Diet, Disease, and Mental Health

The aim of this 2017 study was to examine the relationship between dietary patterns and mental health among elderly patients with a history of myocardial infarction (heart attack). The diets of 2171 adults (aged between 60 and 80 years) were evaluated with a food frequency questionnaire and 2 different assessment scores (the Dutch Healthy Nutrient and Food Score [DHNaFS] and the Dutch Undesirable Nutrient and Food Score [DUNaFS]). One of the dietary assessment scores (DHNaFS) was associated with fewer depressive symptoms and higher dispositional optimism. In fact, the consumption of vegetables, fruits, whole grains, fish, and low fat-dairy were particularly linked with fewer depressive signs and greater optimism. A similar interaction was found between the average DHNaFS score over the preceding 41 months with depression and optimism. Rius-Ottenheim et al. concluded that a healthy dietary pattern, especially a diet high in vegetables, fruit, whole grains, fish and low-fat dairy, was related to fewer depressive symptoms and higher optimism. The findings may be explained by more optimistic participants making healthier food choices, signifying the possible need for further studies to confirm the direction of causality of this relationship.

Since inadequate health perceptions may lead to non-adherence to healthy behaviors, this 2019 study investigated the relationship between health perceptions and psychological states (depressive symptoms and anxiety). The sample (828 adults with 2 or more cardiovascular disease risk factors) rated their perceived health from excellent to poor, and their 10-year cardiovascular disease risk scores were calculated. Lee et al. determined how consistent the subjects’ perceived health ratings were with their risk scores. The objective of the study was to find out whether their psychological states are associated with the level of consistency between health perception and estimated risk for cardiovascular disease. Health perceptions were found to be congruent in around 55% of the sample population, pessimistically biased in 12%, and optimistically biased in ~33%. Depressive symptoms strongly correlated with pessimistic bias. A disconnect between individual health perceptions and their cardiovascular disease risks was linked with depressive symptoms. Since health perception is affected by signs of depression, clinicians may be advised to consider the depressive symptoms when encouraging individuals to make changes to their lifestyle choice.

This 2015 review provides an insight into the more recent nutritional developments in West Africa. While undernutrition remains a big problem, dietary patterns have changed as urbanisation increased and technology improved. There is evidence that intake of fruits and vegetables is low universally in West Africa, and obesity is becoming more prevalent. Most of the countries in Western Africa are at the early stages of nutrition transition but countries such as Cape Verde, Ghana and Senegal are at the latter stages. In the big cities, kids eat as much as 7 times more candies, ice cream and sweetened beverages as fruits and vegetables. In addition to the rise in adult obesity rates (115% in 15 years since 2004), there has been an increase in incidence of hypertension (high blood pressure) in countries such as Burkina Faso and Cape Verde. It has been reported to be more common in the cities. Furthermore, the prevalence of diabetes ranges from 2.5 - 7.9% but it is as high as 17.9% in Dakar, Senegal. And it is not only people in the high socioeconomic classes that are affected by these nutritional factors. In cities such as Accra and Ouagadougout, at least 19% of adults from the poorest households are overweight, while 19-28 % have hypertension. The cooperation of governments, partners, private sector and civil society is needed to regulate the food and drink industry and to promote healthy eating to the public.

Troesch et al. (2015) organized a workshop held in Groningen (The Netherlands) to discuss the general population’s nutritional situation and the role of diet in their lives during critical periods. Nutrition is widely known to influence the risk and the time of onset of many common non-communicable diseases (NCDs). Even in wealthy countries, people find it difficult to eat adequate amounts of nutrients, which results in obesity and suboptimal nutrient status. The provision of information about nutrition density (referring to micronutrient content relative to energy in foods/diets) may help the general public identify foods with low calorie to nutrient ratios, leading to reduced incidence of obesity. The author suggests that researchers, the food industry and governments should team up to develop affordable and appealing nutrient-rich food products. Combined with increased physical activity, we may be able to achieve optimal health throughout our life cycles.

Although the evidence for the health benefits of consuming adequate levels of whole fruits has been growing, Dreher (2018) emphasizes that less than 10% of most Western populations manage to eat sufficient levels of whole fruits and dietary fiber. The purpose of this study was to present these health benefits associated with the adequate intake of whole fruits throughout the human life cycle. Consuming recommended levels reduces/prevents gastrointestinal issues (e.g. constipation, irritable bowel syndrome, inflammatory bowel diseases, and diverticular disease), promotes long-term weight management, and reduces the risk of cardiovascular disease, type 2 diabetes and metabolic syndrome. Furthermore, following this recommendation can protect against colorectal and lung cancers, improve odds of successful aging, reduce the severity of asthma and chronic obstructive pulmonary disease, enhance mental well-being, and contribute to higher bone mineral density. Thus, low consumption of whole fruits may represent a more serious global population health threat than previously thought.

In this 2017 study, 214 patients with prediabetes and 200 control subjects were randomly selected from a clinic in Iran, and assessed on the level of inflammation induced by their diet. Food frequency questionnaires obtained dietary data while dietary inflammatory index (DII) was used to examine dietary inflammation. The purpose of this study was to examine whether this dietary inflammatory index (DII) can predict the risk of prediabetes. Compared to participants calculated to be in the 1st tertile for dietary inflammation, those in the top tertile (with higher inflammatory potential) were found to have significantly higher fasting plasma glucose, oral glucose tolerance, haemoglobin A1C (measures average blood sugar level over past 3 months), low-density lipoprotein (LDL), triglyceride, and body fat, as well as lower high-density lipoprotein (HDL) and lean body mass. After adjustments were made to the analysis model, the most pro-inflammatory DII group were found to be 19 times more likely to develop prediabetes, compared with subjects with the lowest inflammatory potential group. Vahid et al. concluded that the participants who consumed a more pro-inflammatory diet were at increased risk of prediabetes compared with those who consumed a more anti-inflammatory diet.

In this 2019 study, nine outpatients with type 2 diabetes were given personal digital assistants for 6 months to record their psychological stress, anxiety, and depressive mood, as well as food and drink they consumed. The objective was to determine whether preceding psychological factors influence calorie intake within 5 hours. In past studies, questionnaires were used to obtain data, but they include recall bias. The personal digital assistant provides a means to record subjective symptoms and behaviors in participants’ daily lives. Higher psychological stress correlated with higher calorie intake from snacks within the following 5-hour time period. Whereas psychological stress, anxiety, and depressive mood were inversely associated with calorie consumption from regular meals. In summary, psychological factors were shown to affect the number of calories type 2 diabetic patients consume.

In this 2019 study, a group of patients with type 1 diabetes was assessed on emotional state, beliefs, concerns regarding the illness, and other personality, clinical, and sociodemographic variables. The aim of the study was to identify the factors that influence the diabetics’ adherence to self-care behaviors. Among the 428 patients questioned, 60.1% reported difficulty following the treatment recommendations for their disease. The basis for their non-compliance includes mood (25.2%), lack of motivation (13.4%), work (12%), and economic difficulties (3.8%), while 5.7% had other personal reasons. The following variables were found to predict adherence to self-care behaviors: motivation; training in diabetes management; importance the patient attributed to the disease; and self-efficacy. Variables associated with low adherence include depression and anxiety, which were both prevalent in this study group. In conclusion, motivation, training in diabetes management, beliefs regarding the disease, and self-efficacy were the main contributors to adherence to self-care behaviors among patients with type 1 diabetes, while anxiety and depression were linked with lower adherence. In order to increase patient involvement in self-care, Alvarado-Martel et al. suggest the implementation of strategies designed to stimulate discussion of beliefs about the disease, encourage self-efficacy, and elevate motivation levels.

This 2019 study utilized the data of the Boston Puerto Rican Health Study to determine the relationship between diet quality and 2-year changes in cognitive function. The aim was to specifically inspect the association between the Mediterranean diet score (MeDS) with the 2-year difference in cognitive function, comparing those with and without type 2 diabetes, and those with controlled and uncontrolled blood glucose levels. Comparisons were also made with other diet quality scores such as Healthy Eating Index, Alternate Healthy Eating Index, and Dietary Approaches to Stop Hypertension scores. Mediterranean diet score (MeDS) was the only diet quality score that was positively associated with 2-year alterations in cognition in type 2 diabetes but was not in non-diabetics. Similar results were recorded for other cognitive tests (Mini-Mental State Examination, word recognition, digit span, and clock drawing tests). The results also remained consistent for individuals under glycemic control at baseline and either improved or kept stable over the 2 years, but this was not the case for individuals with uncontrolled or poor/declined glycemic control. Other findings include the link between all diet quality scores with higher 2-year memory function in adults without type 2 diabetes. Mattei et al. thus deduce from this study that adhering to a Mediterranean diet and effectively managing type 2 diabetes may support optimal cognitive function.

Although the Western diet-like dietary pattern is strongly linked with obesity and metabolic diseases, Zinöcker & Lindseth (2018) point out the uncertainty over the biological mechanisms involved in this interaction. The Western diet may promote inflammation, as the ultra-processed foods (common feature of the Western diet) creates an attractive gut environment for microbes that induce various forms of inflammatory disease. Looking at food patterns, whole foods appear to be present in diets associated with a low level of diet-related disease. This review supports further analysis of how ultra-processing alters the properties of whole foods and how these foods affect the gut microbiome. In addition to nutritional research, food production industries should also consider the implications of microbiome’s role in disease development. The goal should be to achieve health in the “super-organism” of man and microbes. Finally, stronger regulation of potentially hazardous components of food products may be warranted.