Nutrition Bytes: September 2022

Increased Fruit and Vegetable Intake Reduces ADHD Symptoms in Children

Recent research suggests that eating more fruits and vegetables may improve attention in children with attention deficit hyperactivity disorder (ADHD). This research comes at a time when ADHD—a neurodevelopmental disorder characterized by a pattern of inattention and/or hyperactivity—affects one in 10 children in the United States. While ADHD is related to a variety of factors, researchers are looking at modifiable environmental factors, such as diet, for clues on how to help.

Child holding basket of vegetablesThe MADDY Study, completed in May 2022, analyzed the diets of 134 children between six and 12 years old and compared various aspects of their diet with symptoms of ADHD.1 The study found children who ate less fruits and vegetables were more likely to have severe symptoms of inattention. The findings of this study are consistent with previous studies that show lower fruit and vegetable intake is associated with a higher prevalence of ADHD diagnosis.

Fruits and vegetables are well known to be nutrient dense in a wide variety of vitamins, minerals, and phytonutrients, unique plant compounds known for their health benefits. The micronutrients found in fruits and vegetables play important roles in neurotransmitter synthesis, necessary for healthy brain function. While the MADDY study did not analyze the differences between organic and conventional fruits and vegetables, other studies have found a significant association between pesticide exposure and severity of ADHD symptoms.2 Based on the current research, incorporating more organic fruits and vegetables into your children’s diet is a smart move toward better brain health.

Low Vitamin K Status Associated with Cognitive Decline

Previous research has shown that low vitamin K status is associated with aging-related diseases, including osteoporosis and osteoarthritis, and now a brand-new study adds to these findings, demonstrating a potential connection between vitamin K insufficiency and cognitive impairment in older individuals.3 In the study, 800 older adults with an average age of 75 and living in Tokyo, were given a comprehensive geriatric health examination. The evaluation consisted of a Mini Mental State Examination (MMSE) to assess cognitive function and a blood test to measure levels of undercarboxylated osteocalcin (ucOC), with higher levels of this protein indicating greater vitamin K insufficiency. Researchers then evaluated the relationship between cognitive function and vitamin K status, finding that as levels of ucOC increased or vitamin K insufficiency worsened, so too did the likelihood of cognitive impairment. More specifically, individuals with the highest levels of ucOC had an increased prevalence of worse scores on the MMSE, particularly in the areas of orientation, calculation, and language.

Trees trimmed to the shape of the profile of of a head Vitamin K is an often forgotten about nutrient, but studies like the one just described are an important reminder that getting adequate amounts is vitally important for maintaining our health throughout our years, including our cognition and mental faculties. Technically not a single vitamin, but a group of fat-soluble vitamins that includes two main forms (K1 or phylloquinone and K2 or menaquinone), adequate vitamin K is also essential for proper blood clotting, calcium metabolism, and cardiovascular, immune, bone, and reproductive health.


  1. Robinette, L. M., Hatsu, I. E., Johnstone, J. M., Tost, G., Bruton, A. M., Leung, B. M. Y., Odei, J. B., Orchard, T., Gracious, B. L., & Arnold, L. E. (2022). Fruit and vegetable intake is inversely associated with severity of inattention in a pediatric population with ADHD symptoms: the MADDY Study. Nutritional Neuroscience, 1–10.
  2. Tessari, L., Angriman, M., Díaz-Román, A., Zhang, J., Conca, A., & Cortese, S. (2022). Association Between Exposure to Pesticides and ADHD or Autism Spectrum Disorder: A Systematic Review of the Literature. Journal of Attention Disorders, 26(1), 48–71.
  3. Azuma, K., Osuka, Y., et al. (2022). Association of vitamin k insufficiency with cognitive dysfunction in community-dwelling older adults. Front. Nutri.