Iron and Brain Development

Written by Dr. Steve Chaney on . Posted in Food and Health, Nutritiion, Supplements and Health

Iron and the Teen Brain
Author: Dr. Steve Chaney

 

iron and brain development in teensFor 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.  Let’s look at the association between iron and brain development.

And – no surprise here – what they eat can affect the health of their brain as well.

Which brings me to a study published in the Proceedings of the National Academy of Sciences January 9, 2012 (doi: 10.1073/pnas.1105543109) that looks at the adequacy of dietary iron intake during the teenage years and their brain health as adults.

Basics of Iron Metabolism

Before 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 transferring 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. As a consequence elevated transferrin levels are generally indicative of an iron-deficient diet.

Iron and Brain Development in Teens

iron and brain developmentThe 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 pretty 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.

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 of 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 of 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 (1)

  • Chelia McFowler

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    Very informative, I will pass this on to my children.

    Reply

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High Protein Diets and Weight Loss

Posted October 16, 2018 by Dr. Steve Chaney

Do High Protein Diets Reduce Fat And Preserve Muscle?

Author: Dr. Stephen Chaney

Healthy Diet food group, proteins, include meat (chicken or turkAre high protein diets your secret to healthy weight loss? There are lots of diets out there – high fat, low fat, Paleolithic, blood type, exotic juices, magic pills and potions. But recently, high protein diets are getting a lot of press. The word is that they preserve muscle mass and preferentially decrease fat mass.

If high protein diets actually did that, it would be huge because:

  • It’s the fat – not the pounds – that causes most of the health problems.
  • Muscle burns more calories than fat, so preserving muscle mass helps keep your metabolic rate high without dangerous herbs or stimulants – and keeping your metabolic rate high helps prevent both the plateau and yo-yo (weight regain) characteristic of so many diets.
  • When you lose fat and retain muscle you are reshaping your body – and that’s why most people are dieting to begin with.

So let’s look more carefully at the recent study that has been generating all the headlines (Pasiakos et al, The FASEB Journal, 27: 3837-3847, 2013).

The Study Design:

This was a randomized control study with 39 young (21), healthy and fit men and women who were only borderline overweight (BMI = 25). These volunteers were put on a 21 day weight loss program in which calories were reduced by 30% and exercise was increased by 10%. They were divided into 3 groups:

  • One group was assigned a diet containing the RDA for protein (about 14% of calories in this study design).
  • The second group’s diet contained 2X the RDA for protein (28% of calories)
  • The third group’s diet contained 3X the RDA for protein (42% of calories)

In the RDA protein group carbohydrate was 56% of calories, and fat was 30% of calories. In the other two groups the carbohydrate and fat content of the diets was decreased proportionally.

Feet_On_ScaleWhat Did The Study Show?

  • Weight loss (7 pounds in 21 days) was the same on all 3 diets.
  • The high protein (28% and 42%) diets caused almost 2X more fat loss (5 pounds versus 2.8 pounds) than the diet supplying the RDA amount of protein.
  • The high protein (28% and 42%) diets caused 2X less muscle loss (2.1 pounds versus 4.2 pounds) than the diet supplying the RDA amount of protein.
  • In case you didn’t notice, there was no difference in overall results between the 28% (2X the RDA) and 42% (3X the RDA) diets.

Pros And Cons Of The Study:

  • The con is fairly obvious. The participants in this study were all young, healthy and were not seriously overweight. If this were the only study of this type one might seriously question whether the results were applicable to middle aged, overweight coach potatoes. However, there have been several other studies with older, more overweight volunteers that have come to the same conclusion – namely that high protein diets preserve muscle mass and enhance fat loss.
  • The value of this study is that it defines for the first time the upper limit for how much protein is required to preserve muscle mass in a weight loss regimen. 28% of calories is sufficient, and there appear to be no benefit from increasing protein further. I would add the caveat that there are studies suggesting that protein requirements for preserving muscle mass may be greater in adults 50 and older.

The Bottom Line:

1)    Forget the high fat diets, low fat diets, pills and potions. High protein diets (~2X the RDA or 28% of calories) do appear to be the safest, most effective way to preserve muscle mass and enhance fat loss in a weight loss regimen.

2)     That’s not a lot of protein, by the way. The average American consumes almost 2X the RDA for protein on a daily basis. However, it is significantly more protein than the average American consumes when they are trying to lose weight. Salads and carrot sticks are great diet foods, but they don’t contain much protein.

3)     Higher protein intake does not appear to offer any additional benefit – at least in young adults.

4)     Not all high protein diets are created equal. What some people call high protein diets are laden with saturated fats or devoid of carbohydrate. The diet in this study, which is what I recommend, had 43% healthy carbohydrates and 30% healthy fats.

5)    These diets were designed to give 7 pounds of weight loss in 21 days – which is what the experts recommend. There are diets out there promising faster weight loss but they severely restrict calories and/or rely heavily on stimulants, they do not preserve muscle mass, and they often are not safe. In addition they are usually temporary.  I do not recommend them.

6)    This level of protein intake is safe for almost everyone. The major exception would be people with kidney disease, who should always check with their doctor before increasing protein intake. The only other caveat is that protein metabolism creates a lot of nitrogenous waste, so you should drink plenty of water to flush that waste out of your system. But, water is always a good idea.

7)     The high protein diets minimized, but did not completely prevent, muscle loss. Other studies suggest that adding the amino acid leucine to a high protein diet can give 100% retention of muscle mass in a weight loss regimen – but that’s another story for another day.

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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