Category: Health

You need more daylight to sleep better

An an historian, I’ve often been fascinated about what life must have been like before the dawn of electricity. I have a love-hate relationship with artificial light. On the one hand, I use a lightbox to stave off Seasonal Affective Disorder. On the other hand, I’ve got (my optician tells me) not only pale blue irises but very thin corneas. That makes me photophobic and subject to the kind of glare on a regular basis I can only imagine ‘normal’ people get after staring at a lightbulb for a while.

In this article, Linda Geddes describes an experiment in which she decided to forgo artificial life for a number of weeks to see what effect it had on her health and, most importantly, her sleep.

Working with sleep researchers Derk-Jan Dijk and Nayantara Santhi at the University of Surrey, I designed a programme to go cold-turkey on artificial light after dark, and to try to maximise exposure to natural light during the day – all while juggling an office job and busy family life in urban Bristol.

By the end of 2017, instead of having to manually install something like f.lux on my devices, they all started to have it built-in. There’s a general realisation that blue light before bedtime is a bad idea. What this article points out, however, is another factor: how bright the light is that you’re subjected to during the day.

Light enables us to see, but it affects many other body systems as well. Light in the morning advances our internal clock, making us more lark-like, while light at night delays the clock, making us more owlish. Light also suppresses a hormone called melatonin, which signals to the rest of the body that it’s night-time – including the parts that regulate sleep. “Apart from vision, light has a powerful non-visual effect on our body and mind, something to remember when we stay indoors all day and have lights on late into the night,” says Santhi, who previously demonstrated that the evening light in our homes suppresses melatonin and delays the timing of our sleep.

The important correlation here is between the strength of light Geddes experienced during her waking hours, and the quality of her sleep.

But when I correlated my sleep with the amount of light I was exposed to during the daytime, an interesting pattern emerged. On the brightest days, I went to bed earlier. And for every 100 lux increase in my average daylight exposure, I experienced an increase in sleep efficiency of almost 1% and got an extra 10 minutes of sleep.

This isn’t just something that Geddes has experienced; studies have also found this kind of correlation.

In March 2007, Dijk and his colleagues replaced the light bulbs on two floors of an office block in northern England, housing an electronic parts distribution company. Workers on one floor of the building were exposed to blue-enriched lighting for four weeks; those on the other floor were exposed to white light. Then the bulbs were switched, meaning both groups were ultimately exposed to both types of light. They found that exposure to the blue-enriched white light during daytime hours improved the workers’ subjective alertness, performance, and evening fatigue. They also reported better quality and longer sleep.

So the key takeaway message?

It’s ridiculously simple. But spending more time outdoors during the daytime and dimming the lights in the evening really could be a recipe for better sleep and health. For millennia, humans have lived in synchrony with the Sun. Perhaps it’s time we got reacquainted.

Source: BBC Future

The world’s most nutritious foods

The older I get, the more important (and the more immediately apparent) the health benefits from eating and exercising well.

This article reports on scientists studying 1,000 different foods for their health benefits:

Scientists studied more than 1,000 foods, assigning each a nutritional score. The higher the score, the more likely each food would meet, but not exceed your daily nutritional needs, when eaten in combination with others.

The top ones?

  1. Almonds
  2. Cherimoya
  3. Ocean perch
  4. Flatfish
  5. Chia seeds
  6. Pumpkin seeds
  7. Swiss chard
  8. Pork fat
  9. Beet greens
  10. Snapper

Ever since reading of the value of almonds to non-meat eaters in The 4-Hour Body, I’ve taken a big bag of them on every trip. I also have some in a jar on my desk at home. As for the others on the list, some (pork fat!) are out of the question, and some (cherimoya) I’ve never come across.

Time for some more experimentation…

Source: BBC Future

Alzheimer’s is a kind of ‘type 3’ diabetes

My Great Aunt, who we were close to, developed Alzheimer’s Disease towards the end of her life. This article claims that scientific evidence points to a link between the condition and diabetes:

A longitudinal study, published Thursday in the journal Diabetologia, followed 5,189 people over 10 years and found that people with high blood sugar had a faster rate of cognitive decline than those with normal blood sugar—whether or not their blood-sugar level technically made them diabetic. In other words, the higher the blood sugar, the faster the cognitive decline.

And the reason?

Schilling posits this happens because of the insulin-degrading enzyme, a product of insulin that breaks down both insulin and amyloid proteins in the brain—the same proteins that clump up and lead to Alzheimer’s disease. People who don’t have enough insulin, like those whose bodies’ ability to produce insulin has been tapped out by diabetes, aren’t going to make enough of this enzyme to break up those brain clumps. Meanwhile, in people who use insulin to treat their diabetes and end up with a surplus of insulin, most of this enzyme gets used up breaking that insulin down, leaving not enough enzyme to address those amyloid brain clumps.

Really interesting, and another reason to avoid sugar and heavily-processed foods.

Source: The Atlantic

Depression as an evolutionary advantage?

It’s been almost 15 years since I suffered from depression. Since that time, I’ve learned to look after myself mentally and physically to resist whatever natural tendency I have towards spiralling downwards.

I found this article fascinating.

Some psychologists… have argued that depression is not a dysfunction at all, but an evolved mechanism designed to achieve a particular set of benefits.

The dominant popular view seems to be that there’s something wrong with your brain chemistry, so exercise, antidepressants and counselling can fix it.

Paul Andrews, an evolutionary psychologist now at McMaster University…  noted that the physical and mental symptoms of depression appeared to form an organized system. There is anhedonia, the lack of pleasure or interest in most activities. There’s an increase in rumination, the obsessing over the source of one’s pain. There’s an increase in certain types of analytical ability. And there’s an uptick in REM sleep, a time when the brain consolidates memories.

However, for me, the fix was to get out of the terrible situation I was in, a teaching job in a very tough school.

If something is broken in your life, you need to bear down and mend it. In this view, the disordered and extreme thinking that accompanies depression, which can leave you feeling worthless and make you catastrophize your circumstances, is needed to punch through everyday positive illusions and focus you on your problems. In a study of 61 depressed subjects, 4 out of 5 reported at least one upside to their rumination, including self-insight, problem solving, and the prevention of future mistakes.

I suffer from migraines, which are bizarre episodes. They’re difficult to explain to people as they’re a whole-body response. Changing my lifestyle so I don’t get migraines is a micro-version of the kind of lifestyle changes you need to make to stave off depression.

These theories do cast some of our traditional responses to depression in a new light, however. If depression is a strategic response that we are programmed to carry out, consciously or unconsciously, does it make sense to try to suppress its symptoms through, say, the use of antidepressants? [Edward] Hagen [an anthropologist at Washington State University] describes antidepressants as painkillers, arguing that it would be unethical for a doctor to treat a broken ankle with Percocet and no cast. You need to fix the underlying problem.

I can’t imagine being on antidepressants for any more than a few weeks (as I was). They dull your mind, which allows you to cope with the world as it is, but don’t (in my experience) allow you lead a flourishing human life.

Even if depression evolved as a useful tool over the eons, that doesn’t make it useful today. We’ve evolved to crave sugar and fat, but that adaptation is mismatched with our modern environment of caloric abundance, leading to an epidemic of obesity. Depression could be a mismatched condition. Hagen concedes that for most of evolution, we lived with relatives and spent all day with people ready to intervene in our lives, so that episodes of depression might have led to quick solutions. Today, we’re isolated, and we move from city to city, engaging with people less invested in our reproductive fitness. So depressive signals may go unheeded and then compound, leading to consistent, severe dysfunction. A Finnish study found that as urbanization and modernization have increased over the last two centuries, so have suicide rates. That doesn’t mean depression is no longer functional (if indeed it ever was), just that in the modern world it may misfire more than we’d like.

Source: Nautilus

Meaningless work causes depression

As someone who has suffered in the past from depression, and still occasionally suffers from anxiety, I find this an interesting article:

If you are depressed and anxious, you are not a machine with malfunctioning parts. You are a human being with unmet needs. The only real way out of our epidemic of despair is for all of us, together, to begin to meet those human needs – for deep connection, to the things that really matter in life.

Meaningful work is important. Our neoliberal economy is removing much of this under the auspices of ‘efficiency’.

Source: The Guardian