Causes and Risk Factors

/in /by

Rather than making this a statistics Memo, I’m going to use a couple of examples that illustrate the problems with establishing what prevents or causes disease.

Back in the late 1940s to early 1950s, there was a significant increase in cardiovascular disease. Trying to establish a single cause was complicated because there were so many variables to consider.

The Low-Fat Diet and CVD

If you read any background on the ketogenic diet, you’ll read about two factions: one that claimed a high-fat diet was the problem, while the other claimed carbohydrates from grains were the culprit. The high-fat diet faction won. While many suggest that era was the point when obesity and heart disease increased because of the explosion of carbohydrates, that was never true. They point to the Dietary Recommendations by the U.S. Senate Subcommittee on Nutrition, which focused on vegetables, fruits, and grains as the best sources of those carbohydrates. But without a decent Public Health Education Program, the recommendations were doomed to fail. The food industry flooded the market with simple carbohydrates and sugar; after all, they were carbohydrates.

Numerous randomized studies were conducted, and the largest ones failed because people didn’t follow a low-fat diet. The goal for one study was to reduce fat intake from an average of 38% to only 20%. It dropped to 24% after a year, but by six years fat had climbed back to 28%. Yet even last year, a ketogenic diet advocate was still claiming the low-fat diet failed and the study lied about the results; what the study really proved was that both reducing fat intake to 20% and increasing fruits, vegetables, and whole grains were difficult.

Cholesterol and CVD

The second story is about the relationship between levels of blood fats and CVD. It began with total cholesterol; that was the big deal for years. Then triglycerides became important based on large epidemiological studies. After that, it was LDL-cholesterol that really mattered. Then it was the ratio of total cholesterol to HDL cholesterol. The latest big thing is the size of the LDL cholesterol: fat, fluffy LDL doesn’t seem to be harmful, but small, dense LDL cholesterol does. I’d wager that tomorrow, there will be something else that will be The Big Thing.

The Bottom Line

The first story is about nutrition, and the second is about testing cholesterol. Can we predict with certainty whether you will get CVD if you follow the low-fat or high-fat dietary recommendations? No. Can a cholesterol test diagnose it? No. As the carbohydrate intake goes up, so will the risk of CVD; as blood cholesterol goes up or down, the rate of disease follows the same pattern. There’s no cause and effect. They seem to be related in some way, but they’re not predictive; they’re risk factors.

If you think back to Tuesday’s Memo when I gave the trillions of potential components that led to all the potential combinations, you can see why methods of prevention or causes of many diseases may never be known for sure. But it doesn’t change the approach to trying to find a solution: we can only know what we know today. With a methodical and rigorous approach to the scientific method, we’ll know more tomorrow.

Even if science veers in a new direction next week or next year, the only responsible course of action is for each of us to use the best knowledge we have today. And then be prepared to pivot if necessary. That’s how science works.

So what can the average person do with the flood of sometimes conflicting health information? One possibility is to let someone who understands science help you understand what’s significant and what’s not—which studies really mean something, and which are hopelessly flawed. That’s my job and my commitment to you: to sort through it all and keep you up to date on the best ways to improve your health.

What are you prepared to do today?

        Dr. Chet

What Is Science?

/in /by

Along with all the disagreements and conflicting info about covid-19, there has been some confusion about science. Many people seemed to think anything science discovered about covid was complete and final, but that’s not how science works. Science is a constantly changing body of knowledge, or as the Science Council puts it:

Science is the pursuit and application of knowledge and understanding of the natural and social world following a systematic methodology based on evidence.

We very rarely reach the end of the search. When does something become accepted science? When the evidence is irrefutable. For instance, it’s been proven beyond any doubt that polio is caused by the polio virus, but science rarely reaches that kind of definitive answer.

Does that level of certainty exist as to what causes or prevents other serious diseases such as cancer, cardiovascular disease, high blood pressure, and so on? The question is complicated. I don’t think we have—nor will we ever have—complete answers about what prevents or causes these diseases, and here’s why:

  • Each of our bodies contains trillions of cells, with 20 to 100 times more microbes in the microbiome.
  • We each have an enormous number of genes in our genome, somewhere between 25,000 and a half-million genes—we don’t even know the total number yet.
  • Add to that thousands of environmental factors.
  • And all of the above can interact.

The best we can do is to apply the scientific method and see where it leads. And while we do that, we need to keep an open mind and be prepared to adjust what we think we know.

I think the best way to explain it is to use some examples to demonstrate the complexity, and in that way, explain the difference between risk, cause, and established science. We’ll do that on Saturday.

What are you prepared to do today?

        Dr. Chet

Reference: https://sciencecouncil.org/about-science/our-definition-of-science/

Side 2: Why Powders Are Better than Plants

/in /by

You might have thought that I was a food-only proponent when it comes to nutrition. Not in the least—I’m a big fan of the right kinds of supplements. I think we should start with real food, but we also have to acknowledge that the average person’s plant intake is woefully low: one or two servings per day of vegetables and two or three servings of fruit. It’s even less if we deduct juices. There are many reasons for that lack, but we need a practical solution. Powders can provide a partial answer, whether mixed into smoothies or plain water or consumed as capsules.

The primary reason vegetable and fruit powders are better is consistent content. If the label says 500 mg of blueberry concentrate or 300 mg of acerola cherry concentrate, that content should be there scoop to scoop or capsule to capsule. The produce we buy or even raise ourselves can vary widely in phytonutrient content.

Second, for the most part, the powders are convenient. If you always have a smoothie for breakfast, a scoop or two of the vegetable and fruit powder is a quick way to improve your diet.

The Issue with Powders

The phytonutrient content per scoop or capsule may change depending on when the vegetable or fruit was harvested—even in as little as a couple of hours. It doesn’t mean they won’t be there, only that the types and quantities of phytonutrients may vary slightly.

Another issue is finding a reliable, high-quality manufacturer. This may be a great time to listen to “The Characteristics of a Quality Manufacturer” in my audio on Supplementing Your Diet. If you don’t have a copy, the MP3 is only $4.95 and you be listening in a couple of minutes.

The Bottom Line

There’s room in a healthy diet to get your eight to ten servings of vegetables and fruits from food with an assist from vegetable and fruit powders if you need them. There are small issues with each approach, but using a complementary approach may help you achieve your nutritional goals while giving you the flexibility to meet your nutritional needs even with a demanding, unpredictable schedule. The lesson: Eat better. Some plants plus some powders can give you the best of both worlds, and that can help you get closer to the nutrients your body needs.

What are you prepared to do today?

        Dr. Chet

Side 1: Why Plants Are Better than Powders

/in /by

A month ago I addressed the increased interest in getting vegetables and fruits from powders; now let’s get into more detail.

First, eating vegetables and fruits automatically increases our fluid intake. The exact water content of different plants varies, but the average plant is about 90% water by weight. The water is somewhat purified by the root system; it’s not the equivalent of a water treatment system, but it’s something.

Second, the fiber content of the plants contributes to the 25 to 30 grams of fiber we need every day. The fiber can also add to the prebiotic needed to feed the probiotics. Depending on the way the plants are prepared, they may also contain probiotics.

Those are substances you don’t get in powders unless they’re specifically added or not removed. Are foods always better? No, but they’re the perfect delivery system providing we eat them every day.

But there are two sides to every issue. On Saturday, we’ll talk about how powders are better than foods.

What are you prepared to do today?

        Dr. Chet

How C-Reactive Protein Can Predict Cancer Risk

/in /by

High-sensitivity C-reactive protein (hs-CRP) is a measure of inflammation in the body. This blood test looks for inflammation that’s not apparent; with severe infection you have a fever, but other types of inflammation may go unnoticed. This is subtle because you don’t feel anything. On top of that, CRP hasn’t been shown to be diagnostic for any disease. It still may not be, but a recently published study demonstrated that there’s a chance that if CRP changes over time, that may be indicative of some forms of cancer.

The Study

The researchers examined the relationship between CRP trajectory patterns and new-onset cancers among 52,276 participants over eight years; CRP trajectories were developed from 2006 to 2010 to predict cancer risk from 2010 to 2019. The study was restricted to the population who participated in physical examinations in 2006, 2008, and 2010, and had their CRP measured each time.

If you can think of a variable, they tested for it, as well as collecting demographic information that allowed them to consider confounding variables in the statistical analysis. The subjects were tracked for the next eight years to find out who developed cancer and what type of cancer they developed.

The Results

During the extensive and complicated statistical analysis, four CRP trajectory patterns emerged:

A low-stable pattern (43,258 subjects)
A low-stable pattern was associated with a low risk of new cancers.

A moderate-increasing pattern (2,591 subjects)
Subjects in the moderate-increasing CRP trajectory pattern were associated with an elevated risk of any form of cancer, but especially lung, breast, leukemia, bladder, stomach, colorectal, liver, gallbladder, or extrahepatic bile duct cancer.

An increasing-decreasing pattern (2,068 subjects)
Subjects in the increasing-decreasing trajectory pattern were associated with an elevated risk of any form of cancer, but especially lung, breast, bladder, pancreatic, and liver cancer. This pattern was also associated with decreased risk of colorectal cancer.

An elevated-decreasing pattern (4,359 subjects)
Subjects with an elevated-decreasing trajectory pattern were associated with increased risk of leukemia and decreased risk of esophageal and colorectal cancer.

The Bottom Line

Here’s what we know now: inflammation is definitely one of the hallmarks of cancer. Regular assessment of CRP over many years may now be predictive as a risk factor for cancer but not diagnostic. There’s more research to go, but this study is a step in the right direction.

The good news is that it’s another risk factor that can be changed through lifestyle: Eat less. Eat better. Move more.

What are you prepared to do today?

        Dr. Chet

Reference: Int J Cancer. 2022. 10.1002/ijc.34012

Three Ways to Really Reduce Your Cancer Risk

/in /by

In the last Memo before Spring Break, I said I’d cover ways to reduce your risk of getting cancer that really work. Every cancer website has lists, ranging from 10 to 15 recommendations. I’m going to give you my top three ways to reduce the risk of cancer of the items you can control. You can’t control your age or your genetic risk factors, but there are many elements of your health you can control if you work at them.

I’m not including smoking cigarettes or other tobacco products. That’s a no-brainer and shouldn’t even be mentioned, because no one should smoke. (I’m not saying that from my perch on Mount Olympus; I smoked when I was young and foolish, and quitting was one of the best decisions I ever made.)

Dr. Chet’s Top Three Ways to Prevent Cancer

  1. Eat more vegetables and fruits every day and the wider the variety, the better. They don’t have to be organically farmed; you just have to eat eight to ten servings per day. That seems like a lot, and I’m not perfect at it, but you get a new chance every day. Here’s a tip: weigh your produce instead of measuring it. Find out what constitutes a serving in grams or ounces. You may find out that a large banana is actually two servings. Do supplements matter? Yes, but the important point is to eat the fruits and veggies first, then add a multivitamin as backup.
  2. Exercise for 30 to 45 minutes per day. The fitter you are, the lower your risk of cancer. It doesn’t all have to be aerobic; yoga and strength training count as well.
  3. Reduce your weight until you achieve as close to a normal BMI (under 25) as you can; you’ll find all the info you need in the Body Mass Index article on the Health Info page at drchet.com, including how to adjust your target for your body type. We talked about caloric restriction in February, and that’s a way to slowly reduce your weight. My theory is that the older you are, the more movement matters, so if you are doing well at Numbers 1 and 2, you’re well on your way to accomplishing Number 3.

Those may sound very familiar: Eat less. Eat better. Move more. The reason these are my top three is that they reduce inflammation in different ways.

On Thursday, I’m going to cover a study on the relationship between a test for inflammation and cancer.

What are you prepared to do today?

        Dr. Chet

Artificial Sweeteners and Cancer: The Bottom Line

/in /by

In the paper on artificial sweeteners and cancer risk that I covered on Tuesday, the researchers made it clear that although the study was done well, cause and effect cannot be determined. They also acknowledge that because 80% of the subjects were women, the results couldn’t be applied to the entire French population, let alone the population of any other country. What it could mean is that artificial sweeteners in combination with other dietary, environmental, or genetic factors could contribute to cancer development.

Here are some other issues with the data and the analysis:

  • They did not test the subjects for cancer before the study. They eliminated several thousand people for already having had cancer, but they didn’t check for present cancers that hadn’t reached the point where they could be diagnosed. That would have added to the complexity, but it was possible.
  • They didn’t seem to ask when the subjects began using artificial sweeteners. The mean age was 42 at the beginning of the study, so subjects might have been using them for decades; some may have been using them for only a few days. Most cancers take years to develop, so the possible link between artificial sweeteners and cancer is probably zero in people who’ve used them a short time. The real question is whether long-term users had a higher risk.
  • I would like to have seen scattergrams of artificial-sweetener intake along with fruit-and-vegetable intake on rates of cancer. In other words, could the increase in fruits and/or vegetables reduce the impact of artificial sweeteners? Fiber intake, exercise, and BMI could also have been plotted against artificial-sweetener consumption. They accounted for these statistically, but seeing what happens when plotted could show how behavioral changes might help neutralize the artificial sweeteners.
  • One thing they didn’t is factor in is use of animal products (except dairy) and the risk of cancer—the only factors accounted for were weight-loss, a healthy diet, and a Western diet. All the studies I’ve seen assess meat intake and cancer, especially processed meat.

The Bottom Line

Take this study for what it is: an indicator that there are numerous potential causes of cancers. Clinical trials can determine cause and effect if the studies are well designed. This study did a wonderful job of measuring the intake of artificial sweeteners; they just didn’t take it all the way in analyzing the data they collected.

So what should you do? If you use artificial sweeteners, that’s fine. If you prefer not to or want to cut down, that’s fine as well. There’s nothing from this study that indicates there’s anything to fear. Paula and I both use artificial sweeteners, we’ll continue to use them, and we won’t worry about them at all.

I still believe that obesity is a greater risk, not just for cancer but for many other health issues; if artificial sweeteners help you reduce or maintain your weight, I’d say the scale tips toward using them.

We’re taking next week off for spring break, so I’ll see you back here April 12. Then we’ll look at what science shows you can do to really limit your risk of cancer.

What are you prepared to do today?

        Dr. Chet

Reference: https://doi.org/10.1371/journal.pmed.1003950

Do Artificial Sweeteners Increase Cancer Risk?

/in /by

Last week, my health news feed filled up with headlines that almost all sounded like this: “Artificial Sweeteners Linked to Higher Cancer Risk!” This isn’t the first study to suggest that relationship and it won’t be the last. This French epidemiological study of over 100,000 subjects collected data for more than seven years. One of the things I almost always criticize is data collection using food frequency questionnaires. Not this time.

The subjects completed at least two food diaries per year. Portions were assessed by comparing with pictures of portions sizes. What they did particularly well is to list all the foods that contained artificial sweeteners, including all brand names; then they tested most of the foods in the lab to verify the presence of artificial sweeteners. Researchers collected as many confounding variables as they could to account for everything that contributes to cancer.

After the statistical analysis, the overall hazard ratio demonstrated a 13% increase in the risk of cancer. Aspartame and acesulfame potassium were the artificial sweeteners with the highest hazard ratio among all those tested. Based on this information, do we need to avoid artificial sweeteners or at least lower the amounts we consume? I’ll talk about that Saturday.

What are you prepared to do today?

        Dr. Chet

Reference: https://doi.org/10.1371/journal.pmed.1003950

Do You Need a Fruit-and-Vegetable Concentrate?

/in /by

Vegetable-concentrate and fruit-concentrate products are popular now, judging by the number of ads on TV and the web; the implication is that they can replace real fruits and vegetables in the diet.

For the fruit concentrate, manufacturers remove all the fiber and water, yielding concentrates from various fruits and phytonutrient blends plus aloe vera. The supplements include 2,000 mg per serving with 17 ingredients; that works out to 120 mg per ingredient if equally divided. Are those amounts significant, especially after removing the fiber and water? Hard to say without a lot of research on each nutrient to find the effective amount, both individually and combined; for example, we don’t know if there’s an interaction between the nutrients that affects absorption and utilization.

One more type of concentrate would be single-nutrient supplements, such as a specific type of curcuminoids from a certain species of turmeric. Manufacturing is not my area; it takes some hard-core chemistry to figure out how to get the nutrient you want.

Here’s an example: curcumin is extracted from the dried root of the rhizome Curcuma longa. After drying, the process of extraction requires the raw material to be ground into powder and washed with a solvent that selectively extracts coloring matter, the curcuminoids, which then can be put into supplement form. Might there be some vitamins and minerals remaining? Probably, but that isn’t the point of the supplement. The curcuminoids are.

The Bottom Line

At the end of the day, our bodies need the fiber and water from plants to feed our microbiome. That’s why these types of products complement the vegetables and fruits you’re supposed to be eating—they don’t replace them.

I think the best way to get the best of both worlds is eating the five to ten servings of fruits and vegetables you’re supposed to eat, plus taking a multivitamin-multimineral with plant concentrates as insurance to make sure you get all the basic nutrients. If you know you’re not going to be eating as you should for a while, like an accountant working 14-hour days at tax time or a student cramming for finals, a fruit-and-vegetable concentrate might be a good addition. Then add specific concentrate-phytonutrient blends you may be missing in your diet; for example, if you hate mushrooms, take a mushroom-blend supplement. Now you’ve got all your bases covered.

What are you prepared to do today?

        Dr. Chet

Reference: www.fao.org/fileadmin/templates/agns/pdf/jecfa/cta/61/Curcumin.pdf

Vitamins and Minerals in Supplements

/in /by

I got an interesting question last week about a supplement that contained a blend of fruit and vegetable concentrates: vitamins and minerals aren’t included on the label, so are they in there? The answer is probably. It all comes down to the purpose of the supplement.

A concentrate is typically the entire vegetable or fruit with the water removed by a dehydration process; whatever is in the plant will be in the concentrate. You could liken this to drying a fresh herb to use as a spice. A more sophisticated process is to remove some of the fiber as well; that would remove solids, but some vitamins and minerals could remain.

Another variation is if a company were to focus on a phytonutrient blend, such as the polyphenols and hesperidin from citrus fruit. They would standardize the supplement to the amounts of those phytonutrients but wouldn’t be concerned about vitamins or minerals unless they met a percentage of the RDA.

There is still more precision in concentrate and phytonutrient supplements, and we’ll talk about them on Saturday.

What are you prepared to do today?

        Dr. Chet