Depression-Hypertension Link: DASH Diet is Good for Both!

Hypertension is a condition characterized by high blood pressure that affects many adults worldwide. According to the World Health Organization (WHO), more than 30% of adults aged 30-79 years suffer from hypertension , which is the main risk factor for various cardiovascular diseases such as coronary heart disease, stroke, chronic kidney disease, heart failure, arrhythmia, and dementia. Shockingly, around 80% of people with hypertension do not receive adequate treatment.

However, if countries can scale up coverage and provide proper treatment, approximately 76 million deaths can be prevented between 2023 and 2050.

Similarly, World Health Organization reports that depression is one of the main causes of disability, while suicide is the fourth leading cause of death among individuals aged 15 to 29. Individuals with severe mental health conditions are at risk of premature death - up to two decades earlier - due to preventable physical ailments.

Hypertension and Depression - The Connection

High blood pressure and mental health disorders may seem unrelated, but there is a connection. If you suffer from hypertension, you are at a higher risk of experiencing mood issues like anxiety and depression than those with normal blood pressure levels. Hypertension (HTN) and depression are known to frequently co-occur and increase the risk of cardiovascular disease (CVD) either alone or in combination. Patients with depression are at higher risk of developing HTN. Moreover, vascular risk factors, including HTN, are believed to be responsible for worsening depressive symptoms in older adults due to microvascular brain damage.

Depression is not always a solitary condition. In fact, it can increase the risk of other health issues.

Depression can lessen your motivation to take care of yourself and prevent diseases such as high blood pressure and diabetes.

Additionally, depression can cause physical changes in your body that can disrupt normal functions, such as an increase in inflammation and stress hormones. This can also lead to a change in heart rate, blood flow and metabolism, setting the stage for other conditions. The relationship between depression and related conditions works both ways. Many diseases that affect your quality of life, such as arthritis or multiple sclerosis, can lead to depression. For some people, stress and anxiety can be the cause.

Current Status of Knowledge

Depression and hypertension are closely linked, as suggested by a study conducted in 2013. This study included 40 hypertensive patients, out of which 23 were found to be depressed. Among these depressed patients, 21 had poor control over their blood pressure. The study found that the risk ratio for uncontrolled hypertension in depressed patients was 15.5. Additionally, the study found a significant correlation between depression and systolic and diastolic blood pressure values. Based on these findings, the study concluded that screening for depression in hypertensive patients is a simple and cost-effective tool that can help in improving outcomes. A study by Rabkin et al. , which involved 452 psychiatric outpatients diagnosed with depression, found that those with depression were three times more likely to have hypertension than those without depression. This supports a significant association between depression and hypertension. However, the study did not investigate the relationship between depression and the level of antihypertensive control. Another study by Jokisalo et al. found that a feeling of hopelessness towards hypertension, frustration with treatment, and perceived anxiety with blood pressure measurement were all linked with poor high blood pressure control. In a meta-analysis , it was discovered that depressed patients have an approximately 42% increased risk of hypertension, especially those who were diagnosed with depression three years before the study. These findings further support the correlation between a patient's psychological status and their level of hypertension control.

Some studies have yielded conflicting results. For instance, Hun et al. conducted a four-year study and found no association between depression and hypertension, whereas Licht et al. found a link between depression and decreased blood pressure. Moreover, a 2023 study in the UK involving 502,494 participants found that higher systolic blood pressure was associated with fewer depressive symptoms and greater well-being throughout the assessments.

DASH Diet for Hypertension and Depression

There have been conflicting results in research that assesses the relationship between hypertension and depression. It is important to note that none of these studies establish a cause-and-effect relationship between the two conditions. However, it is clear that both hypertension and depression are detrimental to overall well-being and require preventive measures.

Research suggests that there may be a possible link between hypertension and depression and that a preventive dietary approach such as the DASH diet could benefit both conditions.

DASH for Hypertension

The role of DASH diet in preventing and controlling hypertension is well established. DASH diet, which stands for Dietary Approaches to Stop Hypertension, is a healthy diet designed to lower blood pressure and reduce the risk of cardiovascular disease. The diet encourages the consumption of low-fat, low-cholesterol, and low-sodium foods while being high in potassium, calcium, magnesium, fibre, and protein. The DASH eating pattern emphasizes whole grains, fat-free or low-fat dairy products, fruits, vegetables, poultry, fish, and nuts as food choices. It restricts fatty meats, full-fat dairy products, tropical oils (such as coconut, palm, and palm kernel oils), and sweets. Moreover, the DASH diet is also low in salt, with a recommendation of no more than 1 teaspoon (2,300 mg) of sodium per day, consistent with most national recommendations. The National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health (NIH), promotes the DASH eating pattern as a natural way to prevent and control blood pressure. It is also recommended as a healthy option for the general public.

DASH for Depression

The current data on the impact of the DASH dietary pattern on mental distress is limited. Two studies conducted in 2017 and 2018 showed that following the DASH dietary pattern was inversely associated with depression scores. Additionally, Torres et al. reported that a DASH-type diet could improve mood in postmenopausal women. In 2021, Saharkhiz et al. found that adherence to a DASH diet may be linked to reduced stress and difficulty initiating sleep in young girls.

A recent study discovered that people who closely followed the Dietary Approaches to Stop Hypertension (DASH) diet were less likely to suffer from depression over a period of 6.5 years compared to those who had lower adherence to the diet. Dr Laurel Cherian, one of the study's co-authors, reported that around 16.2 million adults in the United States, approximately 6.7% of the country's adult population, experienced at least one major depressive episode in 2016, making it one of the most common mental health conditions. People with depression may experience persistent feelings of hopelessness, sadness, or irritability and may lose interest in activities they once enjoyed. They may also have difficulty sleeping and even have suicidal thoughts. Risk factors for depression include a family history of depression, traumatic or stressful experiences, and physical illness. The study participants were also assessed for symptoms of depression during the follow-up period.

The study found that individuals who adhered to the DASH diet most closely were 11% less likely to develop depression compared to those who adhered to it the least.

In contrast, a Western diet, which is high in saturated fats and low in fruits, vegetables, and whole grains, was found to have the opposite effect, and the closer the subjects' adherence to this diet, the higher their risk of developing depression.

Nutrition for Mental Health - Putting into Practice

Recent research suggests that a comprehensive approach to treating mental health conditions should include a customized plan addressing nutritional deficiencies, improving gut microbiota, and modifying eating habits. While the connection between nutrition and physical health is well established, clinicians may not always consider the link between nutrition and mental health. Tersavich, a psychiatric PA at Mindbloom Inc., presented research findings indicating that nutrition and healthy gut microbiota are crucial in preventing and treating depression, anxiety, and cognitive issues. She emphasized that consuming nutrients from food, rather than supplements, may have the greatest effect on patient outcomes. Data to support specific supplement dosages in most cases is still lacking.

It's time to start asking patients suffering from mental illnesses what they eat!