This study at Folkhälsan Research Center showed that stress is associated with lower adherence to dietary recommendations and furthermore affects glucose concentrations in individuals with type 1 diabetes. Interventions aimed at relieving stress might improve stress management and simultaneously improve eating habits and glycaemic control
Stress has a negative impact on self-management of diabetes and thus impedes glycaemic control as eating is the most frequently reported stress-release coping mechanism. In this study, conducted at the Folkhälsan Research Center, the researchers investigated the association between perceived stress, dietary adherence, and glycaemic control.
The results show that more stress is associated with lower adherence to the dietary recommendations. In lean individuals, stress is also associated with higher serum glucose concentrations, while individuals with overweight or obesity had high glucose concentrations regardless of perceived stress. The conclusion is that interventions that improve stress management could also improve dietary habits and glycaemic control, and thus potentially improve the long-term health of individuals with type 1 diabetes.
Aila Ahola is a senior researcher in the FinnDiane research group at Folkhälsan Research Center and is the first author of this study. Her dissertation, published in 2012, addresses themes related to the mental well-being and self-care of type 1 diabetes. She has continued on these same research themes after her doctoral dissertation, and this study explores the relationships between stress, diet, and blood glucose levels in individuals with type 1 diabetes.
– We wanted to investigate how stress affects adherence to dietary recommendations. There is a lot of research on diabetes, but type 1 diabetes is sometimes overshadowed by the more common type 2, Ahola says.
Stress is defined as the nonspecific bodily response to any demand made upon it. But more specifically, stress is our physiological and mental reactions to taxing stimuli of various kinds. In modern life however, stress it is often about mental overexertion, and feelings of lack of time, insecurity and inadequacy.
Prolonged stress will eventually result in severe psychological and physiological fatigue, which is bound to affect many health–related outcomes and behaviours. Within the context of this study, perceived stress is the extent to which individuals feel that the demands that are put on them exceed their ability to cope.
Indeed, according to previous research, eating is the most frequently reported stress-release method. Furthermore, some studies show that people are prone to make more unhealthy dietary choices when under stress. The importance of diet and glycaemic control is highlighted in diabetes, where these factors may greatly influence long–term health.
– Stress is usually associated with less planned eating, which increases the tendency for fast food or ready-to-eat meals, says Ahola.
Most individuals with diabetes are probably aware of the role of these factors. However, life is bound to be stressful sometimes, and therefore identifying how stress impacts dietary choices and what implications this dyad might have for blood glucose concentration is important.
– Individuals with type 1 diabetes are typically diagnosed early in life. Via regular contact with the healthcare personnel, they, more often than not, have good knowledge of the self-care and dietary recommendations for diabetes, Ahola says.
In this study, perceived stress was measured by Cohen’s Perceived Stress Scale (PSS). The PSS was developed by social psychologist and professor Sheldon Cohen and his colleagues in the 80’s. The PSS contains questions about the respondent’s experiences and reactions to adversities during the last month or so.
– Stress is a very dynamic and ever-changing phenomenon. It is largely dependent on both external and internal factors such as life situation and the individual’s reactions to it. However, the PSS only measures how stress is experienced at the moment. It does not consider cumulative stress or earlier life events, Ahola explains.
As of today, the PSS is one of the most used questionnaires that measure nonspecific perceived stress. The questionnaire has been shown to predict several objective biological markers of stress, such as cortisol levels, depression, would healing, and immune markers.
Dietary intake was assessed using two separate methods. With a validated diet questionnaire, the habitual consumption of key food products was measured, such as breads, spreads, milk products, and cooking fats. In the same questionnaire, the frequencies of consuming several foodstuffs, including fish, meat, vegetables, and rice were queried. Using this questionnaire, a diet score, reflecting the level of adherence to the dietary recommendations, was calculated.
Furthermore, the participants were also asked to twice complete a three-day diary, recording dietary intake, physical activity, insulin administration, and blood glucose concentration. In the current study, data on dietary adherence were only collected with the diet questionnaire. However, data on blood glucose measurements were collected from the records
For this study, several clinical measurements, relevant in diabetes research, were conducted. The participants’ height and weight were measured to calculate their body mass index. Blood samples were taken to analyse serum lipid, lipoprotein, glycated haemoglobin, and creatinine concentrations. The serum creatinine concentration was used to estimate the glomerular filtration rate of the participants.
Glomerular filtration rate is especially important, as it is a good indicator of kidney health. Diabetes causes vascular changes in the body, which in turn may lead to diabetic nephropathy.
– People with type 1 diabetes have a significantly increased risk for vascular diseases. One being kidney disease, which is one of the major comorbidities of diabetes, says Ahola.
Indeed, previous studies have shown that individuals with diabetes and kidney disease have a higher mortality rate resulting from cardiovascular disease, and thus monitoring the kidney status of individuals with diabetes is central.
The results show that higher perceived stress is associated with reduced adherence to dietary recommendations in participants with type 1 diabetes. Furthermore, participants with overweight had high blood glucose levels regardless of perceived stress, while stress levels seemed to influence glucose levels more strongly in leaner individuals. This discrepancy between lean and obese individuals might be partially attributed to insulin resistance related to obesity, which might hide a latent association between perceived stress and glycaemia among them.
– The key finding is that stress does affect eating habits. Now that this observation has been made, the question is what can be done in clinical practice? Should, for example, perceived stress be screened for within healthcare or could stress reducing interventions perhaps be implemented. Either way, relieving stress may prove important in improving eating habits and thereby in preventing diabetic comorbidities, Ahola says.
Even though this study used fairly reliable and standardised methods it had several notable shortcomings. The most notable limitations being the relatively small sample size, which compromises the statistical power of the study, as well as the use of self-reported dietary intake and blood glucose measures.
Also, questionnaires always have limitations in the form of questionnaire biases. In short, questionnaire biases consist of communication barriers that inevitably arise through the intent, interpretation and preconceptions of those who have developed the questionnaire and the respondents.
Nonetheless, in light of the results, the researchers suggest that interventions improving stress management could simultaneously improve dietary habits and thus glycaemic control. This could have a positive long-term effect on the health of individuals with type 1 diabetes.
The whole study may be read in full text here.
Simon Granroth, Science Communicator
