Possible Link Between Digestive Problems & Depression/Anxiety?
DIGESTIVE IRRITATION IN NEWBORNS MAY CAUSE LIFELONG DEPRESSION
A new study has found that short-term gastrointestinal irritation in the first days of life can permanently re-set the brain to a state of depression or anxiety, suggesting that digestive problems may actually be the cause of certain psychological disorders, and not the result of them as is commonly assumed.
Because not all stomach upsets result in lifelong depressive or psychological disorders, the researchers speculate that the impact of gastric irritation may depend on when it occurs during the development of the genetic makeup of the affected person. Past research shows that individuals who suffer from functional dyspepsia (persistent or recurring pain in the upper abdomen), a group making up about 15-20 percent of the population, are also more likely than others to be depressed or anxious.
Conventional wisdom has held that stress hormones associated with altered mood cause digestive disturbances; however, the gut and brain are actually hard-wired together by the vagus nerve, which sends signals in both directions from the brain to the internal organs.
This just-released study will not be published until a future issue of the journal PLoS One. It is available online now at http://bit.ly/iPmy4w without charge.
Green Tea & Depression
Green Tea May Combat Depression in Elderly
Drinking frequent cups of green tea is linked to a lower incidence of depressive symptoms in elderly people, say Japanese researchers.
A study published in the American Journal of Clinical Nutrition focused on 1,058 elderly Japanese individuals 70 years of age plus with the prevalence of mild and severe and severe depressive symptoms said the authors.
The authors maintain that only a few studies have investigated the relationship between green tea consumption and mental health, while there appear to be few studies assessing the relationship between green tea drinking and depressive symptoms.
According to the team led by Atsushi Hozawa, depression in the elderly is highly prevalent and can increase the risk of medical illnesses, worsen the outcome of other medical illnesses, and may increase mortality.
Growing problem
World Health Organization (WHO) forecasts that within 20 years more people will be affected by depression than any other health problem; it ranks depression as the leading cause of disability worldwide, with around 120 million people affected.
Findings show that the occurrence of depressive symptoms was 44% lower for participants who drank 4+ cups of green tea/day compared to those who drank less than one, after results were adjusted for factors such as age, sex, disease history, BMI, alcohol consumption, cigarette smoking, diet, and other factors.
The authors state that their study is rather limited in scale and a larger population study that uses a standardized comprehensive structured diagnostic interview is required to confirm the effect of green tea consumption on depressive symptoms.
Mental stress
A previous study also led by the Hozawa found that drinking 5 cups of green tea/day may reduce the incidence of psychological distress by 20%.
Green tea consumption was said to improve psychological well-being in a study population of 42,093 Japanese individuals of which 6.6% suffered from psychological stress.
Relaxation benefits
The potential of green tea offers more than its well-known role as an antioxidant.
According to research from Unilever, green tea contains L-theanine, which is said to relax the brain.
Consumption of 50mg of L-theanine (equivalent of 2-3 cups of green tea) stimulates the alpha-brain waves associated with relaxation. By increasing the frequency of these brain waves, the beta-brain waves associated with tension are decreased.
Consumer awareness of the benefits of green tea and green tea extracts continues to rise with growing numbers of studies, from 430 papers in 2000 to almost 1500 in 2003, reporting benefits of the main compounds, catechins.
Source: American Journal of Clinical Nutrition
Published online ahead of print: doi: 10.3945/ajcn.2009.28216
Title: Green tea consumption is associated with depressive symptoms in the elderly
Authors: K Niu, A Hozawa, S Kuriyama, S Ebihara, H Guo, N Nakaya, K Matsuda, H Takahashi, Y Masamune, M Asada, S Sasaki, H Arai, S Awata, R Nagatomi, and I Tsuji