Dr. Roach: Grass-fed beef not best source of omega-3 fatty acid

Keith Roach
To Your Health
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Dear Dr. Roach: I have a question about omega-3 fatty acid intake, either through fish consumption or by dietary supplements like fish oil. Apparently, many American diets are deficient in omega-3 fatty acids. One possible reason is that most American beef cattle are fed primarily on corn rather than their natural diet of grass, leading to meat that is low in omega-3. Omega-3 fatty acids are important for brain health. I’m wondering specifically if there might be a correlation between these dietary-induced low omega-3 levels and our epidemic of dementia and Alzheimer’s disease.

— A.J.S.

Dear A.J.S.: Grass-fed beef has more omega-3 oils than grain-fed beef. However, the amount, even in grass-fed beef, is still fairly small compared with other sources. A standard serving of grass-fed top sirloin beef has about 65 mg of omega-3 fats, about 50% more than grain-fed. There is no “official” recommended intake level for omega-3 fatty acids, but the Institute of Medicine noted that healthy adults take in 1,100 (women) and 1,600 (men) per day.

Grass-fed beef isn’t really a good source to get there. It would take 4.5 pounds of grass-fed beef daily to achieve the goal for men — not a healthy choice. A single serving of salmon has more than 1,800 mg. More importantly, although the data remain mixed, most studies show changing a diet from red-meat-based to plant- and fish-based leads to decreased risk of heart disease and stroke.

Studies on populations have shown that high dietary intake of omega-3 fatty acids is associated with a reduced risk of developing dementia, as well as a reduction in high blood pressure and heart disease. However, clinical studies using omega-3 supplements to treat or prevent dementia such as Alzheimer’s have shown no benefit or at most a small benefit.

Dr. Keith Roach

Dear Dr. Roach: I am a heathy 92-year-old woman. I eat a lot of vegetables, fruit and seafood. My doctor said a 20-year-old would be envious of my bloodwork. I exercise four days a week with slow jogging, stretching and weightlifting. My problem is that my blood pressure is usually around 135/70, sometimes slightly higher or lower. I am concerned that it is too high, but my doctor is pleased with that number. What is your opinion?

— R.Y.

Dear R.Y: A result of 135/70 in a healthy person with no other risk factors is usually not an indication for medication treatment. However, just being 92 years old is a risk for heart disease, and trying to reduce risk where you can is a good idea.

I agree with your doctor that your blood pressure does not need treatment beyond the healthy lifestyle you’ve adopted, but your desires matter. If you really wanted to treat it, I would consider an extremely low dose of one of the safest blood pressure medicines. Any benefit from medication would be small.

Readers may email questions to ToYourGoodHealth@med.cornell.edu.

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