Welcome to the first 2024 issue of Research Extracts. “The Extracts” is designed to keep busy practitioners and savvy consumers up to date on the latest research on diet, nutrients, botanicals, the microbiome, the environment, and lifestyle approaches to good health and wellness. Our medical team, including NDs, MDs, PhDs, RDs, an MS clinical nutrition, and an LAc, summarizes the essence of several interesting recent studies.

Reflective of current research trends, we start out with three recent studies that examine the effects of specific foods or supplements on cognitive function – olive oil, strawberries, and lion’s mane mushroom. The fourth extract takes a comprehensive look at the effects of multi-vitamin/mineral supplements on older men.

Mental Health Moment: Olive Oil and Cognition

Cognitive function and the expected decline with age affects many aspects of life. As the aging population continues to grow, effective preventive methods to protect cognition become key. The Mediterranean diet has been studied in many health capacities, including heart health, cancer prevention, and neurodegenerative diseases. This diet pattern emphasizes a high intake of plant foods, olive oil, and fish as the main sources of fat, and a low-to-moderate intake of animal foods and wine. 

The antioxidants and fatty acids in olive oil are believed to have neuroprotective effects against cognitive decline. This systematic review examined 11 studies that analyzed olive oil intake of adults ages 55 and older; the target outcomes included cognitive performance and the development of neurodegenerative diseases, like dementia. Food frequency questionnaires evaluated olive oil consumption. A variety of cognitive assessments were used, primarily attention, memory, processing speed, and executive functioning.

The results of the three randomized controlled trials in this review show that olive oil increased cognitive performance across the different assessment targets. The cohort and cross-sectional studies had more variability in results, with some studies showing improved memory and fluency and reduced cognitive decline. Overall, this review shows the potential positive effects of regular olive oil intake on cognition in older individuals. More research is needed to evaluate specifically how olive oil affects different aspects of cognition in different populations.

Note: To read more about the Mediterranean diet and how you can incorporate more olive oil and other health-promoting foods into your diet, check out Thorne's Wellness Guides – specifically the Metabolic Syndrome Guide, which includes Mediterranean diet recipes.

Contributed by Carly Duffy, MPH, RD

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Strawberry Supplementation Benefits Cognitive Aging

The polyphenols, like anthocyanins, present in strawberries, blueberries, and other brightly colored fruits and vegetables, offer many health benefits. Nutrients in berries resist the oxidative stress and inflammation that is characteristic of aging, and previous studies show berry consumption is beneficial for metabolic health, cognitive function, and general well-being. Can strawberry supplementation benefit cognitive aging in middle-aged individuals at increased risk for future cognitive decline?

Thirty men and women, ages 50-65, with BMI ≥25 and concerns of mild cognitive decline completed a 12-week trial of strawberry supplementation. Participants were randomized to receive either 13 grams of strawberry powder daily (equivalent to one cup whole fresh strawberries) or a placebo powder. Diet recall, fasting blood samples, anthropometric measures, neuropsychological testing, and a mood questionnaire were administered at baseline and after 12 weeks of supplementation.

The strawberry-treated group had less memory interference, indicating better cognitive control, compared to the placebo group. Regarding mood, strawberry supplementation was associated with lower levels of depressive symptoms, likely indicating improved coping and lowered stress. Although metabolic benefits were not reflected in this study, the authors note the small sample size, lower dose of anthocyanins, and short length of the study were limitations that might have led to the lack of additional findings.

Contributed by Jennifer L. Greer, ND, MEd

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Lion’s Mane Mushroom for Cognitive and Stress Support

Based on previous research showing lion’s mane mushroom (Hericium erinaceus) benefits cognitive function and mood in aging populations, the researchers tested its effects in a younger, healthy population. In a double-blind, placebo-controlled trial, 43 healthy adults (ages 18-45; average age 26) were randomly assigned to 1.8 grams of lion’s mane mushroom (n=21) or placebo (n=20) daily after breakfast for 28 days. Cognition was assessed via numerous cognitive performance tests and mood was measured via several visual analog scales – at baseline, 60 minutes after the first dose of test material (acute effects), and again at the end of 28 days (chronic effects).

After 60 minutes, the participants who took lion’s mane showed significantly better performance on the Stroop Test compared to their performance prior to taking the supplement. This test measures the speed and accuracy at which a person can name the color of a written color name (for example, the word “red” printed in blue). Although this same improvement was not seen in the placebo group, that group did have significantly better word recall than the lion’s mane group. After 28 days, the main outcome noted was a trend toward stress reduction in the lion’s mane group. With this relatively small sample size, statistical significance can be difficult to achieve. Although this study showed some promise, future studies with more participants might be more effective at showing statistical significance.

Note: Although lion’s mane might show promise for cognitive and stress support, combining it with synergistic ingredients might prove more beneficial. Thorne’s Daily Greens Plus combines lion’s mane with four other mushrooms, a seven-greens blend, adaptogenic herbs, and antioxidants for 360-degree support of cellular energy, cognitive performance, and physical endurance. You can also cook with lion’s mane, which is said to taste a bit like crab.

Contributed by Kathi Head, ND

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Multi-vitamin/mineral Supplementation Improves Cellular Energy and Vitamin Status in Older Men

Older adults are at risk of nutrient deficiencies due to decreased appetite and overall nutrient consumption. Although many recognize the benefits of a daily multi-vitamin/mineral supplement to account for nutrient gaps in the diet, a 6-month, randomized controlled trial of 35 healthy men (>67 years; average age 70) assessed whether a multi-vitamin/mineral supplement (MV/M) would impact blood micronutrient status or cellular metabolic function (measured by cellular oxygen consumption) in aging men.

Participants were randomized to receive either a MV/M supplement (n=17) or placebo (n=18) for six months. No other supplements were permitted, except for vitamin D, and those taking supplements prior were required to discontinue use at least two months before beginning the trial.

Fasting blood samples were collected at baseline and again after six months, which included a comprehensive metabolic panel and a complete assessment of micronutrient status, including serum concentrations of vitamin D (calcidiol) and vitamin B12; red blood cell folate; plasma concentrations of carotenoids and vitamins B6, C, E, and K; and plasma levels of the minerals copper, zinc, iron, magnesium, and selenium. Blood concentrations were assigned a status of “deficiency,” “insufficiency” (vitamin D only), or “sub-optimal.” High resolution oxygen consumption measurements of peripheral blood mononuclear cells were conducted, and a dietary recall questionnaire was given. 

At baseline, 33 of 35 participants had sub-optimal status of at least one of eight vitamins. Looking at specific vitamins, more than half of the participants had sub-optimal levels of vitamin C (57%), vitamin B12 (69%), and vitamin D (51%). Four participants had actual deficiencies at baseline, including one in vitamin D and three in vitamin K (phylloquinone).    

At the end of the 6-month study period, participants taking the MV/M supplement had improved their vitamin status compared to the placebo group. Specifically, MV/M usage improved blood concentrations of vitamins B6, D, and E, and beta carotene; whereas, the placebo group showed either no change or declines in blood vitamin concentrations at the trial end. 

MV/M usage also appeared to help prevent declines in cellular bioenergetic status as evidenced by a significant decline in cellular oxygen consumption in the placebo group at the end of the trial, a change not seen in the MV/M group.

Although no changes in blood mineral concentrations were found, it should be noted that the MV/M did not include minerals in their most absorbable forms as amino acid chelates, and that plasma measurements of some minerals, such as magnesium, are not always accurate indicators of nutrient status.

Note: Thorne offers several multi-vitamin/mineral formulations, including Basic Nutrients 2/Day, which is formulated with the active, tissue-ready forms of vitamins and amino acid-chelated minerals for optimal absorption. For more information on the nutrients in Basic Nutrients 2/Day, check out this article at Take 5 Daily. 

Contributed by Carina Toledo, MS Clinical Nutrition, MHI

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