How often is fish on your family’s menu? A new study from the University of Pennsylvania published in the journal Scientific Reports found that children who eat fish once a week or more sleep better and score higher on IQ tests than children who never eat fish or eat it less than once a week.

Previous studies have shown that the omega-3 fatty acids found in fish like salmon, sardines, and tuna can improve intelligence and sleep, and that better sleep can boost IQ scores. This is the first research that has linked all three components, however. In fact, researchers believe that improved sleep resulting from consuming more omega-3s is what increases IQ rather than the fatty acids themselves.

A good night’s sleep is essential for our children’s health and happiness. Besides keeping a child’s temper in balance, sleep provides many essential benefits for our growing children. While asleep, children process and absorb what they have learned. Their bodies have the chance to recover and repair themselves.

Sleep also plays a major role in mood management. Lack of sleep can lead to an increase in negative behaviors, like anxiety, impatience, aggression, irritability, and poor school performance.

During this new study, more than 500 Chinese children between the ages of nine and 11 responded to a survey about how often they ate fish. When the children turned 12, they completed an IQ test that scored their verbal and nonverbal skills. Children who ate fish weekly scored 4.8 points higher on the IQ tests than those who said they “seldom” or “never” ate fish. “Sometimes” eaters of fish scored 3.3 points higher on IQ exams.

In addition, parents answered questions about their children’s sleep patterns, including how often they wake in the middle of the night and their daytime sleepiness. The responses showed that those children who ate more fish had fewer disturbances while sleeping, indicating better overall sleep quality.

Omega-3 fatty acids have been found to affect sleep in several ways. Animal studies suggest the potential role of the fatty acid DHA in regulating the production of melatonin, which has been shown to regulate circadian rhythm and improve sleep.

Essential fatty acids have helped produce prostaglandins, which are believed to be the most effective sleep-promoting substance and regulate sleep/wake patterns. Epidemiological studies have also shown a link between increased fish intake and improved sleep in children.

The researchers recommend that parents gradually add fish to their children’s diet, starting when they are young if possible. As long as the fish has no bones and has been finely chopped up, children can begin eating it by around age two.

There are some concerns regarding the toxicity of fish to keep in mind. Decades of industrial activity, particularly emissions from coal-fired power plants, have released mercury and other pollutants into oceans and waterways. Unfortunately, those contaminants can end up in the seafood we eat. Concentrations vary depending on the fishes’ age, diet, region of harvest, and other factors.

Large predatory fish, including tuna, shark, marlin, and swordfish, accumulate considerable mercury since they eat smaller fish. These types of fish pose a significant risk to children. They should eat no more than one serving of canned light tuna per week and should never eat canned albacore tuna, also known as white tuna.

In addition, not all fish contain beneficial levels of omega-3s. According to the Environmental Working Group (ERG), eight of the 10 seafood species most popular in the American diet are very low in omega-3s. Therefore, it is important to evaluate which types of fish to feed your children.

ERG provides an incredible resource called their Consumer Guide to Seafood, which allows you to look up a customized seafood list based on age, weight, and other factors.