New research is casting doubt on the idea that red meat increases your risk of heart disease.
Researchers at Harvard pooled data from 20 studies to see if different types of red meat — unprocessed versus processed — had different effects on the risk of heart disease, diabetes and stroke. Unprocessed red meat was defined as beef, hamburger, pork, lamb or game. Processed meat included bacon, salami, sausage and luncheon meats — any type of meat preserved by smoking, curing, salting or addition of preservatives.
Data on stroke were too limited for the researchers to draw firm conclusions, but here's what they found regarding heart disease and diabetes:
- Red meat. About 100 grams (roughly the size of a deck of cards) a day was not associated with a higher risk for heart disease and only a slightly higher (but not statistically significant) risk for diabetes.
- Processed red meat. About 50 grams (two-thirds the size of a deck of cards) a day was associated with a 42 percent higher risk for heart disease and a 19 percent higher risk for diabetes.
- Total red meat. A daily total of 100 grams of processed and unprocessed red meat was not associated with risk for heart disease. However, it was associated with a 12 percent higher risk for diabetes.
What is it about processed red meat that seems to increase disease risk? Surprisingly, processed meat has about the same amount of saturated fat as unprocessed red meat — and actually contains less cholesterol and iron. Could it be other ingredients such as sodium? On average, processed meat has about 622 milligrams of sodium in about 2 ounces, while unprocessed meat has 155 milligrams. Researchers hypothesized that salt's effect on blood pressure weakens vessels. What about nitrates added to processed meats? Nitrate preservatives may also damage vessels, reduce insulin secretion and impair control of blood glucose — which may increase risk for heart disease and diabetes.
Should you run out and order a slab of beef? No. For one thing, the studies reviewed had a number of limitations. Additional randomized, controlled studies will be needed to confirm the findings. Keep in mind too that the serving sizes used were quite small — larger servings may have different effects.
I plan to stick with my mostly plant-based diet and keep red meat as an occasional indulgence. And I'll definitely stick to lighter lunch fare in place of subs loaded with processed meat.
How about you?
Jun. 04, 2010