Diabetes is a complicated chronic condition, characterised by an interplay of genetics and environmental variables.
To understand the role that lifestyle factors can play in the prevention and management of diabetes, it is first necessary to clarify the stark differences between type 1 and type 2 variations of the disease.
Type 1 diabetes
Type 1 accounts for only 5-10% of all diagnosed cases, and although it has been associated with strong genetic factors, it cannot be prevented by any means of diet or lifestyle manipulation1.
Furthermore, it is most commonly diagnosed in childhood or adolescence - before an accumulation of causative habits would have time to manifest.
Type 1 diabetes is characterised by a complete insulin deficiency and an absolute reliance on injectable insulin to control blood sugar levels within the body.
Insulin is a hormone that is released by the pancreas in response to high blood sugar levels. Its function is to facilitate glucose uptake from the bloodstream into cells of the body where it can be used as a primary fuel for energy.
In type 1 diabetes, pancreatic insulin production is irreversibly compromised.
Type 2 diabetes
Type 2 is the most prevalent form of diabetes, accounting for 90% of documented cases worldwide2.
This is a growing global health emergency, which affected 531 million people in 2020 and -according to an article in the World Journal of Diabetes- this number is predicted to reach to 783 million by 2045.
Like type 1, there are various genetic components that contribute to the risk of developing type 2 diabetes. However, unlike type 1, preventative action is possible.
Type 2 diabetes is considered a metabolic disorder which develops slowly and is often the result of poor lifestyle choices. However, there are numerous modifiable factors that can reduce genetic risk and delay the onset of disease.
In contrast to type 1, type 2 diabetes is characterised by poor insulin efficiency, not a complete deficiency. The pancreas is still able to produce insulin, but the body’s sensitivity to it becomes compromised. This is known as insulin resistance.
Insulin resistance: An early warning sign
Insulin resistance is sometimes called pre-diabetes and it is defined as the condition in which the body is less responsive to insulin.
As a result, blood glucose levels remain higher than normal. What’s more, circulating levels of insulin also increase as the body attempts to achieve glucose homeostasis by secreting more and more insulin.
Elevated insulin levels cause increased fat accumulation, weight gain, elevated triglyceride levels, and increased cardiovascular risk-which are all hallmarks of type 2 diabetes.
If left unmanaged, insulin resistance will develop into type 2 diabetes. In turn, if type 2 diabetes is poorly controlled, the pancreas may become exhausted from the overproduction of insulin, which may lead to reduced insulin production over time.
If this happens, insulin inefficiency may become an absolute deficiency, which is then identified as insulin dependent type 1 diabetes i.e. reliant on insulin injections.
Managing insulin resistance and type 2 diabetes
Treatment requires the use of medication to stimulate insulin production and enhance insulin sensitivity. However, there are various lifestyle factors that can also improve insulin efficiency and therefore negate medication dependency.
Screening and prevention are the preferable first steps
If there is family history of diabetes, preventative screening is encouraged.
Although a simple glucometer can supply an accurate reading of blood glucose from a finger-prick, this method will not provide the same insights into to the intricate mechanisms of glucose and insulin control that can be obtained from a blood test.
Fasting blood glucose: Seeing that blood glucose is naturally elevated after a meal and can be particularly high for 2-3 hours after a concentrated intake of carbohydrates, a blood test in the fasted state will offer a far more accurate indication of control.
HbA1C%: Seeing that blood glucose levels can also be acutely elevated as a result of stress, infection, and hormonal changes, this blood test gives an indication of average blood glucose levels over the past 2-3 months. It is therefore useful to confirm a diabetes diagnosis and to monitor average diabetes control.
HOMA-IR: This blood test measures fasting insulin and fasting glucose in order to diagnose insulin resistance syndrome.
Nutrigenomic testing: There are certain gene variants which increase your predisposition to developing diabetes. However, the study of nutrigenomics (the study of how your diet affects the way that your genes behave) has taught us that although we cannot change our genes, we can manipulate our environment to keep certain genetic risks dormant.
A 3X4 Genetics home test kit can highlight predisposed areas of risk, as well as specific lifestyle adjustments that would be necessary to prevent genetic predispositions from developing into disease.
Invaluable insights from lifestyle genetic testing
Nutrigenomic screening is non-invasive and non-diagnostic, but it can be used as a tool for preventative medicine.
The 3X4 Genetics test only reports on low-penetrance genes, which means that the identified risks are not inevitable, but can be reduced with dietary or lifestyle adjustment.
Knowing which gene variants you carry, will provide direction for lifestyle management.
The following genes have been identified as role players in the development of type 2 diabetes:
- TCF7L2: Studies suggest that individuals carrying a certain variant of TCF7L2 display higher fasting glucose and HbA1c% levels. However, the adoption of a mediterranean diet plan appears to moderate the effect of genetic risk and improve glucose homeostasis3.
- SLC2A2: Individuals carrying a certain variant of SLC2A2 display increased cravings for sweet foods and have increased susceptibility to developing impaired insulin metabolism4. However, removing sugar and reducing carbohydrates in the diet appears to reduce cravings and achieve better glycaemic control.
- PPARG: This gene is involved in the regulation of lipid metabolism and certain variants are associated with high diabetes risk if obesity is present. However, weight loss and elimination of saturated fat from the diet has been established as an effective preventative approach.
Choosing the best dietary approach for the prevention of diabetes will depend on your personal genetic blueprint. To discover your own genetic blueprint, click here.
Inherited habits
Advancements in genetic testing have led to the identification of numerous genes associated with diabetes, but these can only explain a very small portion of the heritability of the condition.
Unhealthy habits passed down from one generation to the next can also significantly contribute to the development of diabetes, regardless of genetic profiling.
Although diabetes may have roots in genetics, inherited habits are equally to blame.
Thus, to combat the development of chronic diseases of lifestyle, it is important to be armed with both genetic information and healthy lifestyle practices.
References:
- Mahan, K. and Raymond J.(2017). Krause’s Food, Nutrition and the Care Process (14th) Elsevier Inc.
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10294065/
- https://dna.3x4genetics.com/clinic/clinicalguide/result?url=snps%2Frs7903146.html
- https://dna.3x4genetics.com/clinic/clinical-guide/result?url=snps%2Frs5400.html