Lifestyle - scientific aspects
I will focus on just four aspects of lifestyle influenced diseases: Diabetes, Obesity, Metabolic Syndrome, and cardiovascular complications. Coronary artery disease (CAD) was the top killer disease in 2014, and Diabetes made it to rank eight of this list. Obesity is contributing to both diseases (http://www.healthline.com/health/top-10-deadliest-diseases#1).
The intriguing fact about the above mentioned diseases/conditions is that lifestyle changes can have some really profound effects reducing the personal risk of falling victim to one of these diseases. I will summarize corresponding findings from the literature providing the references at the bottom of this entry.
The strategic goals of the American Heart Association (AHA) lists four major positive lifestyle factors (Khera et al, New Engl J Med 2016); see also Figure 4:
- no current smoking
- no obesity (body-mass index, [the weight in kilograms divided by the square of the height in meters], BMI <30, i.e.
a man standing 1.8 meters tall (6 Ft) would weigh 98 kg or more)
- physical activity at least once weekly
- a healthy diet pattern.
I do not think that there is much need to reiterate the many risks associated with smoking, which basically aggravates all of the main ailments mentioned above. Therefore, I would like to go straight to Diabetes.
Often connected to and/or caused by obesity Type 2 Diabetes (T2D) is the acquired form of diabetes, and on top of that also a a major risk factor for cardiovascular diseases (CVD). Finnish Diabetes Prevention studies showed that changes in lifestyle prevented or delayed the onset of new cases of T2DM in subjects with pre-diabetes by 58% (Athyros et al, 2010). The problem is not only occurring in adults but also affects adolescents in increasing numbers. However, lifestyle changes can combat the onset of the disease early on as shown by the success of the Yale Bright Bodies Healthy lifestyle Program, which proved to be a more effective means of reducing the risk of T2D in obese adolescents with elevated 2-h glucose levels than standard clinical care (Savoye et al,, 2013). Nanditha et al (2014) found that lifestyle intervention in pre-diabetic men was associated with a significant reduction in subsequent incidence of diabetes.
It is rather amazing how many different variations of T2D can be dramatically improved by rather simple lifestyle changes. However, this is no magic bullet that will help everybody, there are high- and low-risk phenotypes already in pre-diabetic individuals. These risk profiles are based on corrected insulin secretion and insulin-resistant nonalcoholic fatty liver disease (NAFLD), and prior stratification of patients for these high/low risk phenotypes may help to determine the effectiveness of a lifestyle intervention to revert individuals to NGR (Stefan et al, 2015).
Again, this kind of stratification (grouping of patients) is an integral part of personalized medicine, which helps to determine the best treatment for individuals by assessing their personal risk profiles.
However, diabetes is a complex disease that cannot be tackled by just one intervention like getting up and doing some sports. Changes in dietary behavior are equally important to reduce the risk and to revert and already manifest diabetes.
Figure 4: Lifestyle and wide-spread diseases
Water: There are many elaborate schemes how all kinds of complicated combinations of “super-foods” will do some magic to your body. And the list is changing as specific items move in and out of fashion. So, why not start with the absolute basics, such as have a little water of have a little more water. This does not aim straight at diabetes but at obesity, which often ushers in diabetes later on. “Hydration may deserve more attention when thinking about addressing obesity on a population level.” as suggested by Tammy Chang, M.D., MPH, MS, an assistant professor in the Department of Family Medicine at the U-M Medical School. She continues: “Staying hydrated is good for you no matter what, and our study suggests it may also be linked to maintaining a healthy weight.”
Fruit & Vegetables: A healthy diet pattern was ascertained on the basis of adherence to at least half of the following recently endorsed characteristics: consumption of an increased amount of fruits, nuts, vegetables, whole grains, fish, and dairy products and a reduced amount of refined grains, processed meats, unprocessed red meats, sugar-sweetened beverages, trans fats (Khera et al, New Engl J Med 2016).
Of course, this reminds of the Mediterranean diet always labeled as healthy. But are there any hard facts supporting that view? How would that be beneficial? An important ingredient of this dietary style is lavish use of extra virgin olive oil (EVOO). 2015 Violi et al reported that EVOO improves post-prandial glucose and LDL-C, an effect that may account for the anti-atherosclerotic effect of the Mediterranean diet. Pomegranates ellagic acid (PEA) also has positive effects, e.g. on blood cholesterol by cholesterol removal. (Food Funct., 2015, 6, 780).
The list could be extended and as always individual food ingredient will not have the same effect as a well-balanced diet. Therefore, numerous Dietary Quality Indices or Indicators (DQIs) have been developed to evaluate the overall diet and categorize individuals according to the extent to which their eating behavior is “healthy”. Here are three major categories of DQIs:
- nutrient-based indicators
- food/food group based indicators
- combination indexes, the vast majority of DQIs.
The Healthy Eating Index (HEI), the Diet Quality Index (DQI), the Healthy Diet Indicator (HDI) and the Mediterranean Diet Score (MDS) are the four 'original' diet quality scores that have been referred to and validated most extensively (Gi, et al, 2015).
Obesity is not just a little too much fat on an otherwise healthy body. It influences the functionality of vital organs such as the heart, the kidney, or even the brain directly. For example, prenatal exposure to maternal obesity and/or postnatal exposure to a Western diet has a profound effect on miRNA expression in the heart (Wing-Lun et al, 2016). Obesity is a significant risk factor for the appearance of proteinuria and end-stage kidney disease in a normal population, but can be helped by lifestyle changes: . Weight loss induced by low-calorie diets, physical exercise, or bariatric surgery is accompanied by an important anti-proteinuric effect (Morales et al, 2012). The brain is directly affected by disturbances in peripheral glucose regulation. These are associated with cognitive impairment and depressed mood, especially in older adults. Prevention of obesity and hyperglycemia by adopting a healthy lifestyle will contribute to the maintenance of functional integrity and mental health later in life (Hendrickx et al, 2005). But the effects go beyond a few key organs mentioned here affecting the whole body on a systematic way. Such gross overall changes are often collectively described as the Metabolic Syndrom.
Metabolic syndrome (MetS) typically presents with obesity; however, obesity is not a prerequisite for MetS classification and related vascular risk. The presence of MetS, independent of obesity, is associated with diminished endothelium-dependent vasodilation. Endothelial vasodilator dysfunction may underlie the increased cardiovascular risk in normal-weight adults with MetS (Dow et al 2016). This explains nicely why high blood pressure is one of the hallmarks of MetS.
There is lot more evidence for many other effects of lifestyle on the molecular level. The collection mentioned here is only the proverbial tip of the iceberg. However, it might serve to drive the message home: Bad lifestyle changes your whole body all the way down to the level of how your cells work. And this is the reason why personalized medicine with molecular diagnostic tools can be extremely helpful in guiding us all out of this mess. By assessing the individual patterns of changes we can find the best and most effective lifestyle interventions that will work for us individually.
6. Athyros, V. G., Tziomalos, K., Karagiannis, A. & Mikhailidis, D. P. Preventing type 2 diabetes mellitus: room for
residual risk reduction after lifestyle changes? Curr Pharm Des 16, 3939-3847 (2010).
7. Dow, C. A., Lincenberg, G. M., Greiner, J. J., Stauffer, B. L. & DeSouza, C. A. Endothelial vasodilator function in
normal-weight adults with metabolic syndrome. Appl Physiol Nutr Metab 41, 1013-1017, doi:10.1139/apnm-2016-
8. Gil, A., Martinez de Victoria, E. & Olza, J. Indicators for the evaluation of diet quality. Nutr Hosp 31 Suppl 3, 128-
144, doi:10.3305/nh.2015.31.sup3.8761 (2015).
9. Hendrickx, H., McEwen, B. S. & Ouderaa, F. Metabolism, mood and cognition in aging: the importance of lifestyle
and dietary intervention. Neurobiol Aging 26 Suppl 1, 1-5, doi:10.1016/j.neurobiolaging.2005.10.005 (2005).
10. Morales, E. & Praga, M. The effect of weight loss in obesity and chronic kidney disease. Curr Hypertens Rep 14,
170-176, doi:10.1007/s11906-012-0247-x (2012).
11. Nanditha, A. et al. Early improvement predicts reduced risk of incident diabetes and improved cardiovascular
risk in prediabetic Asian Indian men participating in a 2-year lifestyle intervention program. Diabetes Care 37,
3009-3015, doi:10.2337/dc14-0407 (2014).
12. Savoye, M. et al. Reversal of early abnormalities in glucose metabolism in obese youth: results of an intensive
lifestyle randomized controlled trial. Diabetes Care 37, 317-324, doi:10.2337/dc13-1571 (2014).
13. Stefan, N. et al. A high-risk phenotype associates with reduced improvement in glycaemia during a lifestyle
intervention in prediabetes. Diabetologia 58, 2877-2884, doi:10.1007/s00125-015-3760-z (2015).
14. Violi, F. et al. Extra virgin olive oil use is associated with improved post-prandial blood glucose and LDL
cholesterol in healthy subjects. Nutr Diabetes 5, e172, doi:10.1038/nutd.2015.23 (2015).
15. Wing-Lun, E. et al. Nutrition has a pervasive impact on cardiac microRNA expression in isogenic mice.
Epigenetics 11, 475-481, doi:10.1080/15592294.2016.1190895 (2016).
What’s coming up next?
Next week I will focus of heath monitoring as a way to come up with meaningful alerts and suggestions of a personal basis.