Iron Deficiency In Children May Negatively Affect Their Brains

Written by Dr. Steve Chaney on . Posted in Iron Deficiency in Children, Uncategorized

Is Your Teen Getting Enough Iron?

Author: Dr. Stephen Chaney

 

iron deficiency in childrenFor those of you with teenagers – or who have had teenagers in the past – you may suspect that there’s nothing between their ears. But actually, there is a lot going on between their ears, and some of the neural contacts laid down in the brain during the teen years influence the health of their brain during their adult life.

And – no surprise here – what they eat can affect the health of their brain as well.  Iron deficiency in children may negatively affect their brains later in life.

Which brings me to a study (N. Jahanshad et al, PNAS 109 E851-E859, 2012 ) that looks at the adequacy of dietary iron intake during the teenage years and their brain health as adults.

 

Basics of Iron Metabolism

 

iron deficiency in children metabolismBefore I describe the study perhaps a little bit of what I call Biochemistry 101 is in order.

Free iron is toxic to living cells. For that reason, our body produces multiple proteins to bind and transport the iron. The protein that binds and transports iron through the bloodstream is called transferrin. Under normal conditions 2/3 of the transferrin in our bloodstream has iron bound to it and 1/3 does not. And that is the ideal ratio of bound and unbound transferrin for delivery of iron to brain cells and other cells in our body.

When our diet is iron deficient (or we have excessive blood loss) the percent iron saturation of transferrin decreases. The body tries to compensate by producing more transferrin, but this doesn’t really help since the problem was inadequate iron supply, not inadequate transferrin supply. Consequently, elevated transferrin levels are generally indicative of an iron-deficient diet.

 

Iron Deficiency In Children

 

The study was led by Dr. Paul Thompson of the UCLA Department of Neurology. He and his team performed brain scans on 631 healthy young adults with an average age of 23. The brain scans were of a type that measured strength and integrity of the connections between the nerves in the brain – in other words, the brain’s wiring. They then went back and looked at the amount of iron available to each subject’s brain during adolescence by looking at their blood transferrin levels from routine physical exams performed at ages 12, 14 and 16 (blood transferrin levels are often measured as part of routine physical exams).

The results were clear cut. Elevated transferrin levels during the teenage years were associated with reduced brain-fiber integrity in regions of the brain that are known to be vulnerable to neurodegeneration. These individuals did not show any cognitive impairments as young adults, but the concern is that they might be more likely to develop cognitive impairments as they age.  From this, we can determine iron deficiency in children may make them susceptible to mental disease as they age.

Dr. Thompson summarized his team’s findings by saying that “Poor iron levels in childhood erode your brain reserves which you need later in life to protect against aging and Alzheimer’s. This is remarkable, as we were not studying iron deficient people, just around 600 normal healthy people. It underscores the need for a balanced diet in the teenage years, when your brain command center is still actively maturing.”

 

Questions Every Parent Should Ask

If you have teenagers, you might want to ask yourself questions like:

  • What is your teenager’s diet like?
  • Is it balanced?
  • Are you sure that it meets their nutritional needs?
  • Should you consider supplementation to make sure that they are getting all the nutrients that they need?

 

The Bottom Line

 

  • A recent study suggested that inadequate iron intake in the teenage years may affect how our brains are wired in our adult years. The authors of the study interpreted the study as suggesting that an inadequate diet during the teen years could predispose us to cognitive decline and Alzheimer’s as adults.
  • This study only looked at structural differences in the brain circuitry. We can’t conclude from this study alone that inadequate iron intake as a teenager will doom somebody to cognitive impairment and increased Alzheimer’s risk as they age. But we can conclude that adequate iron intake during adolescence is required for normal brain development.
  • And it’s probably not just iron. This study focused on iron status because transferrin levels are routinely measured during physical exams, so it was easy to go back and determine what each subject’s iron status was during their teenage years. Many other important nutrients are required for normal brain development, but we don’t have an easy way of going back and determining what someone’s nutritional status was for those nutrients in their teen years. What was shown to be true for iron in this study is likely to be true for other nutrients as well.
  • These were normal teens eating a normal American diet. They weren’t from a third world country and there was nothing weird about what they were eating. But, clearly some of the subjects in the study weren’t getting the iron that they needed from diet alone.
  • The teen years are a time of rapid growth and maturation. It’s not just the brain that needs the proper balance of nutrients during the teen years. All their tissues require proper nutrition.

 

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 (5)

  • Merlena Cushing

    |

    I clicked on the tab that said…”questionnaire that will enable us to serve you better you will receive a FREE copy of my latest eBook “The Dangers Of Sports Supplements”.” No questionnaire came up or any way to get this on Dangers of Sports Supplements. Thanks for your help on this.

    Reply

    • Dr. Steve Chaney

      |

      Dear Merlina.
      I was a bit premature announcing that eBook. The website design required to make it available is taking longer than anticipated. Once it is ready, I will add a link for current subscribers to get the book on the next “Health Tips From The Professor” email.
      Dr. Chaney

      Reply

      • Merlena Cushing

        |

        Oh, I see. Thanks for the reply.

        Reply

  • Hamilton C McKelvey

    |

    Hi Dr. Steve, Excellent information. I looked to see if I could receive a copy of your book entitled ” Sports Supplements”, but I did not see how to get it as it was not identified as an option after I was able to scroll down. Best wishes, Ham McKelvey NE42794 mckentwa2@gmail.com

    Reply

    • Dr. Steve Chaney

      |

      Dear Hamilton.
      I was a bit premature announcing that eBook. The website design required to make it available is taking longer than anticipated. Once it is ready, I will add a link for current subscribers to get the book on the next “Health Tips From The Professor” email.
      Dr. Chaney

      Reply

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Latest Article

The Truth About Vitamin D

Posted December 11, 2018 by Dr. Steve Chaney

Does Vitamin D Reduce Risk Of Heart Disease & Cancer?

Author: Dr. Stephen Chaney

 

the truth about vitamin dYou have every right to be confused. One day you are told that vitamin D reduces your risk of heart disease and cancer. The next day you are told vitamin D makes has no effect on those diseases. You are told vitamin D is a waste of money. What should you believe?  What is the truth about vitamin D?

In mid-November a major clinical study called VITAL was published. It examined the effect of vitamin D and omega-3s on heart disease and cancer risk. Last week I wrote about the omega-3 portion of the study. This week I will cover the vitamin D portion of the study.

Once again, if you rely on the media for your information on supplementation, you are probably confused. Headlines ranged from “Vitamin D Is Ineffective For Preventing Cancer And Heart Disease to “Vitamin D Lowers Odds Of Cancer Death.” What is the truth?

The problem is that reporters aren’t scientists. They don’t know how to interpret clinical studies. What they report is filtered through their personal biases. That is why I take the time to carefully evaluate the clinical studies, so I can provide you with accurate information. Let me sort through the dueling headlines and give you the truth about vitamin D, cancer, and heart disease.

How Was The Study Designed?

the truth about vitamin d studyThe VITAL study (JE Manson et al, New England Journal of Medicine, DOI: 10.1056/NEJMoa1811403) enrolled 25,871 healthy adults (average age = 67) in the United States. The study participants were 50% female, 50% male, and 20% African American. None of the participants had preexisting cancer or heart disease. The characteristics of the study group were typical of the American population at that age, namely:

  • The average BMI was 28, which means that most of the participants were significantly overweight.
  • 7% of them had diabetes.

Study participants were given questionnaires on enrollment to assess clinical and lifestyle factors including dietary intake. Blood samples were taken from about 65% of the participants to determine 25-hydroxyvitamin D levels (a measure of vitamin D status) at baseline and at the end of the first year. The participants were given either 2,000 IU of vitamin D/day or a placebo and followed for an average of 5.3 years.

There were two important characteristics of the participants in this study that may have influenced the outcome.

  • The average 25-hydroxyvitamin D level of participants at the beginning of the study was 31 ng/ml (78 nmol/L). The NIH considers 20-50 ng/ml (50-125 nmol/L) to be the optimal level of 25-hydroxyvitamin D for most physiological functions. This means that study participants started in the middle of the optimal range with respect to vitamin D status.

[Note: The NIH defines the 20-50 ng/ml range as “adequate.”  However, I know many of my readers like to aim beyond adequate to reach what they consider to be “optimal.”  In the case of vitamin D, that might not be a good idea. The NIH considers anything above 50 ng/ml as associated “with potentially adverse effects.”  For that reason, I will refer to the 20-50 ng/ml range as optimal for this article. I wouldn’t want to encourage my readers to be aiming for above 50 ng/ml.]

  • Only 12.7% of participants had 25-hydroxyvitamin D levels below 20 ng/ml, which the NIH considers to be inadequate. The results with this group were not statistically different from the study participants with optimal vitamin D status, but it is not clear that there were enough people in this subgroup for a statistically valid comparison with participants starting with an optimal vitamin D status.
  • At the end of the first year, 25-hydroxyvitamin D levels in the treatment group increased to 42 ng/ml (105 nmol/L), which is near the upper end of the optimal range. Thus, for most of the participants, the study was evaluating whether there was a benefit of increasing vitamin D status from the middle to the upper end of the optimal range.
  • The study allowed subjects to continue taking supplements that contained up to 800 IU of vitamin D. While the authors tried to correct for this statistically, it is a confounding variable.

Does Vitamin D Reduce The Risk Of Cancer?

 

the truth about vitamin d and cancerYou may remember from last week that omega-3s were more effective for reducing heart disease risk than for reducing cancer risk. What is the truth about vitamin D and cancer risk?   The results are reversed for vitamin D, so I will discuss cancer first.

The study reported that vitamin D supplementation did not reduce a diagnosis of invasive cancer of any type, breast cancer, prostate cancer, or colon cancer during the 5.3-year time-period of this study. This was the result that was reported in the abstract and was what lazy journalists, who never read past the abstract, reported.

However, the rest of the study was more positive. For example, occurrence of invasive cancer of any type was reduced by:

  • 23% in African-Americans.
  • 24% in patients with a healthy body weight.

Several previous studies have suggested that vitamin D may be more effective at preventing cancer in people with a healthy body weight, but the mechanism of this effect is currently unknown.

Most previous studies have not included enough African-Americans to determine whether they respond more favorably to vitamin D supplementation. However, African-Americans have a higher risk of cancer, so this finding deserves follow-up.

In addition, when the study looked at deaths from cancer, the results were very positive. For example:

  • Cancer deaths during the 5.3-year study period were reduced by 17%.
  • The longer vitamin D supplementation was continued the more effective it became at reducing cancer deaths. For example,
  • When the authors excluded cancer deaths occurring during the first year of supplementation, vitamin D reduced cancer deaths by 21%.
  • When the authors excluded cancer deaths occurring during the first two years of supplementation, vitamin D reduced cancer deaths by 25%.

Finally, no side effects were noted in the vitamin D group.

 

Does Vitamin D Reduce The Risk Of Heart Disease?

 

the truth about vitamin d and heart diseaseThe VITAL study also looked at the effect of vitamin D on heart disease risk. What is the truth about vitamin D and heart disease?  The results from this study were uniformly negative. There was no effect of vitamin D supplementation on all major cardiovascular events combined, heart attack, stroke, or death from heart disease. Does that mean vitamin D has no role in reducing heart disease risk? That’s not clear.

The authors had a thought-provoking explanation for why the results were negative for heart disease, but positive for cancer. Remember that the participants in this trial started with a 25-hydroxyvitamin D level of 31 ng/ml and increased it to at least 42 ng/ml with vitamin D supplementation.

The authors stated that previous studies have suggested the 25-hydroxyvitamin D level associated with the lowest risk for heart disease is between 20 and 25 ng/ml. If that is true, most of the participants in this trial were already in the lowest possible risk for heart disease with respect to vitamin D status before the study even started. There would be no reason to expect additional vitamin D to further reduce their risk of heart disease.

In contrast, the authors said that previous studies suggest the 25-hydroxyvitamin D level associated with the lowest risk of cancer deaths is above 30 ng/ml. If that is true, it would explain why vitamin D supplementation in this study was effective at reducing cancer deaths.

However, previous placebo-controlled clinical studies have also been inconclusive with respect to vitamin D and heart disease. My recommendation would be to think of adequate vitamin D status as part of a holistic approach to reducing heart disease – one that includes a heart-healthy diet and a heart-healthy lifestyle – rather than a “magic bullet” that decreases heart disease risk by itself.

As for heart-healthy diets, I discuss the pros and cons of various diets in my book, “Slaying The Food Myths.”  As I discuss in my book, the weight of scientific evidence supports primarily plant-based diets that include omega-3s as heart healthy. As an example, the Mediterranean diet is primarily plant-based and is rich in healthy oils like olive oil and omega-3s. It is associated with reduced risk of both heart disease and cancer.

 

What Is The Truth About Vitamin D?

 

the truth about vitamin d signThere is a lot of confusion around the question of whether vitamin D reduces the risk of cancer. This study strengthened previous observation suggesting that vitamin D supplementation decreases cancer deaths. However, it is also consistent with previous studies that have failed to find an effect of vitamin D on cancer development. How can we understand this apparent discrepancy? The authors provided a logical explanation. They pointed out that:

  • Cancer development takes 20-30 years while this clinical study lasted only 5.3 years. That means that vitamin D supplementation only occurred at the tail end of the cancer development process. In fact, the cancer was already there in most of the patients in the study who developed cancer. It just had not been diagnosed yet. In the words of the authors: “Given the long latency for cancer development, extended follow-up is necessary to fully ascertain potential effects [of vitamin D supplementation].”
  • In contrast, none of the patients had been diagnosed with cancer when they entered the trial. That means that the patients were diagnosed with cancer during the 5.3-year study period. They were receiving extra vitamin D during the entire period of cancer treatment. Thus, the effect of vitamin D on reducing cancer deaths was easier to detect.

What Does This Study Mean For You?

the truth about vitamin d questionsVitamin D Is Likely To Decrease Your Risk Of Dying From Cancer: When you combine the results of this study with what we already know about vitamin D and cancer, the results are clear. Vitamin D appears to reduce your risk of dying from cancer. More importantly, the longer you have been supplementing with vitamin D, the greater your risk reduction is likely to be.

Vitamin D May Decrease Your Risk Of Developing Cancer: Association studies suggest that optimal vitamin D status is associated with decreased cancer risk, especially colon cancer risk. However, the long time for cancer development means that we may never be able to prove this effect through double-blind, placebo-controlled clinical trials.

Holistic Is Best: When you combine the VITAL study results with what we already know about vitamin D and heart disease, it appears that supplementing with vitamin D is unlikely to reduce your risk of developing heart disease unless you are vitamin D deficient. However, a holistic approach that starts with a healthy, primarily plant-based diet and makes sure your vitamin D status is adequate is likely to be effective.

The same is likely true for cancer. While the latest study suggests that vitamin D supplementation reduces your risk of dying from cancer, those vitamin D supplements are likely to be even more effective if you also adopt a healthy diet and lifestyle.

How Much Vitamin D Do You Need? The optimal dose of vitamin D is likely to be different for each of us. One of the things we have learned in recent years is that there are significant differences in the efficiency with which we convert vitamin D from diet and/or sun exposure into the active form of vitamin D in our cells. Fortunately, the blood test for 25-hydroxyvitamin D is readily available and is widely considered to be an excellent measure of our vitamin D status.

I recommend that you have your blood level of 25-hydroxyvitamin D tested on an annual basis. Based on the best currently available data, I recommend you aim for >20 ng/ml (50 nmol/L) if you wish to minimize your risk of heart disease and >30 ng/ml (75 nmol/L) if you wish to minimize your risk of cancer. If you can achieve those levels through diet and a multivitamin supplement, that is great. If not, I would recommend adding a vitamin D supplement until those levels are achieved.

Finally, you shouldn’t think of vitamin D as a magic bullet. If you are a couch potato and eat sodas and junk food, don’t expect vitamin D to protect you from cancer and heart disease. You should think of maintaining adequate 25-hydroxyvitamin D levels as just one component of a holistic approach to healthy, disease-free living.

 

The Bottom Line

 

There is a lot of confusion around the question of whether vitamin D reduces the risk of cancer and heart disease. A major clinical study has just been published that sheds light on these important questions. It reported:

  • Vitamin D did not decrease the risk of developing cancer during the 5.3-year study duration. The authors pointed out that cancer takes 20-30 years to develop, which means their study was probably too short to detect an effect of vitamin D on the risk of developing cancer.
  • Vitamin D did decrease the risk of dying from cancer, and the longer people were supplementing with vitamin D the bigger the protective effect of vitamin D was.
  • Vitamin D did not decrease the risk of heart disease. However, most study participants had a level of 25-hydroxyvitamin D that was optimal for reducing the risk of heart disease at the beginning of the study. There was no reason to expect that extra vitamin D would provide additional benefit.
  • With respect to both cancer and heart disease the best advice is to:
    • Get your 25-hydroxyvitamin D levels tested on an annual basis and supplement, if necessary, to keep your 25-hydroxyvitamin D levels in what the NIH considers to be an adequate range (20-50 ng/ml).
    • We do not have good dose response data for the beneficial effects of vitamin D on heart disease and cancer. However, according to this article, previous studies suggest you may want to am for 25-hydroxyvitamin D levels above 20 ng/ml to reduce the risk of heart disease and above 30 ng/ml to reduce your risk of cancer.
    • Consider vitamin D as just one component of a holistic approach to healthy, disease-free living.

For more details about the interpretation of these studies and what they mean for 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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