What is Nutrigenomics

Written by Dr. Steve Chaney on . Posted in Nutrigenomics

What Is The Truth About Personalized Nutrition Testing? – Part 2

Author: Dr. Stephen Chaney

 

nutrigenomicsWhen the human genome was sequenced in 2003, many of us in the scientific community thought we were on the verge of a revolution in human health and longevity. We would soon be able to tell individuals their risk of developing various diseases.

Even better, we would be able to tell them the kind of diet and supplementation they needed to avoid those diseases. We would be able to personalize our nutritional recommendation for every individual based on their genome – something called nutrigenomics.

How naive we were! It has turned out to be much more complicated to design personalized nutrition recommendations based on someone’s genome than we ever imagined.

 

What Is Nutrigenomics?

what is nutrigenomicsAs a Professor at the University of North Carolina I specialized in cancer drug development for over 30 years. Over the last decade of my career a field called pharmacogenomics became widely accepted in the field of cancer drug development. In simple terms, pharmacogenomics looks at how an individual’s genes influence the effectiveness and side effects of drugs.

Because of pharmacogenomics, drugs today are being approved to target cancers for people whose cancer cells have a particular genetic makeup. These drugs would not have been approved a decade ago because if you test them on cancer in the general population, they have little or no effectiveness. They only work on a subset of people who have a form of cancer with a specific genetic makeup.

In principle, nutrigenomics is the same principle. You’ve heard for years that we all have unique nutritional needs. Now we are starting to learn why. It’s because we all have unique variations in our genetic makeup. These genetic mutations increase our risk of certain diseases, and they increase our needs for certain nutrients.

For example, mutations in the MTHFR gene increase the risk of certain birth defects, and supplementation with folic acid is particularly important for reducing birth defects in that population group.

Similarly, mutations in the vitamin D receptor, the VDR gene, interfere with vitamin D absorption from foods and are associated with a condition known as “vitamin D-resistant rickets.” Babies born with this genetic defect require mega doses of vitamin D for normal bone formation.

These are the best-established examples of gene mutations that affect nutritional needs. Many more gene-nutrient interactions have been proposed, but they have not been validated by follow-up experiments.

The situation is similar when we look at gene mutations associated with metabolic responses such as fat and carbohydrate metabolism, obesity, insulin resistance and type 2 diabetes. There are a few gene mutations that have strong associations with obesity and diabetes. Many more gene-metabolism interactions have been proposed, but the data are weak and inconsistent.

 

The Promise Of Nutrigenomics

 

promise of nutrigenomicsNow that you understand what nutrigenomics is and have some background information about it, let’s look at the promise of nutrigenomics. One promise of nutrigenomics is personalized supplement programs.

We all have different nutritional needs. Wouldn’t it be wonderful if someone could analyze your genome and provide you with a personalized supplement program that precisely fits your genetically determined nutritional requirements?

There are companies that offer such personalized supplement programs. Are they providing you with something of value or is their testing bogus? Are their supplements worthless?

Another promise of nutrigenomics is personalized diet advice. Some people seem to do better on low-fat diets. Other people do best on low-carb diets. Saturated fats and red meats may be more problematic for some individuals than for others. Wouldn’t it be wonderful if someone could analyze your genome and provide you with a personalized diet program – one that allows you to lose weight easily and gain vibrant health.

There are companies that will analyze your genome and tell you whether you are more likely to lose weight and be healthier on a low-fat or low-carbohydrate diet. Is their testing accurate or is it bogus? Are they providing you with useful information, or is their diet advice worthless?

 

The Problem With Nutrigenomics

 

the truth signThe short answer to the questions I posed in the previous section is that personalized supplement and diet programs are on the horizon, but we are not there yet. Companies promising you personalized nutrition programs based on DNA tests are misleading you. They quote a few studies supporting the tests they run and ignore the many studies showing their tests are worthless.

In case you think that is just my opinion, let me quote from some recent reviews on the current status of nutrigenomics.

For example, a review (C Murgia and MM Adamski, Nutrients, 366, 2017) published in 2017 concluded: “The potential applications to nutrition of this invaluable tool were apparent since the genome was mapped. The first articles discussing nutrigenomics and nutrigenetics were published less than a year after the first draft of the human DNA sequence was made available…However, fifteen years and hundreds of publications later, the gap between the experimental and epidemiologic evidence and health practice is not yet closed.”

thumbs down symbol“The [complexity] of the genotype information is not the only factor that complicates this translation into practice. The discovery of other levels of control, including epigenetics [modifications of DNA that affect gene expression] and the intestinal microbiome, are other complicating factors. While the science of nutritional genomics continues to demonstrate potential individual responses to nutrition, the complex nature of gene, nutrition and health interactions continues to provide a challenge for healthcare professionals to analyze, interpret and apply to patient recommendations.”

Another review (M Gaussch-Ferre et al, Advances in Nutrition, 9: 128-135, 2018 ) published in 2018 concluded: “Overall, the scientific evidence supporting the dissemination of genomic information for nutrigenomic purposes remains sparse. Therefore, additional knowledge needs to be generated…”

In short, the experts are saying we still don’t know enough to predict the best diets or the best supplements based on genetic information alone. Why is that? Why is it so complicated? In part, it can be explained by a term called penetrance. Penetrance simply means that the same gene mutation can have different effects in different people. In some people, its effects may be barely noticeable. In other people its effects may be debilitating.

 

What Is The Truth About Personalized Nutrition Testing?

 

Penetrance is not just a word. It’s a concept. What causes differences in genetic penetrance? Here are the most likely explanations.

  • Human genetics is very complex. There are some gene mutations, such as those causing cystic fibrosis and sickle cell anemia, that can cause a disease by themselves. Most gene mutations, however, simply predispose to a disease or metabolic disturbance and are highly influenced by the activity of other genes. That’s because the products of gene expression form intricate regulatory and metabolic networks. When a single gene is mutated, it interacts with many other genes in the network. And, that network is different for each of us.
  • Many common diseases are polygenic. That includes disease like heart disease, diabetes, and most cancers. Simply put, that means that they are not caused by a single gene mutation. They are caused by the cumulative effect of many mutations, each of which has a small effect on disease risk. The same appears to be true for mutations that influence carbohydrate and fat metabolism and affect nutrient requirements.
  • The outcome of gene mutations is strongly influenced by our diet, lifestyle, and environment. For example, a common mutation in a gene called FTO predisposes to obesity. However, the effect of this mutation on obesity is strongest when it is coupled with inactivity and foods of high caloric density (translation: junk foods and fast foods instead of fresh fruits and vegetables). Simply put, that means most of us are genetically predisposed to obesity if we follow the American lifestyle, but obesity is not inevitable.
  • Epigenetics has an important influence on gene expression. When I was a graduate student, we believed our genetic destiny was solely determined by our DNA sequence. That was still the prevailing viewpoint when the human genome project was initiated. We thought that once we had our complete DNA sequence, we would know everything we needed to know about our genetic destiny.

nutrigenomics microbiomeHow short sighted we were! It turns out that our DNA can be modified in multiple ways. These modifications do not change the DNA sequence, but they can have major effects on gene expression. They can turn genes on or turn them off. More importantly, we have come to learn that these DNA modifications can be influenced by our diet, lifestyle, and exposure to environmental pollutants.

This is the science we call epigenetics. We have gone from believing we have a genome (DNA sequence) that is invariant and controls our genetic destiny to understanding that we also have an “epigenome” (modifications to our DNA) that is strongly influenced by our diet, lifestyle, and environment and can change day-to-day.

  • Our microbiome has an important influence on our health and nutritional status. Simply put, the term microbiome refers to our intestinal microbes. Our intestinal bacteria are incredibly diverse. Each of us has about 1,000 distinct species of bacteria in our intestines.

Current evidence suggests these intestinal bacteria influence our immune system, inflammation and auto-immune diseases, brain function and mood, and our predisposition to weight gain – and this may just be the tip of the iceberg.

More importantly, our microbiome is influenced by our diet. For example, vegetarians and meat eaters have entirely different microbiomes. Furthermore, the effect of diet on our microbiome is transitory. If you change your diet, the species of bacteria in your microbiome will completely change in a few weeks.

Finally, our microbiome also influences our nutritional requirements. For example, some species of intestinal bacteria are the major source of biotin and vitamin K2 for all of us and the major source of vitamin B12 for vegans. Intestinal bacteria may also contribute to our supply of folic acid and thiamine. Other intestinal bacteria inactivate and/or remove some vitamins from the intestine for their own use. Thus, the species of bacteria that populate our intestines can influence our nutritional requirements.

Now that you know the complexity of gene interactions you understand why we are not ready to rely on DNA tests yet. We don’t yet know enough to design a simple DNA test to predict our unique nutritional needs. That science is at least 10-20 years in the future. Companies that tell you otherwise are lying to you.

 

My Recommendations for Supplements and Foods

Here are my recommendations for how to decide which foods or supplements you should eat:

  • steve chaneyThink of DNA testing as only the first step in the process of learning which foods and supplements are best for you. Since DNA testing is not definitive by itself, I wouldn’t recommend spending thousands of dollars on a DNA test.
  • Next, start with diets that we know are healthy long-term. As I discussed in my book, “Slaying The Food Myths,” any primarily plant-based diet ranging from vegan to Mediterranean and DASH diets is likely to be healthy long-term. If you find you need a low carb diet, I recommend the low-carb version of the Mediterranean diet.
  • Don’t eliminate plant food groups like fruits, whole grains, or legumes from your diet unless you have an objective reason to do so (more about that below).
  • Learn to listen to your body. Keep track of the foods and/or supplements you eat and how they make you feel.
  • In terms of listening to your body, start with your digestive system. I have vegan friends who experience constant gas and bloating and think of it as a badge of honor. I have keto friends who experience constant constipation and think of it as a badge of honor. Neither is correct. That is just their body telling them the diet they are eating is not right for them. Here is the process I recommend:
  • Start by trying the various plant-based diets for 4 to 6 weeks until you find the one that works best for you. For example, when I tried that approach it became clear that a vegan diet was not for me. I discovered I do much better on a semi-vegetarian diet.
  • If you are still experiencing digestive issues, start paying more attention to the foods you are eating. If you keep a log of the foods you eat and when you experience digestive issues for a few weeks, you will likely be able to identify foods that are problematic for you. Once you have done that, eliminate them from your diet for a few weeks and then go back and do a food challenge test where you add that food back to your diet to confirm that it is a problem for you.
  • If all this fails, I recommend an elimination diet or FODMAP diet to identify foods to avoid (You can find instructions for both on the internet). [Note: Skin tests are notoriously unreliable, but they may give you some clues about foods to avoid that you could confirm with a food challenge.]
  • Finally, if digestive issues persist, you should make an appointment with your doctor.
  • Also, pay attention to blood sugar control following the same approach I outlined for digestive issues.
  • Symptoms of high blood sugar are fatigue, thirst, headache, trouble concentrating, and frequent urination.
  • Symptoms of low blood sugar are hunger, shakiness, anxiety, irritability, feeling lightheaded, and sleepiness.
  • Biomarkers of disease, like LDL cholesterol, HDL cholesterol, triglycerides, c-reactive protein (a measure of inflammation), and HbA1c (a measure of blood sugar control), can be useful indicators of whether a diet or supplement is right for you. However, you should interpret improvements in disease biomarkers with caution because they can be misleading when you have been following a diet or supplement program for a short time.

Any diet that results in rapid weight loss will improve disease biomarkers in the short term. Similarly, some supplement programs give a transitory improvement in disease biomarkers. It is only when a diet or supplement program has been followed for 5, 10, or 20 years that disease biomarkers become truly reliable indicators of the success or failure of that diet or supplement program.

  • Finally, feelings of well-being, energy, mood, and clarity of thinking are subjective and highly susceptible to the placebo effect. They are the least reliable indicators of the success or failure of a food or supplement program.

 

The Bottom Line

 

Nutrigenomics is defined as the interaction between our genetic makeup and our diet. How far have we advanced in the science of nutrigenomics? Can a simple DNA test provide us with useful information?

For example, we all have different nutritional needs. Wouldn’t it be wonderful if someone could analyze your genome and provide you with a personalized supplement program that precisely fits your genetically determined nutritional requirements?

There are companies that offer such personalized supplement programs. Are they providing you with something of value or is their testing bogus? Are their supplements worthless?

There are companies that will analyze your genome and tell you whether you are more likely to lose weight and be healthier on a low-fat or low-carbohydrate diet. Is their testing accurate or is it bogus? Are they providing you with useful information, or is their diet advice worthless?

Two recent reviews have surveyed the nutrigenomic literature (all published clinical studies) and have concluded that we still don’t know enough to predict the best diets or the best supplements based on genetic information alone. Why is that? It is because:

  • Human genetics is very complex.
  • Many common diseases are polygenic (caused by the cumulative effect of many mutations).
  • The effect of gene mutations on our health and wellbeing is strongly influenced by our diet, lifestyle, and environment.
  • Epigenetics has an important influence on gene expression.
  • Our microbiome has an important influence on our health and nutritional status.

For more details and my personal recommendations on how to determine the best diet and supplement program 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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Latest Article

Eye Pain Relief

Posted August 20, 2019 by Dr. Steve Chaney

A Simple Treatment To Make Your Eye Pain Disappear

Author: Julie Donnelly, LMT –The Pain Relief Expert

Editor: Dr. Steve Chaney

 

good newsAs the song goes: ”…Summertime and the living is e-a-s-y….”  Here in Florida we know that the living is easy because it’s so hot who wants to be doing anything except either sitting in the shade, or inside in the air conditioning.  Personally, I don’t think this summer was so bad, especially the evenings, but then, I really hate the cold so maybe my opinion is biased.

To stay in alignment with “living is easy,” I’m taking the advice of a few experts who teach easy ways to stay calm, motivated, and happy.  I’m taking a 30-day break from the news.  It’s so much in my face lately that it’s really affecting me in a very negative way.  So far, I’m two days into my 30 days.

I’ve decided that I want to take away some of the stress that seems to be normal for everyone. To that end I was listening to a speaker who was talking about the dangers of stress and what it does to the body.  Really frightening! He was saying that negative news sells and, for example, in the 1990’s in one city of the USA, homicides had gone down 42%, but the local TV station increased its coverage of homicides by 700%.  It’s only gotten worse in 2019.  It’s making us think we live in a dangerous country, and it sure isn’t helping our blood pressure.

To solve that problem, this speaker recommended going on a “news fast” for 30 days. Absolutely no negative news of any kind for a full month.  I’m surrounded by news all day so it’s a challenge, but I’ve found a great substitute:  www.GoodNewsNetwork.org.  Their mission is to be an antidote to the barrage of negativity experienced in the mainstream media.

So, I want to share this with you, and if you have any other good news stations/websites you love, please feel free to share it with me.

I think I’m off to the beach with a big umbrella and a thermos of ice-cold tea!  Living the e-a-s-y life!

Have a relaxing month!

 

Eye Strain And Eye Pain

 

eye pain reliefThis week I had a client come to the office with a situation that is pretty rare.  He described his pain as on his eyeball, which then referred to the entire top half of his skull.  It was like drawing a line that went under his eyes, through his ears, and around his head.  It was definitely a headache but concentrated on his eyes.  He was in desperate need of eye pain relief.

This client works in an industry that has the computer screen changing frequently and he’s needing to locate information on the new screen quickly.  He has experienced eye strain before, but other times just having the weekend off has resolved the problem.  This time the pain didn’t go away.

We don’t ever think about the muscles that move our eyes, but they can get repetitively strained just like any other muscle in the body.  This especially happens if you are watching something that has your eye moving back and forth rapidly, like a game on your computer or phone.

The muscles that are most prone to a repetitive strain injury are the ones on the top of the eye and on the outside of the eye.  I’m not an eye doctor so I can’t explain why these two muscles cause more problems than the others, but my experience has shown this to be the truth.

 

Eye Pain Relief

 

eye pain relief massageThe treatment is simple, but you need to do it cautiously.  If you wear contacts, you’ll need to remove them. The pressure is VERY light.

Put your fingertip directly onto your eyeball and press down GENTLY.

Slide your finger from the top of your eyeball to the outside of your eyeball.

If you find a point where it is tender, that’s the spasm that is putting a strain on your eyeball.  Just leave your fingertip on that point for 30 seconds.

You may even get a light show while doing this, with different shapes and colors.

You’ll find that this simple treatment will soothe tired eyes at the end of the day.  But remember, the pressure needs to be light and gentle.

Why stay in pain when it’s so easy to find the muscular source of the problem and eliminate it?

 

 

Treat Yourself to Pain-Free Living (https://julstromethod.com/product/treat-yourself-to-pain-free-living-hardcopy/) is filled with over 100 pictures pain free living bookand descriptions proven to show you how to find and self-treat muscle spasms from head to foot!

Join the 1000’s of people worldwide who have discovered that tight muscles were the true source of pains they thought were from arthritis, fibromyalgia, and other serious conditions.  You have nothing to lose, and everything to gain by releasing tight muscles.

 

Treat Yourself to Pain-Free Living is your step-by-step guide to pain relief!

 

 

Wishing you well,

 

Julie Donnelly

 

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.

 

About The Author

julie donnellyJulie Donnelly is a Deep Muscle Massage Therapist with 20 years of experience specializing in the treatment of chronic joint pain and sports injuries. She has worked extensively with elite athletes and patients who have been unsuccessful at finding relief through the more conventional therapies.

She has been widely published, both on – and off – line, in magazines, newsletters, and newspapers around the country. She is also often chosen to speak at national conventions, medical schools, and health facilities nationwide.

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