Fish in Moms' Diets Fuel Growth of Newborn Brains

Pregnant moms who ate fish fatty acids had more mature newborns

By Adam Marcus
HealthScoutNews Reporter

THURSDAY, Aug. 22 (HealthScoutNews) -- Pregnant women who eat more of a key fatty acid found in fish have babies who show signs of more mature brain development, a new study has found.

Those newborns whose mothers had more of it in their blood had heartier sleep patterns in the first 48 hours after delivery compared to those whose mothers consumed less of the compound, known as docosahexaenoic acid (DHA).

Infant sleep patterns are thought to reflect the maturity of their nervous system, and have been correlated with more rapid development in their first year of life. A report on the findings appears in the September issue of the American Journal of Clinical Nutrition.

An omega-3 fatty acid, DHA, along with another substance, arachidonic acid (AA), are key building blocks in breast milk that contribute to healthy brain and eye development. Indeed, acknowledging the advantages of these compounds, two of the nation's largest formula makers, Ross Products and Mead Johnson Nutritionals, announced earlier this year that they would begin adding them to select brands.

The two substances are also passed from mother to fetus across the placenta. Some 70 percent of brain cell development takes place during gestation.

In the new study, Carol Lammi-Keefe and her colleagues at the University of Connecticut compared DHA levels and newborn sleep patterns in 17 women and their babies. Ten of the women had high blood concentrations of DHA -- considered to be more than 3 percent of their total circulating fatty acids -- while seven had less than that amount.

Lammi-Keefe's group didn't ask the women about their diets. None of the subjects in the study had DHA levels that reflect eating three or more fish meals a week, what many experts recommend. Other foods, like eggs and red meat, contain modest amounts of the nutrient, but cold-water fish such as tuna and mackerel are considered the best source.

Women with low DHA were more likely to be minorities and to have received fewer years of education. They were also five years younger, on average, than those in the high DHA category -- 24 versus 29 years.

All the babies were delivered vaginally, and none of the women had been given drugs known to make newborns lethargic, the researchers say.

Using a motion-sensing pad to measure breathing and movement during sleep cycles, the researchers found babies of women in the low-DHA group had less advanced sleeping patterns than the other infants. They had a greater ratio of "active" to "quiet" sleep, spent more time transitioning between sleeping and waking, and spent less time fully awake than those of women with higher blood levels of the fatty acid.

"As an infant matures, normally you would see the infant spending more time in a wakeful state," Lammi-Keefe says. "Infants born to mothers with more DHA have sleep characteristics of a more mature central nervous system compared with the infants of mothers with lower DHA levels."

The researchers are now organizing a study that will look at dietary intake of DHA in pregnant women. It will follow their children over the course of a year to assess the substance's impact on development. Lammi-Keefe says she hopes to enroll between 140 and 160 women in the project.

June Machover Reinisch, director emerita of the Kinsey Institute and a child development expert, says the findings seem to echo the importance of breast feeding for optimal infant growth. However, she notes it's difficult to draw meaningful conclusions from the research.

After all, many factors, from method of delivery and the use of anesthesia during labor to the infant's gender, can influence a newborn's wakefulness.

"We have to be flexible in our definition of development," Machover Reinisch says. "With the child who sleeps not as well at two days, it may be related to the DHA, but it doesn't necessarily mean that there's going to be a problem with that child."

Researchers have correlated newborn sleep states with performance on mental and motor developmental tests at 9 months of age. However, both Lammi-Keefe and Reinisch say there's no way to predict whether a child with less mature sleeping habits in the first week of life will be anything other than healthy.



Study Ties Fish-Rich Diet to Lower Dementia Risk

NEW YORK (Reuters Health) - Fish may indeed be "brain food," if new study findings are any indication.

French researchers found that among the elderly adults they studied, those who regularly ate fish and other seafood at the study's start were less likely than others to develop dementia--including Alzheimer's disease--over the next 7 years.

The findings do not prove that fish has a direct effect on dementia risk, and the study authors point out that the fish eaters' relatively higher education partly explain the connection they found.

However, they also note that the healthful fatty acids in fish could have brain-protective effects.

Dr. Pascale Barberger-Gateau and colleagues at the Universite Victor Segalen Bordeaux report the findings in the October 26th issue of the British Medical Journal.

The researchers followed more than 1,400 adults aged 68 and older for at least 2 years, and up to 7. At the outset, participants reported whether they ate fish and other seafood daily, weekly, less often or never. Their meat-eating habits, as well as their education levels, were also recorded.

Participants who ate fish or seafood at least once a week were found to be 34% less likely than less-frequent fish eaters to develop dementia over 7 years. When the researchers factored in education levels, the fish-dementia association weakened somewhat, however.

"The 'protective' effect of weekly fish or seafood consumption was partly explained by higher education of regular consumers," Barberger-Gateau's team writes.

A number of studies have suggested that people with higher education may be less vulnerable to memory loss and mental impairment as they age because they have what is called a greater "brain reserve."

However, factors that harm cardiovascular health, such as high cholesterol and high blood pressure, have also been tied to Alzheimer's risk. And one form of dementia called vascular dementia results from an inadequate blood supply to the brain.

The French researchers note that fish fatty acids could be involved in dementia risk by protecting vascular health--or, alternatively, by reducing inflammation in the brain.

Dementia has a number of underlying causes, with Alzheimer's disease being the most common form. Experts believe that age, genetics and lifestyle and environmental factors that are not yet fully clear all contribute to Alzheimer's risk.

SOURCE: British Medical Journal 2002;325:932-933.




Fish-Rich Diet May Reduce Levels of Fat Hormone

fish A diet rich in fish may lower levels of the fat-regulating hormone leptin, scientists say. Previous findings have linked elevated levels of leptin, which is produced by fat cells in the body, to obesity and cardiovascular disease. The substance seems to tell the body when it has consumed enough food, and researchers posit that obese people somehow lose the ability to recognize these chemical cues. But exactly how the system works and what other factors influence the hormone’s levels are unknown. The new work, published today in the journal Circulation, suggests that diet plays a key role.

Scientists have known for some time that fish or fish oil seems to provide some protection against cardiovascular disease in humans. And earlier studies in rats indicated that unsaturated fatty acids in fish may affect leptin levels. Mikolaj Winnicki of the Mayo Clinic and his colleagues thus wanted to see if a fish-rich diet has a similar effect on the hormone in humans. To do this, the team examined the body mass index (a relationship between height and weight), fat content, age, gender, diet, and leptin levels of about 600 individuals from the same tribe in Tanzania. Half of the subjects lived on a lake and ate a lot of fish; the others were vegetarians. The scientists found that for every study characteristic except diet and leptin levels the two groups were identical. The fish-eaters, however, possessed significantly lower levels of the hormone than did their inland counterparts, even though body mass index--typically an important indicator of leptin levels--was the same for both groups. Additionally, although women generally possess higher levels of the hormone than men do, the investigators found the leptin levels of women who ate fish to be less than half that of both the female and male vegetarians. "We speculate that a fish diet may change the relationship between leptin and body fat and somehow help make the body more sensitive to the leptin message," remarks team member Virend Somers, also at the Mayo Clinic.

  The authors caution against extrapolating diet recommendations from these results, however. "These are African individuals living in a fairly rural environment," Somers notes. "We don't know if the findings will apply to a semi-overweight, urban-dwelling North American population." The researchers plan to further probe this relationship by looking at whether leptin levels change in people who increase their fish consumption. --Rachael Moeller