Diagnosing Disease: The Canine Frontier

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Malcolm Gladwell, one of my favorite authors, recently did a show on his podcast “Revisionist History” concerning the use of dogs in screening for prostate cancer. You probably recognize his name from his many books including “The Tipping Point”; if you haven’t tried his podcast, I recommend it.

If there’s one thing that keeps men from getting their prostate examined, it would be the invasive nature of the prostate exam known as the digital rectal exam. This refers to the old meaning of digital: performed with a finger. If any problems are suspected, the typical follow-up procedures include the protein specific antigen test (PSA) and prostate biopsy. I know first-hand how uncomfortable these exams can be, and I understand why men would put it off whenever possible, even to the detriment of their health. But what if there were another way? Time to let the dogs out.

No, this new method did not involve dogs doing what they always seem to do, which is to sniff behinds; these dogs were trained to identify prostate cancer in urine samples. Exactly what they’re trained to identify is still a mystery, but most likely it’s a protein. How accurate were they? Over 95%. Anyone that tests positive by canine would then be followed up by a human physician.

Will we be making appointments to see our canine diagnosticians anytime soon? Probably not—even though just about every type of cancer you can think of has been canine-tested and found to be accurate. Are there other conditions that canines can identify? Yes, and I’ll cover that on Saturday.

The Insider Conference call is tomorrow night. I’m going to talk about the COVID vaccine as well as answer Insider questions. Become an Insider before 8 p.m. Eastern Time, and you can join in on the call.

What are you prepared to do today?

        Dr. Chet

Reference: Urologiia. 2019 Dec;(5):22-26.

When in Doubt…

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It may shock you to know that there are no U.S. Federal laws that mandate the use of dates on foods or supplements with a single exception: infant formula must carry dates. That makes sense—the nutrient content of formula is important for the growth and development of the baby. Other than that, as long as there’s no attempt to mislead the public in any way, manufacturers can put dates on label. The dates relate to the food quality of the food, not the food safety.

Commonly Used Phrases on Food

“Best if Used By/Before” date indicates when a product will be of best flavor or quality. It’s not a purchase date.

A “Sell By” date tells the store how long to display the product for sale for inventory management.

A “Use By” date is the last date recommended for the use of the product while at peak quality.

A “Freeze By” date indicates when a product should be frozen to maintain peak quality. It’s not a purchase date.

None of the phrases indicate the safety of the food.

Our Oldest Food

Because Paula and I went through the pantry a couple of years ago, I was sure there wasn’t anything with a “Use-By” date from 20 years ago like the last time we did it. But I did find some Marmite with a 2015 date on it. I did a little checking and while they put a date on it, Marmite could be good for 60 or 70 years. If you don’t know what Marmite is, it’s a product from the United Kingdom and is about the saltiest spread you can put on bread or crackers. It’s chock full of B vitamins especially B12. The salt prevents the growth of bacteria so it can stay on your shelf for years.

The Bottom Line

The dates put on foods and supplements are about quality, not safety. What affects quality? Temperature, humidity, and light are the major factors. If you store your boxed or canned foods and your dietary supplements in cool and dark conditions, the quality will be sustained for longer, sometimes, much longer, than the “Best if Used By” date. I’ve mentioned our six-year-old Marmite and will have no issue eating it again. I also have a supplement that I use only occasionally that has a date of 2009 on it, and I wouldn’t hesitate to use it.

The only thing time can do is to cause food to spoil or to lose quality. Determining if food is spoiled is easy because you notice the change in odor and whether it’s moldy or not. Quality may impact the flavor and quantity of nutrients because some are less stable than others, but the item would still be safe to use. But here’s one rule that won’t lead you astray: when in doubt, throw it out. If you’re not comfortable, don’t use it or eat it.

What are you prepared to do today?

        Dr. Chet

Reference: Food Product Dating. USDA. https://bit.ly/3twQxUt

Best If Used By

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Here’s a question I’m often asked about dietary supplements as well as food: What should we do with a food or supplement once it’s past the expiration date? One of my health newsfeeds had a title that mentioned milk going bad, so my mind was off and running! What does “Best If Used By” actually mean? Do we have to toss the food or not? We’ll get to that.

Americans discard about one-third of the food they purchase. Fresh food is discarded because it spoils, but a significant contributor to the total foods that are thrown away is those that have reached their “date.” That can include fresh foods as well as foods that are boxed or canned. Is it necessary? In a word, no. I’ll explain why not in Saturday’s Memo.

Until then, here’s a challenge for you. Go into your pantry or wherever you store your dry and canned goods. Search around until you find the box, bottle, or can with the oldest “Best If Used By” date you can find. I did a quick search and found one from 2015. Then let me know what you find. Is it still good? I’ll let you know on Saturday.

What are you prepared to do today?

        Dr. Chet

Reference: Food Product Dating. USDA. https://bit.ly/3twQxUt

By Any Means Necessary, Part 2

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About a year ago, I wrote about the reasons we buy food pouches for Riley. He’s six and a half, and we’re still using them, because my thinking is I’m going to get those fruits and veggies into him by any means necessary. And the battle continues.

Some evenings we have a battle royal over eating vegetables. Riley would rather eat pasta and nothing else almost every night. While he will eat pouches with just about any vegetable in it but broccoli, he won’t eat the same vegetables on his plate. The other night it was green beans. He’s eaten them before, but he’s demonstrating a rebellious streak lately. We’re not insisting he clean his plate, just eat a few green beans. Paula will wait him out; she’ll sit at the table and read a book on her Kindle until he’s done eating them.

Me? Not so much. I decided we will enhance the flavor of the green beans. Hot sauce—which I knew wouldn’t make it onto his plate. Cinnamon sugar. Whip cream. Paula thought of a savory flavor and added a sandwich sprinkle blend. The winner? Close between the cinnamon sugar and the whipped cream with ketchup, which doesn’t taste nearly as bad as you might think. Even the sandwich sprinkles got a thumbs up. All the green beans were gone in short order.

I know that’s not a traditional approach to getting kids to eat vegetables. And yet, people who would never touch an onion will eat a deep-fried one with fat imploded into it and a creamy sauce to dip it into; compared to that, I think a dusting of cinnamon sugar is just fine. My philosophy is: by any means necessary. The benefit of the vegetable outweighs the little bit of sugar or whipped cream in my opinion, especially for a kid in the 4th percentile of BMI for his age.

It’s a long holiday weekend so we’ll be back with the Memo in a week. Be safe if you’re traveling. If you’re going to spend the weekend with picnics and such, don’t forgot about eating those vegetables—by any means necessary.

What are you prepared to do today?

        Dr. Chet

Why Errors in Food Intake Matter

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What is the big deal about errors in food intake in studies most people never hear about? It’s a problem because decisions on gaps in the diet, impact of nutrient intake, and the potential benefit or hazards of food and supplement intake are based on studies that use these techniques. I’ll give you a couple of examples, but let me start with something that has become common knowledge.

Obese subjects underreport food intake at a greater rate than subjects who are normal weight. Female obese subjects are more likely to underreport food intake than male obese subjects. Don’t assume they intend to deceive; I think many people are simply unaware of how much they eat, especially when they graze or sample food as they eat, pick at the kids’ leftovers, or eat little snacks at work.

Diet Change and Heart Disease

The Women’s Health Initiative is one of the largest studies done on examining the role of diet and heart disease in women. Results published in 2006 demonstrated that after a number of years on a low-fat diet, there were no differences in the rates of different forms of heart disease. What struck me at the time was that the goal was to reduce fat intake to 20% of total caloric intake, but using a form of dietary recall, the experimental subjects were able to lower their percentage fat intake from 35% down to 28%. That’s still much higher than the goal of 20%. If we were to estimate an average error in food intake based on dietary recall, it could very well be that these subjects actually had well over 30% fat intake due to under-reporting.

Why is that a big deal? Two reasons. First, they were not on a diet that was designed to reduce fat intake enough to impact cardiovascular disease. Second, in a review just published in 2021, a scientist is calling for the repudiation of the results of that study claiming that a low-fat diet does not work to reduce heart disease (or type 2 diabetes either). Based on the results of that WHI trial, we don’t know that for sure because of the potential for under-reporting food intake including fat, as well as the inability of the subjects to meet the goal of 20% fat in the diet. One error begets more errors. In this case, it’s being used to suggest that low-fat diets are not the way to reduce heart disease, and I’m just not ready to make that leap.

Nutrient Studies

There are a number of studies that have used FFQ as the method of assessing food intake in individual nutrient trials. Aside from the “How many portions of beef did you eat per week over the past year” type of questions, the total number of questions ranges from 138 to 164 on most FFQs. The degree with which people will report that accurately is suspect to begin with. Add to that the potential under-reporting of food intake when you’re trying to assess iron, calcium, folic acid, and other nutrients in the diet can provide significant errors in determining how much nutrients people are getting. As the saying goes: garbage in, garbage out.

One more thing. The FFQ were validated by three-day diet histories, which are also prone to significant error.

The Bottom Line

Research that examines dietary intake may be prone to errors. It doesn’t make it worthless; it just means we have to interpret the results carefully. This is especially true when determining whether any specific diet can help reduce disease or prove whether a nutrient is beneficial or not.

What we can do is speak in global terms. Eat better. Eat less. Move more. Do that first and worry about the details later. Even with the potential errors in assessing food intake, there’s no question about that.

So here’s what I challenge you to do: for the next month, make a strong effort to eat better than you do right now. I think if you take this first step, you’ll feel the difference.

What are you prepared to do today?

        Dr. Chet

References:
1. Front. Endocrinol. 2019. 10:850. doi: 10.3389/fendo.2019.00850
2. JAMA. 2006;295:655-666.
3. Open Heart 2021;8:e001680. doi:10.1136/openhrt-2021-001680

How to Assess Food Intake

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If you’ve been reading the Memo for any length of time, you know that I’m not fond of the methods used for determining food intake in free-living individuals, especially the Food Frequency Questionnaire. When looking at the validity of the doubly-labelled water technique for last week’s Memos on metabolism, I happened upon a review article that examined several methods of collecting food intake in nutritional studies; they also assessed metabolism to see if the calories used equaled the calories taken in.

Researchers from Australia reviewed the published research and selected 59 articles that examined which method of assessing food intake was the most valid as verified by metabolic data. Besides the FFQ, with and without food models, they examined food diaries, food histories, and 24-hour diet recall with and without the use of technology.

They found that with a couple of exceptions, every method of collecting food intake underreported energy intake by 1.5% to 47%. The researchers concluded that while every method had high variability, 24-hour diet recalls were the most accurate with a variability of 8% to 30%. The highest degree of underreporting? The FFQ which had one study top 47%—that’s right, almost half of the food eaten wasn’t reported!

It makes sense to me; Paula and I rarely have pizza or bacon, but do we remember how many times we’ve had those in the last year? Of course not. Here’s a harder recall issue: Paula has a bite or two of chocolate almost every day, but rarely eats a whole chocolate bar. How would she report that accurately? And I often eat Riley’s leftovers—how do I report those two chicken nuggets or one-eighth ear of corn? In the real world, it’s hard enough to accurately record what you’re eating right now, let alone a month or a year ago.

Besides my personal satisfaction of being correct, the real question is: “What does this mean in the real world?” I’ll cover that on Saturday.

What are you prepared to do today?

        Dr. Chet

Reference: Front. Endocrinol. 2019. 10:850. doi: 10.3389/fendo.2019.00850

Metabolism Across Our Lifespan

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It might not surprise you to learn that adjusted for body weight, infants under one year have the highest metabolism of all age groups. It makes sense; they’re growing so fast at that point. From there it’s all downhill, metabolically speaking, at a rate of about 3% per year until about 20 when metabolism stabilizes. The lowest metabolism? We reach that sometime after 60. If we live to 90, researchers found that caloric needs declined by 26%.

That’s the “what.” More important is the “why”; researchers had some but not all of the answers.

Metabolism and Life Events

Researchers examined metabolism during adolescence. The expectation is that metabolism would increase during this period of growth, but they found that it didn’t change significantly.

There was also no significant increase in metabolism during pregnancy, at least, more than what was expected. In Healthy Babies, I talk about the caloric needs of pregnant women by trimester. Those caloric needs prove to be spot on. Sorry, but there’s no need to eat for two.

One more point: carrying extra fat results in an increase in metabolism. That makes sense because every extra pound means the muscles work harder in moving the weight, the heart pumps harder because there are more blood vessels, and so on. But when extra body fat is accounted for, there’s no difference in metabolism on a pound-for-pound basis.

Why Does Metabolism Decline?

Why does our metabolism start to decline faster at around 50 or 60? One factor is the loss of muscle mass; that’s why it’s so important to increase muscle mass and hang on to it as we age.

This study measured caloric use over 24 hours, so the age-related decline in physical activity may play a role in why metabolism declines: most of us are much less active over 50.

But one of the many researchers involved in the projects stated it this way: the reason for the decline in metabolism is that “cells are slowing down.” He went on to say that these changes occur in ways we don’t yet understand. Do the cells get tired? Have a harder time with cell division? Or are there some as yet unknown signal chemicals that are controlling the aging mechanisms that impact metabolism? We don’t know yet.

The Bottom Line

One study is not enough to find out all the answers to what happens to metabolism as we age, but it does provide some insights in where we can look to find the answers. One area that might be interesting is the mitochondria, the powerhouse of the cell; what happens there impacts our ability to make energy and that can definitely impact metabolism. We’ll keep an eye on this research as time goes on.

What are you prepared to do today?

        Dr. Chet

Reference: Science 13 Aug 2021. 373 (6556):808-812. DOI: 10.1126/science.abe5017

What Happens to Our Metabolism?

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Have you ever said or heard someone else say, “I could eat whatever I wanted when I was young and I never gained weight!” What usually follows is something like, “Now I seem to gain weight just by thinking about a donut!”—the type of food may vary depending on the individual. Kids seem to eat anything they want and stay rail thin. Riley grew five inches between his five-year and six-year physicals but gained only three pounds. The logical question is what happens to metabolism as we get older?

Researchers in the Pennington Biomedical Laboratory attempted to find out together with researchers from around the world. As a combined effort, they recruited over 6,000 subjects between the ages of six months and 95 years old. The reason they needed so many research facilities is that the technique used to assess metabolism is labor intensive; it would have taken a decade for a single facility to do it. They didn’t test only resting metabolism. They were able to test the metabolism of subjects over several days under a variety of everyday conditions—in other words, people just living their lives.

There was no surprise from the aging perspective: metabolism declines as we get older. But when metabolism peaks and when it declines the most was surprising. I’ll cover that on Saturday as well as what we might be able to do to deal with it.

Tomorrow night is the Insider conference call. If you have questions you need answered about nutrition, supplements or exercise, this is the forum to get the most complete answers. If you’re not an Insider, join before 8 p.m. Eastern to participate.

What are you prepared to do today?

        Dr. Chet

Reference: Science 13 Aug 2021. 373 (6556):808-812. DOI: 10.1126/science.abe5017

Rehabilitation Becomes Prehabilitation

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After giving some thought to the discussion I had with our physical therapist, I’ve scheduled my knee-replacement surgery. I’ve already been doing everything he recommended to rehab the knee: avoiding any high-impact exercise, using an exercise bike, stretching. His verdict is that none of those will help the problem. The compounding issue is that my lower right leg is roughly 14 degrees off center; if I wait much longer, it becomes more difficult to make the leg straight with knee replacement.

It helps that the surgeon my PT recommended happens to be the surgeon I’ve already been seeing. While the decision is made, the work is now moving to another level. Having been an advocate of surgical prehabilitation for a few years, I get to test it firsthand; I’ve already seen how much it helped Paula before her foot surgery and hip replacement years ago.

I have three prehab goals: to increase my fitness level, to increase the strength in my right leg, and to reduce my body weight a reasonable amount before the surgery. Concurrently, I want to train myself to endure more pain, because it will surely be needed after the surgery.

Prehabilitation Goals

Fitness

Due to localized muscular fatigue, I haven’t been able to push myself as hard as I want during high-intensity interval training (HIIT). As a result, I don’t feel I’m in the physical condition I want to be in, surgery or not. It’s time to double down. That requires cycling adaptive training and HIIT with longer intervals.

What do I mean by cycling adaptive training? It’s spending more time at a higher resistance—higher than normal but not as high as during intervals. The energy systems have to be trained to adapt to higher lactate levels. Fortunately, I’ve been doing that a little bit anyway. Now I’m on a mission.

Strength

Part of the problem is the muscle mass I’ve lost. My right thigh is just over an inch smaller than the left. I know I’ve been compensating because of the perceived muscle weakness in my right leg, and I’ve been limping more than I should.

I’m increasing my effort in leg-strengthening exercises. Nothing fancy, just squats, leg extensions, and leg curls. I’m using as much weight as possible and focusing on overcoming the natural inhibition arthritis pain causes. I’ve already noticed a difference in just a couple of days.

Body Fat

You’ve heard me complain about the fat we all gain due to aging. I can’t lose all of it, but I’m going to bump up the effort a little. Less weight going into surgery and rehab means less force necessary to overcome gravity later.

The Bottom Line

This is not the outcome I wanted, and I still think that the ideas around knee replacement could use some major innovation. However, we play the hand we’re dealt when we’re dealt it, not five years from now. I have things to do, and being mobile is important to those objectives. I’ll provide updates as time goes on as well as provide details on the prehabilitation program.

What are you prepared to do today?

        Dr. Chet

Overcoming Discomfort

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Last month, I did 70 push-ups on my 70th birthday. They were not full push-ups; they went about halfway. It took a year to be able to overcome shoulder weakness and discomfort because of torn bicep muscles in both arms. But by doing push-ups every day, I gradually pushed out the number every few weeks, beginning with 10 and culminating with 70. Most importantly, I don’t have any pain nor discomfort when I do them now.

I attempted to do full push-ups this past Sunday. I was able to do four with the shoulder discomfort starting on the fifth one. But I know the process and I know over time, by gaining strength in the other muscles and with a consistent effort, I will do 70 full push-ups before this year is out.

Now, I’m turning attention to my right knee that’s bone on bone. I saw my physical therapist yesterday to get his direction in strengthening my knee. There’s a lot of work ahead of me, but I’m determined to make my knee function better than it currently does—15 minutes at a time.

While all discomfort is not the direct result of soft tissue problems, many are. The only thing you can do is to get the best direction from physical therapists and other health professionals and then get to work. It will take time and you must be consistent. It may get worse before it gets better.

But stop and think: what if you had 50% less discomfort or 30% more range of motion or 60% more strength? Would it be worth the effort? Only you can decide, but from nothing you get nothing. What can you get from 15 minutes per day?

What are you prepared to do today?

        Dr. Chet