mind/body » The Thinking Meat Project

Loneliness and blood pressure

Mar 182010

This story from Science Daily describes an interesting bit of body/mind research. In a group of 229 people between the ages of 50 and 68, those who perceived themselves as lonely showed an increase in blood pressure over the course of the study compared to those who did not. Other physical and demographic factors were controlled for, and depression and stress alone couldn’t account for the increase. The researchers used a questionnaire to determine whether the participants perceived themselves as lonely, but it’s not clear from this article whether they answered the questions only at the beginning of the study or at different points throughout. (It evidently took at least a year for the increase to appear, and it would be interesting to know if feeling less lonely later in the study might have had any effect on blood pressure.)

It will be interesting to see if anyone follows up to see how general this finding is and what’s behind it. This article suggests that the increase in blood pressure might be linked to anxiety about relationships, in particular an unpleasant stew of feelings involving simultaneous desire to connect and fear of connecting.

I liked the reminder that people who have only a small circle of friends are not necessarily lonely; for some people, a few deep relationships are all they need. However much companionship people need to keep from feeling lonely, maybe it pays to cultivate those connections as much as possible for physiological as well as psychological reasons.

Chocolate and stress

Being human 2 Responses »

Nov 132009

You may have suspected it all along, but researchers have found more evidence that chocolate can be good for you. Eating a small amount of dark chocolate every day for two weeks appears to change the metabolism of highly stressed people for the better. In a small sample of volunteers, eating 1.4 ounces a day of dark chocolate (it didn’t say how dark) reduced levels of cortisol and also lessened stress-related differences in metabolism. This article from Science Daily has a little more information.

The article itself is:
Metabolic Effects of Dark Chocolate Consumption on Energy, Gut Microbiota, and Stress-Related Metabolism in Free-Living Subjects, Francois-Pierre J. Martin, Serge Rezzi, Emma Per-Trepat, Beate Kamlage, Sebastiano Collino, Edgar Leibold, Jürgen Kastler, Dietrich Rein, Laurent B. Fay, and Sunil Kochhar. Journal of Proteome Research, Article ASAP; Published online October 7, 2009. DOI: 10.1021/pr900607v

Mediterranean diet and depression

Brain health, Psychology Comments Off

Oct 142009

A recent study of nearly 11,000 people indicates that following the so-called Mediterranean diet, which is high in monounsaturated fatty acids, fish, and plants (e.g., veggies, fruits, whole grains), can lower the risk of developing depression. Those who most closely followed the eating patterns of this diet were 30% less likely to develop depression over a 4.4-year period. This press release from EurekAlert gives the details. It’s not clear in any detail why this diet should have this effect. It could well be a synergistic effect of the combination of all the different components of the diet, rather than arising from the presence of any particular nutrient or food. And of course there are plenty of other health benefits of the Mediterranean diet.

While I’m on the soapbox here, I will mention that I’ve been reading about omega-3 and omega-6 fatty acids and health. The typical American diet contains far more omega-6 than omega-3 fatty acids, and the evidence so far suggests that this is deleterious to health in a number of ways. In particular, a more balanced intake of omega-3 and omega-6 might be useful in treating depression. If you’re curious, you can check out the Linus Pauling Institute’s Essential Fatty Acids page for more information. Also, several good books about omega-3 fatty acids and health are available, many with recipes; check your local library. [I'm reading The Ultimate Omega-3 Diet: Maximize the Power of Omega-3s to Supercharge Your Health, Battle Inflammation, and Keep Your Mind Sharp by Evelyn Tribole (very clearly written, includes recipes and suggestions for modifying existing recipes). Next on my list is The Queen of Fats: Why Omega-3s Were Removed from the Western Diet and What We Can Do to Replace Them by Susan Allport, which provides more historical context as well as dietary suggestions.]

Reading your own body language

Psychology 1 Response »

Oct 052009

Sitting up straight might boost your confidence in your own thoughts, according to a recent study. Your mother may have told you to sit up straight so that you presented a better appearance to others, but your posture could also be sending a message to yourself.

When volunteers were asked to write down their own positive and negative qualities with respect to a professional job and then asked to rate themselves as future professionals, their judgements on the two tasks were much more likely to coincide when they were sitting up straight with their chests out than when they were slouched down in their seats. This is interpreted as indicating that they gave more credence to their own thoughts when they were sitting up straight. I wonder how this would play out in something like cognitive-behavioral therapy, where you consciously try to change your own thoughts. Would it help to sit up straight in a confident posture when you are trying to reshape your mental landscape? On the other hand, I suppose you might want to avoid sitting confidently upright if you’re down on yourself.

You can read more in this article at Science Daily or in the paper itself: Body posture effects on self-evaluation: A self-validation approach, by Pablo Briñol, Richard E. Petty, Benjamin Wagner. European Journal of Social Psychology, October 2009, p. 1053-1064. (Link goes to the abstract.)

Genes, environment, and depression

Brain and mind, Male/female Comments Off

Nov 292007

This press release from Duke has some surprising news about a common variant of a gene that affects the availability of serotonin in the brain. Women who had experienced significant stress at some time in their lives and carried a shorter form of the gene showed more signs of depression than women who had the longer variant or were not stressed, but for men it was the long variant that was associated with more symptoms of depression, and the short variant was linked to fewer symptoms. The two sources of stress the study looked at were growing up poor, or caring for someone with Alzheimer’s disease or another form of advanced dementia. (I.e., they didn’t necessarily have to be current stressors.) I’m assuming the gene in question is SLC6A4, which encodes for the serotonin transporter (SERT) protein. (If you’ve heard earlier news about a gene related to serotonin transport being linked with depression, that’s the one.) This story gives an interesting twist to the fact that genes by themselves do not tell the whole story of who we are and how we work; environmental factors are also part of the story.

Mirror neuron news

Brain and mind Comments Off

Jul 172007

Mirror neurons are hot these days, and here’s a mirror neuron story with a twist. You probably know that you don’t need to do something yourself to activate the relevant motor pathways in your brain; just watching another person perform a physical motion is enough to get your neurons going, mirroring the activity you see. How does the brain respond, though, in people who are physically incapable of making the moves they’re seeing others make? It turns out that their brains react in ways that capture the intent of the motion, even if they can’t mimic the actual motion itself. A recent study looked at 16 normal subjects and 2 aplasic subjects (born with no arms or hands). The subjects’ brains were scanned with fMRI while they watched a video of hands doing various handy things. When the hands in the video reached for a cup, the brains of the normal subjects showed activity in the parts of their brains involved in holding a cup. However, the brains of the aplasic subjects showed activity in the motor pathways responsible for moving their feet, indicating that they were mirroring the fact of cup-moving (which they can do with their feet) rather than the specific method of cup-moving. This article from Science Now has more information.

Spring fever!

Brain and mind Comments Off

Mar 292007

We’ve had a wave of unusually warm weather here over the past couple of weeks; the early spring flowers are in full bloom and the trees are starting to show their first green. It’s safe to say that spring has arrived. (Time to see if my wireless signal is strong enough out on the patio to work out there…) This article from Scientific American Mind talks about a possible biochemical basis for the physical manifestations of springtime in humans known collectively as spring fever. Although the phenomenon is not as obvious now as it was in earlier centuries, the number of human births shows a peaks in March, hinting at a peak of sexual activity in June (which is when luteinizing hormone production, linked to reproductive functioning in both sexes, also peaks). It’s not clear yet what causes this in humans; in other mammals, similar changes are triggered by the changing length of daylight.

There’s a little bit in the article about SAD (seasonal affective disorder) and how day length affects that. (Incidentally, I wrote this essay a year and a half ago that covers some research into the possible adaptive value of SAD.) I hadn’t realized that it’s the increase in morning daylight that is most important for driving off the winter blues; someone’s found that on the western edges of time zones, where the sun rises later, there’s more depression. Indiana is on the western edge of a time zone, and it’s always a big deal to me when, in late January, the sun here starts rising before 8am. The difference is mostly symbolic, but it matters to me to turn that particular corner. (This is one reason, by the way, that Daylight Saving Time (DST) makes less sense in Indiana; we tend to have darker mornings and lighter evenings anyway. There’s also a fundamental lunacy to DST that I will not go into here, but I’m generally willing to expound on the subject indefinitely for anyone who cares to listen.) Going clear back to an 8am sunrise when DST started in March this year was disheartening, to say the least. (See this article from the Los Angeles Times for more about DST and SAD.)

Why it’s so hard to be a higher primate

Psychology Comments Off

Feb 272007

Here’s an article from Science Daily about Robert Sapolsky’s research into primate behavior and stress. Sapolsky, a neuroscientist at Stanford, has written an excellent book about how humans respond to stress (Why zebras don’t get ulcers), and this article sums up some of his material on how our fight-or-flight response works against us when we’re reacting to psychological rather than physical threats. Basically his point is that while we’ve eliminated or reduced many of the dangers that used to threaten us, our lives haven’t gotten any easier because we’re putting our energy into interacting with each other, often in stressful ways. This article provides a nice overview of some of the things we know about stress and its effects on health and happiness.

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