In Part One of this article, the breadth of Metabolic Disorders was discussed.

The important take away points from Part One include the following:

• Metabolism is the sum total of all chemical reactions in the human body. Referring to metabolism by a simple reference to weight loss and weight gain is not entirely correct.
• Metabolism consists of thousands of chemical reactions, where chemical entities are either synthesised for the body (anabolism) or broken down by the body (catabolism).
• Enzymes accomplish metabolic reactions. The functionality of these enzymes is critical to your health and is governed by your genes.

Treatment of Metabolic Disorders

As discussed in part one, the vast majority of metabolic disorders are genetic. They are heritable and exceptionally atypical. Most are autosomal recessive conditions, meaning that an affected child would need to inherit two copies of a faulty gene, one from each parent. Each parent would be a carrier of the defective gene, and would likely be unaware of their genetic carrier status. Each carrier parent has one functional copy of the gene and one faulty copy. The functional gene copy will correctly synthesise its enzyme product and compensate for the defective gene + enzyme. No signs or symptoms of the disease would be present for the parents.

The autosomal recessive inheritance pattern of metabolic disorders does prove problematic for prevention. Most parents are unaware they are carriers of specific genetic mutations, and the likelihood of having a child with a partner carrying the same mutation is exceedingly rare, too rare for prenatal genetic screening of all babies to be necessary or feasible.

In reality, the genetic mutation would have occurred many generations ago and has been passed on through families, often undetected. Additionally, there are literally hundreds of metabolic disorders, and all require their own unique treatment approach. There is no blanket clinical protocol for treatment.

If a metabolic disorder is inherited, treatment options usually follow this clinical pattern:

• If a specific food, drug or amino acid cannot be adequately metabolised, its intake must be reduced or completely eliminated
• Enzymatic replacement of the faulty enzyme. This is only an option if enzymatic replacement (usually in the form of medication) of the defective enzyme actually exists
• Removal of toxic substances that accumulate via the faulty metabolic pathway
• Specific diets can remove specific macro or micronutrients that are not metabolised correctly
• Specific micronutrient supplements can support defective metabolic pathways, depending on the specific metabolic disease in question
• Specific drug treatments to detoxify the blood of toxic metabolic by-product may be possible, depending on the condition in question.

Altering diets to such a significant extent to reduce the possibility of other deficiencies and to prevent further illness requires the assistance of medical and nutritional experts.

Prevention of Metabolic Disorders (Nutrigenomics and Epigenetics)

Searching for information on the prevention of metabolic diseases is often fraught with frustration, as most sources will lead you to information regarding how to combat and prevent the metabolic syndrome (i.e. the cluster of conditions involving insulin resistance, obesity, dyslipidaemia and type II diabetes mellitus). Additionally, metabolic disorders have been classified as inherited and genetic and the traditional approach has deemed prevention impossible.

Discoveries in the field of Nutrigenomics (how nutrition impacts on gene expression) and epigenetics (how lifestyle measures such as exercise, sleep, and relationships impact gene expression) offer hope for future treatment and prevention.  Emerging research indicates that there are ways of eating and living life that protect DNA and enhance the correct replication of DNA (preventing further mutations and even providing the healthiest genome possible to your future offspring). While they may not prevent 100% of metabolic disorders in affected families, there are diet and lifestyle measures that safeguard the general health of all individuals and support healthy genes, from their replication through to gene expression. Additionally, well-functioning organs and tissues (from healthy eating and living) will enhance conventional treatments for metabolic disorders.

• Many nutrients regulate gene expression, including folate, zinc, EPA and DHA, to name just a few. An integrative health professional specialising in clinical nutrition and wholefood eating can formulate a meal plan high in genome protecting nutrients

• Phytochemicals such as flavonoids, carotenoids, coumarins and phytosterols are also known to regulate gene expression. The solution for this is simple, eat a varied and abundant amount of fruit and vegetables, every day. This is especially important for both men and women in their reproductive years

• Healthy levels of folate, vitamin B12, niacin, vitamin E, retinol, and calcium are linked to decreased levels of DNA damage. Riboflavin, pantothenic acid, and biotin are associated with an increase in DNA damage to the same extent observed with occupational exposure to genotoxic and carcinogenic chemicals. It’s recommended that you work with an integrative health professional before taking nutritional supplements

• Avoid smoking and excessive alcohol consumption. Both are known to have detrimental effects on our genes and how they function

Where to seek assistance

Many countries employ newborn screening programs to investigate the presence of metabolic disorders at birth. For example, screening for PKU forms part of the newborn screening panel. The diseases chosen for screening at birth have met specific clinical criteria for their inclusion; the testing is reliable and non-invasive, and the treatment is straightforward and life-saving. Many metabolic conditions do not manifest clinical signs at birth and are diagnosed in infancy or even later once evident signs and symptoms appear. In most cases, infants and children will be under the care of a specialist Paediatrician, and one who sub-specialises in specific metabolic conditions.

Children and adults with metabolic disorders will require lifelong care and can often become ill very quickly. It is essential that they receive care from both their medical specialists and ideally an integrative doctor with their allied health teams.

The MINDD Foundation is an excellent resource for locating doctors, nutritionists, naturopaths, pharmacists, dieticians and nurses experienced in the treatment of these rare and high-care diseases. See our Directory to find an integrative health practitioner near you.

“There is increasing evidence that genome instability, in the absence of overt exposure to genotoxicants, is itself a sensitive marker of nutritional deficiency”.

–Michael Fenech, CSIRO Genome Health and Nutrigenomics Laboratory

Written by Annalies Corse BMedSc, BHSc

References

1. Fernandes, John; Saudubray, Jean-Marie; Berghe, Georges van den (2013-03-14). Inborn Metabolic Diseases: Diagnosis and Treatment. Springer Science & Business Media. p. 4. ISBN9783662031476
2. Jorde, et al. 2006. Carbohydrate metabolism. Medical Genetics. 3rd edition. Chapter 7. Biochemical genetics: Disorders of metabolism. pp139-142
3. Meade, N. (2007). Nutrigenomics: The Genome-Food Interface. Environmental Health Perspectives. 115 (12): A582-A589.
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