Children may Benefit from Omega 3 Fatty Acids in Fish

 According to a new report from the University of Pennsylvania, children who eat fish at least once a week sleep better and have IQ scores that are 4 points higher, on average, than those who consume fish less frequently or not at all. These findings were recently published in Scientific Reports, a Nature journal.

Previous studies showed a relationship between omega-3s, the fatty acids in many types of fish, and improved intelligence, as well as omega-3s and better sleep. But they've never all been connected before. This work, conducted by Jianghong Liu, Jennifer Pinto-Martin and Alexandra Hanlon of the School of Nursing and Penn Professor Adrian Raine, reveals sleep as a possible mediating pathway, the potential missing link between fish and intelligence.

"This area of research is not well-developed. It's emerging," said Liu, lead author on the paper and an associate professor of nursing and public health. "Here we look at omega-3s coming from our food instead of from supplements." For the work, a cohort of 541 9- to 11-year-olds in China, 54 percent boys and 46 percent girls, completed a questionnaire about how often they consumed fish in the past month, with options ranging from "never" to "at least once per week. They also took the Chinese version of an IQ test called the Wechsler Intelligence Scale for Children-Revised, which examines verbal and non-verbal skills such as vocabulary and coding (!).

Their parents then answered questions about sleep quality using the standardized Children Sleep Habits Questionnaire, which included topics such as sleep duration and frequency of night waking or daytime sleepiness. Finally, the researchers controlled for demographic information, including parental education, occupation and marital status and number of children in the home. Analyzing these data points, the Penn team found that children who reported eating fish weekly scored 4.8 points higher on the IQ exams than those who said they "seldom" or "never" consumed fish. Those whose meals sometimes included fish scored 3.3 points higher. In addition, increased fish consumption was associated with fewer disturbances of sleep, which the researchers say indicates better overall sleep quality.

"Lack of sleep is associated with antisocial behavior; poor cognition is associated with antisocial behavior," said Adrian Raine, who has appointments in the School of Arts and Sciences and Penn's Perelman School of Medicine. "We have found that omega-3 supplements reduce antisocial behavior, so it's not too surprising that fish is behind this.

The researchers see strong potential for the implications of this study. "It adds to the growing body of evidence showing that fish consumption has really positive health benefits and should be something more heavily advertised and promoted. Children should be introduced to it early on. That could be as young as 10 months, as long as the fish has no bones and has been finely chopped, but should start by around age 2.  Introducing the taste early makes it more palatable. It really has to be a concerted effort, especially in a culture where fish is not as commonly served or smelled. Children are sensitive to smell. If they're not used to it, they may shy away from it."

Given the young age of this study group, Liu and colleagues chose not to analyze the details participants reported about the types of fish consumed, though they plan to do so for work on an older cohort in the future. The researchers also want to add to this current observational study to establish, through randomized controlled trials, that eating fish can lead to better sleep, better school performance and other real-life, practical outcomes.

For the moment, the researchers recommend incrementally incorporating additional fish into a diet; consumption even once a week moves a family into the "high" fish-eating group as defined in the study.

"Doing that could be a lot easier than nudging children about going to bed," Raine said. "If the fish improves sleep, great. If it also improves cognitive performance -- like we've seen here -- even better. It's a double hit."  

Families who are vegetarians may consider making an exception and giving their children chewable fish oil capsules. 

Dear Reader – I will be going away for a month, so my columns will not resume until late in February. Past issues are at sadjascolumns.blogspot.com. Call me with any questions – I’m in the Bolinas Yellow pages, and you can get my cell phone from that number.   Sadja Greenwood, MD

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Colon Cancer Survival Helped by Nut Consumption

 A new study sponsored by the Dana Farber Cancer Institute in Boston looked at people diagnosed with colon cancer, and found that eating tree nuts  lowered their chances of cancer recurrence. An observational study of 826 patients with stage III colon cancer showed that those who consumed two ounces or more of nuts per week had a 42% lower chance of cancer recurrence and 57% lower chance of death than those who did not eat nuts. The questionnaire was given after completion of chemotherapy in a study that began in 1996.  Stage III colon cancer is defined as cancer that has spread to surrounding lymph nodes.

 “Basic healthy eating can often be overlooked during cancer treatment. This study shows that something as simple as eating tree nuts may make a difference in a patient's long-term survival," said Dr. Daniel F. Hayes. "Nut consumption and a healthy diet are generally factors that clinicians and patients should perhaps pay attention to as they design the approach to treatment for colorectal cancer." A secondary analysis revealed the benefit of nut consumption was limited to tree nuts. Tree nuts include almonds, walnuts, hazelnuts, cashews, and pecans, among others. There was no associated reduction in cancer recurrence and death among patients who consumed peanuts or peanut butter. According to the authors, the reason may be that, being legumes, peanuts have a different metabolic composition than tree nuts

"Numerous studies in the fields of heart disease and diabetes have shown the benefits of nut consumption, and we felt that it was important to determine if these benefits could also apply to colorectal cancer patients," said lead study author Temidayo Fadelu, MD, a clinical fellow in medicine at Dana Farber Cancer Institute. "Patients with advanced disease who benefit from chemotherapy frequently ask what else they can do to reduce their chances of recurrence or death, and our study is an important contribution to the idea that modifying diet and physical activity can be beneficial."

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Researchers were particularly interested in nut consumption because it has been linked to lower incidence of obesity, type 2 diabetes, and reduction in insulin resistance. These health conditions are each associated with a higher risk of recurrence and death from colon cancer. The benefit of eating nuts was consistent across known factors that can influence cancer recurrence, including patient age, body mass index, gender, and common genomic changes in the tumor.

"It should be emphasized that the authors are not suggesting that eating nuts should be considered a substitute for standard chemotherapy and other treatments for colon cancer, which have dramatically improved survival," said Dr. Hayes. "Rather, patients with colon cancer should be optimistic, and they should eat a healthy diet, including tree nuts, which may not only keep them healthier, but may also further decrease the chances of the cancer coming back."

"We need to look at the potential positive impact of nut consumption on survival at other stages of colon cancer, particularly stage IV. (Stage IV colon cancer is defined as cancer that has spread to other organs, such as liver or lungs.) Ultimately, we need to understand how nuts confer this protective effect, as well as possibly conduct a randomized, controlled clinical trial where diet recommendations are given at the start of the study to prove that tree nuts can reduce recurrence and death after treatment for colon cancer," said Dr. Fadelu.

Here’s a take-home message from this positive finding.  It’s a good idea to put nuts into your diet now – they can also help to prevent overweight, diabetes and heart disease.  Peanuts have also been found to have positive effects on our health.  If they fill you up with healthy fat, you’ll be ahead when it comes to super-sweet deserts!

Sadja Greenwood, MD, MPH