Wednesday, February 29, 2012

Research Update: Red Meat And Risk Of Stroke

Red meat consumption and risk of stroke in Swedish men.  American Journal of Clinical Nutrition 2011: 94:417-21.

Objective:  The objective of this study was to examine the association between red meat consumption and risk of stroke in 40,291 Swedish men over a 10 year follow-up period.

Methods: All men filled out a 96 item food frequency questionnaire that assessed usual diet.  This enabled the researchers to compute total red meat, fresh red meat, and processed red meat consumption for the analysis.  Fresh red meat was considered minced pork, beef, or veal.  Processed red meat was considered sausage, hot dogs, salami, ham, and processed cold cuts.  Total red meat was the sum of fresh red meat and processed red meat.

Results: After 10 years of follow up, there were 2,409 new cases of stroke among these men.  Men who consumed more than 2 ounces of processed red meat per day had a 23% increased risk of stroke when compared to men consuming less than ¾ ounce of processed red meat per day. Fresh red meat was not associated with risk of stroke.  Total red meat was associated with a borderline significant 15% increased risk of stroke when comparing men who consumed the most red meat (greater than 5 ounces per day) to men who consumed the least (less than 2 ounces per day).

Discussion: A number of studies have recently shown that fresh red meat is not as strongly associated with risk of cardiovascular disease as once thought.  Processed red meat, on the other hand, is strongly associated with risk of heart disease and stroke.  It is believed that the high levels of nitrates and sodium in the processed red meat are the mechanism behind the increased risk. 

Take Home Message:  It seems like the problem with red meat largely lies in the processing.  I tell my clients to limit portions of red meat to once per week.  Choosing lean and fresh sources of red meat like filet mignon and lean hamburger is a good idea.   Strictly limit the processed red meats like bacon, sausage, hot dogs and fatty deli meats.  Keep in mind that red meat has also been associated with colon cancer incidence so don’t go overboard with the red meat consumption.


Pedro Sun CSCS said...

Dr. Halton

Do you know of any sound long term studies looking at societies that have consume a high red meat diet (3-4x/week)and chronic disease risk? I would love to see more studies in which they follow people's dietary habits/exercise habits. I feel this must be extremely hard and costly. The studies I know of so far are the 7th day adventist folk, and that's about it. Thanks for your help in this

Pedro Sun CSCS

Dr. Thomas Halton said...

Hey Pedro,
Ecological studies are great for hypothesis generation, but it is very difficult to control confounding with them. The best bet is a long term cohort study since a randomized trial for illnesses with long development periods is not feasible. A great study in the Nurses' Health cohort and the Health Professional Follow-up just came out on red meat and all cause mortality. Here's the reference: Pan, An, et al. Red meat consumption and mortality. Archives of Internal Medicine, published online March 12, 2012. This will be a great start for you with a lot of references to earlier studies.

Pedro Sun CSCS said...

You know what's funny is when I wrote my first comment, the next day this study came out that you just hooked me up with. The paleo world was extremely upset w/ this study. Thanks for the information.