process occurs, the more errors are made.”

Based on the way I understand the methods, they did impact protein synthesis by knocking out the eEF2K enzyme. As of this writing, I haven’t heard back from Dr. Proud, so I have yet to find how they overfed the cells, flies, or worms to effect that change.


The Bottom Line

I don’t think that the research done in this series of studies proves that high protein intake decreases longevity. As excited as the corresponding author was during the interview, it wasn’t as clear as he made it out to be. The research didn’t do anything to help set a target goal for human protein intake. How is it supposed to help without practical applications?

What is important is that we need to seek balance in our nutritional intake. It may be true that too much protein will impact the correct production of proteins, which would have long-term effects, and it’s hard to go wrong eating more fruits and vegetables. But longevity isn’t tied to a single nutrient or a single habit. We need to strike a balance. Eat less. Eat better. Move more.

What are you prepared to do today?

        Dr. Chet

References: Cell Biology 2019. https://doi.org/10.1016/j.cub.2019.01.029.

Is Protein Bad? The Research

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Let’s think about this logically. If we wanted to prove that a high-protein diet would decrease lifespan, we would have to feed some type of animal a diet high in protein until all the animals had died. It would be preferable to have animals that don’t live very long such as rodents. Then we compare the lifespans and causes of death with a control group. Simple and straightforward.

That’s not what the research group did. As I said in Tuesday’s Memo, they identified an enzyme called eukaryotic elongation factor 2 kinase (eEF2K) that slows the rate of protein synthesis. That enzyme is also found in C. elegans, a nematode, as well as in fruit flies and humans. They knocked out the eEf2K enzyme, therefore causing protein synthesis to happen faster. This is supposed to be what happens when too much protein is eaten. They noted more mistakes in protein synthesis as a result.

The methodology for this series of experiments is beyond my expertise. By a lot. Whether the research was on cancer cell lines, the nematodes, or the fruit flies, what I could not find in the Methods section is where they added protein or amino acids to the food for any culture or animal to mimic a high-protein diet. I wrote to the study’s lead author to see if my analysis was correct, but I haven’t gotten a response yet.

What does all this mean? I’ll wrap it up on Saturday.

What are you prepared to do today?

        Dr. Chet

Reference: Cell Biology 2019. https://doi.org/10.1016/j.cub.2019.01.029/