Swedish study links early fish consumption to a 24 percent reduction in risk of eczema among infants
by Craig Weatherby
Last Friday’s edition of The New York Times included a story about rising rates of eczema among American children.
The article quoted Dr. Anthony Mancini, head of dermatology at the Northwestern University School of Medicine: “It used to be, 20 years ago, one baby in 20 was affected by it. Now, that number is roughly one in five or six” (Sweeney C 2008).
This sharp rise in eczema rates tracks an 18 percent rise in food allergies between 1997 and 2007, reported earlier this month by the Centers for Disease Control and Prevention (CDC).
- Childhood eczema affects one in 10 young children and is on the rise.
- Swedish study links early fish eating to a reduced risk of developing eczema.
- Recent studies support the anti-eczema potential of omega-3s for kids and adults alike.
- Omega-3s probably explain the positive effect, but fatty fish higher in omega-3s did not provide greater protection.
- U.S. pediatricians recently reversed their advice for infants and toddlers to avoid fish.
About 27 percent of children with a food allergy also have eczema or a skin allergy, compared to just eight percent of children without a food allergy (CDC 2008).
Explanations for the tandem rise in eczema and food allergies include two leading hypotheses:
If a child’s immune system is not exposed to the natural world, it never learns the difference between benign and toxic agents, and overreacts to innocuous substances, thereby turning them into “allergens”.
- Immune system irritants including pollution and food preservatives.
- Excessively sterile environments. Eczema and hay fever are less common in children from larger families, who get exposed to more infectious agents through their siblings. Allergies are also less common in children raised on farms, surrounded by siblings, who come into close contact with soil and a range of plants and animals.
What is eczema?
The red, itchy rashes characteristic of eczema (pronounced ek-zuhmah) can wreak havoc on personal peace and social confidence. The condition can even be tormenting and seriously disfiguring.
Doctors call eczema “atopic dermatitis” (AD). This medical term means an inflammation of the skin, presumably caused by hypersensitivity to an allergen that may not even contact the skin directly.
The exact cause or causes are unknown, but eczema is associated with family history of the disease.
A variety of factors may trigger the condition and can exacerbate it greatly. These include dry air, excessive use of skin cleansers, and exposure to clothes and bedding that is scratchy or carries traces of laundry chemicals.
Eczema usually develops in children older than 3 months, and it usually occurs before a child's second birthday.
There is no cure; the condition is chronically relapsing, and there is almost always an associated family or personal history of allergy, asthma, or eczema.
Good skin care and medicines can help control the problem. (Omega-3s are essential to proper immune system function and overall skin health, but have not been proven as a treatment or cure.) As children get older, eczema tends to get better or may disappear.
Other rashes also can start at that time, so it may be confusing at first, but most rashes disappear within a few days to weeks, while eczema persists.
Childhood eczema is very itchy, and much of the skin damage comes from scratching and rubbing that the child cannot control.
Fish goes from suspected allergy risk to eczema-fighter
At least half of children with eczema outgrow it, but, as the story in the Times showed, it can seriously degrade the quality of a young child’s life and that of his or her family.
Until this year, the American Academy of Pediatrics had advised the parents of children at hereditary risk for eczema to withhold various foods
—including fish, cow’s milk, and eggs
—until they turned three.
But the Academy now says that children as young as four months can be given potentially allergenic foods, including fish.
And while the jury remains out, the results of a few relevant studies indicate that fish or fish oil may help reduce the risk or severity of asthma, hay fever type allergies and various other inflammatory conditions.
To learn more, see our prior articles on this subject:A recent controlled clinical study from Germany
—conducted in eczema patients aged 18 to 40
—showed therapeutic benefits following two months of taking 5.4 gm of omega-3 DHA daily, in the form of supplemental fish oil (Koch C et al. 2008).
And a Korea study published last year linked higher blood levels of omega-3s with reduced risk of childhood eczema (Hwang I et al. 2007).
Now, epidemiological evidence indicates that post-natal diets rich in fish may help reduce the risk of eczema in infants and toddlers.
Swedish study finds mothers’ and infants’ fish intake protective
Researchers at the University of Gothenburg followed 4,921 Swedish infants, whose mothers were participating in a larger health study.
The scientists asked the parents about their children’s diets and signs of eczema at six months and again when the babies were one year old.
By six months of age, 14 percent of the babies had developed eczema, and more than 20 percent had developed the disease by age one.
The researchers noted that kids who had a mother or sibling with the condition were more likely to develop eczema.
Compared to babies who did not eat fish before nine months of age, babies who started eating fish before 9 months of age were 24 percent less likely to develop eczema by age one.
Surprisingly, given the anti-inflammatory influences exerted by omega-3s—and past indications that diets higher in omega-3s may tend to reduce allergy risks and symptoms—the effect was the same regardless of whether the fish consumed were fatty—hence, higher in omega-3s—or lean.
Lead author Bernt Alm, M.D., suggested that pureed boneless fish be slowly introduced together with other solids, at about five months of age (Very few baby foods contain fish, so fish puree has to be home made).
No links found to suspected eczema deterrents or promoters
The authors reported finding no connection between the risk of developing eczema and the age at which dairy products or eggs were introduced into the diet.
And unexpectedly, breastfeeding was not linked to lower eczema risk, despite the American Academy of Pediatrics advice that babies at high risk for developing asthma and other allergic diseases be breastfed exclusively for the first year of life.
Nor did the presence of smokers or pets in the home raise the kids’ risk of eczema.
Children who lived with a pet bird were also less likely to develop eczema. Birds can carry toxins released by disintegrating disease bacteria, and exposure to these “endotoxins” could help the immune system distinguish between real and phony threats.
Needless to say, more research is needed before we can be certain that fishy infant diets reduce the risk of childhood eczema.
But given all of the known benefits of fatty fish—linked largely to its omega-3s and vitamin D—there is no reason not to give infants fish oil and carefully pureed, strained fish.
- Alm B, Aberg N, Erdes L, Möllborg P, Pettersson R, Norvenius G, Goksör E, Wennergren G. Early introduction of fish decreases the risk of eczema in infants.Arch Dis Child. 2008 Sep 25. [Epub ahead of print]
- Hwang I, Cha A, Lee H, Yoon H, Yoon T, Cho B, Lee S, Park Y. N-3 polyunsaturated fatty acids and atopy in Korean preschoolers. Lipids. 2007 Apr;42(4):345-9. Epub 2007 Mar 20.
- Koch C, Dölle S, Metzger M, Rasche C, Jungclas H, Rühl R, Renz H, Worm M. Docosahexaenoic acid (DHA) supplementation in atopic eczema: a randomized, double-blind, controlled trial. Br J Dermatol. 2008 Apr;158(4):786-92. Epub 2008 Jan 30.
- Mayser P, Mayer K, Mahloudjian M, Benzing S, Krämer HJ, Schill WB, Seeger W, Grimminger F. A double-blind, randomized, placebo-controlled trial of n-3 versus n-6 fatty acid-based lipid infusion in atopic dermatitis. JPEN J Parenter Enteral Nutr. 2002 May-Jun;26(3):151-8.
- Prescott SL, Calder PC. N-3 polyunsaturated fatty acids and allergic disease. Curr Opin Clin Nutr Metab Care. 2004 Mar;7(2):123-9. Review.
- Purvis DJ, Thompson JM, Clark PM, Robinson E, Black PN, Wild CJ, Mitchell EA. Risk factors for atopic dermatitis in New Zealand children at 3.5 years of age. Br J Dermatol. 2005 Apr;152(4):742-9.
- Sweeney C. Skin Deep: Learning to Cope With, if Not Cure, Infant Eczema. The New York Times, October 30, 2008. Accessed online October 31, 2008 at http://www.nytimes.com/2008/10/30/fashion/30skin.html