Welcome to the February 2023 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. Our medical team, which includes NDs, MDs, PhDs, RDs, an MS, and an LAc, has summarized the essence of several interesting recent studies.

In this issue: (1) Mental Health Moment: carotenoids and brain health, (2) green tea and telomere length, (3) Mediterranean diet and pregnancy outcomes, and (4) vitamin D, folate, and iodine during pregnancy.

Mental Health Moment: Dietary Carotenoids and Cognitive Performance

Although aging is often associated with cognitive decline, there are preventive measures that a person can take to help decrease the risk for cognitive impairment, including Alzheimer’s disease. Alzheimer’s disease affects more than 6.2 million U.S. adults and is an increasing cause of death within the elderly population. Risk factors, including physical activity, diet, smoking status, and education level all play a role in cognitive decline. This study looked at the consumption of two dietary carotenoids, α-carotene and β-carotene, in relation to cognition.

Using National Health and Nutrition Examination Survey (NHANES) data from 2011-2014, the researchers compared carotenoid intake from 24-hour diet recalls with the results of several cognition tests. They found that elderly participants who consumed higher amounts of β-carotene in their diet performed better with delayed recall, verbal fluency, and digit/symbol recognition. The participants who consumed higher amounts of α-carotene saw positive associations with verbal fluency. 

Carotenoids are present in many foods, particularly brightly colored fruits and vegetables, like leafy greens, carrots, winter squash, cantaloupe, and pumpkin. So, incorporating a variety of colorful foods into meals and snacks provides the body and brain with many essential vitamins and minerals they need, including carotenoid nutrients.

Contributed by Carly Duffy, MPH, RD

Reference

Do Green Tea, Coffee, and Soda Consumption Affect Biological Aging by Altering Telomere Length?

The term “biological aging” describes how cells and tissues age as compared to chronological age. One way to assess biological age is to measure telomere length. Telomeres are DNA sequences that protect chromosomes, and shortened telomere length is associated with increased biological aging. Both genetic and lifestyle factors – like diet, exercise, alcohol consumption, smoking, stress, and environmental exposures – play a role in telomere length. 

A recent study of 2,000 Korean adults investigated the association between beverage consumption and telomere length. After the participants completed a questionnaire on caffeinated beverage consumption, the average consumption per week for each beverage was calculated. Telomere length was measured at baseline and six years later at follow-up.

Among participants, daily consumption of green tea was associated with less telomere shortening, while soda consumption resulted in increased telomere shortening. Both associations were more pronounced among women than men, and green tea consumption was also significantly associated with less telomere shortening in individuals younger than 65. Coffee consumption was not significantly associated with changes in telomere length. The authors conclude that drinking green tea is likely protective against biological aging due to the high antioxidant content of the beverage. The authors note there were limitations to the study, including a lack of information regarding beverage consumption at follow-up, and they recommend further investigation on coffee consumption and telomere length to better determine if an association exists.

Contributed by Jennifer L. Greer, ND, MEd

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The Mediterranean Diet and Pregnancy Outcomes

The benefits of a Mediterranean diet (MedDiet) have been studied extensively, particularly in regard to cardiometabolic conditions – cardiovascular disease, metabolic syndrome, etc. Less research has focused on the effect of a MedDiet pattern in pregnancy outcomes. 

In a recent study, 7,798 racially and geographically diverse U.S. women from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be were evaluated. Their degree of adherence to a Mediterranean-style diet pattern was compared to the prevalence of recognized adverse pregnancy outcomes (APO): pre-eclampsia, eclampsia, gestational diabetes, gestational hypertension, preterm birth, small-for-gestational age infant, and stillbirth. Degree of adherence to the MedDiet was divided into tertiles: low, medium, and high adherence during the three months around conception. 

High adherence compared to low adherence to the MedDiet was associated with 21-percent lower risk of any APO, 28-percent lower risk for pre-eclampsia or eclampsia, and 37-percent lower risk for gestational diabetes. There were no significant associations between the MedDiet and other APOs. 

Contributed by Kathi Head, ND

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Note: In addition to following a healthy diet, you can support a healthy pregnancy with a high-quality prenatal supplement and DHA.

Folate, Vitamin D, and Iodine in Pregnancy

Although a complete multi-vitamin/mineral formula is important before and during pregnancy, there are several nutrients that have particular significance in helping to assure a healthy pregnancy, including folate, vitamin D, and iodine. Deficiencies of one or more of these nutrients can contribute to adverse fetal and maternal outcomes; they are seen more often in women with obesity. 

This study evaluated the dietary and supplemental intakes of these three nutrients among 75 pregnant women in the United Kingdom (UK) with a body mass index of 30-40 (categorized as obese). Participants were recruited at the end of the first trimester – at 12 weeks gestation. The evaluation was conducted using a questionnaire regarding supplement use preconception and during the first trimester. The participants also completed a 4-day diet diary that included supplementation. 

Folate was used most prevalently, with 96 percent of women taking it at some point during the first trimester; however, only 26 percent were taking the UK’s 5-mg dose recommended for pregnant women with obesity (considerably less conservative than the U.S. Government’s recommendation). Only 56 percent of the women were taking the recommended amount of vitamin D, while only 44 percent took the recommended amount of iodine. Although these nutrients are needed for many aspects of fetal development, some of the most important are: folate for neural tube development, iodine for brain and thyroid development, and vitamin D for skeletal development. A low vitamin D level is also associated with risk for pre-eclampsia and low-birthweight infants.

Contributed by Kathi Head, ND

Reference

Note: A well-crafted prenatal multi- with sufficient folate, vitamin D, and iodine should fill the nutrient gaps, which can occur even when a woman is eating a well-balanced diet. The American Thyroid Foundation recommends all prenatal supplements contain 150 mcg of iodine per day. The U.S. RDA for vitamin D during pregnancy is 600 IU and is 400 mcg for folate. Thorne’s Basic Prenatal contains 1,000 IU vitamin D3; 1,000 mcg (1 mg) of folate in its fully-active, tissue ready form – 5-MTHF; and 150 mcg of iodine in a 3-capsule daily dose.