Vindicated

On my first day of medical school one of the first lectures we attended we were told that even though we would be studying and memorizing facts we should expect that everything would change and that in 20 years we would probably find out everything we had learned was no longer correct. I took that bit of wisdom to heart and I maintained a healthy skepticism of everything we were taught.

About six months in to medical school we were studying renal, kidney, physiology and the associated pathologic diseases.  One of the most important of these is hypertension or high blood pressure. The kidney in the process of filtering our blood is responsible for controlling how much water is excreted as well as maintenance of our electrolytes such as potassium and sodium.

According to our professor increased sodium intake in the form of table salt leads to water retention and therefore hypertension. According to our professor the main way to manage this was via sodium restriction. The study referenced basically showed that if a group of patients went on a severe restriction of sodium their blood pressure went down. Also if they took medication that depleted sodium it would have the same impact. The conclusion was that sodium intake caused high blood pressure.

To my critical mind the conclusion wasn't necessarily supported by the facts. Just because the blood pressure decreases in a person with hypertension when the sodium goes down didn't mean the sodium caused the problem in the first place. At the time in the mid 80's we didn't have a lot of medication and this was one of the primary treatment methods.

At the end of the lecture I approached the professor and stated my concern that the conclusion made wasn't necessarily supported. The professor looked at me like I was a complete idiot and said I was wrong and of course he was right. Unfortunately, the way I was spoken to discouraged me from confronting faculty in the future. I chose to keep my criticisms to myself. I can only assume other students of medicine or science must have experienced this as well and may have held back on their expresson of critical thinking which is vital to the advancement of science and medicine.

Over the years we have all learned of previous dogma that many years later was proven wrong. One recent major example had to do with cholesterol and heart disease. Decades ago when heart disease started increasing scientist looked at the blood vessels especially in the heart and saw atherosclerosis plaques blocking the blood flow. These plaques looked like cheese under the microscope and were indeed full of cholesterol.  The conclusion was that cholesterol caused heart disease. The result was a complete change of the American diet to low fat, low protein, high carbohydrate diets. Ironically these changes have had no benefit in managing heart disease and has caused a huge jump in diabetes. We now know that the food pyramid was wrong and it is OK to eat meat, eggs, butter, and milk.

The pharmaceutical industry is still focused on lowering our cholesterol but there are no studies showing benefit in otherwise healthy people and very limited benefit in those with heart disease. In fact what does help is advice any mother could give. Eat a balanced diet, fresh vegetables, get plenty of rest, and exercise regularly.

Now back to the original reason why I wrote this story. Yesterday I was reading time magazine and they quoted a scientific study that showed that dietary sodium intake in otherwise healthy people had no impact on high blood pressure. While i was glad to see this l can only guess it took 30 years to reverse this dogma because inquisitive critical thinkers were discouraged from questioning these ideas. In fact, I think it takes a great deal of courage to be willing to go against accepted opinions. When a courageous person is shot down early in their career we as a society potentially lose a great deal.

Fortunately, those who know me will confirm that despite the occasional episode of discouragement I remain eager to express my critical reviews of dogmatic ideas that aren't well supported by the facts. We should all remember to be patient and supportive of those who are willing to swim against the current for they may be the next one to discover the real answer to that which plagues us.