Thursday, March 26, 2009

Discussing the Latest Red Meat and Heart Disease Study

A study called Meat Intake and Mortality was released recently and has attained a great deal of media attention. The study found populations that most frequently consumed red meat and processed meat have higher death rates from cardiovascular disease and cancer than those who consumed less red meat and more white meat. Here are some important notes regarding the red meat finding:
  • The study mentioned red meat as a cause of colon cancer and said a vegetarian lifestyle is a healthier way to live. Two other studies were published around the same time frame. One found red meat to have no correlation to colon cancer. Another study found vegetarians in England to have the same death rate as meat eaters over a ten year period.
  • Meat Intake and Mortality is an observational study, as Dr. Michael Eades pointed out. Eades said that observational studies "can't be used to prove causation". It wasn't a controlled study, where all variables are under strict watch from professionals. The subjects were sent questionnaires which were to be filled out from their recollections and answered as best as possible. Could a dozen other variables have played roles?
  • The study found that subjects who smoked (past or present) and ate white meat or high amounts of red meat had lower death rates from cardiovascular disease than their non smoking counterparts. So, basically, if you eat mostly white meat or a lot of red meat (22 grams/1000 calories per day), you should pick up smoking to decrease your risk of dying from a heart attack. Do you consider that sound advice? 
These studies aren't useless, but they don't prove causation either. Studies that find associations between factors are precursors to controlled studies that can prove whether a causal relationship exists.

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