The maxim ‘you are what you eat’ takes on new meaning when we consider how our diet affects our emotions. Peta Bee looks at how scientific research supports this belief.
WHAT makes you happy? Scientists say it could be the food and drinks you consume on a daily basis. Eat the right things and you really can prime your brain to remain positive and even ward off depression. Latest good mood foods range from a daily cuppa to curry and from yoghurt to porridge.
A recent study led by scientists from Kings College London and published in the journal Biological Psychiatry confirmed that the omega-3 fatty acids found in mackerel, sardines and other oily fish can leave you less likely to get depressed. But can your diet really make that much difference to your state of mind?
“Food plays a really important role in psychological health and wellbeing,” says psychologist Dearbhla McCullough. “It is well documented that skipping meals and missing out on essential nutrients can play havoc with your mood.”
However, no single happy food can transform your mood on its own.
“There’s no magic bullet,” McCullough says. “The key thing is to get a varied and healthy diet with plenty of different mood boosting foods.”
THE HAPPY FOODS
Oily fish: Mackerel and sardines are among the oily fish that could contribute to a reduced risk of depression, announced researchers recently. Oily fish contain beneficial omega-3 fatty acids, which have a long list of health benefits and are also known to have anti-depressant and anti-inflammatory properties. Previous studies have suggested that raising the intake of omega-3 ‘fish oils’ can help to combat depression and the latest, which included scientists from the Institute of Psychiatry, Psychology & Neuroscience at King’s College London, suggested that “even a short course (two weeks) of a nutritional supplement containing one such omega-3 polyunsaturated fatty acid (EPA) reduced the rates of new-onset depression to 10%, in a group of patients with hepatitis C, a chronic virus infection that triggers depression in 30% of sufferers.
Spices: Adding spice to your weekly menu in the form of turmeric could make for a brighter outlook. The spice gets its bright yellow colour from curcumin, a compound that has been shown to have increase levels of the brain chemicals serotonin and dopamine, both key components of a good mood. One recent study by Dr Adrian Lopresti of the School of Psychology and Exercise Science at Murdoch University, showed that a 500g extract of curcumin taken twice daily for eight weeks was “significantly more effective than a placebo in improving several mood-related symptoms” in a group of volunteers with ‘a major depressive disorder’. Don’t be shy with the black pepper either. Indian studies have shown that the main active component, piperine, can help the body absorb curcumin and enhance its antidepressant effect long-term.
Turkey sandwich: Turkey is one of the best sources of tryptophan, an essential amino acid which is converted in our bodies into serotonin, a neurotransmitter, or chemical in the brain. Low levels of seretonin are linked to depression, so increasing your intake of tryptophan (other sources include eggs and chicken) is a good move. A turkey sandwich gives an even bigger brain boost. Eating a slice or two of whole-grain bread triggers the body to release insulin, which in turn increases the amount of tryptophan that gets into your brain.
Oats: There’s some evidence that raising dopamine levels through a smart diet and possibly supplementation might help raise mood — and oats, rich in l-tyrosine, an amino acid that is an important component of dopamine — are a great way to do it. Oats also help to stabilise blood glucose levels much better than sugary cereal or refined carbs and, as glucose is the brain’s main fuel, it really helps to avoid the kind of sugar crash that can send mood plummeting.
Berries: A bowl of berries for breakfast could set you up for the day in a positive frame of mind. After studying the composition of blueberries, raspberries and strawberries, scientists from the Torrey Pines Institute for Molecular Studies in Florida found that the chemicals they contain are similar in structure to valproic acid, a widely used prescription mood-stabilising drug. Reporting at the American Chemical Society two years ago, they added that tea and dark chocolate hold similar benefits.
Nuts and seeds: All nuts and seeds are great to include in the diet because they provide mood-boosting selenium. But Brazil nuts are among the richest supplies and just six a day gives you the selenium you need for a mood boost. Other nuts and seeds are beneficial. Arizona State University researchers reported that high intakes of alpha-linolenic acid (ALA), a form of omega-3 fat found in walnuts, flaxseed and chia seed, can keep you perked up mentally.
Dark chocolate: Antioxidant-rich dark chocolate contains mood-boosting compounds such as theobromine and phenylethyamine and has been shown to help people cope with emotional stress. A report by the American Chemical society showed that eating a little over 25g of dark chocolate (about 6 squares) daily for two weeks reduced levels of stress hormones in the bodies of people feeling highly agitated. The daily treat also corrected other stress-related biochemical imbalances. Some experts think that gorging on chocolate, particularly the milk variety, can make depression worse.
Coffee: Drinking two to four cups of black coffee a day could reduce depression and cut the risk of suicide by 50% in men and women, according to a study from the Harvard School of Public Health. Using data obtained from previous studies, the researchers looked at the caffeine intake of around 200,000 people in the form of drinks such as coffee and cola as well as chocolate. They found the risk of suicide among adults who drank several cups of coffee a day was about half that of that compared to those who drank decaffeinated coffee, or no coffee at all. Of the caffeine consumers, coffee was the main source and during the seven-year investigation, there were just 277 deaths from suicide. Don’t overdo it, though. More than six cups a day can leave you tetchy and anxious.
Red meat: It has its critics, but surprisingly red meat seems to help prevent depression in some women. Professor Felice Jacka, a psychiatric health researcher at Deakin University, Australia, says she expected red meat to have a negative effect on mood, yet found the opposite to be true when she studied its effects on the mental health of 1,000 women. Those who cut down on their consumption of lamb and beef, she discovered, were more likely to be depressed. “We found they were twice as likely to have a diagnosed depressive or anxiety disorder as those consuming the recommended amount of around three servings of red meat a week,” Jacka said. However, excessive consumption “was related to increased depression and anxiety”.
Yoghurt: Eating plain yoghurt twice daily has a powerful effect on mood by reducing activity in areas of the brain associated with emotion and pain. It comes down to the probiotics — or beneficial bacteria — contained in yoghurt which experts now think can affect brain function in different ways. It’s long been known that the brain sends signals to the gut, which is why stress can trigger IBS and other gastrointestinal symptoms.
Latest studies suggest signals travel the opposite way too. To test this, a group of young, female subjects at the University of California were split into one of three groups: one group ate a plain yogurt with live bacterial cultures containing probiotic strains twice daily, another had a dairy product with no live bacteria, the third group ate no dairy products. Before and after the month-long trial the women took part in an ‘emotional task’ involving some stress. MRI scans revealed the yoghurt eaters had reduced activity in a brain network that included the somatosensory cortex — which receives sensory information — as well as in the prefrontal cortex, precuneus, and basal ganglia, all of which handle aspects of emotion.
BAD MOOD FOOD
Burgers, pizzas and doughnuts: Numerous researchers have shown that diets containing too much fast food is a fast route to depression. In a study at the University of Las Palmas de Gran Canaria and the University of Granada a couple of years ago, it was shown that people eating too many commercial baked foods such as cupcakes and doughnuts, and fast food including burgers, hotdogs and pizza had 51% higher rates of depression than those eating a healthier diet. And the more fast food you eat, the more likely you are to be depressed, said Almudena Sánchez-Villegas, lead author of the study. “The intake of this type of food should be controlled because of its implications on both health (obesity, cardiovascular diseases) and mental well-being,” she said.
Diet cola : Switching to the diet version of a fizzy drink might seem like a healthier move, but not for the mind. Last year, researchers at the US National Institutes of Health reported that drinking sweet fizzy, especially diet drinks, are associated with an increased risk of depression in adults. The study looked at the dietary patterns of 263,925 people, including their consumption of a range of drinks – from coffee to fruit juice. After ten years, the researchers asked the group if they had suffered depression in the intervening period. Those who drank more than four cans or cups per day of fizzy drinks were 30% more likely to develop the condition than those who drank none, with levels higher among the low calorie drinks. Neurologist and study author Dr Honglei Chen said the results confirmed that cutting out or down on sweetened diet drinks or replacing them with other drinks “may naturally help lower your depression risk”.
White pasta and bread: Switching from white pasta, rice and bread to wholemeal and wholegrain versions could result in an upswing in your mood. For 12 years, Dr Michael Lucas and colleagues at the Harvard School of Public Health tracked the diet habits and health of more than 43,000 women. None of the women reported depression at the start of the study, but by the end those who consumed refined grains like pasta and white bread daily along with fizzy drinks were 29-41% more likely to have been diagnosed with depression. When blood tests were taken, the refined carbs group also had higher levels of markers for inflammation which might be linked to the downturn in mood, the researchers suggested.
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