Does Processed Food Cause Cancer?

Written by Dr. Steve Chaney on . Posted in Processed Food and Cancer

What Are Processed Foods Doing To Your Health?

Author: Dr. Stephen Chaney

 

does processed food cause cancerDoes processed food cause cancer?

We Americans have a love, hate relationship with processed foods. We love how they taste. We love the convenience. All our friends eat them, so it is the socially acceptable thing to do. But, we also worry about them. We know they aren’t good for us.

We know they increase our risk of becoming obese. We have been warned that they may increase our risk of heart disease, diabetes, and hypertension. But, what if they also increased our risk of cancer? A new study strongly suggests that ultra-processed foods significantly increase our cancer risk.

What Are Ultra-Processed Foods?

udoes processed food cause cancer ultra processed foodsUntil recently it had been very difficult to determine the effect of processed foods on our health because there was no uniform system for classifying the processed food content of our diet. With no consistent classification system, the outcomes varied from one study to the next. That changed around 2016 with the development of the NOVA food classification system. The NOVA system divides foods into four categories:

 

  • Ultra-processed foods.
    • These are foods most Americans would consider junk foods.

 

  • Commercially Processed foods.
    • These are commercially processed foods using natural ingredients like salt, sugar, and fats. For example, frozen peas would be considered a minimally processed food (category 4). Frozen peas with added salt or frozen creamed peas would be considered a commercially process food.

 

  • Restaurant Foods.
    • These are foods processed in a kitchen (either in people’s homes or a restaurant) using salt, sugar, and/or fats to produce a culinary masterpiece (As you might suspect from the emphasis on culinary masterpiece, this is a European classification system).

 

  • Unprocessed or minimally processed foods.
    • These are foods that most Americans would consider whole foods. They are either raw or minimally processed.

 

Intuitively, you have probably already guessed that foods in category 1 are likely to be bad for us and foods in category 4 are likely to be good for us. Categories 2 and 3 start with healthy foods but often end up with foods that are higher in salt, sugar, and/or fat than most experts would consider to be healthy.

With this classification system in mind, the next step was to classify every food in large food databases into one of these four categories. In this case the 3,300 item French NutriNet-Santé food composition database was used.

 

How Was The Study Performed?

does processed food cause cancer studyThis study (T. Fiolet et al, British Medical Journal, 2018;360:k322 doi: 10.1136/bmj.k322) was performed as part of the 8-year NutriNet-Santé web-based program launched in France in 2009 with the objective of studying the associations between nutrition and health. This study enrolled 104,980 participants who were 18 or older. The average age of participants was 42.8 years. There were 82% women and 18% men enrolled in the study.

Dietary intake was assessed using an online 24-hour dietary recall survey administered every 6 months over a two-year period. The survey was administered on random days so that every day of the week was covered in the survey. On average, participants completed 5 diet surveys during the study. The validity of these dietary surveys has been established in other studies that were part of this project.

Over an average 5-year follow-up, cancer incidence was assessed via a check-up questionnaire for health events that was administered every three months.  Participants were also encouraged to self-report health events at any time. Any time a cancer diagnosis was received, a physician from the study team contacted the participant and requested their medical records, which were provided in 80% of the cases. Finally, French death records were also screened to identify any study participants who died from cancer during the study.

In short, this was a very well-done study.

 

Does Processed Food Cause Cancer?

 

does processed food cause cancer junk foodsUsing the NOVA classification system, this question is concerning ultra-processed food.

Here is what the study showed:

  • Every 10% increase in the proportion of ultra-processed foods (junk foods) in the diet was associated with a 12% increase in overall cancer and a 11% increase in breast cancer.
  • No association was seen between commercially processed foods or restaurant foods in the diet and cancer.
  • Every 10% increase in the proportion of unprocessed foods in the diet was associated with a 9% decrease in overall cancer and a 58% decrease in breast cancer.

Just in case you might be tempted to say that a 12% increase in cancer risk is insignificant, remember it is the cancer risk associated with just a 10% increase in ultra-processed foods in the diet. Recent studies have suggested that ultra-processed foods contribute from 25% to 50% of the calories consumed by most Americans.

The authors concluded “[The] rapidly increasing consumption of ultra-processed foods may drive an increased burden of cancer and other non-communicable disease.”

 

What Does This Study Mean For You?

does processed food cause cancer unprocessed foodsBecause the NOVA classification system for identifying the processed food composition of the diet is a recent introduction, this is the first study of its kind. While it is a very good study, it needs to be confirmed by further studies in different population groups.

It would be tempting to ascribe the higher cancer incidence to secondary consequences of ultra-processed food consumption. For example, consumption of ultra-processed food is associated with:

  • Obesity which, in turn, is associated with increased cancer risk.
  • Increased intake of fat, saturated and trans fats, and sugar and decreased intake of fiber and essential nutrients. The effect of these dietary changes is uncertain but could be associated with higher cancer risk.
  • Decreased intake of fruits, vegetables, and whole grains which would result in increased cancer risk.
  • Increased intake of neoformed contaminants (a fancy term for contaminants formed during processing such as acrylamide, heterocyclic amines, and polyaromatic hydrocarbons). These are all carcinogenic compounds. They are usually present in very small amounts, so their effect on cancer risk is uncertain.
  • Increased consumption of food additives of uncertain safety.

While this is an interesting area for future research, it represents a danger and shows that we will try to “have our cake and eat it too.”  Let me explain what I mean by that.

  • does processed food cause cancer restaurant foodWe love our junk foods. Food manufacturers will be only too happy to provide us with “healthier junk foods” by removing salt, sugar, and/or fat and replacing them with a chemical smorgasbord of artificial ingredients. They will reduce calories (again by adding artificial ingredients) so they can claim their junk foods won’t make us fat. They can reduce neoformed contaminants like acrylamide and claim their junk foods are now healthy. But, are they really any healthier? Not necessarily, according to this study.
  • The investigators performed a very sophisticated statistical analysis. The 12% increase in cancer they reported had already been adjusted for differences in age, sex, BMI (a measure of obesity), physical activity, smoking habits, alcohol intake, family history of cancer, and educational level. They also adjusted for fat, salt, and sugar content of the diet.
  • Some supplement companies may tell you that it’s OK to eat junk foods as long as you take the supplements they are trying to sell you. I have head dietitians say it’s OK to eat junk foods as long as you “balance” your diet with lots of fruits and vegetables. The results of this study suggest those approaches won’t be much help either.
  • Further analysis of their data by the investigators showed that the 12% increase in cancer risk was independent of overall fruit and vegetable consumption and supplement use.

The only variables left were increased intake of food additives and neoformed contaminants, and it is unlikely that those would have been sufficient to cause a 12% increase in cancer.

So, does processed food cause cancer?

Once again it appears to be the foods we eat rather than the individual components in those foods that are either good for us or bad for us. The inescapable conclusion from this study is that we are more likely to be healthy if we eat fewer processed foods and more unprocessed foods. Who would have guessed?

 

The Bottom Line:

 

A recent study looked at the effect of ultra-processed foods (otherwise known as junk foods) on cancer  risk. This was a very well-designed study, and it showed.

  • Every 10% increase in the proportion of ultra-processed foods in the diet was associated with a 12% increase in overall cancer and a 11% increase in breast cancer.
  • Every 10% increase in the proportion of unprocessed foods in the diet was associated with a 9% decrease in overall cancer and a 58% decrease in breast cancer.

Just in case you might be tempted to say that a 12% increase in cancer risk is insignificant, remember it is the cancer risk associated with just a 10% increase in ultra-processed foods in the diet. Recent studies have suggested that ultra-processed foods contribute from 25% to 50% of the calories consumed by most Americans.

This is the first study of its kind. While it is a very good study, it needs to be confirmed by further studies in different population groups.

When you look at the details of this study it appears to be the foods we eat rather than the individual components in those foods that are either good for us or bad for us. The inescapable conclusion from this study is that we are more likely to be healthy if we eat fewer processed foods and more unprocessed foods. Who would have guessed?

For more details, read the article above:

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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Comments (1)

  • Kathryn Farries

    |

    Dr Chaney,

    Thank you. Again!
    This information is very well explained. And it should be confirmation that what you don’t know can/might kill you.

    Regards,
    Kathryn

    Reply

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Latest Article

Does Magnesium Optimize Vitamin D Levels?

Posted February 12, 2019 by Dr. Steve Chaney

The Case For Holistic Supplementation

Author: Dr. Stephen Chaney

 

Does magnesium optimize vitamin D levels?

magnesium optimize vitamin dOne of the great mysteries about vitamin D is the lack of correlation between vitamin D intake and blood levels of its active metabolite, 25-hydroxyvitamin D. Many people who consume RDA levels of vitamin D from foods and/or supplements end up with low blood levels of 25-hydroxyvitamin D. The reason(s) for this discrepancy between intake of vitamin D and blood levels of its active metabolite are not currently understood.

Another great mystery is why it has been so difficult to demonstrate benefits of vitamin D supplementation. Association studies show a strong correlation between optimal 25-hydroxyvitamin D levels and reduced risk of heart disease, cancer, and other diseases. However, placebo-controlled clinical trials of vitamin D supplementation have often come up empty. Until recently, many of those studies did not measure 25-hydroxyvitamin D levels. Could it be that optimal levels of 25-hydroxyvitamin D were not achieved?

The authors of the current study hypothesized that optimal magnesium status might be required for vitamin D conversion to its active form. You are probably wondering why magnesium would influence vitamin D metabolism. I had the same question.

The authors pointed out that:

  • Magnesium status affects the activities of enzymes involved in both the synthesis and degradation of 25-hydroxyvitamin D.
  • Some clinical studies have suggested that magnesium intake interacts with vitamin D intake in affecting health outcomes.
  • If the author’s hypothesis is correct, it is a concern because magnesium deficiency is prevalent in this country. In their “Fact Sheet For Health Professionals,” the NIH states that “…a majority of Americans of all ages ingest less magnesium from food than their respective EARs [Estimated Average Requirement]; adult men aged 71 years and older and adolescent females are most likely to have low intakes.” Other sources have indicated that magnesium deficiency may approach 70-80% for adults over 70.

If the author’s hypothesis that magnesium is required for vitamin D activation is correct and most Americans are deficient in magnesium, this raises some troubling questions.

  • Most vitamin D supplements do not contain magnesium. If people aren’t getting supplemental magnesium from another source, they may not be optimally utilizing the vitamin D in the supplements.
  • Most clinical studies involving vitamin D do not also include magnesium. If most of the study participants are deficient in magnesium, it might explain why it has been so difficult to show benefits from vitamin D supplementation.

Thus the authors devised a study (Q Dai et al, American Journal of Clinical Nutrition, 108: 1249-1258, 2018 ) to directly test their hypothesis.

 

How Was The Study Designed?

magnesium optimize vitamin d studyThe authors recruited 180 volunteers, aged 40-85, from an ongoing study on the prevention of colon cancer being conducted at Vanderbilt University. The duration of the study was 12 weeks. Blood was drawn at the beginning of the study to measure baseline 25-hydroxyvitamin D levels. Three additional blood draws to determine 25-hydroxyvitamin D levels were performed at weeks 1, 6, and 12.

Because high blood calcium levels increase excretion of magnesium, the authors individualized magnesium intake based on “optimizing” the calcium to magnesium ratio in the diet rather than giving everyone the same amount of magnesium. The dietary calcium to magnesium ratio for most Americans is 2.6 to 1 or higher. Based on their previous work, they considered an “ideal” calcium to magnesium ratio to be 2.3 to 1. The mean daily dose of magnesium supplementation in this study was 205 mg, with a range from 77 to 390 mg to achieve the “ideal” calcium to magnesium ratio. The placebo was an identical gel capsule containing microcrystalline cellulose.

Two 24-hour dietary recalls were conducted at baseline to determine baseline dietary intake of calcium and magnesium. Four additional 24-hour dietary recalls were performed during the 12-week study to assure that calcium intake was unchanged and the calcium to magnesium ratio of 2.3 to 1 was achieved.

In short this was a small study, but it was very well designed to test the author’s hypothesis.

 

Does Magnesium Optimize Vitamin D Levels?

 

does magnesium optimize vitamin d levelsThis was a very complex study, so I am simplifying it for this discussion. For full details, I refer you to the journal article (Q Dai et al, American Journal of Clinical Nutrition, 108: 1249-1258, 2018).

The most significant finding was that magnesium supplementation did affect blood levels of 25-hydroxyvitamin D. However, the effect of magnesium supplementation varied depending on the baseline 25-hydroxyvitamin D level at the beginning of the study.

  • When the baseline 25-hydroxyvitamin D was 20 ng/ml or less (which the NIH considers inadequate), magnesium supplementation had no effect on 25-hydroxyvitamin D levels.
  • When the baseline 25-hydroxyvitamin D was 20-30 ng/ml (which the NIH considers the lower end of the adequate range), magnesium supplementation increased 25-hydroxyvitamin D levels.
  • When the baseline 25-hydroxyvitamin D level approached 50 ng/ml (which the NIH says may be “associated with adverse effects”), magnesium supplementation lowered 25-hydroxyvitamin D levels.

The simplest interpretation of these results is:

  • When vitamin D intake is inadequate, magnesium cannot magically create 25-hydroxyvitamin D from thin air.
  • When vitamin D intake is adequate, magnesium can enhance the conversion of vitamin D to 25-hydroxyvitamin D.
  • When vitamin D intake is too high, magnesium can help protect you by lowering 25-hydroxyvitamin D levels.

The authors concluded: “Our findings suggest that optimal magnesium status may be important for optimizing 25-hydroxyvitamin D status. Further dosing studies are warranted…”

 

What Does This Study Mean For You?

magnesium optimize vitamin d for youThis was a groundbreaking study that has provided novel and interesting results.

  • It provides the first evidence that optimal magnesium status may be required for optimizing the conversion of vitamin D to 25-hydroxyvitamin D.
  • It suggests that optimal magnesium status can help normalize 25-hydroxyvitamin D levels by increasing low levels and decreasing high levels.

However, this was a small study and, like any groundbreaking study, has significant limitations. For a complete discussion of the limitations and strengths of this study I refer you to the editorial (S Lin and Q Liu, American Journal of Clinical Nutrition, 108: 1159-1161, 2018) that accompanied the study.

In summary, this study needs to be replicated by larger clinical studies with a more diverse study population. In order to provide meaningful results, those studies would need to carefully control and monitor calcium, magnesium, and vitamin D intake. There is also a need for mechanistic studies to better understand how magnesium can both increase low 25-hydroxyvitamin D levels and decrease high 25-hydroxyvitamin D levels.

However, assuming the conclusions of this study to be true, it has some interesting implications:

  • If you are taking a vitamin D supplement, you should probably make sure that you are also getting the DV (400 mg) of magnesium from diet plus supplementation.
  • If you are taking a calcium supplement, you should check that it also provides a significant amount of magnesium. If not, change supplements or make sure that you get the DV for magnesium elsewhere.
  • I am suggesting that you shoot for the DV (400 mg) of magnesium rather than reading every label and calculating the calcium to magnesium ratio. The “ideal” ratio of 2.3 to 1 is hypothetical at this point. A supplement providing the DV of both calcium and magnesium would have a calcium to magnesium ratio of 2.5, and I would not fault any manufacturer for providing you with the DV of both nutrients.
  • If you are taking high amounts of calcium, I would recommend a supplement that has a calcium to magnesium ratio of 2.5 or less.
  • If you are considering a magnesium supplement to optimize your magnesium status, you should be aware that magnesium can cause gas, bloating, and diarrhea. I would recommend a sustained release magnesium supplement.
  • Finally, whole grains and legumes are among your best dietary sources of magnesium. Forget those diets that tell you to eliminate whole food groups. They are likely to leave you magnesium-deficient.

Even if the conclusions of this study are not confirmed by subsequent studies, we need to remember that magnesium is an essential nutrient with many health benefits and that most Americans do not get enough magnesium in their diet. The recommendations I have made for optimizing magnesium status are common-sense recommendations that apply to all of us.

 

The Case For Holistic Supplementation

 

magnesium optimize vitamin d case for holistic supplementationThis study is one of many examples showing that a holistic approach to supplementation is superior to a “magic bullet” approach where you take individual nutrients to solve individual problems. For example, in the case of magnesium and vitamin D:

  • If you asked most nutrition experts and supplement manufacturers whether it is important to provide magnesium along with vitamin D, their answer would likely be “No”. Even if they are focused on bone health, they would be more likely to recommend calcium along with vitamin D than magnesium along with vitamin D.
  • If your doctor has tested your 25-hydroxyvitamin D levels and recommended a vitamin D supplement, chances are they didn’t also recommend that you optimize your magnesium status.
  • Clinical studies investigating the benefits of vitamin D supplementation never ask whether magnesium intake is optimal.

That’s because most doctors and nutrition experts still think of nutrients as “magic bullets.” I cover holistic supplementation in detail in my book “Slaying The Supplement Myths.”  Other examples that make a case for holistic supplementation that I cover in my book include:

  • A study showing that omega-3 fatty acids and B vitamins may work together to prevent cognitive decline. Unfortunately, most studies looking at the effect of B vitamins on cognitive decline have not considered omega-3 status and vice versa. No wonder those studies have produced inconsistent results.
  • Studies looking at the effect of calcium supplementation on loss of bone density in the elderly have often failed to include vitamin D, magnesium, and other nutrients that are needed for building healthy bone. They have also failed to include exercise, which is essential for building healthy bone. No wonder some of those studies have failed to find an effect of calcium supplementation on bone density.
  • A study reported that selenium and vitamin E by themselves might increase prostate cancer risk. Those were the headlines you might have seen. The same study showed Vitamin E and selenium together did not increase prostate cancer risk. Somehow that part of the study was never mentioned.
  • A study reported that high levels of individual B vitamins increased mortality slightly. Those were the headlines you might have seen. The same study showed that when the same B vitamins were combined in a B complex supplement, mortality decreased. Somehow that observation never made the headlines.
  • A 20-year study reported that a holistic approach to supplementation produced significantly better health outcomes.

In summary, vitamins and minerals interact with each other to produce health benefits in our bodies. Some of those interactions we know about. Others we are still learning about. When we take high doses of individual vitamins and minerals, we create potential problems.

  • We may not get the full benefit of the vitamin or mineral we are taking because some other important nutrient(s) may be missing from our diet.
  • Even worse, high doses of one vitamin or mineral may interfere with the absorption or enhance the excretion of another vitamin or mineral. That can create deficiencies.

The same principles apply to our diet. I mentioned earlier that whole grains and legumes are among the best dietary sources of magnesium. Eliminating those two foods from the diet increases our risk of becoming magnesium deficient. And, that’s just the tip of the iceberg. Any time you eliminate foods or food groups from the diet, you run the risk of creating deficiencies of nutrients, phytonutrients, specific types of fiber, and the healthy gut bacteria that use that fiber as their preferred food source.

The Bottom Line

 

A recent study suggests that optimal magnesium status may be important for optimizing 25-hydroxyvitamin D status. This is one of many examples showing that a holistic approach to supplementation is superior to a “magic bullet” approach where you take individual nutrients to solve individual problems. For example, in the case of magnesium and vitamin D:

  • If you asked most nutrition experts and supplement manufacturers whether it is important to provide magnesium along with vitamin D, their answer would likely be “No.”  Even if they are focused on bone health, they would be more likely to recommend calcium along with vitamin D than magnesium along with vitamin D.
  • If your doctor has tested your 25-hydroxyvitamin D levels and recommended a vitamin D supplement, chances are he or she did not also recommend that you optimize your magnesium status.
  • Clinical studies investigating the benefits of vitamin D supplementation never ask whether magnesium intake is optimal. That may be why so many of those studies have failed to find any benefit of vitamin D supplementation.

I cover holistic supplementation in detail in my book “Slaying The Supplement Myths” and provide several other examples where a holistic approach to supplementation is superior to taking individual supplements.

In summary, vitamins and minerals interact with each other to produce health benefits in our bodies. Some of those interactions we know about. Others we are still learning about. Whenever we take high doses of individual vitamins and minerals, we create potential problems.

  • We may not get the full benefit of the vitamin or mineral we are taking because some other important nutrient(s) may be missing from our diet.
  • Even worse, high doses of one vitamin or mineral may interfere with the absorption or enhance the excretion of another vitamin or mineral. That can create deficiencies.

The same principles apply to what we eat. For example, whole grains and legumes are among the best dietary sources of magnesium. Eliminating those two foods from the diet increases our risk of becoming magnesium deficient. And, that’s just the tip of the iceberg. Any time you eliminate foods or food groups from the diet, you run the risk of creating deficiencies.

For more details about the current study and what it means to you read the article above.

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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