MY WORLD OF TRUTH
Thursday 28 March 2019
TEN BOOKS TO READ IN APRIL
Wednesday 20 March 2019
HOW TO EAT YOURSELF HAPPY....
How to eat yourself happy
Everyday foods could hold the key to unlocking your body’s natural cheerful chemicals.
Today is the International Day of Happiness, so a great time to explore how changing your diet can help to boost your mood.
Your body’s feel-good chemicals
Nutrients in food can promote the production of your body’s feel-good chemicals: serotonin and dopamine.
Serotonin regulates your mood and promotes sleep. Low serotonin is associated with depression, although it’s not known whether it causes depression or depression causes it.
Dopamine manages motivation, attention and emotional reward. The satisfaction you feel when accomplishing a goal is partly due to a dopamine rush. Low dopamine is associated with loss of interest.
Here’s what to eat
Fruit, veg and wholegrains
All vegetables and many fruits contain complex carbohydrates. These are important for stabilising your mood, as they release sugar into your body slowly. Other sources of complex carbs include wholemeal bread, brown rice, whole grain pasta, beans, pulses and oats. These foods avoid giving you the blood-sugar spikes and dips that can be caused by eating simple carbs such as sugar, white bread and white pasta.
Complex carbs also help indirectly with the production of serotonin. This is because serotonin can be made using an amino acid from your diet called tryptophan. It can be difficult to absorb tryptophan into your brain, but more may be absorbed when tryptophan-rich foods such as eggs, oily fish and chocolate with at least 70% cocoa solids are eaten alongside carbs. It’s not certain how accessible tryptophan is to the body, but it’s worth a try!
Poached, boiled, fried and scrambled eggs
Eggs are packed with healthy fats, protein and all-important B vitamins. All of these contribute to healthy brain function and have been known to protect against depression.
Studies suggest vitamin B deficiencies can result in a reduced production of feel-good chemicals and lead to tiredness. Other sources of B vitamins include whole grains, red meat, dairy, beans, bananas, green vegetables and beetroot.
A diet low in folate (vitamin B9) may increase the chance of feeling depressed, particularly in older people. Folate is found in green vegetables, citrus fruits, liver, beans and fortified foods.
Salmon, sardines, mackerel and co.
Oily fish, including salmon, pilchards, sardines, trout and mackerel, contain long-chain Omega-3 fats, which are important for brain function and the communication of serotonin and dopamine. Seafood is also a source of zinc, which is involved in almost every aspect of brain function, and research suggests reduces anger and depression in young women (many of whom don’t consume enough zinc).
Vary your diet for gut and brain health
Scientists know that more than 90% of serotonin is produced in the gut – but how does what you eat affect your mood?
Studies have found that people with depression and people who sleep poorly often have abnormal gut microbes. Eating to boost your gut bacteria (hungry yet?) could improve your mood as well as your diet. How to achieve this is different for everyone, and you may need to try changing your diet more than once to find the best foods for you. Try eating pre and probiotics, more veg and fibre and vary your diet.
Pre and probiotics
Eating pre and probiotics has been found to decrease anxiety and increase happiness.
Probiotics are live bacteria and yeasts found in fermented foods and some dairy products. Perhaps you’ve come across a few of these “Insta-famous” foods?
- Kombucha (a type of tea beverage, fermented by bacteria and yeast cultures)
- Sauerkraut (German fermented cabbage)
- Kimchi (spicy Korean fermented vegetables)
- Yoghurts found in the fridge in supermarkets (these are “live” yoghurts)
- Kefir (fermented milk drink)
- Yoghurt
Prebiotics are found in complex carbohydrates that we can’t digest, but your good gut bacteria like to eat them – hurrah! Here are some everyday food prebiotics sources:
- Oats
- Bananas
- Legumes, beans and peas
- Berries
- Onions, leeks and asparagus
The foods that might bring you down
Sugary foods, white bread, pasta and rice
Tucking into cakes, biscuits and other sugary snacks and drinks can give you a lift if you’re feeling down. They release sugar into your blood quickly, which can swiftly increase and decrease feelings of happiness. Eating something you’ve been craving makes the body release dopamine. However, it is easy to overeat them, leading to feelings of sluggishness and guilt, which can have a negative effect on your psychological well-being.
Saturated fat
Foods high in saturated fat, such as butter, palm oil and coconut oil, have been linked to reduced dopamine signalling in the brain. However, more research is needed before conclusions can be drawn.
5 more ways to stabilise and heighten your mood
- Eat regular meals to avoid blood sugar peaks and troughs. Eat a healthy breakfast, space out your meals throughout the day and don’t overindulge at one meal. Aim for three small meals with one or two healthy snacks a day.
- Don’t underestimate the power of hydration. Drinking throughout the day will help you stay alert and chipper.
- Manage your caffeine intake. Anything that provides a quick burst of energy can also take it away, leaving you wearier than before. Caffeine can also affect the quality of your sleep, leaving you feeling anxious. Try decaffeinated versions or switch to a new beverage.
- If you’ve lost interest in eating or you’re short of time, it is better to eat simple nutritious meals that only take a few minutes to prepare than a ready meal or nothing at all. A good meal for this is beans or eggs on wholemeal toast.
- The NHS recommends getting active to better your mental wellbeing.
Wednesday 13 March 2019
THE TRUTH ABOUT THE NITRATES IN YOUR FOOD..
“Nitrates” may make you think of school chemistry lessons or fertilisers. They’re probably less likely to be something you’d associate with dinner.
If you do think of nitrates in the context of food, it is probably a negative image that comes to mind – in particular, perhaps, the recent call for nitrate and nitrite preservatives to be banned from bacon and ham because of potential cancer-causing effects.
But the relationship between dietary nitrates/nitrites and health is a lot more nuanced than merely saying “they’re bad for us”. For example, the high natural nitrate content of beetroot juice has been credited with lowering blood pressure and enhancing exercise performance. Nitrates are also the active ingredient in some medications for angina, a condition in which reduced blood flow causes chest pain.
So are nitrates and nitrites actually bad for us?
Nitrates and nitrites, such as potassium nitrate and sodium nitrite, are naturally occurring chemical compounds which contain nitrogen and oxygen. In nitrates the nitrogen is bonded with three oxygen atoms, while in nitrites the nitrogen is bonded with two oxygen atoms. Both are legal preservatives which suppress harmful bacteria in bacon, ham, salami and some cheeses. (Read more about how cured meats protect us from food poisoning).
Only around 5% of nitrates in the average European diet come from processed meats, while more than 80% are from vegetables
From all the furore around processed meat, you may imagine it is the major source of nitrates in our diet. But in fact only around 5% of nitrates in the average European diet come from this source, while more than 80% are from vegetables. Vegetables acquire nitrates and nitrites from the soil they grow in – nitrates are part of natural mineral deposits, while nitrites are formed by soil microorganisms that break down animal matter.
Leafy greens like spinach and rocket tend to be top of the crop for nitrate content, with other rich sources include celery and beetroot juices, and carrots. Organically grown vegetables may have lower levels than non-organic vegetables as synthetic nitrate fertilisers aren’t used.
However, there’s an important difference between the way nitrates and nitrites are packaged in meat versus from vegetables – and that affects whether they’re carcinogenic, too.
Cancer connection
Nitrates are fairly inert by themselves, meaning they are unlikely to get involved in chemical reactions in the body. But nitrites, and the chemicals formed from them, are much more reactive.
Most of the nitrites we encounter aren’t consumed directly, but are converted from nitrates by the action of bacteria found in our mouth. Interestingly, research shows that use of an anti-bacterial mouth wash can massively cut down this oral manufacture of nitrites.
When the nitrites manufactured in our mouth are swallowed, one of the things that can happen is that they react in the strongly acidic environment of the stomach to form nitrosamines – some of which are carcinogenic and have been linked with bowel cancer.
But for this to happen, a source of amines, chemicals related to ammonia that are found abundantly in protein foods, is required. Nitrosamines can also be created directly in foods through high-heat cooking, as with fried bacon.
It’s not so much nitrates/nitrites that are carcinogenic, but the way they are cooked and their local environment – Kate Allen
“It’s not so much nitrates/nitrites per se [that are carcinogenic], but the way they are cooked and their local environment that is an important factor,” says Kate Allen, executive director of science and public affairs at the World Cancer Research Fund. “For example, nitrites in processed meats are in close proximity to proteins (specifically amino acids). When cooked at high temperatures this allows them to more easily form nitrosamines, the cancer-causing compound.”
But Allen adds that nitrites are just one reason processed meats contribute to bowel cancer, and their relative importance is uncertain. Other factors that may contribute include iron; PAHs (polycyclic aromatic hydrocarbons) which are formed in smoked meats; and HCAs (heterocyclic amines), which are created when meat is cooked over an open flame – and which also are tumour-promoting.
It’s also important to keep the dangers of processed meat in context. While the International Agency for Research on Cancer categorises processed meat a “probable carcinogen”, the risk is quite small.
In the UK, for example, six out of 100 people will get bowel cancer in their lives. Of those who eat 50 grams processed meat (about three rashers of bacon) daily, the chance is seven out of 100.
Good chemicals
Nitrites aren’t all bad. There’s increasing evidence they may provide cardiovascular and other benefits thanks to a molecule called nitric oxide.
In 1998, three US scientists received the Nobel prize for their discoveries around the role of nitric oxide – a gas – in the cardiovascular system. We now know it dilates blood vessels, lowers blood pressure and is part of the body’s armoury against infections. Limited capacity to produce nitric oxide is associated with heart disease, diabetes and erectile dysfunction.
One way the body makes nitric oxide is from an amino acid (a building block of protein) called arginine. But it’s now known that dietary nitrates can also significantly contribute to nitric oxide formation. We also know that this may be particularly important in older people, since natural nitric oxide production via arginine tends to drop with ageing.
While the nitrates found in ham are chemically identical to those in a salad, it’s the vegetable-based ones you should shoot for
Still, while the nitrates found in ham are chemically identical to those in the salad you might eat with it, it’s the vegetable-based ones you should shoot for.
“We have observed increased risks associated with nitrate and nitrite from meats for some cancers, but we haven’t observed risks associated with nitrates or nitrites from vegetables – at least in large observational studies where intake is estimated from self-reported questionnaires,” says Amanda Cross, a reader in cancer epidemiology at Imperial College, London.
Cross adds that it’s “a reasonable assumption” that nitrates in leafy greens are less likely to be harmful (ie to form nitrosamines). This is because they aren’t protein-rich foods and also contain protective components like vitamin C, polyphenols and fibre, which have all been shown to reduce nitrosamine formation.
When most of the nitrates in our diets come from vegetables – and in turn encourage nitric oxide formation – they are probably good for us
So when most of the nitrates in our diets come from vegetables – and in turn encourage nitric oxide formation – they are probably good for us.
One nitric oxide expert has gone further, arguing that many of us are deficient in nitrates/nitrites and that they should be classified as essential nutrients that can help prevent conditions such as heart attacks and strokes.
Right amount
It’s virtually impossible to reliably estimate dietary nitrate intake because content in food is hugely variable. “Levels can vary up to 10,000-fold for lettuce, and nitrates within drinking water can also vary considerably within the legal limit (50mg/litre),” says nutritional epidemiologist Gunter Kuhlne of the UK’s Reading University.
“It means that studies investigating the effects of nitrate on health need to be interpreted very carefully, as ‘nitrate’ might simply be a marker of vegetable intake”.
A 2017 European Food Safety Authority (EFSA) report endorsed an Acceptable Daily Intake or ADI (the amount that can be consumed over a lifetime without appreciable health risk) that equates to 235mg of nitrate for a person weighing 10 stone (63.5kg/140lb). But the report also noted that people of all age groups can exceed this ADI quite easily.
Nitrite intakes are generally much lower (one estimate of average intake in the UK being 1.5mg per day), and EFSA says exposure to nitrite preservatives is within safe levels for all population groups in Europe, except for a slight exceedance in children with diets high in the additives.
Some experts contend that nitrate/nitrite ADIs are outdated anyway, and that higher levels are not only safe but actually beneficial – as long as they come from vegetables, not processed meats.
Having 300-400mg of nitrates in one go – potentially provided by a large rocket and spinach salad, or a beetroot juice shot – is the amount that’s been linked with falls in blood pressure, for example.
As always, dose makes the poison, and levels of 2-9 grams (2000-9000mg) of nitrate can be acutely toxic, causing changes in haemoglobin that present as a blueish tinge to lips and skin. But that would be a difficult level to reach in one sitting, and very unlikely to happen from food itself – it’s more of a risk from, say, exposure to fertiliser-contaminated water.
The upshot? If you want to eat the right kinds of nitrates and nitrites and avoid the potentially carcinogenic ones, then eat a widely varied diet with at least five servings a day of fruit and vegetables, and avoid nibbling on processed meats too often. That way, the benefits of nitrates and nitrates will almost certainly outweigh the downsides.
Wednesday 6 March 2019
HOW MEAL TIMINGS AFFECT YOUR WAIST LINE
When young adults start university, they often gain weight. In the United States, they have a name for this phenomenon: the "freshman 15", referring to the 15lbs typically accrued during students’ first year of living away from home. In part, this weight gain can be explained by the substitution of home-cooked meals for ready meals and fast food, combined with reduction in physical activity.
Increasingly, however, scientists are fingering an additional suspect: circadian disruption, brought about by a culture of late-night eating, drinking, and inconsistent sleep patterns.
For decades, we’ve been told that weight gain, together with associated diseases such as type 2 diabetes and heart disease, are a simple matter of the quantity and type of food we consume, balanced with the number of calories we expend through exercise. But mounting evidence suggests that timing is also important: it’s not just what you eat, but when you eat that matters.
The idea that our response to food varies at different times of day dates back a long way. Ancient Chinese medics believed that energy flowed around the body in parallel with the sun’s movements, and that our meals should be timed accordingly: 7-9am was the time of the stomach, when the biggest meal of the day should be consumed; 9-11am centred on the pancreas and spleen; 11am-1pm was the time of the heart, and so on. Dinner, they believed, should be a light affair, consumed between 5pm and 7pm, which was when kidney function predominated.
Although the explanation is different, modern science suggests that there is plenty of truth in that ancient wisdom.
Dieters consumed most of their calories at breakfast lost two and a half times more weight than those who had a light breakfast and ate most of their calories at dinner
Consider studies of dieters. Most weight-loss schemes revolve around reducing the overall number of calories consumed – but what if the timing also determined the benefits? When overweight and obese women were put on a weight-loss diet for three months, those who consumed most of their calories at breakfast lost two and a half times more weight than those who had a light breakfast and ate most of their calories at dinner – even though they consumed the same number of calories overall.
Many people think that the reason you gain more weight if you eat late at night is because you have less opportunity to burn off those calories, but this is simplistic. “People sometimes assume that our bodies shut down when asleep, but that’s not true,” says Jonathan Johnston at the University of Surrey, who studies how our body clocks interact with food.
So, what else could be going on? Some preliminary evidence suggests that more energy is used to process a meal when it’s eaten in the morning, compared with later in the day, so you burn slightly more calories if you eat earlier. However, it’s still unclear how much of a difference this would make to overall body weight.
Another possibility is that late-night eating extends the overall window during which food is consumed. This gives our digestive systems less time to recuperate and reduces the opportunity for our bodies to burn fat – because fat-burning only occurs when our organs realise that no more food is coming their way.
The majority of North Americans eat over the course of 15 or more hours each day
Prior to the invention of electric light, humans woke at roughly around dawn and went to bed several hours after the sun set, with almost all food being consumed during daylight hours. “Unless we have access to light, we struggle to stay awake and eat at the wrong time,” says Satchin Panda, a circadian biologist at the Salk Institute in La Jolla, California, and author of The Circadian Code. His own research has revealed that the majority of North Americans eat over the course of 15 or more hours each day, with more than a third of the day’s calories consumed after 6pm, which is very different to how our ancestors must have lived.
Now consider those college students, eating and drinking long into the night. “A typical college student rarely goes to sleep before midnight, and they also tend to eat until midnight,” Panda says. Yet, many students will still need to get up for classes the next day, which – assuming they eat breakfast – reduces the length of their night-time fast still further.
It also means that they are cutting short their sleep, and this too could make them more likely to gain weight. Inadequate sleep impairs decision-making and self-control, potentially leading to poor food choices, and it disrupts levels of the “hunger hormones”, leptin and ghrelin, boosting appetite.
It is now becoming clear that our circadian rhythms are intimately connected to our digestion and metabolism in many other ways, through the body’s intricate signalling pathways – a new understanding that could explain the long-term effects of jet lag and shift work.
Inside every cell of your body, there ticks a molecular clock which regulates the timing of pretty much every physiological process and behaviour, from the release of hormones and neurotransmitters, to your blood pressure, the activity of your immune cells, and when you feel more sleepy, alert, or depressed. There clocks are kept in synchrony with each other, and with the time of day outside, through signals from a small patch of brain tissue called the suprachiasmatic nucleus (SCN). And its window on the outside world are a subset of light-responsive cells at the back of the eye called intrinsically photoreceptive retinal ganglion cells (ipRGs).
The point of all these “circadian” clocks is to anticipate and prepare for regular events in our environment, such as the arrival of food. It means that different biochemical reactions are favoured at various times of day, allowing our internal organs to task-switch and recuperate.
When we travel abroad, the timing of our light exposure changes, and our body clocks are pulled in the same direction – although the clocks in different organs and tissues adapt at different rates. The result is jet lag, which not only leaves us feeling sleepy or awake at the wrong times, but can also trigger digestive problems and general malaise.
However, light isn’t the only thing that can change the timing of our clocks. When we eat our meals can also shift the hands of the clocks in the liver and digestive organs, even though the clocks in our brain cells are unaffected. Recent evidence also suggests that the timing of exercise can tweak the clocks in our muscle cells.
When we fly across time zones, or eat, sleep and exercise at irregular times, the various clocks in our organs and tissues fall out of synchrony with one another. This is unlikely to be a problem if you just have the occasional late-night meal or lie-in, but if it’s a regular occurrence this may have longer-term consequences for our health.
Complex processes, such as the metabolism of fats or carbohydrates from the diet, require the coordination of numerous processes occurring in the gut, liver, pancreas, muscle and fatty tissue. If the conversation between these tissues becomes scrambled, they become less efficient, which over the long term may increase our risk of various diseases.
In one recent study, researchers compared the physical effects of sleeping for five hours per night for eight days in a row, with getting the same amount of sleep but at irregular times. In both groups, people’s sensitivity to the hormone insulin dropped and systemic inflammation increased, escalating the risk of developing type 2 diabetes and heart disease. However, these effects were even greater in those who were sleeping at irregular times (and whose circadian rhythms were therefore knocked out of alignment): in men, the reduction in insulin sensitivity and increase in inflammation doubled.
That could be a problem for frequent flyers, students who regularly sleep in, or any shift workers. According to European and North American surveys, some 15 to 30% of the working population is engaged in some form of shift work, which often equates to eating or being active when the body isn’t expecting it. Shift work has been linked to a host of conditions, including heart disease, type 2 diabetes, obesity and depression, and circadian disruption brought about by this irregularity is a prime suspect.
However, we are all shift workers at least some of the time, says Panda. An estimated 87% of the general population maintains a different sleep schedule on weekdays, compared to weekends, resulting in social jet lag. People also tend to eat breakfast at least an hour later at the weekends, which can result in so-called “metabolic-jetlag”.
It’s not only consistency in the timing of meals, but in the amount of food we eat at each meal that seems to be important.
Gerda Pot is a nutrition researcher at King’s College London, investigating how day-to-day irregularity in people’s energy intake affects their long-term health. She was inspired by her grandmother, Hammy Timmerman, who was rigorous about routine. Each day she’d eat breakfast at 7am; lunch at 12.30pm, and dinner at 6pm. Even the timing of her snacks was intransigent: coffee at 11.30am; tea at 3pm. When Pot came to visit, she soon learned that sleeping in was a mistake: “If I woke up at 10am, she’d still insist I ate breakfast, and then we’d be having coffee and a cookie half an hour later,” she says. Increasingly, though, she is convinced that her grandmother’s rigid routine helped keep her in good health until she was almost 95.
There are some good reasons why this might be. Our sensitivity to the hormone insulin, which enables the glucose from the food we eat to enter our cells and be used as fuel, is greater during the morning than at night. When we eat late (as Hammy Timmerman never did), that glucose remains in our blood for longer, which over the long term can increase the risk of developing type 2 diabetes, where the pancreas no longer produces enough insulin. It can also damage tissues elsewhere, such as blood vessels or nerves in the eyes and feet. In the worst cases, this can result in blindness, or amputations.
Using data from a UK national survey which has tracked the health of more than 5,000 people for over 70 years, Pot found that, even though they consumed fewer calories overall, people who had a more irregular meal routine had a higher risk of developing metabolic syndrome – a cluster of conditions, including high blood pressure, elevated blood sugar levels, excess fat around the waist and abnormal fat and cholesterol levels in their blood, which together increase the risk of cardiovascular disease and type 2 diabetes.
So, what should we do about it? Striving for greater consistency in the timing of our sleep and meals is a good first step, and ideally, all our clocks should be operating on the same time zone. When we open the curtains and see bright light in the morning, this resets the master clock in the brain, so by eating breakfast soon afterward, this reinforces the message that its morning to the clocks in our liver and digestive system. Eating a good breakfast may therefore be essential to keeping our circadian clocks running in synchrony.
Indeed, a recent study involving 18 healthy individuals, and 18 with type 2 diabetes, found that skipping breakfast led to disrupted circadian rhythms in both groups, as well as greater spikes in blood glucose levels when they finally did eat.
However, regularising our schedules shouldn’t come at the expense of missed sleep. Although it’s unlikely that the occasional lie-in will cause you any harm, we should generally be striving to go to bed at a time that will allow us to get adequate sleep – the recommended amount is seven to eight hours for most adults – on every day of the week. Here, light exposure could help. Dimming the lights in the evenings and getting more exposure to bright light during the day time has been shown to shift the timing of the master clock in the brain (the SCN) several hours earlier, making people more lark-like. (Read more: What I learnt by living without artificial light.)
Some are advocating a more hardcore approach of forgoing all food for at least 12 hours, and possibly for as long as 14-16 hours overnight. In a landmark study published in 2012, Panda and his colleagues compared one set of mice that had access to fatty and sugary foods at any time of day or night, with another group that could only consumed these foods within an eight to 12-hour window during their “daytime”. Even though they consumed the same number of calories, the mice whose eating window was restricted appeared to be completely protected from the diseases that began to afflict the other group: obesity, diabetes, heart disease and liver damage. What’s more, when mice with these illnesses were placed on a time-restricted eating schedule, they became well again.
“Almost every animal, including us, evolved on this planet with a very strong 24-hour rhythm in light and darkness, and the associated rhythms in eating and fasting,” explains Panda. “We think a major function [of these cycles] is to enable repair and rejuvenation each night. You cannot repair a highway when the traffic is still moving.”
Human trials of time-restricted eating are just beginning, but some of the early results look promising – at least in certain groups. For instance, when eight men with prediabetes were randomised to eat all their meals between 8am and 3pm, their sensitivity to insulin improved and their blood pressure dropped by 10-11 points on average, compared to when they consumed the same meals within a 12-hour period.
Quite what this means for the rest of us is unclear at this point, but the adage that you should breakfast like a king, lunch like a prince and dine like a pauper has never seemed truer. And it’s almost certainly worth fitting a padlock on the fridge overnight.
