Seafood may Affect Mood During Pregnancy

New evidence suggests that a diet rich in omega-3 fatty acids from seafood may be associated with mood-altering affects in pregnant women.

The study included 9,960 pregnant women in Britain who were 32 weeks pregnant. They each completed questionnaires about their mood and seafood intake during 1991 and 1992.

The researchers found that women who ate no seafood were 50 percent more likely to experience depressive symptoms than those who ate at least three servings of seafood (about 1.5 grams of omega-3 fatty acids) per week. 

In the journal Epidemiology, the author concluded that “these observational data support an association between low omega-3 intake from seafood and increased risk of high levels of depressive symptoms during pregnancy. Eating seafood during pregnancy may have beneficial effects on mental well-being.”

However, additional research is needed to confirm these findings. The authors also caution against eating too much seafood during pregnancy, as it may be contaminated with harmful substances such as dioxins, methylmercury and polychlorinated biphenyls (PCBs)

For more information about depression during pregnancy, please visit Natural Standard’s Medical Conditions database.

Comments

[Kara]

It seems a little odd to me that researchers would conclude that eating seafood during pregnancy may have beneficial effects on well-being and then caution against eating too much seafood during pregnancy. Why couldn't pregnant women just take the supplement and be safe?

[P.K.]

I can think of one con-founder to this study. Seafood is expensive. Perhaps people with less financial means were eating less seafood than people with more financial means. Some consider poverty one risk factor for depression or low mood. I would like to see if this relationship mediated the correlation between seafood and depression. Did the study measure economic status?

[Mary S.]

More than just seafood is rich in omega-3. Flaxseed and walnuts are quite high. Also, seafood has varying amounts. For example, salmon has more omega-3 than shrimp. I think, but I’m not sure, that even salmon ranges in amount of omega-3. Some species have more than others. I wonder if the way fish is prepared impacts omega-3 content, and whether there is something people can eat with the fish in order to increase absorption of omega-3.

[T. Miller]

Does omega-3 improve mood only among pregnant women or everyone? Or does pregnancy enhance its mood-improving capacity? Or perhaps it is more effective for women than men. If any of these scenarios are true, perhaps the efficacy of omega-3 is enhanced by certain hormones. Or omega-3 changes female hormones in such a way that they better regulate mood.

[Amanda]

After looking at the conclusion of the study, it was not statistically significant between women who ate fish and who did not eat fish. There may be some benefit, but i don't think it's from the fish alone. There are other factors that may influence whether women may be predispose to depression or not, such as the support from husband and family, work-related stress, or maybe the women have some complications with their pregnancies, etc. Also, the outcomes were measured with questionnaires, which may be interpreted differently among the women. I would still eat fish because I love it, but if a woman doesn't like to eat fish, i think it's fine. They can get the benefit of omega-3 and other vitamins from other food sources, such as vegetables, meat, etc.

[Ron]

It is very interesting that omega-3 fatty acids from seafood may have a positive effect on mood in pregnant women. But I agree it seems like a better idea to try and get the omega-3 fatty acids from alternative sources during pregnancy just to avoid any potential dangerous exposure to mercury or other harmful chemicals.

[Jamie]

According to the Environmental Protection Agency, pregnant women should only eat up to 12 ounces (2 average meals) a week of a variety of fish and shellfish that are lower in mercury. Five of the most commonly eaten fish that are low in mercury are shrimp, canned light tuna, salmon, pollock and catfish. Albacore tuna has more mercury than canned light tuna, so a pregnant woman may eat up to 6 ounces (one average meal) of albacore tuna per week. Pregnant women should not eat shark, swordfish, king mackerel or tilefish because they contain high levels of mercury.

[Jess]

According to the NS monograph on omega-3, moderate and severe depression in the general population has been associated with low levels of omega-3. There is also a correlation with omega-3 levels and the the severity. Unfortunately, the reason for this still remains obscure.

[Grant]

My mother currently takes omega-3 for mood after a man at a natural food store recommended it to her. She says she can tell a big difference when she takes it. I would also be curious to see studies on its mood effects on non-pregnant women and on men. I wonder if it would have similar effects on both men and women.

[Tom]

I would still be careful eating fish during pregnancy. Methylmercury has been shown to accumulate in fish meat, and methylmercury may be harmful in pregnant/nursing women. An improvement in mood could be a trade off.

[barry]

P.K.,

I read in the abstract that the statistical analysis took social and lifestyle factors into account. Unfortunately, I don’t know how heavily this means they took it into account. However, it shows strength in the study that the researchers were cognoscente of this.

[Electronic Medical Records]

This is a rather interesting piece of information to me. I had never heard something like this. Indeed researchers are coming up with such new findings every day.

[Zoey F.]

Interesting study on the effects of omega-3 fatty acids during pregnancy. The researchers found that women who ate at least three servings of seafood a wee, were less likely to have depressive mood episodes. On the other hand, doctors currently advise pregnant women to limit their seafood intake to two servings a week. So there is a discrepancy there. I wonder if, instead of eating actual seafood, pregnant women could take omega-3 fatty acid daily supplements to achieve the same effect.

[Tilly J]

Interesting. I tend to think there's some sort of hormonal connection, too, since hormones certainly send pregnant women on a roller coaster. There was a study reported in JAMA two or three years ago that indicated that women who are depressed and go off their medication during pregnancy are highly predisposed to a relapse during pregnancy.

Another thing: I'm curious about why the data for this study was taken from so far back (1991, 1992). Were these women asked to think that far back? Data must have been collected for some other purpose then and now is being re-examined? Interesting also that back then, the mercury scare from fish hadn't reared its head yet. . .

[Dan]

Zoey, you make a very good point. The researchers concluded that pregnant women who eat seafood may experience beneficial effects on mental well-being, but isn't that benefit just from the omega-3? I wonder if there is something else in the seafood that adds to the benefit. If it is just the omega-3, wouldn't it be safer for the mothers to be on omega-3 supplements? The researchers said they calculated the amount of omega-3 the pregnant women got from the seafood. I want to know if they were able to determine at what dose of omega-3 did they started seeing the beneficial effects or if was the case of the more they took the more benefits they experienced.

[Nikki J]

I agree with Kara on the notion that it would be much safer to take a supplement containing omega-3 fatty acid rather than consuming seafood. The authors of the study mentioned that high consumption of seafood could increase the risk of ingesting methylmercury and other contaminants. Safety should be a priority especially with pregnant women. On that note, supplements and vitamins products for pregnant patients should be strictly regulated to ensure quality and safety.

[Gayle Branson, PharmD]

Experts can agree that the ingredient omega-3 fatty acid found in seafood is essential to brain function.
Interestingly enough, I just saw that an article that was published last Friday in the Lancet that concluded that women who eat seafood while pregnant may be boosting their children’s IQs in the process.

The flip-side is that the metal found in seafood can cause damage to the nervous system, particularly to that of a developing fetus. So, it may be best for moms-to-be to seek out other sources of omega-3, rather than risk damage to their children.

[Kelly]

I would love to see an alternate therapy for depression during pregnancy and lactation. Most drug therapies out there affect the fetus and are considered pregnancy category C – meaning that the fetus is at risk of reversible damage. Thus, mothers have to face a difficult decision when trying to decide whether or not to treat their depression during pregnancy. This dietary supplement would offer a safe treatment option for pregnant women suffering from depression.

[A]

I agree that one thing to watch out for is the methylmercury level. Pregnant women especially should be cautious of how much mercury they are consuming since it can be harmful to the fetus. Also, since mercury levels accumulate in the body, the women who are trying to get pregnant should try to avoid certain types of fish, especially the ones that are high in methylmercury (i.e. swordfish).

[M. Scott]

I think that it may not be that simple to just tell pregnant women to eat more seafood during pregnancy. It is expensive, as P.K. pointed out, and supplements can also be costly, not to mention huge and cumbersome to swallow. Studies should be done to evaluate whether omega-3 fatty acids from other sources also have a positive effect on depressive symptoms to improve compliance to the diet and avoid the worry of toxins.

Another area for further study should be the benefit on depression in other populations. Sometimes pregnancy can be a challenging population because of fluctuation hormones and mood. If pregnancy remains a focus, then it may be helpful to establish a baseline in the depressed patient before she becomes pregnant.

[Mart Inni]

Let's get one thing clear, this article is not condoning eating sushi during pregnancy. And instead of risking methylmercury or PCB ingestion, why not just advise pregnant women to take omega-3 supplementation? I am sure that seafood has multiple health benefits during pregnancy, but depending on where in the country you live and where the fish comes from, it is a risky thing to recommend for pregnant women, in my opinion. I wonder if this study reported any adverse health effects on the fetus in any of the women who consumed seafood during the trial?

[JB]

Omega-3 fatty acid is very important during pregnancy for the proper neural and retinal development of the fetus. According to the Natural Standard monograph and epocrates database, research shows that taking the recommended amounts of DHA and EPA by eating fish or fish oil supplements may reduce the risk of death, heart attack and strokes in people with heart disease. They may also prevent the arteries from clogging up with atherosclerotic plaques. However, high doses may have harmful effects, such as an increased risk of bleeding. According to the FDA, fish that have higher methymercury levels, such as shark, swordfish and king mackerel, should be avoided, as they can harm the fetus.

[bg]

New technology and research is finding ways to incorporate omega-3 fatty acid into our foods. For example, omega-3 eggs, milk and cheese contain higher amounts of omega-3 than conventional eggs. Furthermore, chickens and cows that are fed flax (a great alternative source of omega-3 versus fish) in their meals and are then consumed by humans are another way to supplement a pregnant woman's diet with omega-3. Fish oil is also being incorporated into other products, such as margarine, breads and juices. This technology keeps the fish oil from going bad and surpasses any negative side effect from eating fish during pregnancy.

[Mike]

That's amazing that a supplement for high blood pressure, such as omega 3 fatty acid, can have a positive effect on mood. In pregnant women, this is especially important since so many drugs are off-limits during that critical time in a woman and child's life. It would be nice to find out if this can also be applied to the general population. Also, it would be interesting to know if the pregnant women that did the study experienced changes in blood pressure.

[mj]

I also find it interesting that nowhere in this study does it mention safety of the baby. As a woman, if I were to become pregnant I would like to think I would start to think of my baby’s health and well being right alongside my own. While I understand the article is not talking about eating mercury-filled fish, even supplements can be harmful, so it would be interesting to hear of the research in respect to the safety of the fetus.

[Rachel]

It is important for an expectant mother to eat a healthy diet. Unless she has a specific health problem (such as diabetes mellitus or heart disease) common sense nutritional advice should be followed: balancing carbohydrates, fat, and proteins and eating a variety of foods, including dairy products and several fruits and vegetables, daily.

Oils from salmon, trout, tuna, herring, sardine, mackerel, eggs and some chicken contain omega-3 fatty acids that are needed to build brain tissue. Intake of omega-3 fatty acids during pregnancy may provide nutrition for proper brain and retina development of the fetus.

However, large fish, such as tuna and swordfish, may contain high levels of mercury. Mercury can be toxic to the fetus and the mother. Eating omega-3 rich fish two or three times a week is recommended (no more than 12 ounces/week of low-mercury fish should be consumed). Omega-3 fatty acids are also present in walnuts, flaxseed and seaweed.

[Mike]

This finding on omega-3 and depression during pregnancy isn’t all that surprising. There have been numerous studies implicating that omega-3 may have positive effects in the treatment and prevention of depression. Omega-3 seems to have some sort of neuroprotective effect, but the exact mechanism by which it may do this is still unclear.

One thing to note, as one of the bloggers pointed out, is to watch for the mercury content in large, open-water fish, such as tuna, swordfish and mackerel. Although there seems to be a correlation with seafood high in omega-3 and reduced risk of depression during pregnancy, the mercury content in most of these animals is too much of a risk to recommend taking on a daily basis. A much safer alternative would be to take fish oil capsules.

[Jeremy D]

These results are very interesting. It is already well-known that diet is strongly linked to hormonal fluctuations in women. Does this information apply to the general population? If the results could be replicated, it could provide insight on the development of depressive symptoms.

Also, is the effect similar post-partum? Post-partum depression seems to be a huge mental health hazard affecting quality of life in many new mothers.

However I am always reluctant to spread data such as this because many people interpret this as an isolated part of the diet is more important than the other. The bottom line is that our diets must be complete all the time. There seems to be a response when studies such as this are published, and for the next month or so after publication, every pregnant woman in the grocery store is waiting for a cold cut of salmon.

There is an abundance of literature in support of eating a meal with seafood two to three times a week. If this can be done instead of loading up on fish in our diets during pregnancy, I think the effects would be similar. Being a big fan of seafood myself, I am looking forward additional data on this topic.

[tisane]

Fish and shellfish can be an important part of a balanced diet during pregnancy. They are a good source of high-quality protein, healthy omega-3 fatty acids and other nutrients, and are low in saturated fat.

[Pregnant]

I've been taking my omegas and am still in a crappy mood.

[5 months pregnant]

During the 5th month of pregnancy, the skin on your belly is stretching, tightening and itching. A good moisturizing cream hydrates your skin and can relieve the itching, but it fails to prevent or eliminate stretch marks.

[Dana Greene]

Some good points. A good friend of mine who is a complete fish fiend told me to stay away from swordfish and mackerel because of the mercury content. To be honest, I'm not that bothered about that, but I do eat a considerable amount of tuna. Should i completely cut it out? I'm slightly concerned, as i just found out I'm pregnant again.