By Katherine Lee | Medically reviewed by Pat F. Bass III, MD, MPH
Food allergies may be connected to adult ADHD symptoms. Learn how following an elimination program, such as the Feingold Diet, may help you identify your triggers and create your own ADHD diet.
Eating certain foods and following an elimination diet such as the Feingold Diet, which cuts out food additives among other guidelines, can help.
Keep in mind that there is no such thing as a set adult ADHD diet.
“There is no one diet because there is not one cause,” says Sally Hara, MS, RD, a spokesperson for the American Dietetic Association and a nutritionist in Kirkland, Wash. “The ADHD diagnosis is made based on a description of symptoms.”
The second point to remember is that for adult ADHD patients it’s not only what you eat, but also when you eat that matters.
“I look at basic overall nutrition,” says Hara. “Adults get busy and distracted. They may skip meals. When blood sugar is not stable, we don’t multitask as well.”
When people have low blood sugar, they may get grumpy and may not be able to process sensory stimulations such as a TV, phone, and people talking, says Hara. “It happens to everybody, but it’s amplified in people with ADHD.”
What to Include and Avoid in an ADHD Diet
Within the last 10 years, researchers have been making the link between diet and ADHD, says Elizabeth Strickland, MS, RD, an integrative dietitian specializing in ADHD and autism in San Antonio, Texas. Studies have found some foods worsen symptoms while others may improve them.
Among foods that have been connected to worsening symptoms of adult ADHD are:
- Sugar. “We consume over one hundred and fifty pounds of white sugar a year,” says Strickland, pointing out that a 32-ounce cola has 32 teaspoons of sugar. “The blood sugar level rises quickly in our bloodstream and dumps insulin into the body. The body dumps adrenaline in response, and the blood sugar levels go up and down. This aggravates aggression and makes you crave more sugar.” While high-fructose corn syrup is a major culprit, honey and raw sugar can also contribute to this blood sugar spike.
- Food additives. “Manmade artificial chemicals such as food coloring, flavors, and preservatives are toxins that your body has to remove,” says Strickland. “If your body isn’t able to remove them efficiently, it can lead to problems such as headaches, asthma, and aggression.”
These foods may aid brain function and help reduce the symptoms of adult ADHD:
- Omega-3 fatty acids. Research has shown that a deficiency of omega-3 fatty acids may be linked to an increased risk of ADHD. “It likely has to do with myelin sheaths [the protective membrane surrounding the nerves of the brain and spinal cord] being made up almost entirely of fatty acids,” says Hara. “Supplements can be helpful for a lot of people. I recommend 3,000 milligrams a day.”
- Caffeine. “Studies have shown a small amount of caffeine can improve concentration and attention,” says Strickland. “Try having one cup of coffee in the morning and a cup of green tea in the afternoon.”
- Protein. “Protein is extremely critical,” says Strickland. “Protein provides amino acids used to make neurotransmitters for the brain, such as dopamine and serotonin. These chemical messengers control mood and concentration.”
- Complex carbohydrates. “Our primary source for fuel is carbs,” says Hara. “We have very low glycogen stores — that’s what we use for fuel after our bodies have broken down carbs. If you don’t have enough glycogen stores, you’re setting yourself up for low blood sugar, which is counter-productive to concentrating.” Getting the right carbs is a must. “Most individuals are consuming too much soda, sugar, and white grains,” says Strickland. “We need to transition to whole grains.”
- Herbs. “Research shows that ginkgo biloba and ginseng may improve brain function and attention and may prevent dementia,” says Strickland. “Try it for one month. Do you respond? If so, continue. If not, don’t.” Some people see benefits from herbs while others do not, she explains.
Trying an ADHD Elimination Diet
“Research within the last 15 years shows that people with ADHD have a higher rate of food allergies,” says Strickland. But many adults do not associate their symptoms with food sensitivities, says Hara. “They may be depressed or agitated and write it off to normal aging or stress when it isn’t,” she explains. “I’ve had adult ADHD patients in their 20s and 30s who couldn’t sit during appointments. Then once [certain] foods were eliminated, they were able to sit still six months later.”
The idea behind trying an elimination diet is to take away potential allergens and slowly add them back in to see which foods might be triggering symptoms of adult ADHD. “The same foods will not have the same effects for everybody,” says Hara.
One elimination diet in particular is the Feingold Diet, developed by the late pediatrician and allergy specialist Ben Feingold, MD, in the 1960s and originally intended only to help allergy symptoms. It is based on eliminating foods and medications containing salicylate compounds, such as aspirin, as well as additives like food colorings. The diet had the unexpected benefit of easing certain behavior problems and, in the decades that followed, has grown in popularity as an option for children and adults with ADHD.
ADHD Nutrient Research Update
A recent review looked at numerous studies evaluating the role certain supplements might have in the treatment of ADHD. So far, only zinc showed that it may help ADHD symptoms. Results were mixed on L-carnitine, pycnogenol, and essential fatty acids and inconclusive for iron and magnesium, SAM-e, and tryptophan. St. John’s wort, tyrosine, or phenylalanine in particular showed no ability to help ADHD symptoms.
As research continues, hopefully more specific nutrients will be found to help manage adult ADHD. But for now, trying an elimination diet holds the most promise.