August Research Extracts: Omega-3s, Magnesium, and Chocolate and Menopause
Welcome to the August 2021 edition 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 you will find new studies on: (1) omega-3’s in pro basketball players, (2) low magnesium and hostility, (3) benefits of chocolate in the morning, and (4) timing of specific foods and mortality.
Are professional basketball players deficient in omega-3 fatty acids?
Omega-3 fatty acids come from dietary sources such as fatty fish, fish oils, and krill oils. EPA and DHA are the two most bioactive forms of omega-3 fatty acids, and they have been well-studied for their impact on cardiovascular and neurological health, as well as for promoting a healthy inflammatory response and enhancing post-exercise recovery. Recent studies of college athletes have found most athletes have a low omega-3 status, due at least in part to a low intake of fish or omega-3 containing supplements.
Prior to the 2019-2020 NBA G-League season, blood samples were collected from 119 professional basketball players. Samples were analyzed for omega-3 index (O3I), a measure of the percent EPA and DHA in red blood cell membranes that reflects omega-3 intake over the previous 120 days. O3I scores are associated with cardiovascular disease risk in the following way: <4% = high risk, 4-8% = intermediate risk, >8% = low risk. The athletes also completed a survey regarding dietary and supplement intake of omega-3 fatty acids.
Most athletes had an O3I score in either the high or intermediate risk categories with only 2% of them achieving an O3I >8%. The athletes also reported an intake of less than two servings of fish per week for 92% of participants, and only 10% reported use of omega-3 supplementation. Of those who used omega-3 supplements, the mean O3I score was higher (6.0%) than those who didn’t (4.9%). The authors note that due to the length of the professional basketball season, extensive travel, and limited turnaround time between games, monitoring of omega-3 status might be an important nutritional strategy for supporting performance and recovery.
Contributed by Jennifer Greer, ND, MEd
- Davis J, Freese E, Wolfe A, et al. Evaluation of omega-3 status in professional basketball players. J Strength Cond Res 2021;35(7):1794-1799. doi:10.1519/JSC.0000000000004023
Low magnesium and hostility
Because of its potential benefit for mood support, researchers hypothesized that sufficient magnesium levels could result in decreased feelings of hostility among young adults. Why the interest in hostility? For one thing, feelings of hostility have been associated with numerous cardiovascular risk factors.
This prospective analysis followed 4,716 young adults (ages 18-30) from four U.S. cities for five years, using data from the Coronary Artery Risk Development in Young Adults (CARDIA) study. Magnesium was estimated at intake via a dietary questionnaire and supplement usage. Hostility was measured via the Cook-Medley Scale at the beginning and end of the study (year 5). For those enamored with statistical analysis, Generalized Estimating Equations were used to determine the relationship between magnesium levels and hostility at baseline and year 5.
After adjusting for lifestyle and socio-demographic factors, the researchers found an inverse relationship between magnesium intake and hostility levels over five years of follow-up. In other words, the higher the magnesium intake, the less hostility the person reported.
Note: But despite magnesium’s importance, many of us are likely deficient in it.According to World Health Organization statistics, as much as75% of the U.S. adult population does not meet the U.S. Food and Drug Administration’s Recommended Daily Intake of 420 mg. Because magnesium has benefits beyond improving mood – for cardiovascular, muscular, neurological, sleep, and bone support, supplementation might be advisable.
Contributed by Amanda Frick, ND, LAc
- Lyu C, Tsinovoi C, Xun P, et al. Magnesium intake was inversely associated with hostility among American young adults. Nutr Res 2021;89:35-44. doi: 10.1016/j.nutres.2021.01.001.
Chocolate in the morning improved metabolism in postmenopausal women
This study examined the metabolic effects on postmenopausal women of eating milk chocolate in the morning or in the evening. In a three-armed, crossover design, 19 women who were at least one-year post menopause (ages 45-65) were randomly assigned to one of three groups: (1) 100 g milk chocolate (containing 542 calories) with breakfast within one hour of waking; (2) 100 g of milk chocolate within an hour of bedtime, or (3) no chocolate. Each intervention period lasted two week and then, after a one-week washout period, each participant was assigned to another intervention, until they had engaged in all three. They otherwise ate whatever they wanted to (ad libitum). Various metabolic factors were assessed, including stool tests for microbiome changes.
Overall, the timing of the chocolate consumption did make a difference in several parameters, believed by the researchers, at least in part, to have been related to changes in the microbiome. The following were observed:
- When eating chocolate in the morning, the women ate an average of 300 fewer calories of other foods; when eaten in the evening the ad libitum eating was decreased by 150 calories (neither of which makes up for the 542 calories provided by the chocolate).
- Morning chocolate consumption reduced fasting blood sugar by 4.4%.
- Morning chocolate decreased waist circumference by 1.7%.
- Evening chocolate consumption resulted in greater appetite decrease than eating chocolate in the morning or eating no chocolate.
- Women had less craving for sweets when eating chocolate in the morning or the evening than when not eating chocolate.
- Daily cortisol levels decreased in women eating chocolate in the morning, but not in the evening.
- Eating chocolate in the evening resulted in increased physical activity by 6.9%, compared to no chocolate.
- Eating chocolate in the evening increased metabolism as measured by increased wrist temperature.
- Eating chocolate in the morning resulted in increased frequency of napping compared to no chocolate.
- Eating morning chocolate resulted in increased fat metabolism, while eating evening chocolate increased carbohydrate metabolism.
- There were differences in gut microbiota, which were reflected in the highest increase of short chain fatty acids in the evening-chocolate group, a moderate increase in the morning-chocolate group, and no increase in the no-chocolate group.
- There was no weight gain in either chocolate group.
The researchers concluded: “The intake of a rather high amount of chocolate (100 g) concentrated in a narrow (1 hour) timing window in the morning could help burn body fat and decrease glucose levels in postmenopausal women.”
Editor’s note: Since different positive things happened in the morning compared to the evening when consuming chocolate, why not eat it both times?
Contributed by Kathi Head, ND
- Hernández-González T, González-Barrio R, Escobar C, et al. Timing of chocolate intake affects hunger, substrate oxidation, and microbiota: A randomized controlled trial. FASEB J 2021 Jul;35(7):e21649. doi: 10.1096/fj.202002770RR.
Timing and type of meals and snacks can impact all-cause, cardiovascular, and cancer mortality
Although it is generally accepted that the quantity and quality of food consumed has an impact on health and wellbeing, it is less well understood how the timing of consumption (“chrono-nutrition”) alters the effects of the consumed food. Data from 21,503 participants (51% female) in the National Health and Nutrition Examination Survey was used to investigate whether the types and timing of meals and snacks had an impact on all-cause mortality or deaths associated with cardiovascular disease (CVD) or cancer. Included in the study were 2,192 deaths, with 676 attributed to CVD and 476 to cancer.
Diet information from two nonconsecutive days was categorized by predominant food type for each of six times (three meals and a snack following each meal). Breakfast was categorized as “Western,” “starchy,” or “fruit” type, while lunch and dinner was categorized as “Western,” “vegetable,” or “fruit.” Snacks were categorized as “grain,” “starchy,” “fruit,” or “dairy.” Western meals included higher quantities of refined grains, added sugars, solid fats and cheeses, processed meats, and the like. Fruit meals emphasized fruit, but could have included whole grains, dairy, and nuts. Vegetable meals emphasized colorful vegetables, tomatoes, and starchy vegetables. Eggs appeared prominently in the starchy breakfast and Western dinner. Grain snacks emphasized refined and whole grains and could have included dairy, eggs, and added sugars. Starchy snacks emphasized starchy foods, such as white potatoes. Fruit snacks emphasized fruits, including melons and berries. Dairy snacks emphasized dairy products, with inclusion of whole grains during the after-dinner time period.
After categorization into a dietary pattern for each meal and snack, groups were compared for significant differences in risk of death due to CVD, cancer, or any cause. Several chrono-nutrition categories were associated with a reduced risk (measured by hazard ratio (HR) in one or more mortality categories). Participants in the “fruit snack after breakfast” category had lower mortality from cancer (HR 0.55) and lower risk of all-cause death (HR 0.78). “Fruit lunch” had lower all-cause risk of death (HR 0.82). “Vegetable dinner” corresponded with lower cancer (HR 0.63), all-cause (HR 0.69), and CVD risk (HR 0.77); however, “vegetable lunch” did not. “Dairy snack after dinner” corresponded with lower risk of all-cause (HR 0.82), cancer (HR 0.74), and CVD (HR 0.67) death, but “dairy snack after lunch” did not.
In contrast, some chrono-nutrition categories were associated with higher risk of death. Participants in the “Western lunch” category had a higher risk of death due to CVD (HR 1.44). Similarly, “starchy snack” showed a higher risk of CVD-related death (breakfast HR 1.55, lunch HR 1.44, dinner HR 1.57) and all-cause mortality (breakfast HR 1.50, lunch HR 1.52, dinner HR 1.50) regardless of timing.
The authors note that these associations are stronger for participants with poorer diet quality, with “starchy breakfast” emerging as an additional association with higher risk of CVD or all-cause death for this group. By comparison, only “fruit lunch” and “vegetable dinner” meals showed significant associations with mortality (lower risk) for the subset of participants with high diet quality. In this context, “dairy snack after dinner” was associated with reduced all-cause and CVD risks for both low- and high-quality diets, with a reduction in cancer-related risk for the high-quality diet group.
This evidence points to several potential positive health effects from:
- emphasizing fruit in the middle of the day
- eating vegetables and dairy at the end of the day
- avoiding Western-style lunches
- avoiding starches after breakfast
It is important to note this was an observational study incorporating short-term dietary information, so the ability to draw actionable conclusions is limited.
Contributed by Sheena Smith, MS MA