Welcome to the June 2019 issue of Thorne’s Research Extracts – designed to keep busy practitioners and savvy consumers up-to-date on the latest research on the microbiome, the environment, diet, nutrients, botanicals, and lifestyle approaches to good health. Our medical team, which includes NDs, MDs, PhDs, RDs, and an MS, LAc, and CCN, has summarized the essence of several of the most interesting studies.

In this issue: (1) lutein supports brain function, (2) dietary effects on depression and cognitive function, (3) yoga can improve attention and decrease hyperactivity in kindergarteners, and (4) aerobic exercise effects on cognition.

Lutein supports brain function in overweight adults

Carotenoids, the orange and yellow compounds found in a range of foods, include beta-carotene, lutein, lycopene, astaxanthin, and zeaxanthin. While carotenoids can act generally as antioxidants, they are also known to be supportive of specific tissues such as the eye, the brain, the prostate, and the heart.

It has long been known that being overweight or obese are both risk factors for decreased memory and brain function. Because carotenoids are safe and easy-to-obtain nutrients, researchers sought to determine if carotenoids could help to support healthy brain function in overweight adults. 

Ninety-four individuals (ages 25-45) were evaluated for dietary carotenoid levels, as well as blood and eye carotenoid levels (because some carotenoids concentrate in the eye). Relational memory performance and IQ were also evaluated.

The researchers found that a higher lutein level in the blood was associated with greater relational memory performance.

Dietary levels of lutein and zeaxanthin, and also dietary and serum levels of beta-carotene, correlated with performance, although not at a statistically significant level. The results indicate that lutein might help to protect brain function in adults who are at risk due to being overweight.

Contributed by Jacqueline Jacques, ND

Reference

  • Cannavale C, Hassevoort K, Edwards C, et al. Serum lutein is related to relational memory performance. Nutrients 2019;11(4):E768. doi: 10.3390/nu11040768

Diet affects cognitive function and mood

Subjective cognitive decline (SCD) is a precursor to mild cognitive impairment and a reflection of a person’s own observations of their cognitive decline. Although the person reports that their memory is not what it used to be, the decline is so mild it can’t be verified with objective testing.

A group of 165 Dutch adults, average age 64, took part in a memory clinic study of the effect of diet on cognitive function. The Dutch Healthy Diet Food Frequency Questionnaire was used to assess dietary intakes of vegetables, fruit, fiber, fish, saturated fat, trans fatty acids, salt, and alcohol.

Global cognition was assessed according to the Mini Mental State Examination (MMSE). Subjective cognitive complaints were assessed by a Cognitive Change Index self-report, while depression symptoms were assessed with the Center for Epidemiologic Studies Depression Scale. 

In assessing the food questionnaires, three distinct dietary patterns were identified: (1) low-fat, low-salt; (2) high veggie; and (3) low-fish, low-alcohol.

High vegetable intake was associated with higher scores on the MMSE, while low adherence to the low-fat, low-salt diet was associated with higher rates of depressive symptoms.

The low-fish, low-alcohol dietary pattern was not associated with any differences in test evaluations.

Contributed by Kathi Head, ND

Reference

  • Wesselman L, Doorduijn A, de Leeuw F, et al. Dietary patterns are related to clinical characteristics in memory clinic patients with subjective cognitive decline The SCIENCe Project.  Nutrients 2019 May 11:11(5): doi: 10.3390/nu11051057

Editor’s Note: Based on these first two Research Extracts, it might be wise to eat your fruits and veggies, especially those that are high in lutein. According to a study in the British Journal of Ophthalmology, the foods highest is lutein, in order of molar percent carotenoids, include: corn, egg yolks, kiwi, red seedless grapes, zucchini, pumpkin, spinach, yellow squash, cucumber, and peas. Orange peppers are the highest in zeaxanthin, but not so high in lutein.

Or you can try Memoractiv™ – Thorne’s new formula for cognitive support.*

Memoractiv contains both lutein and zeaxanthin, along with several other unique ingredients.

Following are two Research Extracts pointing to the importance of exercise for cognitive function – yoga and aerobic exercise.

Yoga improves attention and decreases hyperactivity in 5-year-old children

The ancient practice of yoga has been used for thousands of years to help maintain the health of body and mind. Advancements in modern science and solid scientific studies are revealing the mechanisms behind the benefits of yoga, long known to yogis.

Studies have now demonstrated that yoga supports working memory, alleviates stress, and promotes cognitive performance in adults.

These benefits could in part be explained by anatomical changes observed in the brains of yoga practitioners, such as increases in: (1) gray matter (important to intelligence), (2) the prefrontal lobe (center for communication, reasoning, time management), (3) the amygdala (to modulate stress emotions and motivation), and (4) the hippocampus (long-term memory and emotional response). 

Functional effects and structural brain changes are also being observed in children who engage in yoga. For example, significant improvements in anger control, spatial memory, strategic planning, concentration, academic performance, and several measures of executive function (impulse control, emotional regulation, flexible thinking, self-monitoring, prioritizing, and organization) have been documented.

These improvements have often been accompanied by reductions in the symptoms of stress and behavioral problems.

In this current 12-week study, 45 Tunisian kindergarteners were divided into three groups: 15 participated in 30 minutes of yoga twice weekly, 15 participated in non-yoga exercise twice weekly, and 15 did not engage in any structured exercise.

Although none of the children had been diagnosed with ADHD, behaviors of inattention and hyperactivity were evaluated by their teachers. At the end of the study, significant improvements in skills related to cognitive function, such as visual attention and visual motor precision, along with improvements in behaviors related to attention and hyperactivity were reported.

Based on these findings, the authors concluded that yoga has great potential to facilitate learning, contribute to academic achievement, and improve quality of life in children.  

Contributed by Danielle Paciera, RD, CCN

Reference

  • Jarraya S, Wagner M, Jarraya M, Engel FA. 12 weeks of kindergarten-based yoga practice increases visual attention, visual-motor precision and decreases behavior of inattention and hyperactivity in 5-year-old children. Front Psych 2019 Apr 10;10:796. doi:10.3389/fpsyg.2019.00796

Aerobic exercise increases protection for brain health as you age

We all know that exercise has many health benefits. Long-mounting evidence points to exercise for improving memory and supporting healthier brain aging, although very few controlled studies have been conducted.

This study compared the benefits of aerobic exercise and a non-aerobic activity (stretching and toning exercises) in 132 individuals, ages 20-67. All participants were assessed as generally healthy non-smokers with normally assessed cognitive function, with the exception of being “sedentary habitual non-exercisers who qualified as below average fitness by American Heart Association standards.”

After 24 weeks, the study found that aerobic exercise led to significant improvement in executive function in participants of all ages, with the effect being more profound as age increased.

Positive changes followed the same pattern in the subset of individuals who had a genetic marker related to Alzheimer’s Disease (the APOE e4 allele), although improvement in that group was not as pronounced. This study clearly adds to our knowledge that exercise is important for a healthy brain, and it’s never too late to start!

Contributed by Jacqueline Jacques, ND

Reference

  • Stern Y, MacKay-Brandt A, Lee S, et al. Effect of aerobic exercise on cognition in younger adults: A randomized clinical trial. Neurology 2019;92(9):e905-e916.