FATS OF LIFE NEWSLETTER. December 2012 Contents. Volume 7 Issue 3. Fats of life Staff

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1 FATS OF LIFE NEWSLETTER Volume 7 Issue 3 Contents HEART HEALTH Consumption of Alpha-Linolenic Acid Unrelated to Risk of Heart Failure in 3 Studies...2 Omega-3 Benefits Outweigh Mercury Risks in Chance of Heart Attack...3 IMMUNE FUNCTION Fatty Acid Intake in Pregnancy May Affect Risk of Allergic Rhinitis in Offspring...4 High Omega-6 Fatty Acids in Breast Milk and Child s Risk of Asthmatic Symptoms...6 Omega-3s Given to High-Risk Infants After Birth Suggest Improved Immune Function...6 MENTAL HEALTH AND LEARNING Higher Reading Scores in DHA-Supplemented Children with Low Baseline Scores...7 Maternal PUFAs, Not Methylmercury, Associated with Child s Language Scores...9 Fish Consumption in Pregnancy Linked to Fewer Symptoms of ADHD Behavior in Child BRAIN AND NERVE Older Adults with Higher Blood EPA Lose Less Amygdala Gray Matter with Aging Fats of life Staff Editor Joyce A. Nettleton, DSc joyce@fatsoflife.com Communications Manager Angela Dansby angela@fatsoflife.com Sponsor DSM Nutritional Products, Inc., Columbia, MD, USA Letters and editorial comments should be submitted to Nettleton at joyce@fatsoflife.com and technical comments to Dansby at angela@fatsoflife.com. DHA After Spinal Cord Injury Linked to Improved Recovery of Motor Function in Mice CLINICAL CONDTIONS Fish Oil Pretreatment Before Exercise Linked to Some Improvements in Immune Function

2 HEART HEALTH Consumption of Alpha-Linolenic Acid Unrelated to Risk of Heart Failure in 3 Studies Alpha-linolenic acid (ALA) is the one omega-3 fatty acid found in some plants flaxseed oil, chia seeds, walnuts, soybean and canola oils, Heart failure is the inability for example. to pump sufficient blood Consumption of foods rich in ALA throughout the circulation is associated with to meet the body s needs. a modestly lower The condition occurs more risk of overall frequently in individuals heart disease, with diabetes, hypertension, according to a heart disease and obesity. recent statistical analysis of 13 studies, but if one looks at the ALA content in blood or red blood cells instead of diet, ALA is not related to the risk of heart disease. Unavoidable errors in estimating food intakes mean that studies relying on measurements in blood or tissues are considered more reliable. Research on the consumption of long-chain omega-3s from seafood or supplements has frequently reported significantly lower risks of heart disease, in contrast to the findings on ALA. However, not all types of heart disease respond to differences in dietary fats in the same way. Recently, three groups of investigators reported on the relationship between dietary intakes or blood levels of ALA and the risk of developing heart failure. In this type of heart disease, the heart is unable to pump sufficient blood throughout the circulation to meet the needs of the body. As a result, individuals with heart failure experience shortness of breath, fatigue and swollen ankles, feet or abdomen. Half the people with heart failure die within the first 5 years of diagnosis. Can people protect themselves from this disease? Because heart failure is more likely to develop in individuals with diabetes, hypertension, heart disease and obesity, controlling these conditions with medical therapies and changes in lifestyle substantially lowers the risk of heart failure. Consuming fish on a regular basis may also reduce the risk of heart failure according to several studies, especially among women, but not all studies agree. Does the consumption of foods rich in ALA protect against the risk of heart failure? In the first of 3 studies described here, researchers examined the data from the Swedish Mammography Cohort, a large study that is monitoring women for modifiable factors related to the occurrence of several chronic diseases. Food intake information from this study permitted the researchers to look at the relationship between ALA consumption and hospitalization for or death from heart failure. Over the 9-year study period, they found no link between the consumption of ALA and the risk of heart failure. The second study looked at dietary and blood fatty acid data from the Cardiovascular Health Study of older adults who were monitored for at Three recent studies found no link between ALA consumption and the risk of developing heart failure in older adults. One study reported a lower risk of heart failure with higher blood levels of ALA and with eating fish 1 to 3 times per month. least 10 years. The investigators found that neither dietary intakes nor blood ALA levels were related to the risk of developing heart failure. The third study analyzed data from the Physicians Health Study in the U.S. This trial was designed to evaluate whether lowdose aspirin and β-carotene could reduce the risk of developing cancer or cardiovascular disease. The analysis 2

3 looked at blood levels of ALA and long-chain omega-3 fatty acids and the occurrence of heart failure in men between the ages of 40 and 84 years. The investigators also examined the dietary data available from the study. Perhaps surprisingly, the study showed no connection between blood levels of long-chain omega-3 fatty acids and the risk of heart failure. In contrast, higher blood levels of ALA were associated with a significantly lower risk of heart failure. When the investigators examined the dietary intakes of ALA, long-chain omega-3s and fish, they found no relationship between the amount of ALA or longchain omega-3s consumed and the risk of heart failure. However, those who ate fish at least 1 to 3 times per month had a significantly lower risk of heart failure. Eating fish more frequently was not linked to any further reduction in risk. All 3 studies concluded that dietary ALA was not associated with a lower risk of heart failure. One study reported a lower risk of heart failure with higher blood levels of ALA, but not with the level of long-chain omega-3s in blood. Thus, the findings from the Physicians Health Study stand in contrast to the other studies. In common with other investigations, however, fish consumption was associated with a lower risk of heart failure. These recent studies generally confirm that ALA contributes little to lowering the risk of heart failure. Consuming fish or fish oil supplements continues to be associated with a significantly lower risk of heart disease and mortality. Still, in many countries where heart disease is the leading cause of death, fish consumption remains low. One reason is the concern about contaminants, especially methylmercury. The greatest risk from high levels of methylmercury is to the developing fetus. For nonpregnant adults, the possible risk from methylmercury in fish is less clear. This is particularly true with respect to heart disease and heart attack (myocardial infarction, Figure). Most exposure to mercury comes from eating fish, which provides many nutrients that lower the risks associated with mercury. Two examples are selenium, which makes mercury unavailable to cells, and long-chain omega-3 fatty acids, which are associated with protection against heart disease. Thus, the real effects of small amounts of mercury in fish are part of a complex situation. If studies do not account for these confounding factors, the risk attributed to mercury may seem greater than it really is. Similarly, the benefits may be overstated. Omega-3 Benefits Outweigh Mercury Risks in Chance of Heart Attack Eating fish regularly or consuming supplements containing fish oil or long-chain omega-3 fatty acids has been associated with a significantly lower risk of developing heart disease and dying from it according to many studies. Although not all studies have reached the same conclusion, there is enough evidence favoring the heart-health benefits of eating fish that many health authorities worldwide have recommended that all adults increase the amount of fish they consume. Still, in many countries where heart disease is the leading cause of death, fish consumption remains low. One reason for this is concern about contaminants, especially methylmercury, the form of mercury found in fish. Figure. Heart muscle with dead tissue resulting from a heart attack (A) and coronary artery with plaque (B). Image: National Heart Lung and Blood Institute. 3

4 Researchers in Sweden took a closer look at the risks of a heart attack associated with mercury and nutrients in fish. They combined data from 2 large studies in Sweden and Finland where consumption of long-chain omega-3s and mercury differ because of the different types of fish eaten in each country. Mercury measured in hair was higher in the Finnish participants, while blood levels of EPA and DHA, the two main long-chain omega-3s in fish, were higher in the Swedish participants. Fish consumed in Finland include more freshwater species with higher levels of mercury and less omega-3s. In contrast, Swedes eat more fish with higher levels of omega-3s and less mercury. Combining the data from both populations provided a wider range of omega-3 and mercury intakes. The investigators also relied on measurements in tissues for their assessment of exposure, a more reliable approach than food intake information. Higher blood levels of EPA + DHA were associated with a lower risk of heart attack, while hair mercury content above 2 μg/g was linked to a higher risk. Hair mercury below 2 μg/g was not associated with the risk of heart attack. The data analysis showed that higher blood levels of EPA + DHA were associated with a significantly lower risk of heart attack. However, the association was weakened by exposure to higher levels of mercury greater than 2 μg/g. Hair mercury concentrations below 2 μg/g had no effect on the lower risk associated with EPA + DHA in blood. Hair mercury levels were associated with a higher risk of heart attack, but the effect was weakened by higher levels of EPA + DHA in blood. Thus, the lowest risk of a heart attack (44% lower risk) was observed in those with the highest levels of blood EPA + DHA and the lowest hair mercury. At the opposite end of the risk spectrum, the risk of heart attack was twice as great in those with the highest hair mercury content and the lowest levels of EPA + DHA in blood. How closely do the extremes of risk mirror real-world conditions? One is most concerned about the highest risk, but this situation is highly unusual. Most fish species found Higher levels of EPA + DHA are associated with lower risk of heart attack and they weaken the potential risk of mercury. The lowest risk of heart attack was observed in those with high levels of EPA + DHA and low hair mercury content. in the market place have low levels of mercury, even though the amount of EPA + DHA they contain varies with the species. Oily fish such as salmon, sardines, pilchards and rainbow trout have the greatest amount of long-chain omega-3s, while lean white species such as flounder, sole, cod and plaice have much less omega-3s. The less common situation of fish with high mercury levels is more likely to occur from eating fish from fresh-water environments that have been contaminated with industrial pollutants or from the frequent consumption of very long-lived species of fish. These fish are mostly caught by recreational fishers, not commercial fishing. This study is valuable for several reasons. First, it demonstrates that higher levels of EPA +DHA are associated with lower risk of heart attack and they weaken the potential risk of mercury. Second, they show that exposure to mercury may only increase risk when the accumulation of mercury is substantial, above 2 μg/g in hair. For perspective, hair mercury in adult women in the U.S. is one-tenth that amount. The authors of the study also point out that there were very few participants who had such high hair mercury levels. Finally, a more accurate picture of the risks and benefits associated with eating fish regularly is given when the analysis includes multiple factors, such as omega-3s and mercury. The study also found that the benefits of fish consumption associated with the risk of a heart attack outweighed the potential risks. IMMUNE FUNCTION Fatty Acid Intake in Pregnancy May Affect Risk of Allergic Rhinitis in Offspring The search for ways to reduce the occurrence of childhood allergies has led to studies on how polyunsaturated 4

5 Immune function is affected by dietary fatty acids. Both omega-3 and omega-6 fatty acids have been linked to the symptoms of allergic disease in children, but the findings are inconsistent. A new report suggests that dietary fatty acids in pregnancy may be linked to childhood rhinitis. fatty acids (PUFAs) might be involved. The huge increase in the consumption of vegetable oils, which supply large amounts of omega-6 PUFAs, has contributed to the reduced intake of omega-3 PUFAs, especially those from fish. The immune system is affected by fatty acids and several observational studies have reported a lower severity or delay of allergic symptoms in the offspring of mothers who consumed fish during pregnancy. Studies where mothers have consumed fish oil or long-chain omega-3 PUFAs during pregnancy have had mixed results in allergic symptoms of high-risk children. Some have observed decreases in childhood asthma and fewer positive skin prick tests for various allergens, while others have reported less occurrence or severity of eczema. Overall, the findings have been inconsistent, yet sufficiently encouraging to warrant further investigation. The effect of high levels of omega-6 PUFAs, mainly linoleic acid, on allergic symptoms is generally considered detrimental. This is mainly because omega-6 fatty acids tend to promote the production of inflammatory substances, which contribute to disease symptoms. But here, too, results have been inconsistent. Higher levels of omega-6 PUFAs in maternal blood were associated with a higher risk of childhood rhinitis, but a lower risk of eczema. Others have observed no association with the proportions of omega-6 and omega-3 fatty acids in the mother s blood, while a reduction in omega-6 PUFAs was linked to a significant reduction in asthma in 8-year-old children. A new observational study reported its findings from the study of the usual maternal diet during pregnancy and lactation and the child s development of allergic disease at the age of 5. The report focused on the consumption of fat and fatty acids. None of the mother s dietary fats or fatty acids was related to the occurrence of eczema or wheeze in the children. However, children whose mothers consumed a high proportion of omega-6 PUFAs compared with omega-3 PUFAs were more likely to develop allergic rhinitis, a finding that supports a previous report linking omega-6 PUFAs with a higher risk of rhinitis. Children whose mothers consumed a high proportion of omega-6 fatty acids compared with omega-3 fatty acids were more likely to develop allergic rhinitis at age 5. High maternal consumption of alpha-linolenic acid, a plant-based omega-3, was associated with a lower risk of rhinitis. These investigators also observed that rhinitis occurred less frequently in infants whose mothers had high intakes of alpha-linolenic acid (ALA), the plantbased omega-3. A Japanese study reported a link between the mother s consumption of alpha-linolenic acid and a lower risk of wheeze in the infants. The investigators in the present study also observed a lower risk of asthma in the infants of mothers with higher ALA intakes. Unfortunately, the study did not examine blood fatty acid levels and these might have provided additional insights. This study raises questions about the healthfulness of high intakes of omega-6 PUFAs and low omega-3 PUFAs for the risk of allergic rhinitis. It also points to the possible benefits of ALA in the risk of allergic rhinitis and possibly wheeze or asthma. No conclusions are possible from observational studies, but the study confirms that maternal fatty acid intakes influence the development of childhood allergies. Unfortunately, we are still far from knowing what an optimum pattern of food fatty acids during pregnancy might be. 5

6 High Omega-6 Fatty Acids in Breast Milk and Child s Risk of Asthmatic Symptoms One of the advantages of breastfeeding may be a lower risk that the child will develop symptoms of allergic disease. Studies have reported a lower occurrence of asthma in breastfed Canadian, U.S. and Many studies have linked breastfeeding with a lower risk of allergic symptoms in the offspring. In this study, the fatty acids in breast milk were associated with the risk of asthmatic symptoms in infants up to 12 months of age. Dutch children, but one study reported a higher risk of asthma and wheeze in breastfed children whose mothers were asthmatic. Children whose mothers ate oily fish during pregnancy were also less likely to develop asthma in some studies, while children whose mothers consumed diets rich in linoleic acid, an omega-6 fatty acid, experienced a higher risk of asthma in later childhood. As breast milk contains many immunological substances and omega-3 fatty acids, which have been associated with less severe allergic symptoms, the question arises whether breast milk fatty acids affect a child s risk of allergic symptoms. Most studies focus on children who are at high risk of allergic diseases because a parent has at least one allergic condition. These children have the greatest need for conditions that might reduce their risk of developing allergic diseases. This study examined the relationship between the fatty acid composition of breast milk and the risk of allergic disease and asthma in the offspring at 6 and 12 months of age. Participating mothers did not necessarily have a history of allergic disease. Infants were evaluated for symptoms of asthma and sensitivity to a variety of allergens using a skin prick test. Breast milk fatty acids were measured in samples obtained 2 weeks after delivery. The investigators observed that infants whose mothers had the highest levels of omega-6 fatty acids in their breast milk were nearly 3 times more likely to develop asthmatic symptoms compared with all other infants. Breast milk omega-3 fatty acid content was not related to the risk of asthmatic symptoms. These findings were noted at either 6 or 12 months of age. Infants of mothers with the highest levels of omega-6 fatty acids in their breast milk were nearly 3 times more likely to develop asthmatic symptoms compared with all other infants. Results from the skin prick tests showed that 12-month-old infants of mothers with the highest levels of omega-3 fatty acids in their breast milk were the least likely to have a positive skin prick test. Breast milk omega-6 fatty acids were not related to the skin prick test results. These findings suggest that higher levels of omega-6 fatty acids in breast milk, which reflect the fatty acid intake of the mother, may be associated with a greater risk of asthmatic symptoms in the offspring. Omega-3 fatty acid levels showed no protective effects on these symptoms, but were associated with lower sensitivity to other allergens. These findings provide additional evidence that maternal diet, particularly the pattern of polyunsaturated fatty acid intake, may affect the child s risk of developing asthmatic symptoms in the first year of life. Omega-3s Given to High-Risk Infants After Birth Suggest Improved Immune Function To evaluate whether long-chain omega-3 fatty acids might improve the occurrence or symptoms of allergic disease in infants at high risk of these conditions, investigators have often provided the omega-3s through the mother s diet. It is generally believed that the earlier an infant is exposed to these fatty acids, the greater the likelihood of benefit. However, findings have been contradictory and inconsistent. We still cannot say 6

7 Long-chain omega-3 fatty acids may have some benefits in easing allergic symptoms in infants at high risk of allergies, but findings have been mixed. A new study provided omega-3 fatty acids to high-risk infants in the first 6 months of life. with confidence that providing these fatty acids through maternal supplementation in pregnancy will help the offspring. There is enough encouraging evidence of some benefit that researchers continue to pursue studies with omega-3 fatty acids. For one, we know that increased intake of longchain omega-3s reduces the production of substances that promote inflammation. That may be one reason why the symptoms of allergic disease are less severe in some individuals who were exposed to higher levels of omega-3s in early life. Less attention has been paid to providing omega-3s to high-risk infants shortly after birth. One reason is that such studies have yielded only limited success. But a research team in Australia pursued this strategy in breastfed infants. They developed a novel yet simple approach to giving the infants fish oil the mother simply squirted the contents of omega-3 capsules into the infant s mouth during feeding. For formula-fed infants, the capsule contents were mixed into the formula. Participating families were asked to provide the omega-3s for the first 6 months of the infant s life. Nearly all infants received some breast milk after birth, even though duration of breastfeeding varied. Infants were evaluated for symptoms of allergic disease and sensitivity reactions to skin prick tests at 6 and 12 months of age. At one year of age, there were no differences in allergic symptoms between the omega-3 supplemented infants and the placebo group. However, among the infants who received more than 75 percent of the intended amount of omega-3s, symptoms of eczema were significantly less. Supporting this observation, infants with higher omega-3s in their blood at 6 months were also less likely to have eczema at 12 months of age. Infants with higher DHA or total omega-3s in their blood also had less wheeze than infants with lower Infants who consumed at least 75 percent of the dose of omega-3s were significantly less likely to develop allergic eczema at 12 months of age. Infants with higher levels of DHA in their blood also had less wheeze. levels. No other allergic symptoms differed between the groups. As others have observed, the omega-3s did not prevent the development of allergic symptoms, but they were associated with fewer occurrences of eczema and wheeze. A limitation of the study was the fact that only 57% of the omega-3 group actually provided the omega-3 supplement. Thus, for the whole treatment group, the amount of omega-3s provided was substantially less than the study intended. The fact that infants who did receive most of the supplement experienced improved results suggests that the omega-3s were effective in reducing allergic symptoms. Further, the omega-3 infants also had lower levels of some inflammatory substances and increased markers of a more mature immune system. These encouraging findings suggest that infants at high risk of developing allergic diseases may benefit from higher intakes of long-chain omega-3s in early infancy through at least 6 months of age. Even if the mother does not increase her consumption of omega-3s during pregnancy, her child might benefit from early supplementation. Studies with larger numbers of mothers and infants are needed to confirm this possibility. MENTAL HEALTH AND LEARNING Higher Reading Scores in DHA-Supplemented Children with Low Baseline Scores Brain function depends on having all its systems working well together. Damage to the brain from injury or disease, impaired production of transmitter molecules or insufficient amounts of substances needed for brain 7

8 DHA is a long-chain omega-3 fatty acid needed for brain structure and function. Insufficient amounts in early life may slow brain development and learning. A new study reports DHA supplements may improve reading in children with very low scores. responses are some ways brain function can go awry. DHA, a long-chain omega-3 fatty acid is important for the structure of brain cells and for brain function. When it is not available in sufficient amounts in early life, brain development and learning may be slowed or harmed. There is evidence of this in suboptimal visual function, childhood learning and development, behavioral problems and in learning or cognition in later life. There is growing evidence that some children with develop mental disorders, attention or behavior difficulties or learning disabilities may be affected by having too little long-chain omega-3 fatty acids. Moreover, the high levels of omega-6 fatty acids in most Western diets may aggravate the problem. Several studies where children have been given long-chain omega-3s have reported modest improvements in learning, behavior and memory, but not all studies agree. We do not know whether all long-chain omega-3s are involved, but providing additional DHA has been linked to higher performance scores and visual function in children. There are wide-ranging implications if children s school and behavioral performance could be improved through the increased availability of longchain omega-3s. To further explore whether long-chain omega-3s might benefit under-performing school children, researchers in the U.K. provided omega-3 supplements to 7- to 9-year-old children who were in the bottom third of scores on a standardized reading test. Reading at this level is about 18 months behind the level expected for this age. The study used an adult dose of DHA, 600 mg/day, for 16 weeks and compared test results before and after supplementation. Although the investigators focused mainly on reading scores, they also evaluated the children s working memory and behavior as rated by parents and teachers. British 7- to 9-year-old children in the lowest third of reading scores were given DHA for 16 weeks and then re-evaluated. Those in the lowest 20 percent in reading scores showed significant gains in reading after consuming DHA. After 16 weeks of treatment, the reading scores in the DHA group did not differ from the placebo control group. However, when the investigators compared the scores for children who originally scored in the bottom 20 percent or the lowest 10 percent, consumption of DHA was associated with significantly higher scores for both groups, with the most dramatic increases observed in the bottom 10 percent. The researchers determined that the improvement in the lowest 20 percent group would be the equivalent of a 20 percent gain in reading age. For the lowest 10 percent group, the change was even more dramatic, a gain of about 50 percent. The evaluations of working memory did not change significantly with the consumption of DHA. When the parents rated their child s behavior, they noted significant improvements in 6 of the 7 measures, such as ADHD index, restlessness and emotional liability. Teachers scores did not suggest behavior changes. This study is provocative and encouraging if others can confirm its findings. Other investigators have reported improved reading scores with fatty acid supplementation, but some have failed to detect improvements. This study suggests that for a modest investment in nutrition and time, children with the greatest reading difficulties 8

9 might be able to boost their reading ability substantially. Such an achievement would also improve the child s self-esteem and school performance. These findings also reinforce the importance of DHA in childhood learning. Higher maternal intakes of long-chain omega-3 fatty acids are associated with better developmental outcomes in the offspring. Whether early language development is affected is uncertain as findings are mixed. Maternal PUFAs, Not Methylmercury, Associated with Child s Language Scores The importance of long-chain polyunsaturated fatty acids (PUFAs) in brain development and learning is well known. Less clear are the effects of these fatty acids on specific outcomes, such as language development. Some studies have reported no differences in vocabulary or language development with higher intake of longchain PUFAs or DHA, a long-chain omega-3 PUFA. Others have observed transient effects of DHA supplementation in early infancy on later language development and some have reported improved language scores with higher levels of DHA in blood. Yet others have reported language deficits in children exposed to methylmercury in fetal and early life. It would appear that DHA or long-chain omega-3s have an uncertain place in language development or that mercury associated with eating seafood may be harmful to language development. What is really happening? One of the best ways to answer this question is to follow the development of children whose mothers consumed large amounts of fish during pregnancy and thus were exposed to long-chain omega-3 fatty acids and mercury. Two such studies, one in the Faroe Islands and the other in the Seychelle Islands have conducted such studies. Results from the Faroe Islands have consistently reported detrimental effects on language, largely attributable to the children s exposure to mercury during fetal life and infancy. This results from maternal consumption of pilot whale meat, which is especially high in mercury. When Faroe A mother s frequent fish consumption during pregnancy exposes the fetus to nutrients and mercury. A new report suggests that exposure to DHA is linked to higher language scores, but mercury is not related to early language development. Island children whose mothers did not eat pilot whale were evaluated, there were developmental benefits associated with fish consumption without the harmful effects of mercury. So data from the Faroe Islands does not represent the effect of typical fish consumption in most countries. In contrast, results from the Seychelles Islands, where women eat 10 times more fish than in the U.S. and most Western countries, the offspring have consistently shown developmental benefits from high levels of long-chain omega-3s, even with exposure to mercury. In a new report from the Seychelles Islands, investigators examined the language development of children at 5 years of age. They collected information about the mothers consumption of omega-3 Higher blood DHA levels in the mother during pregnancy were significantly associated with higher total language and verbal ability scores in the children. Mercury levels were not linked to the child s language development. PUFAs and mercury and evaluated the children s language development, verbal ability and intelligence scores. When they analyzed the test scores for associations with mercury, taking into consideration the consumption of omega-3s, the investigators found no relationship between the language scores and exposure to mercury. In contrast, higher blood DHA levels in the mother during pregnancy were significantly associated with higher total language and verbal ability scores in the children. The researchers also noted that higher levels of arachidonic acid, a long-chain omega-6 PUFA, were linked to lower language scores in all tests. 9

10 These findings provide reassurance that eating plenty of fish, which provides appreciable amounts of longchain omega-3 PUFAs, is associated with higher language scores in the offspring, even though the infant is exposed to mercury. In fact, the mothers hair mercury levels are 12 times higher than in the U.S., yet their children do not experience developmental deficits. The Seychelles Island data provide the strongest evidence available that the benefits of maternal fish consumption during pregnancy far outweigh the risks from mercury in the development of their offspring. This does not mean one should eat fish with high levels of mercury one should not. But for pregnant and nursing women, consuming most fish species, which have only small amounts of mercury, such as most fish available in the marketplace and restaurants, does not pose a risk to children s development. This study suggests that high levels of DHA from eating plenty of fish may also benefit the child s language development. Fish Consumption in Pregnancy Linked to Fewer Symptoms of ADHD Behavior in Child Attention deficit/hyperactivity disorder (ADHD), a common childhood behavioral disorder, may be increasing. Worldwide, ADHD affects about 8% to 12% of school-age children, with some estimates closer to 5%. In the U.S., the prevalence increased from 7.5% to 9.0% from 2001 to As the criteria for determining ADHD have changed, more cases may be Symptoms of ADHD behavior in children may be increasing in some countries. The cause is uncertain, but it has been linked to genetic and environmental factors. Whether maternal fish consumption in pregnancy is linked to ADHD risk has been examined in a new report from Boston, U.S. identified. Even with uncertain numbers, the condition puts a burden on families, teachers and health care providers, as treatments are limited. We do not know the causes of ADHD, but genetic and environmental factors, such as organic contaminants have been suggested. Prenatal exposure to mercury has been Example of ADHD-like inattentive behavior. Image: U.S. Centers for Disease Control. linked to ADHD in at least one long-term study, but no evidence of association was observed in another. Investigators in Boston, U.S., took a fresh look at the possible association between prenatal mercury exposure and ADHD-like behaviors in children 8 years later. The researchers had data on fish consumption and the mothers hair mercury content from a sample of women living close to a contaminated harbor into which PCBs and other contaminants had been discharged decades ago. The children were given various neuropsychological tests that reflect the symptoms of ADHD, but were not clinically evaluated for the condition. For example, the evaluations included inattentive, impulsive and hyperactive behaviors and combinations of these. The investigators analyzed the test results to see whether the children s behaviors were related to the mothers hair mercury levels. They observed a significant increase in the risk of inattentive and impulsive/hyperactive behaviors once hair mercury levels reached or exceeded 1μg/g. When the mothers fish consumption was taken into consideration, the higher risks with hair mercury above 1 μg/g remained. For comparison, hair mercury levels in a national sample of U.S. women are half that amount. However, when the mothers fish consumption was evaluated for a link to the children s behavioral scores, risk of higher scores was significantly reduced for children whose mothers ate more than 2 meals of fish per week. When the analysis took into account the exposure to 10

11 Although maternal hair mercury greater than 1 μg/g was associated with a greater risk of ADHDlike behaviors, children whose mothers ate more than 2 meals of fish per week had significantly fewer ADHD-like behaviors compared with children whose mothers ate less fish. mercury, test scores were still significantly lower that is, fewer problem behaviors in the children whose mothers ate fish. Thus, in spite of being exposed to mercury, the children of mothers who consumed more than 2 meals of fish per week experienced fewer ADHD-like behaviors. These children also had higher mental processing speeds and improved distractibility scores compared with children whose mothers ate less than 2 meals of fish per week. These findings support those described in the preceding article in which children in the Seychelle Islands whose mothers consumed plenty of fish had higher performances in behavioral, language and other neurodevelopmental evaluations than children whose mothers ate little or no fish. They are also consistent with reports from a long-term study in the U.K. where children whose mothers ate more than 340 g/week (12 ounces) were significantly less likely to develop social, behavioral or other learning difficulties compared with the children whose mothers did not eat fish. Continued reports about the benefits to children s and adults health associated with frequent fish consumption continue to provide a strong basis for concluding that the benefits of eating fish considerably outweigh the risks that might accrue from exposure to contaminants. BRAIN AND NERVE Older Adults with Higher Blood EPA Lose Less Amygdala Gray Matter with Aging As people live longer, they are more likely to develop one or more of the chronic diseases of aging, particularly dementia. The most common type of dementia in older Scientists are trying to identify the earliest signs of Alzheimer s disease, before the symptoms of memory loss set in. This study examined images of certain brain structures, fatty acids in blood and cognitive evaluations for significant relationships that might signal early disease. adults is Alzheimer s disease, a progressive condition of brain degeneration. We still do not know why some of us develop the condition and others do not. Neither do we know how to prevent it. Moreover, once Alzheimer s disease sets in, there are few treatment options for improvement. Some treatments may be more effective if they are begun in the earliest stages of the condition. The key is to identify those very early symptoms. Preclinical Alzheimer s disease may be assessed by certain measurements in blood and cerebrospinal fluid, the liquid that bathes the brain. New, non-invasive imaging techniques are being used to detect early changes in various brain structures that might signal the development of the disease. As the disease progresses, symptoms of mild cognitive impairment develop. These are recognized as memory loss, declining ability to think clearly and greater difficulty in taking caring of oneself. More than half of individuals who develop mildly impaired cognition progress to Alzheimer s disease. Scientists are intensively searching for ways to halt the progress of impaired cognition and maintain brain function. It would be helpful if there were good markers for early tissue changes in the aging brain, prior to the decline in cognition. Using both biochemical markers in blood and brain images, a team of investigators in Canada and France examined whether changes in blood omega-3 fatty acids were related to structural changes in different brain structures. Changes in the brain s content of DHA and blood levels of EPA and DHA have been linked to the development of Alzheimer s disease, but findings have been inconsistent. The study included 72-year-old residents in Bordeaux, France, who agreed to have their 11

12 blood omega-3 fatty acids measured, brain images taken and cognitive scores evaluated at the beginning of the study and after 4 years. The participants brain regions were assessed using magnetic resonance imaging, which enabled the investigators to measure the gray matter in specific structures in the medial temporal region. This area involves memory, learning and other functions and is among the earliest affected by Alzheimer s disease. The researchers evaluated the participants cognitive ability and depressive symptoms with widely used tests. Temporal lobe (green) of the brain, which includes the hippocampus, amygdala and other structures. Image: Wikipedia. Over the 4-year period, gray matter decreased in the whole brain at an average rate of 0.2% per year. But atrophy (brain tissue loss) was greater in the hippocampus, parahippocampus and amygdala regions, varying from 0.5% to 1.0% loss. Blood EPA levels were significantly associated with these changes, with higher EPA levels associated with less gray matter loss, especially in the right amygdala. Further, greater loss in the right amygdala was associated with higher scores for depressive symptoms. Losses in the left amygdala were linked to poorer cognitive scores, while losses in both areas were associated with a decline in verbal fluency. Thus, decreases in the gray matter of the amygdala might signal greater cognitive decline later. Over 4 years, the brains of 72-year-old adults lost gray matter, with losses greatest in the hippocampus and amygdala. Losses in the right amygdala were associated with higher scores for depressive symptoms. Another interesting observation was the association with EPA, and not DHA, with changes in the right amygdala. Many studies have linked DHA levels to different aspects of brain function and behavior, while EPA has less frequently been linked to brain function. The main exception to that general statement is the association between EPA and depressive symptoms. The observed association might mean that change in EPA might predict a loss of gray matter in the amygdala, for example. The association does not mean that one factor causes the other. There is evidence from other studies supporting these observations. For example, higher EPA levels in blood were associated with less severe depressive symptoms in an earlier study by these investigators. Changes in the volume of the Higher blood EPA levels were associated with less loss of gray matter, especially in the right amygdala. Gray matter loss in the left amygdala was linked to poorer cognitive scores. amygdala have also been reported in patients with depressive symptoms. This important study provides good evidence that brain imaging could be a useful approach to identify brain changes in the early stages of cognitive decline. It also suggests that low blood EPA might be an additional marker for the risk of cognitive decline and for depressive illness. The hope is that others will replicate this approach to the early detection of impaired cognition so that these observations can be confirmed or refuted. 12

13 DHA After Spinal Cord Injury Linked to Improved Recovery of Motor Function in Mice About 12,000 new spinal cord injuries occur every year in the U.S., often with crippling consequences. Most of the injuries occur in men as a result of automobile accidents, falls, violence and sports. Decompression surgery, rehabilitation therapy and pharmacologic agents may ease the damage, but functional recovery remains very limited. More promising therapies may be on the horizon as scientists examine substances that limit the damage to nerve cells and promote cell and functional recovery. A leading candidate in this research is DHA, one of the principal long-chain omega-3 fatty acids. DHA is also a key component of nerve cells. Possible spinal cord injury from a motor vehicle accident. Auto injuries account for about 42% of new spinal cord injuries per year in the U.S. Research in animals with brain, spinal cord and nerve damage has demonstrated that DHA, when administered shortly after an injury, reduces the loss of nerve cells, increases the survival of neurons and improves functional recovery, such as the ability to move a limb or bear weight. It also promotes the growth of new nerve cells, improves the connections among them and reduces the inflammation that accompanies the injury. In fact, damage from inflammation contributes substantially to the poor outcomes of patients with these injuries. Ultimately, the goal of this type of research is to identify therapies and treatments that halt the damage, repair Investigators evaluated the effect of a DHA infusion or a DHAenriched diet in animals with spinal cord compression injury. They looked at nerve cell loss, functional recovery and nerve cell damage after treatment. tissues, stimulate new nerve growth and promote the restoration of limb function in humans. Leading to that are studies in animals with various types of brain and spinal cord injuries. Moreover, different animals respond in different ways to such injuries, so studies in several species are required prior to studies in humans. This report builds on previous work in rats with new experiments in mice, which respond differently to spinal cord compression injury. This type of study might also provide detailed insights into how DHA contributes to recovery from spinal cord injury. Investigators at Queen Mary University, London, examined the effect of treating injured animals with different amounts of DHA provided by infusion immediately following the injury or in the diet. After spinal cord compression injury, the animals continued to lose nerve cells 1 and 4 weeks later. Further, the neurons sustained substantial damage to their axons, the cell projections that communicate with other cells. Injury to the axons prevents nerve cell communication, tissue repair and limb function. The injured animals also experienced severe, but not total paralysis, with only partial recovery after 4 weeks without treatment. What effect did DHA treatment have? Infusion with the highest level of DHA evaluated gave the best results. The animals improved their motor and movement activity significantly as early as 4 days after injury. Scores for their motor activity continued to improve over the 4-week period, with the DHA-treated animals scoring more than one-third higher than the control animals not given DHA. Animals given both the DHA infusion and the DHAenriched diet recovered motor function faster than those given just the DHA infusion. However, the difference 13

14 Animals given both the DHA infusion and the DHA-enriched diet recovered motor function faster than those given just the DHA infusion. DHA infusion or both diet and infusion resulted in fewer nerve cells lost and less nerve cell damage. The DHA-rich diet alone had no effect. in scores did not reach statistical significance, possibly because of the variability in scores and the relatively small differences between the two DHA-treated groups. The investigators noted that in spite of the lack of significant differences, animals given both the DHA-rich diet and the DHA infusion fared better than the DHA-infused animals. Providing DHA only in the diet without the infusion did not improve the animals recovery. In addition to the benefits of DHA on functional recovery, the investigators reported that DHA infusion plus the DHA-enriched diet was associated with fewer nerve cells lost and less damage to the nerve cell axons. The investigators noted that provision of DHA immediately following the injury was essential for protecting the nerve cells and for functional improvement. A DHA-enriched diet alone was insufficient to achieve these results. Pretreatment of the animals with DHA prior to the injury was not evaluated in this study, but others have reported that pretreatment with DHA was associated with fewer functional losses and improved cell survival. These studies add to the growing evidence that DHA provided to injured animals immediately after traumatic injury is associated with less loss of nerve cells, less damage to the structure of the cells and improved functional recovery. The findings strengthen the suggestion that DHA might have similar effects in humans with spinal cord injuries. Addendum: After the newsletter was written, the editor obtained a prepublication case report of an adolescent who suffered severe traumatic brain damage in an automobile accident. Eleven days after the accident, high doses of fish oil were added to the patient s tube feeding. Fish oil was continued for over one year. The patient regained consciousness, was discharged home 4 months after the accident and has continued to gain cognitive and motor function. He now walks with a cane and continues with physical therapy, but has speech and balance difficulties related to his injury. Initially, he was not expected to survive. CLINICAL CONDITIONS Fish Oil Pretreatment Before Exercise Linked to Some Improvements in Immune Function The health benefits of regular exercise have been abundantly described, but for some people that is just not enough. Regular exercise just The effect of omega-3s and exercise on immune function has been studied mainly in trained athletes or those with asthma. This study examined immune responses in young untrained adults who consumed fish oil prior to an exercise test. going for a daily walk is something you have to work into your daily routine and consider essential. Once you do, a better feeling of wellbeing, improved circulation and breathing and sometimes a happier outlook usually follows. For older adults, regular exercise, which means a planned, structured and repetitive activity such as an aerobics class or brisk walking, improves muscle strength, balance and coordination. These benefits reduce the risk of falls and bone fractures, too. Less well known is the association between regular moderate exercise and immune function. There is accumulating evidence that individuals who exercise regularly have reduced inflammation, a low-grade condition that underlies many chronic diseases, such as obesity, heart disease and type 2 diabetes. Physically fit, active individuals have a lower risk of respiratory tract and viral infections, an important consideration for older adults. 14

15 Omega-3 fatty acids also reduce inflammatory responses and have been evaluated in athletes with asthma. Findings from these studies indicated that fish oil supplementation in competitive athletes with asthma was associated with improved lung function and less use of bronchodilators. But what happens in non-athletes, the rest of us? A recent study wanted to find out if taking fish oil or longchain omega-3s affected selected immune responses after exercise in young, healthy individuals who were not trained athletes. In this study, the participating men consumed 1.6 g/ day of EPA + DHA for 6 weeks prior to their exercise test. They had been given an exercise test upon entry to the study to determine the appropriate workload for the test. The investigators measured several markers of immune function 3 hours after performing the exercise on a stationary bicycle. The researchers reported that the production of interleukin-2 and the number of natural killer cells increased in the men who pretreated with fish oil, but not in those given a placebo. Interleukin-2 is a signaling molecule that regulates the activities of white Consumption of fish oil for 6 weeks prior to endurance exercise in untrained young men was associated with increased production of substances associated with protective immune responses. blood cells and responds to microbial infection. Along with other signaling molecules, it activates natural killer cells, which respond to viral infections a n d r e c o g n i z e stressed cells. These functions stimulate additional immune responses. The observed responses suggest that the consumption of fish oil enhanced protective immune responses after intense exercise. Whether these observations would have longer-term associations with susceptibility to infections was not examined in this short-term study. It would also be interesting to know whether similar responses would occur in older individuals who undertook endurance exercise. It has been reported that these immune responses are reduced in older adults, but the effect of exercise has not been explored. 15