The scientific community has recently established a very crucial area in our lives that we in layman’s language call genetic nutrition. Normally however the correct term to use would be nutrigenomics. So what exactly is nutrigenomics and how does it affect your quality and lifespan.
What is nutrigenomics?
You can think of nutrigenomics as two words; nutrition and genome. Therefore nutrigenomics is the relationship between your genes and your nutrition. As a species our genes carry out the same function. However these genes do the same function in a unique way for every individual. This is known as gene polymorphism and these similar but uniquely functional genes are known as alleles.
For example, we all have a gene known as APOE gene. This gene produces a class of proteins known as Apolipoprotein E (ApoE). The function of ApoE is to bind with fats (lipids) in the body to form molecules known as lipoproteins. The fats that bind to these proteins are then transported to various cells where there can be used to make the cell membrane; synthesize hormones; metabolized to produce energy; or stored as fat. The ApoE in some people is able to bind with fats quite well while in other people ApoE binds poorly to fats. The ApoE that binds well with fats is called APOE-ε3 (Apolipoprotein epsilon 3). This is known as the normal or neutral allele. On the other hand people who’s ApoE does not bind well to fats or behaves abnormally have either one of the following two alleles; APOE-ε2 or APOE-ε4.
The nutritional significance of gene polymorphism then comes in here; people with the “abnormal” alleles APOE-ε2 or APOE-ε4 have to carefully regulate their fat intake. Too much will lead to an increased circulation of plasma lipids while too little fats means that the cells will not have enough to make cell membranes and hormones. As such people with these alleles are predisposed to Parkinson’s disease, atherosclerosis, Alzheimer’s disease, among other diseases.
Other than gene polymorphisms, nutrigenomics also encompasses genome stability. Here the focus is on specific nutrients that protect our genome from damage.
Many people have no idea of what happens inside our cells. So in case you had no idea, one of the major things that happen every day is DNA damage. Yes. Our DNA gets damaged up to 1 million times per cell per day. Although this might seem like a huge number, it only represents 0.000165% of the human genome’s approximately 6 billion bases (counting all the 46 chromosomes). The crucial balance between DNA damage and DNA repair is the basis of aging, where aging is a plethora of many diseases.
The good thing is we have various repair mechanisms based on the type of damage. Specific genes have been tasked with the crucial function of encoding proteins that are involved in the repair of DNA damage. But for these genes to function properly they require external support. A significant part of this support comes from the micro nutrients we consume from our diet. Failure to support these genes basically disrupts the balance between gene damage and gene repair. Gene damage becomes higher than gene repair and we are basically bombarded with many diseases and aging sets in earlier than we anticipated.
Here we will talk about genome stability. So what are some of the nutrients identified as crucial in supporting or protecting the genome from damage?
Nutritional factors that protect or support the genome from damage.
1. Folate (vitamin B9)
DNA methylation is a phenomenon in our DNA where a methyl group can be added to specific DNA bases. DNA methylation controls gene expression. Abnormal DNA methylation is expressed as excessive addition of methyl groups, which is known as hypermethylation. Genes that have been hypermethylated do unnecessarily more work and may lead to various gene abnormalities such as cancer. Undermethylation on the other hand is another abnormal DNA methylation which makes a gene to be lazy and does not do what it is supposed to do. This is called hypomethylation. DNA methylation is extensively researched in a sister area of nutrigenomics known as epigenetics.
Folate has been identified as a compound that regulates gene methylation which in turn ensureS normal gene function. Folate deficiency leads to DNA hypomethylation as well as increased chromosome breaks. This shows that folate plays a role in reducing DNA damage while controlling gene expression.
Folate is naturally present in many foods such as green leafy vegetables, asparagus, broccoli, Brussels sprouts, citrus fruit, legumes, dry cereals and whole grains.
For a biochemical reaction to take place, enzymes are used to speed up the reaction. Without enzymes reactions would be impossible. Enzymes on the other hand require helpers. These helpers are known as cofactors. Magnesium is one such extremely crucial cofactor that is involved in not just one but all human biochemical processes. One such biochemical process that happens in our cells is genome repair and genome processing.
Magnesium is used in almost all enzymatic systems involved in DNA processing. It is also essential in DNA repair mechanisms such as nucleotide excision repair, base excision repair and mismatch repair. Magnesium deficiencies result in DNA replication errors; significantly reduced DNA repair capacity as well as general impaired cellular function. Magnesium is that important.
Green leafy vegetables are the major sources of magnesium. Sadly most people do not eat their greens and consequently do not reach the current recommended daily dietary allowances. Magnesium deficiency therefore is one of the major contributors of the onset of various diseases as well as accelerated DNA damage and aging.
Other important metal ion cofactors that ensure genome stability include zinc, manganese and calcium. Zinc and manganese are present in high amounts in legumes, nuts, seeds and whole grains. Calcium is found in chia seeds; yoghurt; and in some leafy greens such as kale, collard greens and amaranth.
Enzyme cofactors can either be organic or inorganic. Inorganic cofactors are normally metal ions one of which we have said is magnesium. Organic cofactors on the other hand are normally vitamins. Vitamins are commonly termed coenzymes and just like magnesium, biochemical processes would be crippled without vitamins.
As such there are 13 essential vitamins that you are supposed to acquire from your diet without which biochemical processed would be crippled. These include: vitamin A (retinols and carotenoids), vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B7 (biotin), vitamin B9 (folic acid or folate), vitamin B12 (cobalamins), vitamin C (ascorbic acid), vitamin D (calciferols), vitamin E (tocopherols and tocotrienols), and vitamin K (quinones).
Just like vitamin B9 (folate), various vitamins play different roles in ensuring genomic stability. Vitamins C and E inhibit cellular oxidation thereby functioning as antioxidants. A deficiency of these two vitamins is associated with increased DNA strand breaks; oxidative DNA lesions; lipid peroxidase adducts on DNA; as well as increased chromosome breaks.
Vitamin B2, B6 and B12 have a similar function with folate. These vitamins are involved in the regulation of DNA methylation.
Among the many sources of Vitamin C are: citrus fruits; green and red peppers; leafy vegetables broccoli; brussel sprouts and strawberries. Vitamin E on the other hand can be found in wheat germ oil, sunflower seeds, almonds, peanuts, hazelnuts, spinach, kiwi fruit, broccoli and tomato.
Our bodies are normally able to handle the two basic reactive oxygen species superoxide and hydrogen peroxide produces as byproducts metabolism. It does this this by producing three groups of antioxidant enzymes namely superoxide dismutases, Peroxiredoxins, glutathione Peroxidase and Catalases. In the absence of these antioxidant enzymes, these ROS can cause oxidative and damage. Even worse in the absences of these antioxidant enzymes, hydrogen peroxide can be converted into an extremely reactive and unstable ROS known as a hydroxyl radical in the presence of iron ions.
Of interest however is the existence of another group of antioxidant enzymes and proteins that neutralize reactive oxygen species. These antioxidant compound known as selenoenzymes and selenoproteins contain selenium. Human beings have approximately 25 selenoproteins.
The synthesis of proteins being dependent on selenium has an important role in preventing oxidative damage to our cells and consequently our DNA. Oxidative damage is associated with all kinds of cell malfunction hence disease and accelerated aging. Intake of selenium has been associated with decreased oxidative damage and overall reduction of cancer incidences. A deficiency in selenium on the other hand is associated with increased oxidative damage, Increased DNA strand breaks as well as telomere shortening.
Selenium can be found in many foods such as fish, nuts, lentils, sunflower seeds, brown rice and cereals.
5. Caloric restriction
One of the major topics in anti-aging and longetivity communities is caloric restriction. This is significant reduction of the amount of calories one consumes while ensuring adequate intake of both macro and micronutrients. The amount of calories consumed should be neither significantly above or below the RDA values. Caloric restriction should be practiced with a lot of preparedness and precise calculation.
When done well caloric restriction has been shown to enhance major DNA repair pathways as well as decrease the amount of oxidative damage observed in cells.
To understand more about the intimate relationship between DNA damage and aging you can donate 10 dollars to get our RESEARCH SERIES 1 which explains step by step the genetic basis of reversing aging. Your financial support will enable us to do more research. Thank you for reading up to this point, we value our Eldulani community.