- Mood Changes
- Tender Breasts
- Increased Appetite
- Feeling Bloated
- Gaining Weight
Wait, don’t answer now, there’s something I want to tell you first.
When you read something interesting on the internet, don’t run off and write a lazy, potentially dangerous info page designed to scare people. And if you do decide to write a three line shock piece, at least try and be responsible with your headlines! This is precicely what News24 did NOT do when they published this page entitled “The Pill Makes You Stupid. Fact!”. This “article” is so short that I will reproduce it here:
A recent study published in the journal Brain Research reveals that the effect of the oral contraceptive on the brain is likely to be extensive.
The report found that our faithful pilletjie has structural effects on parts of the brain that controls higher-order cognitive activities, suggesting that a woman taking it may not be herself – or is herself, on steroids.
Shocked? So are we!
As a regular user of the Pill I thought I had better check this out. So I followed the link provided by News24 for the study and I found myself at the Scientific American website. I like the SciAm website and was quite happy to read their excellent article about how the pill makes women stupid. What I found, however, made me pretty upset. It seems as though the person at News24 responsible for putting together the shock article above had not bothered to read more than the first two paragraphs of the SciAm article; which she copied almost word for word.
She certainly didn’t read as far as the sentence which states:
Again, we do not know whether this increased gray matter translates into better or worse performance
Well, I did. In fact, I read the SciAm article twice AND read the abstract of the paper (Menstrual cycle and hormonal contraceptive use modulate human brain structure, Pletzer. B et al, Brain Research 12 August 2010) and I did not come to the conclusion that The pill makes women stupid. Fact! I came to a very different conclusion.
Before I go any further let me give you the executive overview of the findings of this study (as I understand it): fMRI scans of the brains of 14 women using the pill were compared to those of 14 men and 14 women not using the pill and they found that women using hormonal contraceptives showed “significantly larger prefrontal cortices, pre- and post central gyri, parahippocampal and fusiform gyri and temporal regions” than naturally cycling women.
Wait! Wait! Don’t run away yet, I will explain what each of those regions of the brain does.
The prefrontal cortex is the front part of the brain and it is responsible for executive functions: mediating conflicting thoughts, deciding between right and wrong, and governing social control. This is one important little squishy bit. A sixfold increase in the size of the prefrontal cortex over the past five million years of hominid evolution has led scientists to believe that there is significant selection pressure favoring it’s continued growth.
The following two images represent the lateral and medial surfaces of the cerebral cortex, basically the inside and outside of your grey matter. The cerebral cortex is folded in on itself to allow for more processing power in a smaller space and at a higher speed. The ridges formed by the folds are called gyri.
The primary motor cortex is located in the precentral gyrus which controls voluntary movement.
The postcentral gyrus receives sensory information from the skin and muscles.
The parahippocampal gyrus is important for the encoding and retrieval of memories.
The role of the fusiform gyrus is disputed, but it does seem to play a role in the recognition of colours, faces, words and numbers.
Finally, the temporal lobe is important for auditory perception, processing semantics in speech and vision, and it plays a key role in the formation of long term memories.
It would be a very bad thing for you to suffer any damage to any of these parts of your brain. And a study which investigates a potentially harmful effect to all of them should be a rigorous exercise. That’s where I am a little concerned about the findings of the Pletzer study.
My main concern is the size of the study; 42 participants is a very small number. When you are putting a study together you need to make sure that you have enough participants to ensure a statistically significant result. The more people you have, the less weight an “outlier” will have on the study. A general rule of thumb is that you should have 20 times as many subjects as variables in your study. I do not have access to the full text of the paper, but SciAm points out quite a few variables which do not seem to have been accounted for:
- The authors did not examine levels of circulating hormones in the male and female subjects.
- The hormonal contraceptives were all considered in a single group instead of accounting for the different ratios in levels of estrogen and progesterones in birth control pills.
Those are two broad categories of variables which were not accounted for and they are not the only procedural slip ups in the paper. Other serious errors are:
- The authors did not perform behavioral or cognitive tests of their subjects. Such tests may account for the meaning or functional consequences of the changes.
- Birth Control pills keep the natural levels of hormones low, this confounds the data. The lower levels of natural hormones might account for the structural changes and the hormonal contraceptives might be innocent.
Despite it’s flaws, however, Pletzer’s study does reinforce the fact that we need to carefully consider the effects of the drugs we take. I would love to see more research into this subject because it is extremely important. For now, I will continue to take the advice of my doctor and I will not allow lazy journalism and sensation seeking headline writing to dictate the medical decisions I make for my body.
P.S. In case you are wondering, “Stupidity” is the answer to the mini-quiz at the beginning of this article.