How Long Does Fitness Last?

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Does exercise when you’re young have any impact when you’re older? That’s the question researchers sought to answer in a very unique study. They recruited men who competed in running events in the 1968 Olympics and evaluated fitness variables to see how they had changed since then. The subjects were tested in 1993 and retested in 2013. Did their fitness and cardiovascular measures decline at the same rate as their age would predict?

Maximal heart rate is calculated by subtracting your age from 220. There are formulas that make it a little more precise, but the shortcut is close enough for most purposes. At every retest, the runners measured max heart rate was significantly higher than predicted. The maximal amount of oxygen they used was also higher than would be expected for their age.

What does this mean? The fitness you attain when you’re younger can impact your fitness when you’re older. This study shows that there are some measures related to the cardiovascular system that can be sustained. You may never have trained like an Olympian, but even if you start later, the fitness you gain may yield benefits years later. Improving your fitness now will still pay dividends twenty or thirty years ahead when you may have more physical restrictions than you have now.

That raises another question: will being fit help you live longer? We’ll tackle that on Saturday.

If you want the best way to combine a change in your diet with an exercise program to maximize fat loss, no matter what your current fitness level may be, make sure you sign up for the Super Bowl Webinar.

What are you prepared to do today?

Dr. Chet

 

Reference: Med Sci Sports Exerc. 2018 Jan;50(1):73-78.

 

How Chromium Conflicts with Levothyroxine

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In the recent series of Memos on thyroid issues, I explained what you need to know about levothyroxine, the medication prescribed for an underactive thyroid gland. New research highlights a key factor in ensuring its effectiveness.

Researchers examined a dietary supplement to see what impact it would have on absorption of levothyroxine. They found that chromium picolinate reduced the absorption of the drug in subjects who took a high level of levothyroxine.

If chromium picolinate, typically used in weight loss supplements, interferes with high levels of the drug, it could impact lower doses even more; less would be available to be absorbed. If not as much of the drug is absorbed, it will not be as effective.

If you’re trying to lose weight, the last thing you want to do is lower your metabolic rate, so what should you do if you take both levothyroxine and chromium? The researchers recommended that people taking the medication be warned to take it at a different time from the supplement; four hours is the time frame. Take your levothyroxine as soon as you get up—that’s when you should be taking it anyway—and begin the supplement with lunch and throughout the rest of the day, depending on how much you take.

What are you prepared to do today?

Dr. Chet

 

Reference: Thyroid. 2007 Aug;17(8):763-5.

 

Bioavailability Ends with Bioactivity

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Here’s where we stand: we’ve digested a nutrient and it’s been absorbed into the bloodstream. How is it going to be used? How do we get the benefit of vitamin C, magnesium, alpha-carotene, or caffeine? Let’s take a look.

Many target cells have receptors that are specific to a nutrient, like a wrench that fits only one size of bolt. For example, when blood sugar rises after pasta is digested and absorbed, insulin is released from the pancreas. Insulin will attach to a specific insulin receptor on the cell membrane, and that will allow a glucose molecule to enter the cell to be used. Cells also have receptors for vitamin C to be absorbed into cells.

That’s fairly straightforward. The next step would be actually performing a function once the nutrient enters the target tissue. Let’s look at caffeine for example. There’s a genetic factor; one version of a gene can process caffeine quickly while a mutation of that gene processes it slowly. I can drink coffee and immediately go to sleep. Others may process it slowly and may not be able to sleep in the evening after a cup of coffee for lunch. Same nutrient, different effects on different people.

In addition, there are numerous enzymes that help make chemicals such as hormones or structures such as cartilage. If enough of an enzyme isn’t being manufactured or it’s blocked from being utilized, that can have an impact on how well a nutrient works. An example would be insulin; if cells are not producing enough receptors, or the receptors are resistant to insulin, blood sugar would rise. That leads to overall insulin resistance, one aspect of being prediabetic.

Another example would be the manufacture of glucosamine. The process requires fructose-6-phosphate and the amino acid glutamine; the first is a result of the breakdown of sugar while the later is the most prevalent protein-building amino acid in the body. The manufacture of glucosamine also requires an enzyme. If a person doesn’t make enough of that enzyme, that affects the production of glucosamine which then impacts the production of other forms of connective tissue such as cartilage, ligaments, and bone.

The Bottom Line

Every day there are new nutrition products introduced that are supposed to be better for you because more nutrients are available, but nutrition just doesn’t work that way. As I’ve tried to show you this week, the problem is that it isn’t quite as simple as what you see in Internet ads. Nutrients have to be digested, absorbed, and used by the body, and things can go wrong at any step along the way. Each individual’s body is unique and comes with its own idiosyncrasies and difficulties, and that’s what makes nutrition so complicated.

Maybe you’re thinking, “What’s the point if so much can go wrong?” What you have to remember is that most of the time everything works just as it should; not everything related to bioavailability goes wrong in every person. It’s also a matter of degree—maybe absorption will be cut by 50% or activity reduced 10%. I want you to understand why some nutrients won’t work as expected for a particular person, and why claims of better bioavailability aren’t a guarantee.

Yet we’re still here, aren’t we? We’re here because our ancestors survived. To steal a line from “Jurassic Park”: Nature finds a way.

What are you prepared to do today?

Dr. Chet

 

Reference: http://bit.ly/2raDviy

 

Bioavailability Continues with Absorption

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On Tuesday I talked about some of the processing required to get nutrients ready for absorption. The next phase of bioavailability is the absorption of the nutrient from the gut into the bloodstream. Let’s look at what’s involved.

The absorption process occurs via the intestinal epithelial cells and they vary in size and function in the small and large intestine. Some nutrients such as lipids may use a passive process to be absorbed. Sugars, amino acids, and others will use an active process involving transporter enzymes as well as using energy to be absorbed. Vitamin B12 absorption is much more complicated; it requires something called intrinsic factor and then is passed to another protein carrier for absorption.

Here’s where absorption can go wrong. Maybe you don’t produce enough of a transporter enzyme for one or more amino acids. Perhaps you have a condition such as irritable bowel syndrome, and some of the areas where absorption occurs are missing. There are more scenarios related to absorption, but they can all lead to a lack of bioavailability. Then there’s the fact that all our bodies are the tiniest bit different. Because most absorption studies are done with simulations of the digestive system cells, product claims of greater bioavailability can easily differ from what actually goes on in your digestive system.

Let’s say that you have digested and absorbed a nutrient. Does that mean your body will actually be able to utilize the nutrient? That’s the topic of Saturday’s Memo.

What are you prepared to do today?

Dr. Chet

 

Reference: http://bit.ly/2raDviy

 

Bioavailability Begins with Digestion

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Last Saturday’s Memo introduced a new concept: a systems approach to nutrition. One term that gets bounced around a lot related to dietary supplements or different types of food is bioavailability. Claims are made that “this form of our supplement is 10 times more bioavailable than that form.” It sounds so simple, right? It’s not—we’ll spend this week looking at all that’s involved in bioavailability. It begins with the entire digestive system.

Digestion is the process of breaking down a food or nutrient for absorption. There may be plenty of a nutrient consumed, but it has to be broken down into a form that can be absorbed. That begins in the mouth by chewing, and then the action really heats up in the stomach; acids are released to break the food into smaller molecules, if required. After leaving the stomach, the digestive enzymes begin to work on the food to continue the process. If it’s a nutrient from a supplement, it may be absorbed as it is or it may need to be modified biochemically. As the nutrient continues through the small and the large intestine, it may require a modification by bacteria before it can be absorbed.

There are many points in the process that can affect absorption. Does a person’s stomach release enough acid? Does the pancreas make enough digestive enzymes? Is there enough food that provides chelating agents for minerals? Is the microbiome healthy enough to continue the breakdown of the nutrient? You can see how the system can be affected in numerous places. But we’re not done yet. On Thursday, we’ll talk about absorption.

What are you prepared to do today?

Dr. Chet

 

Reference: http://bit.ly/2raDviy

 

Why Nutrition Is a Process

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A celebrity doctor who specializes in cancer treatment said something that caught my attention, and it goes to this question: why are some people cured by specific treatments while others don’t respond at all? In his opinion, it’s because the cancer creates a new system in the body that competes with the other systems.

The new system may be different in each body once the cancer is established, which could mean that everyone really requires an individual approach. A systems approach would be necessary only if the cancer gets too established; early diagnosis can use treatments that work in most people. Late diagnosis means the cancer has established a system with strengths and weaknesses that are unknown. But the systems approach isn’t limited to cancer.

What’s a Systems Approach?

A systems approach is simply this: we attempt to reach a goal by looking at the interactive nature and interdependence of all the factors in an entity.

Here’s an analogy: you flip the switch for the light in your kitchen, but the light doesn’t go on. What could be wrong? The light won’t work if:

  • Your bulb is burned out
  • Your circuit breaker needs to be reset
  • An electrical outlet somewhere has a tripped GFCI
  • Your switch has gone bad
  • A wire is loose in your light fixture
  • The power is out to your whole house

Turning on a light is easy—my grandson Riley is very good at it and he’s not even three. But if it’s not working, you have to look at each element of the system to find the problem and get the kitchen light back on.

How Vitamin D is Part of Your Bone Health System

While osteoporosis or weight gain doesn’t create a new system like cancer does, there are numerous steps in both processes. On top of that, if we’ve been on the path to bone loss or weight gain, there may be changes in normal metabolism that have to be overcome.

Let me explain using vitamin D for bone health. Whether we make vitamin D in our skin, get it from food, or take it in supplement form, it has to be processed by the liver to become the active form to promote bone growth. If there’s a defect in getting the raw vitamin D from food or a supplement into the bloodstream and on to the liver, not enough vitamin D would be made into the active form. Or there may be a defect in the processing of the raw vitamin D once it gets to the liver. Or there may a defect in the receptor for the active vitamin D on the target tissue. I could go on and on about where issues could occur, but I hope you get the point. Right now, we have no idea where the issue might be for the use of vitamin D in an individual just as we don’t know where the weak point of a cancer system might be and thus where we should attack.

Do we quit? No. We simply use a systems approach—we look at every step necessary to reach our goal and what we can do at each step. We begin with taking vitamin D for a specific period of time. We then get re-tested, most likely a bone density scan. If there’s growth, great. If there’s not, then we either add more D or add calcium or switch to a different form of calcium. Then retest. If that doesn’t work we can add vitamin C or glucosamine, both critical to the manufacture of connective tissue. There are other factors such as smoking and exercise that also impact bone growth. We systematically add new variables or add more of some that we’re already doing. Might this take a long time? Yes. Would we have to pay attention? Yes. But is it a natural approach to complicated conditions? Again, yes. No matter what the condition, if you’re going to try to deal with it nutritionally, that’s the approach you’ll have to take. You have to find what works for you.

The Bottom Line on Vitamin D

The systems approach goes a long way to explain why some people benefitted from vitamin D and calcium to prevent fractures and others did not. The only fact the meta-analysis study proves is that vitamin D and calcium supplementation don’t work for everyone. The key is to move on to the next approach; it may be different supplements or it may even be a medication. More options must be tried until a solution is found for each individual.

Over time, I’m going to continue to explore this concept of a systems approach to nutrition. I have no idea where it will lead, but it’s worth spending more time thinking and researching it.

What are you prepared to do today?

Dr. Chet

 

Reference: JAMA. 2017;318(24):2466-2482. doi:10.1001/jama.2017.19344.

 

You Actually Have to Take the Supplements

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The authors of the study on calcium and vitamin D supplementation as they relate to fractures were all orthopedic surgeons, as stated in the paper. They had no known training in nutrition. Maybe not statistics either.

When you perform a meta-analysis, each research study included is given a weight in the form of a percentage, which indicates how much it contributed to the outcome. Not all studies should contribute equally; that helps to eliminate the bias of a tremendous benefit in a very small study versus a large study with no benefit. They didn’t seem to read something in three studies that contributed close to 90% of the analysis (2-4): the authors of those papers said that the reduction in fractures did occur, or at least bone was restored, when the subjects took over 80% of the doses of calcium and vitamin D they were supposed to take. The problem: average compliance was around 50%.

What these surgeons could have done was tease out the data on those subjects who were compliant and analyzed that data. What they might have had were results that demonstrated that in order to get a benefit, subjects had to take the supplements regularly. That would have been meaningful. Instead, inexperience or ignorance left us with headlines but little else.

Still, there are some questions that were raised in my mind and I’ll cover them on Saturday. But one thing won’t change: if you’re going to take supplements of any kind, you’ve got to actually take them if you want a benefit.

What are you prepared to do today?

Dr. Chet

 

References:
1. JAMA. 2017;318(24):2466-2482. doi:10.1001/jama.2017.19344.
2. Lancet. 2005;365(9471): 1621-1628.
3. Arch Intern Med. 2006;166(8):869-875.
4. Am J Med. 2006;119(9):777-785.

 

Are Vitamin D and Calcium Still Worth Taking?

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Maybe you recently read a headline that went something like this: “Vitamin D and Calcium Do Not Prevent Fractures.” Many headlines were much worse. Over this past weekend I read the research paper published in JAMA. Is it real? Should you not bother taking your calcium and vitamin D to protect your bones? No—keep taking them. But it does give me an opportunity to talk about some of the issues surrounding these types of papers as well as the complexity of nutrition for our health. That’s our topic this week.

The study was a meta-analysis of studies that examined the relationship between the risk of fractures in elderly populations and supplementation with calcium, vitamin D, and both supplements together. After a rigorous database search, 33 randomized controlled trials were included in the meta-analysis. Some studies lasted several months, and some lasted several years. The amounts of calcium and vitamin D in the supplements varied in every study. After analysis, the researchers determined that neither calcium nor vitamin D nor the combination of both reduced the rate of fractures when compared to placebo. That led to their conclusions.

This was a mess as you probably guessed with differing quantities and lengths of the trials. What bothered me most was that if they really understood nutrition as well as the results of the studies they included, they could have done something special. I’ll cover that on Thursday.

What are you prepared to do today?

Dr. Chet

 

Reference: JAMA. 2017;318(24):2466-2482. doi:10.1001/jama.2017.19344.

 

What’s New on DrChet.com

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With a new year just beginning, it’s time to update you on what’s happening in the next month or so.

New: The Bottom Line on Alzheimer’s Disease

Your brain makes you who you are. We may fear cancer or diabetes but we dread the thought of losing our ability to think. In this Bottom Line, I examine programs that claim they can treat and perhaps reverse cognitive decline and Alzheimer’s disease. Are they right? I’ll give you the state of the research today and what you can do now to protect your brain no matter how young or how old you are. It’s available in both PDF and MP3—choose the format you prefer and get the most up-to-date information for only $1.99, free for Insiders.

Insider Conference Call

The next Insider conference call is Thursday, January 18 at 10 p.m. ET. This is a good time to decide to become an Insider; the conference calls give you the most recent information as well as preferred access to me. There are other benefits as well, but start the New Year with a commitment to be more informed about your health. Check it out here.

Are You Eating Better?

If you’re going to eat healthier, go the extra step and eat the foods that will help your body detox itself. Get all the details in Real-Life Detox, available as either a spiral-bound book or as an e-book, either in ePub format or Mobi, so you can keep a copy on your phone as well as read it on your new Kindle or your laptop.

One More Thing

I’m working on the Annual Super Bowl Webinar and this one is going to be special: it’s all about losing body fat. I’ve taken the ultimate fat-burning program from the old Optimal Performance DVD and made it appropriate for anyone, no matter your current fitness level—no athleticism required. The Super Bowl Webinar will be at noon ET on February 4. You really don’t want to miss this one so put it on your calendar today, and I’ll let you know when you can register.

What are you prepared to do today?

Dr. Chet

 

Excuses for Avoiding the Gym

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The New Year is upon us and with that, a commitment by many to exercise regularly. No matter where you live, that may involve joining a gym, but all gyms are not created equal. What you need, besides a convenient location and reasonable price, is a facility that provides you with the equipment you need to accomplish your goals and short-circuits your excuses.

“I don’t know what to do.”
I’m going to challenge conventional thinking in how you solve that problem: once you have clearance from your physician to exercise, ask for a referral to a physical therapist. He or she will work with you to determine the best exercises for your body and your history, especially the more years you have in your body. Broken bones, sprains, strains, injuries, gaining weight, losing weight—we all have a physical history. If you have a problem with the mechanics of your body or reinjure yourself, that will impact your ability to exercise, so begin with a physical therapist if possible.

Paula and I both have done that. Once we worked with our physical therapist to find what exercises to do on which machines or weights or tubes, we selected a gym which had the resistance and aerobic equipment most suited to our needs. I still do the exercises I was shown and I’ve been running for close to a year with no time off for injuries. That’s the longest I haven’t been forced to take time off.

You may even find out you don’t need a gym; walking or running plus exercises you can do at home may be all you need. Your physical therapist will get you headed in the right direction. The downside: if you’re exercising at home you can do it anytime, and that may lead to eternal procrastination. If you’re letting exercise slide day after day, maybe you need a more formal workout setting.

“I just don’t feel comfortable there.”
Think about how your social needs may affect your adherence to your workout plan as well. Paula reads while she bikes and I listen to podcasts on the treadmill so a big gym works for us, but you may need a more social environment with friends to keep you honest and engaged.

“It’s too far.”
Another factor is location. When Paula worked out on the way home from her job, she found that the farther the gym was from work, the less likely she was to get there; it was too easy to run errands on the way and never quite make it to the gym.

“I got hurt and I’m too sore, so I can’t exercise.”
Besides getting input from your physical therapist, here’s the most important advice I can give you: start slow. If you begin by doing too much, you’ll be sore or injured and you’ll be out. Your objective is to keep going—it’s a marathon, not a sprint—so an easy start is your best plan.

It turned out that Planet Fitness works for Paula and me: plenty of resistance equipment and all the aerobic machines we could want at a very reasonable price. I also must add that there are more really overweight people working out at the Planet than anywhere I’ve ever been, which I love to see.

For you, it may be someplace different; maybe you’ll do better with swimming and workout classes at the Y. The important point is to select your gym by what you need and you might find it becomes a lifetime habit.

What are you prepared to do today?

Dr. Chet