Welcome to the first Research Extracts of 2022. “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: (1) this month’s Mental Health Moment – a study on fruits and vegetables and mood, as well as studies on (2) intermittent versus continuous calorie restriction and weight loss, (3) gradual weight gain during aging might not be all bad, and (4) yoga for menopausal symptoms.


Mental Health Moment: Make a Habit Out of Fruits and Vegetables to Support Mood

You have probably heard a thousand times that eating fruits and vegetable is good for you. Most of us could probably eat more than we do, but if you need some extra motivation, then it might help to know that in addition to the many benefits – from immune function to brain health – regular consumption appears to have a positive impact on mood.

Australian researchers analyzed data from more than 4,000 adults who participated in the Australian Diabetes, Obesity, and Lifestyle Study.1 During the 12-year study, participants periodically completed a Food Frequency Questionnaire to assess what they regularly ate. Mood was assessed by a separate standardized questionnaire called the CESD-10.2 Overall, participants who regularly consumed more than 250 grams of fruits and vegetables daily, as well as those with a more diverse intake of fruits and vegetables, achieved the best odds of a positive benefit.

The researchers divided intake into four groups based on total daily consumption. Participants in group 1 consumed 0-273 g/day; group 2 consumed 274-361 g/day; group 3 consumed 362-464 g/day; and group 4 consumed 465 g/day or more. While group 2 participants had a 20-percent lower chance of having poor mood compared to group 1, no further benefit was seen in the groups with consistently higher consumption. This finding indicates that individuals wanting to receive potential mood benefits from increased fruit and vegetable consumption don’t need to consume massively larger amounts than what they normally eat. However, the kinds of vegetables consumed had a significant impact. Individuals with higher intakes of red, orange, and yellow vegetables, as well as leafy greens, had the lowest chance of developing depressed mood. Those who had a more diverse vegetable intake of 4-6 kinds of vegetables daily also saw the best benefits for their emotional state. No similar results were found for any kind of fruit intake.

So how do you know if you are targeting a good intake of fruits – and especially vegetables – to support your mood? Because the average-sized portion of most vegetables is about 80 grams, 3-4 servings daily is a good target based on this data. While providing diversity in what you eat might take more thought, based on this study, a daily goal of eating at least one yellow, orange, or red vegetable, as well as something green, would be a good goal. If you are looking for a well-studied plan that can help you meet your vegetable goals and more, then Thorne’s Modified Mediterranean Diet is a great choice to support not just mood but overall health. And you can get recipes and menu ideas in this Wellness Guide.

 Contributed by Jacqueline Jacques, ND

References

  1. Radavelli-Bagatini S, Anokye R, Bondonno N, et al. Association of habitual intake of fruits and vegetables with depressive symptoms: the AusDiab study. Eur J Nutr 2021;60(7):3743-3755. Doi:10.1007/s00394-021-02532-0.
  2. Andresen E, Malmgren J, Carter W, Patrick D. Screening for depression in well older adults: evaluation of a short form of the CES-D (Center for Epidemiologic Studies Depression Scale). Am J Prev Med 1994;10(2):77-84.

Intermittent Energy Restriction versus Continuous Calorie Restriction for Short-Term Weight Loss

Two strategies employed by athletes for weight reduction are continuous energy restriction (CER), which is reduced caloric intake by the same amount every day, and intermittent energy restriction (IER), which is reduced caloric intake for five days with two days of higher carbohydrate and calorie intake. In previous studies, while both strategies reduced fat mass and bodyweight, only IER retained fat-free mass and resting metabolic rate at completion. IER by athletes is also less likely to result in adverse physiological effects, such as loss of menstrual function, bone mass, and immune function, as well as negative cardiovascular effects and decreased protein synthesis.

 This study examined whether CER or IER is beneficial in sedentary adults with normal body weight. Twenty-six sedentary participants, ages 18-60 and in good health, were studied. The participants were randomized to either CER (500 calorie deficit daily) or IER (1-4 days of calorie restriction alternating with “cheat days”). Body weight and resting metabolic rate were measured at baseline and completion of the 4-week dietary intervention.

Both groups experienced significant reductions in body weight during the intervention. Contrary to previous research, the CER group did not experience a significant decrease in resting metabolic rate, which could have been due to the intervention’s short length compared to previous studies. The lack of physical activity among participants and extremely low-calorie intake of the IER group might have also contributed to the results, indicating that both daily caloric intake and physical activity are important in energy restriction strategies.

Contributed by Jennifer L. Greer, ND, MEd


Gaining Small Amounts of Weight as One Ages Might Improve Mortality Rate

Elevated body mass index (BMI) is associated with numerous co-morbidities, including heart disease, metabolic syndrome, and type 2 diabetes. But does gradual weight gain or loss over decades have an effect on mortality rates? In this study, BMI trajectories were evaluated for two cohorts of adults, ages 31-80, from the Framingham Heart Study – the original cohort and a second cohort comprised of the first cohort’s offspring. In assessing weight:

  1. Normal weight was a BMI between 18.5 and 24.9 kg/m²
  2. Overweight was having a BMI between 25 and 29.9 kg/m²
  3. Class I obesity was having a BMI between 30 and 34.9 kg/m²
  4. Class II/III obesity was having a BMI greater than or equal to 35 kg/m²

Groups were also comprised by date of birth – seven cohorts in the first group (born in 1876-1915+) and six in the offspring cohort (born 1903-1950+). BMIs were plotted over time.

The results are somewhat reassuring for those whose weight creeps up over time. The BMI trajectories compared to overall mortality rate were similar in both cohorts. The individuals who were normal weight at age 31 and gradually became overweight by mid-50s or above had the lowest mortality rate. This was followed in mortality-rate order by those who maintained normal weight throughout adulthood, individuals who were overweight at age 31 and remained stable throughout adulthood, a group that was low-normal weight, individuals with class I obesity and an upward trajectory, and finally the highest mortality risk group was comprised of those with class II/III obesity and continued upward trajectory. The authors note that by using the trajectory method for evaluating BMI, weight loss caused by disease is factored out.

This study supplements a previous study that found individuals who were not overweight until age 51 and continued as stable overweight until at least age 77 had the lowest mortality rate.

This study does not imply that you should not strive for a healthy weight. If you need a little guidance, then you can check out Thorne’s Weight Management Program guide, which gives diet and lifestyle recommendations that can be used with the products in Thorne’s Weight Management bundle.

Contributed by Kathi Head, ND


Yoga Can Benefit Menopausal Symptoms

Growing evidence indicates that yoga can benefit multiple health concerns. In this study, 80 menopausal women, ages 40-50, were randomly divided into a yoga group and a brisk walking group. The 1-year intervention consisted of either three weekly 45-60-minute sessions of Sudarshan Kriya Yoga (SKY) or 30-40 minutes of daily early morning brisk walking. Participants had to complete more than 70 percent of the yoga sessions or have walked more than 70 percent of the days to be included in the final analysis.

Yoga participation resulted in significant improvement and/or prevention of menopause-related physical and psychosocial symptoms. After one year, significant improvements were observed in systolic and diastolic blood pressure and fasting blood sugar in the yoga group compared to the brisk walking group. Hot flashes and other vasomotor symptoms were also improved in the yoga group compared to the brisk walking group – 15 percent in the yoga group experienced moderate-to-severe vasomotor symptoms compared to 89 percent in the brisk walking group. Other psychosocial symptoms also improved in the yoga group compared to the walking group, including anxiety, difficulty sleeping, low mood, and poor memory. Yoga also significantly increased antioxidant status – both superoxide dismutase and glutathione peroxidase levels increased during the year-long yoga intervention. 

Thorne’s Meta-Balance also provides support for women during menopause.

Contributed by Kathi Head, ND