Study firms up diet and depression link

October 10, 2018

Science Daily/James Cook University

In an unusual experiment, researchers have found that among Torres Strait Islander people the amount of fish and processed food eaten is related to depression.

A JCU research team led by Professors Zoltan Sarnyai and Robyn McDermott looked at the link between depression and diet on a Torres Strait island, where fast food is available, and on a more isolated island, which has no fast food outlets.

Dr Maximus Berger, the lead author of the study, said the team interviewed about 100 people on both islands.

"We asked them about their diet, screened them for their levels of depression and took blood samples. As you'd expect, people on the more isolated island with no fast food outlets reported significantly higher seafood consumption and lower take-away food consumption compared with people on the other island," he said.

The researchers identified nineteen people as having moderate to severe depressive symptoms: sixteen were from the island where fast food is readily available, but only three from the other island.

"People with major depressive symptoms were both younger and had higher take-away food consumption," said Dr Berger.

The researchers analysed the blood samples in collaboration with researchers at the University of Adelaide and found differences between the levels of two fatty acids in people who lived on the respective islands.

"The level of the fatty acid associated with depression and found in many take-away foods was higher in people living on the island with ready access to fast food, the level of the fatty acid associated with protection against depression and found in seafood was higher on the other island," said Dr Berger.

He said it was important to remember that contemporary Western diets have an abundance of the depression-linked fatty acid (n-6 PUFA) and a relative lack of the depression-fighting fatty acid (n-3 LCPUFA).

"In countries with a traditional diet, the ratio of n-6 to n-3 is 1:1, in industrialised countries it's 20:1," he said.

Professor Sarnyai said depression affects about one in seven people at some point in their lives and Aboriginal and Torres Strait Islander people are disproportionately affected by psychological distress and mental ill-health compared with the general population.

"Depression is complex, it's also linked to social and environmental factors so there will be no silver bullet cure, but our data suggests that a diet that is rich in n-3 LCPUFA as provided by seafood and low in n-6 PUFA as found in many take-away foods may be beneficial," he said.

Professor Sarnyai said with the currently available data it was premature to conclude that diet can have a lasting impact on depression risk but called for more effort to be put into providing access to healthy food in rural and remote communities.

"It should be a priority and may be beneficial not only to physical health but also to mental health and wellbeing," he said.

https://www.sciencedaily.com/releases/2018/10/181010093645.htm

Diet shown to reduce stroke risk may also reduce risk of depression

February 25, 2018

Science Daily/American Academy of Neurology

People who eat vegetables, fruit and whole grains may have lower rates of depression over time, according to a preliminary study.

The study found that people whose diets adhered more closely to the Dietary Approaches to Stop Hypertension (DASH) diet were less likely to develop depression than people who did not closely follow the diet. In addition to fruit and vegetables, the DASH diet recommends fat-free or low-fat dairy products and limits foods that are high in saturated fats and sugar. Studies have shown health benefits such as lowering high blood pressure and bad cholesterol (LDL), along with lowering body weight.

"Depression is common in older adults and more frequent in people with memory problems, vascular risk factors such as high blood pressure or high cholesterol, or people who have had a stroke," said study author Laurel Cherian, MD, of Rush University Medical Center in Chicago and a member of the American Academy of Neurology. "Making a lifestyle change such as changing your diet is often preferred over taking medications, so we wanted to see if diet could be an effective way to reduce the risk of depression."

For the study, 964 participants with an average age of 81 were evaluated yearly for an average of six-and-a-half years. They were monitored for symptoms of depression such as being bothered by things that usually didn't affect them and feeling hopeless about the future. They also filled out questionnaires about how often they ate various foods, and the researchers looked at how closely the participants' diets followed diets such as the DASH diet, Mediterranean diet and the traditional Western diet.

Participants were divided into three groups based on how closely they adhered to the diets. People in the two groups that followed the DASH diet most closely were less likely to develop depression than people in the group that did not follow the diet closely. The odds of becoming depressed over time was 11 percent lower among the top group of DASH adherers versus the lowest group. On the other hand, the more closely people followed a Western diet -- a diet that is high in saturated fats and red meats and low in fruits and vegetables -- the more likely they were to develop depression.

Cherian noted that the study does not prove that the DASH diet leads to a reduced risk of depression; it only shows an association.

"Future studies are now needed to confirm these results and to determine the best nutritional components of the DASH diet to prevent depression later in life and to best help people keep their brains healthy," said Cherian.

https://www.sciencedaily.com/releases/2018/02/180225191804.htm