Omega-3 Updates

It seems like omega-3 fatty acids are competing with vitamin D for "most famous nutrient" award this year. There has been so much research published this year on these nutrients that it's almost more confusing for the public.

There have been several newsworthy pieces on omega-3 fats lately that have generated enough email to my in-box that I think they are worth blogging about.

1) In this study - Plasma n-3 polyunsaturated fatty acids are negatively associated with obesity - published in the British Journal of Nutrition, researchers examined blood levels of omega-3 fats in 124 people of varying body mass index (BMI). They found that, in general, people with higher BMIs (those who weighed more) had lower levels of omega-3 that those with lower BMIs. Most of the questions I have received are from people who want to know if this studying is saying that taking more omega-3 will cause you to weight less. There is no data yet to support that. However, there are other profound health benefits of these fats that make including them in your diet or taking them in a supplement worthwhile. Keep in mind that an average serving of salmon can have 2 or more grams of omega-3 - so those in the very high fish intake group may have been getting levels well above those shown to be health-supportive.

2) A study (Long-chain omega-3 fatty acids, fish intake, and the risk of type 2 diabetes mellitus) that hit the news more recently followed the health of 195,204 US adults for 14 to 18 years. Part of what researchers tracked was intake of fish and other sources of essential fatty acids. During the course of the study, 9380 people developed type 2 diabetes. Intake of fish and other essential fats was not associated with a reduced risk for developing diabetes. Actually, the highest intakes of fish (5 times or more per week), were associated with a 20% INCREASED risk. The researchers called this "modest". I do not call that modest. There is other research indicating that in those with diabetes or at risk for diabetes high intakes of omega-3 may elevate blood sugars. I think that until we know more, we should caution people against high intakes if omega-3 fats, and encourage the modest intakes that are associated with so many health benefits.

3) This leads me to the final story on this topic. A new review published in the Journal of the American College of Cardiology looked at studies involving approximately 40,000 people. They concluded that overwhelming evidence suggests that for prevention of heart disease, everyone should take 500 mg per day of omega-3 fatty acids as EPA and DHA (eicosapentanoic acid and docosahexanoic acid - the omega-3s from fish). For those with a known risk for heart disease, they suggest a higher dose of 800 to 1000 mg/day is well-supported by research. To read more on this review, click here: Omega-3 review: Half a gram needed for heart benefits.

So the conclusions for now:
Omega-3 fatty acids are important for good health. They have been shown to support the health and development of the brain and the eye, and we know they modulate inflammation, benefit the skin, joints, hormone balance and more. It does not, however, appear that they help you lose weight - but you never know what future studies might show. Levels of 500 to 1000 mg are appropriate for those who are looking to prevent heart disease. Very high intakes seem to increase the risk for diabetes - so until we know more, go for moderation. My final added advice - if you are relying on fish as your main source of omega-3, please seek clean sources. Fatty fish like salmon and tuna are often contaminated with pesticides, herbicides, and heavy metals that accumulate in your body and are truly harmful. Here is a great list of fish rated by average mercury levels: NRDC Fish List

In Health,

Dr. Jacques