Previously, we discussed the question of Do Carbs Make You Crazy?, reviewed some literature to suggest that a bolus of sugar to a fasting person could certainly make some people crazy (or at least rather rotten-tempered), and yet MIT researchers suggest the same carby bolus will keep people sane with a nice happy squirt of serotonin. Personally I think the MIT advice to snack on marshmallows and pretzels for serenity's sake to be misguided, whereas I agree with the wise orthomolecular doctor from New York who told the young Mr. Ellsberg, suffering from insomnia, grandiosity, and bouts of suicidal depression, to cut out the coffee, alcohol, and sugar already.
(Music - Beastie Boys/Santigold Don't Play No Games That I Can't Win - right click in new tab)
We all agreed, I think, in the comments of the previous posts, that these studies are weakened by some lack of accounting for confounders (nutritional status, alcohol, sleep, insulin resistance, etc. etc. etc. etc.), and of course one can never just change carbohydrates - one has to alter another variable. AND of course I think inflammation and industrial food and micronutrient deficiencies cause or increase insulin resistance and violence and depression… so when one just examines blood glucose level and mood state, one is missing the electrified third rail, so to speak.
And I have to say, the state of the literature ain't that great. Among 15 papers I read for this series, there was one great review paper. Everything else was rather distractingly haphazard. And so we go to two more papers (thanks to Jamie Scott, Jackie, Ambimorph, and Zooko for helping me with the paper chase!): Daily Negative Mood Affects Fasting Glucose in Type 2 Diabetes and The impact of eating behavior on psychological symptoms typical of… (long title - it's about PCOS and blood glucose and mood).
The first paper is about a study following 206 people who kept daily food diaries, morning fasting blood sugar measurements, and daily mood records for 21 days. What is nice about this study is that the participants were phoned every night to get the data for that day. They were also paid $35 for the first week, $45 for the second week, and $55 for the third week, so motivation to keep up with the information gathering was pretty good.
After gathering all the data, there was really only one major finding. There were no real significant correlations between meals, daily mood, and blood glucose - except… if you had a crappy mood one day, you were more likely to have a higher fasting glucose on the morning of the next day. This makes sense if a crappy mood coincides with cortisol increasing, worsening glucose control that is reflected in the next morning's fasting glucose. It doesn't seem to say much about a correlation between carbohydrates and mood in diabetics. There was no relationship between glucose level on day one, for example, and mood on day two.
The second paper with the exhausting title is a little more interesting (well, sort of). This study looked at women with polycystic ovary syndrome (PCOS - known to coincide with insulin resistance), reactive hypoglycemia symptoms, mood, and diet. PCOS affects 10% of women, and between 50-70% of women with PCOS (particularly the lean ones) have symptoms of reactive hypoglycemia. That is, they have a "sugar crash" feeling about 90-120 minutes after a high carb meal. In this study, 24 women with PCOS, 299 controls, 47 self-reported women with symptoms of PCOS, and 92 men filled out an online survey.
Interestingly, 58% of the PCOS group reported having "binge and/or comfort eating" compared with 32% of the control women. More of the PCOS women were also reporting being on a "low-GI diet" - presumably at the advice of their doctors or nutritionists to help control PCOS symptoms. Of the participants, 53% were on no medicines, 13% were on contraception, 5% were on psych meds, 2.2% were on metformin, and 10% were on other meds (typically vitamins or allergy meds). 13% reported psychiatric issues (usually anxiety or depression), and 1.9% reported insulin resistance. The PCOS group was more likely than the controls to have mood or behavioral issues and to have reactive hypoglycemia symptoms.
In a subset of the study, 12 women with PCOS were matched with 12 healthy controls. The women with PCOS were, again, significantly more likely to have reactive hypoglycemia symptoms. Women with PCOS were more likely to have less energy, more tension, less happiness, and more behavioral symptoms associated with hypoglycemia. These differences remained significant after controlling for age, BMI, and "eating behavior."
So what do we find? Women with poor glucose control have, well, poor glucose control, and they have moods and fatigue to match, though underlying inflammation and hormonal badness could cause all of the above. And, not surprisingly, women with poor glucose control have more bingeing and emotional eating - again, perhaps a symptom and a cause wrapped all in one. There were not enough folks on the "low GI" diet to make any intelligible statistical conclusions.
Here's my conclusion. If you have PCOS or type II diabetes, do not eat 300 grams of carbohydrate a day. Don't do it. Keep it low, keep it nutrient rich*, keep it basic happy natural food. I'm guessing your moodiness and your glucose control will improve.
* my idea of nutrient rich and the USDA's idea of nutrient rich are rather different. I think bone marrow and grassfed beef liver are nutrient rich. They prefer skim milk and whole grains. You do the math.