Mood is a matter of more than mere chemistry ... but there's ample evidence that nutrition can affect the way we feel.

The results of a new epidemiological study and two new clinical trials support prior findings, most of which link increased intake of omega-3s to reduced risk of depression.

In fact, an expert panel of the American Psychiatric Association concluded in 2007 that adequate intake of omega-3s may help people maintain a good mood. For more on that, see “Top Psych Panel Says Omega-3s Deter Depression, Bipolar Disorder”.

UNC study finds omega-3s lighten women’s mood, but not men's

Researchers from Chicago’s Feinberg School of Medicine, the University of North Carolina, and the University of California

Key Points U.S. epidemiological study finds a 25-34 percent drop in depressive symptoms among women who consume higher levels of omega-3s. Canadian pilot clinical trial finds omega-3 EPA superior to placebo for women with mild depression. Anglo-Iranian pilot clinical trial finds omega-3 EPA as effective as Prozac.

joined to conduct an epidemiological study among 3,317 African-American and Caucasian men and women (Colangelo LA et al. 2009).

The average age of the participants at the start of the study was 35.

The researchers, led by Laura Colangelo, compared the participants’ reported dietary intakes of fish and long-chain omega-3s from fish oil (EPA and DHA) to the symptoms of depression measured using a standard test (Center for Epidemiological Studies Depression Scale).

Dr. Colangelo and her team reported that, for the population as a whole, higher intake of EPA, DHA, and EPA plus DHA were associated with a reduced risk of depressive symptoms after ten years.

Women showed more benefit, with those reporting highest intakes of fish reporting 25 percent less depressive symptoms.

Among women, the highest estimated intakes of EPA, DHA, and EPA plus DHA — based on the amounts and kinds of fish they reported eating — were associated with a 34, 34, and 29 percent reduction in risk, compared to women with the lowest average intakes.

However, the male participants did not report the same benefits. This could be due to differences in how men and women regulate mood. See “Women’s Mood-Control System May Differ from Men’s”.

The researchers noted that a study with rats suggested that omega-3s may increase dopamine levels, and thereby boost mood, while another mechanism may be linked to inflammation, which omega-3s tend to reduce or moderate.

As they wrote, “Our results are consistent with … other epidemiologic studies that have examined the association of fish intake or dietary omega-3s with depressive disorders or mental disorders. In addition, several small, randomized, double-blind trials found that adjunctive treatment with omega-3s improved depression.” (Colangelo LA et al. 2009)

Canadian clinical trial finds mood benefits

Researchers at Quebec’s Université Laval conducted a small placebo-controlled clinical trial in menopausal women.

The results, according to a Université Laval press release, “present the first evidence that omega-3 supplements are effective for treating common menopause-related mental health problems,” and show that “Omega-3s ease ...

A few years ago, the U.S. FDA approved a qualified health claim for animal foods that contain long-chain omega-3s:

“Supportive but not conclusive research shows that consumption of EPA and DHA omega-3 fatty acids may reduce the risk of coronary heart disease.” (FDA 2004)

In 2000, FDA announced a similar qualified health claim for dietary supplements (i.e., fish or algae oil) containing EPA and DHA.

Fish, shellfish, algae, and eggs from chickens fed DHA are the only foods that provide substantial amounts of EPA and/or DHA.

Key Points Finding in mice reveals an important new way that omega-3s guard arteries. Finding adds a fifth protective mechanism to the four discovered previously. Only omega-3s from fish deliver the full benefits associated with this class of fats.

Sea turtles and salmon rank near the top of nature's most impressive navigators.

No matter how far they journey, both possess the uncanny ability to find a natal needle — their birthplace, that is — in a humongous oceanic haystack.

Salmon hatch in rivers, then migrate hundreds of miles out into the ocean before returning to their home river several years later to spawn.

Salmon return to the freshwater river of their origin to spawn, although some may stray to other nearby streams.

And some populations of sea turtles cross entire oceans and roam for more than a decade before returning to reproduce on their home beach.

The question of how marine animals migrate such vast distances to return to their own birthplace — sometimes bypassing other suitable locations along the way — has mystified scientists for more than a century.

Scientists speculate that natal homing evolved because individuals that returned to their home areas to reproduce left more offspring than those that tried to reproduce elsewhere.

Researchers have proven that once salmon get close to their birth river, a keen sense of smell guides the fish the rest of the way.

Sense of smell may explain how both creatures home in on their birth rivers and beaches.

But it has been unclear how they find their way close enough for smells or other aquatic cues — such as to guide them on the final, short legs of their epic journeys.

Marine biologists at the University of North Carolina summarized the conundrum in a recent article, in which they propose a magnetic solution to the mystery:

“Salmon are known to use chemical cues to identify their home rivers at the end of spawning migrations. Such cues, however, do not extend far enough into the ocean to guide migratory movements that begin in open-sea locations hundreds or thousands of kilometers away.

“Similarly, how sea turtles reach their nesting areas from distant sites is unknown. However, both salmon and sea turtles detect the magnetic field of the Earth and use it as a directional cue.” (Lohmann KJ et al. 2008)

Now, marine biologists at the University of North Carolina at Chapel Hill think they might have unraveled the secret of how salmon and sea turtles can get close enough to their ultimate goal for their “noses” to lead the rest of the way.

Magnetic explanation for homing accuracy

At the beginning of their lives, salmon and sea turtles may read the magnetic field of their home area and “imprint” on it, according to a new theory in the latest issue of the journal Proceedings of the National Academy of Sciences.

The Earth's magnetic field varies predictably across the globe, with every oceanic region having a slightly different magnetic signature.

By noting the unique “magnetic address” of their birthplace and remembering it, animals may be able to distinguish this location from all others when they are fully grown and ready to return years later, researchers propose.

As the authors wrote, “… we propose that salmon and sea turtles imprint on the magnetic field of their natal areas and ...

Today’s recipe features rosemary, whose heady, “piney” aroma makes it the perfect seasoning for grilled or broiled fish.

In the Middle Ages, rosemary’s apparent ability to fortify the memory transformed it into a symbol of fidelity known as the “herb of remembrance”.

In fact, rosemary’s phenolic compounds increase circulation to the head and brain, thereby improving concentration and memory, and also reduce systemic inflammation.

Rosemary is also shown to protect the liver, inhibit tumor activity, enhance digestion, and reduce the severity of asthma attacks.

But in this case, we’re content with the deep flavor it adds to an easy dish!

To serve two people, simply halve the proportions.

Rosemary Roasted Salmon

Makes 4 servings

4 (6 oz each) wild Alaskan salmon fillet portions

4 medium garlic cloves, minced

2 tablespoons organic extra virgin olive oil

1 tablespoon Dijon mustard

1 tablespoon organic chopped rosemary

1/4 teaspoon sea salt

1/4 teaspoon organic black pepper

Heat oven to 475°F.

• Place salmon, skin-side down, on small rimmed baking sheet.
• Combine garlic, oil, mustard and rosemary in small bowl. Sprinkle salmon with salt and pepper; spoon rosemary mixture over salmon. Refrigerate 10 minutes.
• Bake salmon 8 to 10 minutes or until it just begins to flake.