Attention Deficit/ Hyperactivity Disorder (ADHD) is the most common and fastest growing disease among children in the United States, although adults can be affected as well. Characterized by inattention, hyperactivity and impulsiveness, ADHD is a complex condition commonly treated with stimulants such as Ritalin. As an alternative or adjunct to conventional medication, dietary changes are often helpful. Addressing the four most important nutritional issues – essential fats, pesticides, food allergens and simple carbohydrates – can have a positive impact on learning ability, focus, concentration and memory in children and adults affected by ADHD.
Essential Fatty Acids
The brain is sixty percent fat, so it is no wonder that essential fatty acids play a prominent role in mental function. Omega-3 fat docosahexaenoic acid (DHA) is the primary fatty acid in brain cells and accounts for approximately 30 percent of the total brain fat. Studies have shown that, on average, children diagnosed with ADHD have lower levels of omega-3 fats such as DHA in their blood. Other studies have shown that supplementing these important nutrients can correct symptoms.
In a randomized, double-blind clinical trial, researchers at Purdue University studied fifty children with ADHD. For four months, one of the two groups received a daily supplement containing omega-3 fatty acids, including 480 milligrams of DHA. The other group was given olive oil, which is a healthy fat but low in omega-3 fatty acids. Results were based on reports from parents and teachers and evaluated children in four areas: hyperactivity, attention, conduct and Oppositional/Defiant Disorder. Although children in both groups showed significant improvement in most symptoms, those receiving the supplement containing DHA had consistently better results, especially in the areas of conduct and attention.
The best dietary sources of DHA are small, wild fish that live in cold water like salmon, halibut, herring, sardines and anchovies. Avoid large predatory fish at the top of the food chain, like tuna, shark and marlin because they are often contaminated with industrial pollutants like mercury, a heavy metal that can interfere with brain function, learning ability and behavior. Visit the Seafood Watch website of the Monterey Bay Aquarium to search for safe choices in your area. For those who don’t eat fish, or don’t eat it several times per week, fish oil is the next best thing.
Although anyone can be adversely affected by pesticides, children are most susceptible because their brains are still developing. Infants under one year of age are especially at risk because their blood-brain barrier, a protective membrane that filters compounds passing from the blood to the central nervous system, isn’t fully formed yet and harmful substances pass more easily into areas where they can cause permanent impairment.
A study at the University of Arizona demonstrated a clear connection between pesticide poisoning and cognitive problems in children. Researchers looked at four- and five-year olds in Mexico with similar diets, water mineral contents, genetic backgrounds, and cultural and social traditions. One group lived in areas where pesticide use was routine on local farms and in households, while the other group lived in areas where pesticides were not used. The children exposed to pesticides scored lower in gross and fine eye-hand coordination, stamina, thirty-minute memory and drawing ability.
Eating organic ensures that foods contain no pesticide residue. When an organic-only diet isn’t possible, make smart produce choices. The most recent report from the nonprofit research organization Environmental Working Group (EWG) analyzed more than 43,000 tests performed by the Department of Agriculture and the Food and Drug Administration (FDA). They found that the 12 most contaminated fruits and vegetables are (in descending order) apples, peaches, sweet bell peppers, celery, nectarines, strawberries, cherries, pears, imported grapes, spinach, lettuce and tomatoes. The 12 least contaminated produce items include (in ascending order) onions, avocado, frozen sweet corn, pineapples, mango, asparagus, frozen sweet peas, kiwi, bananas, cabbage, broccoli and papaya. EWG concluded that consumers can cut their pesticide ingestion by almost 90 percent when they replace the most contaminated fruits and vegetables with those that are least contaminated.
Eliminating certain foods from the diet is sometimes helpful for individuals with ADHD. Allergies and intolerances to foods can have negative effects on any body system, including the brain. While only a small number of people are affected by true food allergies, food intolerance is much more common. The difference is that food allergies involve an immune reaction, which can be life threatening, while intolerances involve a problem with metabolism or digestion that can be uncomfortable but not fatal. The most common foods to offend include wheat, cow’s milk, eggs, soy, nuts, fish and shellfish. Blood tests are available, but an elimination diet can also be used to identify problematic foods.
Additives in processed foods also have great potential for food allergy and intolerance. The FDA has approved more than 28,000 chemicals for addition to foods – including sweeteners, dyes, artificial flavors, preservatives, hydrogenated oils and flavor enhancers like monosodium glutamate (MSG) – and estimates that the average child consumes 150 to 300 milligrams of additives per day from processed foods, beverages and candy. Replace processed foods with whole foods to avoid food additives.
Foods high in sugar affect individuals with ADHD in a unique way. All cells in the body require glucose, the simple sugar produced when carbohydrates are digested. Unlike other cells, brain cells do not have the ability to store glucose for later use and require a constant supply. After eating carbohydrates, blood glucose levels rise and the pancreas secretes insulin to allow the glucose to enter cells, reducing levels circulating in the blood. As blood sugar levels begin to drop, the adrenal glands produce epinephrine and norepinephrine, neurotransmitters that increase the uptake of glucose into brain cells to offset the effects of insulin and increase alertness and concentration. In individuals affected by ADHD, this process may be impaired.
Researchers at Yale University used PET scans and a meal high in glucose to compare children with and without ADHD. They found that glucose and insulin levels were similar in both groups, but levels of epinephrine and norepinephrine were much lower in children who had been diagnosed with ADHD. These children scored lower on cognitive tests and exhibited increased physical activity and faster reaction times. Physical activity stimulates the adrenal glands to produce more norepinephrine, which compensates for the lower levels found in children with ADHD.
Individuals with ADHD should avoid simple carbohydrates, such as foods made with sugar and flour, as well as processed foods and those that are individually problematic. A balanced diet of healthy fats, protein and complex carbohydrates like vegetables, fruits, beans and whole grains, will balance both blood sugar and brain chemistry.