Superfoods: myth or miracle?
I think one of my new year’s resolutions should have been to not tell people – when out in social situations – that I am a nutritional therapist. I guess that means to become a liar? As soon as I admit my vocation, I frequently find myself listening to people’s nutritional woes, practically giving mini consultations when I’m effectively ‘off duty’. And quite frankly there is a time and a place to talk bowels and bloating. More often I’m asked quick fire questions such as ‘can cherry juice really help my insomnia?’ or ‘will green tea help me loose weight?’ or ‘what foods are real superfoods?’ So here is a little note about the latter.
The term ‘superfood’ is applied to foods with an above average number of disease-fighting-antioxidants. Experts believe that a diet rich in these foods will improve your overall health. The sentiment is true – antioxidants are important in disease prevention and overall health – but when most of the products heralded as superfoods are charged at premium prices, are we right to be slightly dubious as to whether the actual claims such as (‘broccoli may undo diabetes damage’) are legitimate or is it all just a clever marketing ploy?
In 2007, EU legislation banned the use of the term ‘superfood’ on packaging unless it is accompanied by convincing research. But this ban hasnt stopped the media continuing to hail a new superfood on an almost weekly basis. If we believed everything we read, we might think that a diet of curry, wine and chocolate is the secret to eternal life!
The facts about the latest dietary discoveries are rarely as simple as the attention grabbing headlines imply and to accurately test how one food may affect our health is arduous and complex. There is no real harm in the superfood claims if they get us eating more nutritious food but it’s important to remember that the studies behind the claims are riddled with limitations, bias and confounding factors. For example, the effects of a particular potent property is likely to have been carried out in a test tube or on an animal. Our bodies act very differently to a test tube or a mouse. Certain vitamins, such as Vitamin C for example, are water soluble and any excess our body does not require is excreted in our urine. Therefore once you have hit your daily remit, it doesnt matter how many blueberries you guzzle, the vitamin C will be flushed away. Much like the £4 you spent on the punnet of them in the first place.
Here is the lowdown on a few of the classics.
GREEN TEA: there is some evidence that green tea helps heart health but the links to weight loss and cancer are contradictory. It will certainly help you remain hydrated and as it’s calorie free it’s a good alternative to tea with milk if you are dieting.
● GOJI BERRIES: The test that marked Goji berries No1 on the antioxidant scale (ORAC)were done in test tubes and doesn’t reflect what happens in the human body. The vitamin content of Goji berries are high but you would have to consume a huge quantity to make a significant difference.
COCONUT WATER: Claims to be more hydrating than water. There are some vitamins and minerals in coconut water but it is not a particularly rich source. And as for being more hydrating than water – that’s actually impossible.
EDAMAME BEANS: There is no evidence that they can help you loose weight. They are high in fibre, especially soluble fibre, which can help lower cholesterol levels.
The message is really this: it’s great to include these foods as part of an all round healthy diet as long as you dont expect any overnight miracles. Eat a balanced diet with a range of foods to ensure you get enough of the nutrients your body needs. Limiting your intake of alcohol and high fat, high sugar, salty and processed foods and regular exercise are also important.
For more nutrition advice with Jo Lewin go to Breathe London nutrition
(Skinny) Sleeping Beauty
As a nation we are getting fatter. We’ve heard it. We’ve seen it. We are well aware we are supersizing at an alarming rate. Over the next two decades, the UK will become home to a whopping 11 million obese adults, costing the NHS £2 billion per year. Brits are the fattest in Europe, we’re basically guzzling gastric bands. And as for the kids… we’ll they are certainly not alright. It’s the fault of fast food outlets, video games and our ever increasing portion sizes. Fingers are pointed at advertising agencies, teachers and parents. Although we are brainwashed with cookery programmes on the TV, left alone in the kitchen too many of us are stumped when it comes to making a healthy meal. No time, no money, just deliver me a pizza and leave me alone…..
It is estimated that we spend approximately 217,175 hours asleep in our lifetime. Interestingly in 1960, we slept on average 8.5 hours per night and obesity rates were around 12%. By 2011, the average number of hours had fallen to 6.5 and obesity rates had increased to around 30%. A recent study published in the British Medical Journal found that a lack of quality sleep is contributing to the obesity epidemic. Thestudy in question was focused on children aged 3-5 and it found that those who slept longer were 61% less likely to be overweight aged 7. A positive correlation between lack of sleep and increased body weight was apparent even when accounting for confounding factors such as household income (not only the poor kids with crap food got fat), fruit and vegetable intake, television watching (not only the couch potatoes got fat) and the mother’s education.
So how is sleep related to weight gain? Can it really be possible for an adult to sleep themselves thin? No more diets and exercise? Sounds too good to be true. Well let’s start by highlighting the obvious. Less sleep means more time awake = more time scoffing. Less sleep also means greater tiredness during the day = less likely to be active and more likely to make poor food choices (sugary fast releasing energy fixes). But interestingly the key link is that sleep deprivation triggers a hormonal response, sending appetite control haywire.
The hormones in question are call leptin and ghrelin. Leptin is produced by fat cells and plays a role in the regulation of appetite and metabolism – important functions for weight management. As a messenger, leptin communicates directly with the central nervous system, decreasing the “hunger signal” that the hypothalamus in the brain sends to the body. Leptin, in effect, is your body’s own natural appetite suppressant. When your leptin levels are optimal, you tend to consume less food, as well as make healthier food choices. Great. Additionally, leptin increases your metabolic rate, or energy level, so it increases thermogenesis (fat-burning capability) therefore more calories are burned up. Double great. The hormone ghrelin does the opposite of leptin; it tells the brain that we are hungry and surprise surprise, levels of ghrelin increase when sleep is restricted.
Studies at The University of Chicago and Stanford University have proven that subjects who had trouble sleeping had lower levels of leptin and higher levels of ghrelin than those who received optimal amount of sleep. When you sleep well at night, one of your body’s many jobs is to re-calibrate the levels of your hormones, including leptin and ghrelin. After a good night of restful sleep, leptin, ghrelin and many other important hormones have had enough time to be replenished and are more likely to be back to optimal levels.
● Aim for 7-9 hours per night
● Try to go to sleep at the same time every night
● Avoid caffeine, alcohol and eating large meals before bed
● Limit use of internet and TV watching in bed as it tends to stimulate our senses
● Magnesium is a muscle relaxant and natural sedative. Foods rich in magnesium are legumes and seeds, dark leafy green vegetables, wheat bran, almonds, cashews, blackstrap molasses, brewer’s yeast, and whole grains.
● Tryptophan is an amino acid (from protein) that makes the brain chemicals serotonin and melatonin involved in sleep. Snacks containing carbohydrates and proteins rich in tryptophan such whole grain crackers with warm milk or cottage cheese before bedtime may help to promote sleep.
For more nutrition advice with Jo go to Nutrition at Breathe London