The New Science of Nutrition & Your Genes
- What are you bringing to the table besides your appetite?
- What is the new way of looking at food?
- What do we know about protecting your DNA?
Nutrigenomics — Or nutritional genomics, is the study of how foods affect our genes and how individual genetic differences can affect the way we respond to nutrients (and other naturally occurring compounds) in the foods we eat.
This new science is already being used in a limited way to personalize our nutrition and lifestyle choices to match our genes. At some point in time, this will change.
In the future, tests will reveal our complete genetic fingerprint (our unique assortment of genes from the human genome) as well as our levels of nutrients, essential biochemicals, and metabolic status.
At that unknown time, a lifestyle assessment with integrated individualized instructions for leading a healthy life will result. It will include a personalized supplement program and a list of foods appropriate for each genotype.
Look inside and discover 10 ways you keep your genes healthy….
The New Science of
Nutrition & Your Genes
• What are you bringing to the table besides your appetite?
• What is the new way of looking at food?
• What do we know about protecting your DNA?
Look inside and discover 10 ways
you keep your genes healthy….
Topic: NUTRITION & YOUR GENES
Unbalanced intake of any of the three major macronutrients — fat, carbohydrates, or protein — contribute to the initiation, development, progression, and/or severity of chronic diseases. Fad diets, which are often unbalanced, may produce short-term weight loss, but are often unhealthy over long time periods. HYPERLINK “http://www.nutrigenomics.ucdavis.edu” www.nutrigenomics.ucdavis.edu
Americans are beginning to understand that we bring two things to the dinner table — our appetites and our genotypes. Raymond L. Rodriguez, PhD, Director
Center of Excellence in Nutritional Genomics
University of California, Davis
Or nutritional genomics, is the study of how foods affect our genes and how individual genetic differences can affect the way we respond to nutrients (and other naturally occurring compounds) in the foods we eat. This new science is already being used in a limited way to personalize our nutrition and lifestyle choices to match our genes. At some point in time, this will change.
In the future, tests will reveal our complete genetic fingerprint (our unique assortment of genes from the human genome) as well as our levels of nutrients, essential biochemicals, and metabolic status. At that unknown time, a lifestyle assessment with integrated individualized instructions for leading a healthy life will result. It will include a personalized supplement program and a list of foods appropriate for each genotype.
Although we’re not there yet, exciting research is being done and rapid advances are being made in this new field. The genomic researchers have announced that we’re involved in a paradigm shift. Rather than looking at food as a source of calories, food is being seen as a complex of dietary chemicals, some of which have the potential to prevent, reduce, or treat disease. The interface here may depend on our individual genomic profile.
Taking a closer look, only 0.1% of the human gene is responsible for the differences between any two individuals. Just 1/1000 of our total genes account for our personal genomic profile. The truth is we’re more alike than we are different. According to U.C. Davis researchers Kaput and Rodriguez, “Genomic analysis reveals that humans are 99.9% identical at the DNA level.” This means that about three million single nucleotide polymorphisms (called SNiPs) are responsible for all the morphological (i.e., form or shape), physiological, biochemical and molecular differences between us.
WOW! What a paradox. We’re 99.9% the same — yet we have some 3 million little differences! What can those three million SNiPs do? In addition to determining our appearance, they can program parts of our health status and pre-dispose us to certain diseases.
It Can Get Complicated
There are some well-known diseases that are linked to single genes, such as Tay Sachs and sickle-cell anemia. However most of the major chronic disorders, such as cancer, heart disease, diabetes, metabolic syndrome, arthritis, Alzheimer’s, and others are not caused by just one gene.
These diseases do have a genetic component, but they are triggered by interactions between multiple genes, working in combination with diet, exercise, stress, and environmental influences. These complicated interactions mean that a test for a single gene is not likely to tell us much about our potential for developing these diseases.
In Feed Your Genes Right, author Jack Challem suggests that most diseases involve hundreds or sometimes thousands of genes that have gone awry. For example, up to 5,000 malfunctioning genes may play a role in heart disease. For that type of disorder, it may be more helpful to know whether heart disease “runs in your family,” than it is to pay for genetic testing.
Incidentally, the first company to offer gene SniP analysis to the public tests only 19 genetic markers per DNA sample. In their “gene assessment”, they identify which of these 19 genes in your genetic profile could have an impact on your health. An assessment covers bone health, heart health, insulin sensitivity, inflammation, and antioxidant—detoxification response.
The area of degenerative eye diseases is one in which genetic research has made significant progress. Scientists have identified more than 130 genes associated with retinal diseases. The University of Michigan’s Kellogg Eye Center is one of the leading centers for this research. Even though some of their successes are striking, the researchers caution that genetic variations may alter how a gene functions. Genetic tests confirmed clinical diagnoses in only about half of the tests conducted. At the center, Dr. Radha Ayyagari says it is difficult for patients to understand that genetic test results may not be definitive. She remarks, “Genetic testing may not always yield the firm facts we receive in other kinds of testing, such as blood tests for cholesterol levels.”
Gene therapy remains a goal for the future. Our biochemical knowledge does not permit us to “fix” our genes. Basically, we’re stuck with the ones we’re born with. However, it is the interactions of dietary chemicals with genetic machinery and information that play a key role in maintaining health and preventing diet-influenced chronic diseases. (Diet x Genotype = Result) We control our diets. We also make our own exercise, nutritional supplement, and other lifestyle choices.
You Are What You Eat
urprise! Surprise! There is a “Dietary Defense Against DNA Damage”. As with every condition we have ever discussed in Nutrition News, when it comes to genetic disorders, a healthy diet is one of the most important recommendations that can be made. In this case, good nutrition can protect our healthy genes and prevent “sick” (variant) genes from being expressed. As UC Davis’s Rodriguez writes, “No genotype is completely immune to the deleterious effects of poor diet.”
The general recommendations given by nutrigenomics researchers closely match those we have repeatedly stressed. Staying lean and active is one basic guideline for health. In addition to avoiding excess calories, other recommendations include: reduce fat intake, use non-hydrogenated plant cooking oils, eat whole grains, reduce sugars, emphasize fresh fruits and vegetables, restrict meat consumption, consider calcium needs and those for vitamin D, keep salt intake low, and take a multivitamin-mineral.
Avoiding obesity is easier said than done for many of us. Statistical evidence suggests that genes can have a big influence on obesity. More work needs to be done with humans, but studies with animals have shown that using the same diet, some gain weight while other strains of the same animals stay lean. Hmmm. Maybe my genes made me do it!!
Unfortunately, a genetic predilection for weight gain doesn’t make it healthy. It just makes it more difficult to be lean. Nutritional, biochemical, and genetic factors are all involved in the development of obesity and diabetes. And, it’s a downward spiral. Elevated blood sugar can damage DNA. Then, elevated insulin levels (resulting from elevated blood sugar) can alter normal gene behavior. This bad combination causes fat around the belly, promotes heart disease and diabetes, and increases the risk of some cancers. And, yes, metabolic disorders also have a basis in our genes.
Supplement Your Genes
Researchers suggest that there are about 50 human genetic diseases due to defective enzymes, and these disorders can be remedied by taking extra doses of the vitamins that correspond to the enzymes. Bruce Ames (of antioxidant research fame) has explained that about one-fourth of the genetic diseases that can be remedied with vitamin therapy involve “defects in mitochondrial enzymes”. Since mitochondria are our energy producers, it follows that sufficient vitamin intake is helpful.
One way to be sure you’re getting the basic nutrients you need is to take a daily multivitamin-mineral formula. As well known Harvard nutritionist Walter Willett put it, “the use of a daily multiple vitamin appears rational for the majority of Americans.” The effectiveness of this type of vitamin therapy has been demonstrated, particularly with some of the B vitamins. In addition to a daily multi- formula, we recommend these extra vitamins: C (up to 3 grams daily — we use a revolutionary new form of C); E (up to 1200 IU with tocotrienols and mixed tocopherols); D (at least 1000 IU); and K2 (menaquinone, 100 mcg for bone health). Build your calcium intake to 1200 mg/d and magnesium to at least half of that (bones and more). Take omega-3 in the fish oil form (heart and mind, plus brings body essential fatty acids not easy to get otherwise).
Lastly, if you are over 40, be sure to take at least 30 mg of CoQ10 daily. We stop making this integral vitamin-like substance in middle age and it is vitally important to replace it for overall health and energy production.1
Antioxidants are imperative to protecting our DNA. These substances “disarm” free radicals. Free radicals not only injure cells and genes, they can also damage mitochondrial DNA. Further, this damage can increase with age. Well-known antioxidants include vitamins E and C. Fresh plant foods contain many helpful compounds, such as carotenoids (lutein, lycopene, beta-carotene) and flavonoids (quercetin, hesperidin). Others include selenium, N-acetylcysteine, and lipoic acid. Some studies have shown lower incidences of various cancers in people who consume green tea (green tea polyphenols). There have been inconsistencies in these studies. One possible explanation may be that only people with certain genetic profiles benefit.
According to Challem, people at risk for inflammatory diseases (including heart disease) or cancer may wish to consider supplementing with extra flavonoids, such as pine bark or grapeseed extracts. Here, we have been exceedingly pleased with a formulation containing boswellia and curcuminoids (the active component of turmeric). Speaking of inflammation, the aging brain is another area where both antioxidant and anti-inflammatory action is important. Ames has observed the improvement of both thinking and movement in lab animals given a combination of lipoic acid and acetyl L-carnitine.2
Difficulties in the Differences
Nutrigenomics increases our awareness that what’s “healthy” for one person may not be good for another person, depending partly on our genes. For example, milk isn’t healthy for someone who is lactose intolerant. Interestingly, lactose tolerance in adults is the result of a SNiP variation in people of Northern European descent. This brings attention to the importance of being conscious of the foods we should avoid, as well as those to meet our own particular nutritional needs.
Researchers caution that there are both dangers and ethical questions in this new field. In Nutritional Genomics, Castle et. al. warn us, “…nutrigenomics is not yet at the point where the science is strong enough to support a large number of claims of health benefits to individuals.” In other words, nutrigenomic information should not be used to mislead us as consumers or make us overly afraid about our health. Ethically, there are privacy issues. We do not want to see employers or insurance companies use genetic information to discriminate against individuals or against different races. In this melting-pot world, one of the potential problems with race-specific nutritional recommendations is that, without detailed DNA testing or thorough ancestral histories, we do not know the extent of our genetic heritage.
In conclusion: It is now accepted that nutrients alter molecular processes such as DNA structure, gene expression, and metabolism. In turn, these may alter disease initiation, development, or progression. The bottomline is that individual genetic variation can influence how nutrients are assimilated, metabolized, stored, and excreted by the body.
Castle et al.state, “Not everyone wants to wait until there is irrefutable scientific evidence of benefit before instituting a low-risk nutritional measure.” Challem strongly urges preventive nutritional actions. He remarks that those who wait for absolute proof and for the development of innovative gene therapies may have to wait longer than a lifetime. Jack gives us this very important caution: “A genetic predisposition indicates only risk, not destiny…”!
Optimizing Personal Health
Interestingly and thankfully, the same healthy tactics that protect against gene damage can sometimes help to overcome, or compensate for the action of our potentially “detrimental” genes. It may not be helpful to think of having a “bad” gene. In fact, currently, it’s generally not possible to know for sure whether a particular nutritional observation is due to a gene, a gene-gene interaction, a gene-nutrient interaction, or a gene-environment interaction.
Optimizing health also includes maintaining healthy lifestyle choices. According to Kaput, “environmental” factors that can influence gene expression include:
Amount and quality of sleep.
Oxygen intake, altitude.
Drugs and medications.
Intake of water and other beverages.
Physical activity, exercise.
Stress, and other psychological factors.
Exposure to allergens and pollutants.
Daily rhythms and seasonal changes.
Balance between intake and expenditure of energy.
Nutrigenomics is a huge topic! For those interested in knowing more, we suggest the asterisked references below.
*Challem, J. (2005). Feed Your Genes Right: Eat to Turn Off Disease-Causing Genes and Slow Down Aging. John Wiley & Sons, Inc., Hoboken NJ.
*Kaput, J & Rodriguez, R, eds. (2006). Nutritional Genomics: Discovering the Path to Personalized Nutrition. Wiley Interscience, Hoboken NJ.
Khalsa, S. (July 2007). Nutrition News: Breakthrough With CoQ!
Khalsa, S. (February 2007) Nutrition News: Metabolic Syndrome.
Khalsa, S. (February 2004). Nutrition News: Awesome Aging.
Khalsa, S. (June 2001). Nutrition News: Supplement Your Heart.
Genetic testing sheds light on degenerative eye diseases. University of Michigan. Dated February 13, 2007. Retrieved March 2007 from www.kellogg.umich.edu/news/20070213_eyegene.htm.
Higdon, J & Drake, V. Coenzyme Q10. Micronutrient Information Center, Linus Pauling Institute. Dated February 2007. Retrieved March 2007 from www.lpi.oregonstate.edu/infocenter/othernuts/coq10.
*The NCMHD Center of Excellence for Nutritional Genomics at the University of California, Davis. Retrieved September 2007 from http://nutrigenomics.ucdavis.edu.
Gene SNPTM DNA Screening Analysis. From the Labs of ScionaTM Optimal Health Through Genetics. See www.mycellf.com.
Nutrition News „ 2007 VOL XXXI, No. 10