Flavonoid Intake Associated With Decreased Depression Risk

Depression is the leading cause of disability worldwide, according to the World Health Organization. And, while treatments exist for it, many people do not respond fully to treatment. Prevention of depression has the potential to improve the health and quality of life of millions of people.

Diet is one way to address depression risk, and recent research has shown the potential of dietary flavonoids to reduce risk of the condition. Flavonoids are compounds in plant foods that have been shown to have effects that may interrupt the pathophysiology of depression—including by combating neuroinflammation and neuronal cell death. In addition, some flavonoids seem to improve blood flow, and that may help prevent age-related depression, which is influenced by vascular health.

A study published in 2016 in the American Journal of Clinical Nutrition looked at whether long-term dietary intake of the different subclasses of flavonoids (ie, flavonols, flavones, flavanones, anthocyanins, flavan-3-ols, polymeric flavonoids, proanthocyanidins) were related to depression incidence. They also examined the connection between specific flavonoid-rich foods and depression risk.

Among the more than 80,000 women followed for this study, approximately 10,000 cases of depression were noted at the 10-year follow-up. Analyzing food frequency questionnaires and other data, the researchers found inverse associations between depression risk and flavonol, flavone, and flavanone intake. In addition, the women who consumed more citrus fruits or juices had a lower incidence of depression. In older women (65 years or older at baseline), all subclasses of flavonoids except flavan-3-ols were associated with significantly lower risk of depression. The strongest associations were seen with flavones (good dietary sources include oranges, apples, celery, etc.) and proanthocyanidins (apples, chocolate, grapes, etc).

The researchers concluded that, while further studies are needed to confirm these associations, higher flavonoid intake may be associated with reduced risk of developing depression, particularly later in life.

Reference: Chang SC, Cassidy A, Willett WC, Rimm EB, O’Reilly EJ, Okereke OI. Dietary flavonoid intake and risk of incident depression in midlife and older women. Am J Clin Nutr. 2016;104(3):704-714.

Reposted from TAP Integrative

Mice fed more fiber have less severe food allergies

The development of food allergies in mice can be linked to what their gut bacteria are being fed, reports a study published June 21 in Cell Reports. Rodents that received a diet with average calories, sugar, and fiber content from birth were shown to have more severe peanut allergies than those that received a high-fiber diet. The researchers show that gut bacteria release a specific fatty acid in response to fiber intake, which eventually impacts allergic responses via changes to the immune system.

“We felt that the increased incidence of food allergies in the past ten years had to relate back to our diet and our own microbiome rather than a lack of exposure to environmental microbes–the so-called ‘Hygiene Hypothesis’,” says Laurence Macia, co-senior author on the study with Charles Mackay, both immunologists at Monash University in Australia. “Most researchers in this field look at excess fat as the problem–we were one of the first looking specifically at fiber deficiency in the gut.”

Gut bacteria are known to break down dietary fiber into their byproducts–primarily short-chain fatty acids. Macia and Mackay take this a step forward and show that these fatty acids support the immune system by binding onto specific receptors on T regulatory cells–immune cells known to suppress the immune response. This binding promotes a cascade of events that regulate inflammation in the gut–something that can be out of flux during an allergic reaction to food.

In the study, mice that were bred to have an artificially-induced peanut allergy were fed a high-fiber diet to produce a healthy population of gut bacteria. The bacteria were then given to a group of “germ-free” mice that had no gut microbes of their own. Despite not having consumed any fiber themselves, this second group of mice was protected against allergy, showing a less severe response when exposed to peanuts. In short, their microbiota was “reshaped” by having this transplant, says Mackay, adding that these mice clearly evolved mechanisms for responding to fiber and its byproducts. “It’s almost an essential component of their nutritional health,” he says.

“My theory is that the beneficial bacteria that predominate under consumption of fiber promotes the development of regulatory T cells, which ensures the bacteria have a healthy, anti-inflammatory system to thrive in,” says Macia. “So it’s a win-win for everybody.”

This anti-inflammatory effect was even seen with an artificial administration of these fatty acid byproducts. When the researchers gave groups of allergy-induced mice a water supply that was enriched with short-chain fatty acids for three weeks prior to exposure to peanuts, the mice had a reduced allergic response, even in the absence of a “protected” microbiota.

Both researchers expressed cautious optimism that their results can be effective in humans, and further preclinical trials would be required before studying the fiber-allergy relationship in people. “Right now, we need to identify what form of fiber to give,” says Macia. “That’s the main limitation at this stage.”

“It’s likely that compared to our ancestors, we’re eating unbelievable amounts of fat and sugar, and just not enough fiber” says Mackay, “And these findings may be telling us that we need that high-fiber intake, not just to prevent food allergy, but possibly other inflammatory conditions as well.”


Original Story:

https://www.sciencedaily.com/releases/2016/06/160621121700.htm


Journal Reference:

  1. Tan et al. Dietary fiber and bacterial SCFA enhance oral tolerance and protect against food allergy through diverse cellular pathways. Cell Reports, 2016 DOI: 10.1016/j.celrep.2016.05.047

Link between stress hormone, obesity in depressed, bipolar patients

Low levels of the stress hormone cortisol are linked to obesity, high levels of fat in the blood and metabolic syndrome among patients with recurrent depressions or bipolar disorder. This according to a study at Umeå University in Sweden published in the Journal of Affective Disorders.

“These results provide clues to better understand the high prevalence of cardiovascular diseases in people with recurrent depressions or bipolar disorder. The results may in the future contribute to better preventative treatments of cardiovascular diseases in these disorders,” says Martin Maripuu, researcher at the Department of Clinical Sciences, Division of Psychiatry at Umeå University.

Bipolar disorder and recurrent depressions are lifelong diseases that are associated with a 10-15 year reduction in life expectancy. A strong contributing factor to the shortened life expectancy is the high prevalence of cardiovascular diseases. Stress, low physical activity and high energy intake are lifestyle factors linked to increased risk of metabolic and cardiovascular diseases.

One of the most important stress system in the body is called the HPA-axis. This system regulates the production and levels of the vital stress hormone cortisol. Cortisol is also important for metabolism.

High cortisol levels over a long period of time is considered to contribute to the accumulation of fat. Stress normally leads to HPA-axis over activity, which in turn leads to increased levels of cortisol. If the additional stress is prolonged, it may lead to underactivity in the stress system, with low levels of cortisol as a result.

In people with recurrent depressions and with bipolar disorder it has previously been shown that metabolic risk factors for cardiovascular diseases are common and that disturbances in the stress regulation system often occur.

In order to study the link between cortisol levels and metabolic diseases, 245 patients with bipolar disorder or recurrent depressions were analysed, together with 258 people in a control group. Researchers measured cortisol levels in participants after they had taken a so-called dexamethasone suppression test, which is used to discover early deviations in the stress system.

What the Umeå researchers now can show is that patients with bipolar disorder or recurrent depressions with low levels of cortisol to a larger extent than other patients suffer from:

  • obesity (34 percent in comparison to 11 percent among other patients)
  • dyslipidaemia, i.e. high levels of fat in the blood (42 percent compared to 18 percent among other patients), and
  • metabolic syndrome (41 percent in comparison to 26 percent among other patients).

On the other hand, there was no correlation between cortisol levels and high blood sugar levels or high blood pressure.

“The results show that cortisol regulation is linked to worsened physical health in people with bipolar disorder or recurrent depressions. However, further studies are needed in order to better understand these associations,” says Martin Maripuu.


Original Story:

https://www.sciencedaily.com/releases/2016/07/160705111917.htm


Journal Reference:

  1. Martin Maripuu, Mikael Wikgren, Pontus Karling, Rolf Adolfsson, Karl-Fredrik Norrback. Relative hypocortisolism is associated with obesity and the metabolic syndrome in recurrent affective disorders. Journal of Affective Disorders, 2016; 204: 187 DOI: 10.1016/j.jad.2016.06.024

Fruit and veggies give you the feel-good factor

University of Warwick research indicates that eating more fruit and vegetables can substantially increase people’s later happiness levels.

To be published shortly in the American Journal of Public Health, the study is one of the first major scientific attempts to explore psychological well-being beyond the traditional finding that fruit and vegetables can reduce risk of cancer and heart attacks.

Happiness benefits were detected for each extra daily portion of fruit and vegetables up to 8 portions per day.

The researchers concluded that people who changed from almost no fruit and veg to eight portions of fruit and veg a day would experience an increase in life satisfaction equivalent to moving from unemployment to employment. The well-being improvements occurred within 24 months.

Cancer

The study followed more than 12,000 randomly selected people. These subjects kept food diaries and had their psychological well-being measured. The authors found large positive psychological benefits within two years of an improved diet.

Professor Andrew Oswald said: “Eating fruit and vegetables apparently boosts our happiness far more quickly than it improves human health. People’s motivation to eat healthy food is weakened by the fact that physical health benefits, such as protecting against cancer, accrue decades later. However, well-being improvements from increased consumption of fruit and vegetables are closer to immediate.”

The work is a collaboration between the University of Warwick, England and the University of Queensland, Australia. The researchers found that happiness increased incrementally for each extra daily portion of fruit and vegetables up to eight portions per day. The study involved an examination of longitudinal food diaries of 12,385 randomly sampled Australian adults over 2007, 2009, and 2013 in the Household, Income, and Labour Dynamics in Australia Survey. The authors adjusted the effects on incident changes in happiness and life satisfaction for people’s changing incomes and personal circumstances.

Western diet

The study has policy implications, particularly in the developed world where the typical citizen eats an unhealthy diet. The findings could be used by health professionals to persuade people to consume more fruits and vegetables.

Dr. Redzo Mujcic, research fellow at the University of Queensland, said: “Perhaps our results will be more effective than traditional messages in convincing people to have a healthy diet. There is a psychological payoff now from fruit and vegetables — not just a lower health risk decades later.”

The authors found that alterations in fruit and vegetable intake were predictive of later alterations in happiness and satisfaction with life. They took into account many other influences, including changes in people’s incomes and life circumstances. One part of the study examined information from the Australian Go for 2&5 Campaign. The campaign was run in some Australian states which have promoted the consumption of two portions of fruit and five portions of vegetables each day.

Antioxidants

The academics think it may be possible eventually to link this study to current research into antioxidants which suggests a connection between optimism and carotenoid in the blood. However, they argue that further research is needed in this area.


Original Story:

https://www.sciencedaily.com/releases/2016/07/160710094239.htm

Food’s transit time through body is a key factor in digestive health

The time it takes for ingested food to travel through the human gut – also called transit time – affects the amount of harmful degradation products produced along the way. This means that transit time is a key factor in a healthy digestive system. This is the finding of a study from the National Food Institute, Technical University of Denmark, which has been published in the renowned journal Nature Microbiology.

Food has to travel through eight meters of intestine from the time it enters the mouth of an adult person until it comes out the other end. Recent research has focused mainly on the influence of the bacterial composition of the gut on the health of people’s digestive system.

Taking this a step further, Postdoc Henrik Munch Roager from the National Food Institute has studied how food’s transit time through the colon affects gut bacteria’s role in the activity and health of the digestive system by measuring the products of bacterial activity, which end up in urine.

The effect of food’s transit time

Intestinal bacteria prefer to digest dietary carbohydrates, but when these are depleted, the bacteria start to break down other nutrients such as proteins. Researchers have previously observed correlations between some of the bacterial protein degradation products that are produced in the colon and the development of various diseases including colorectal cancer, chronic renal disease and autism.

“In short, our study shows that the longer food takes to pass through the colon, the more harmful bacterial degradation products are produced. Conversely, when the transit time is shorter, we find a higher amount of the substances that are produced when the colon renews its inner surface, which may be a sign of a healthier intestinal wall,” Henrik’s supervisor and professor at the National Food Institute, Tine Rask Licht, explains.

It is commonly thought that a very diverse bacterial population in the gut is most healthy, however both the study from the National Food Institute and other brand news studies show that bacterial richness in stool is also often associated with a long transit time.

”We believe that a rich bacterial composition in the gut is not necessarily synonymous with a healthy digestive system, if it is an indication that food takes a long time to travel through the colon,” Tine Rask Licht says.

Better understanding of constipation as a risk factor

The study shows that transit time is a key factor in the activity of the intestinal bacteria and this emphasizes the importance of preventing constipation, which may have an impact on health. This is highly relevant in Denmark where up to as much as 20% of the population suffers from constipation from time to time.

The National Food Institute’s findings can help researchers better understand diseases where constipation is considered a risk factor, such as colorectal cancer and Parkinson’s disease as well as afflictions where constipation often occurs such as ADHD and autism.

Influencing food’s transit time

Tine Rask Licht emphasizes that people’s dietary habits can influence transit time:

”You can help food pass through the colon by eating a diet rich in fibre and drinking plenty of water. It may also be worth trying to limit the intake of for example meat, which slows down the transit time and provides the gut bacteria with lots of protein to digest. Physical activity can also reduce the time it takes for food to travel through the colon.”


Original Story:

https://www.sciencedaily.com/releases/2016/06/160627125525.htm


Journal Reference:

  1. Henrik M. Roager, Lea B. S. Hansen, Martin I. Bahl, Henrik L. Frandsen, Vera Carvalho, Rikke J. Gøbel, Marlene D. Dalgaard, Damian R. Plichta, Morten H. Sparholt, Henrik Vestergaard, Torben Hansen, Thomas Sicheritz-Pontén, H. Bjørn Nielsen, Oluf Pedersen, Lotte Lauritzen, Mette Kristensen, Ramneek Gupta, Tine R. Licht. Colonic transit time is related to bacterial metabolism and mucosal turnover in the gut.Nature Microbiology, 2016; 1: 16093 DOI: 10.1038/nmicrobiol.2016.93