The four research extracts in this issue discuss: (1) sarcopenia/obesity and breast cancer mortality; (2) dietary influences on the age of menopause onset; (3) omega-3s and exercise benefits; and (4) saunas and stroke risk.

Welcome to the fourth edition of Thorne’s Research Extracts. This is Thorne’s monthly research update on diet, nutrient, botanical, and lifestyle approaches to good health. Knowing that busy practitioners can’t always focus on the latest research, our medical team of NDs, MDs, PhDs, RDs, and MS (Biol) has summarized the essence of the very most interesting studies.


Are sarcopenia and/or obesity risk factors for breast cancer mortality?

Contributed by Mario Roxas, ND

A study of 3,241 women with either stage II or stage III breast cancer looked at the relationship between sarcopenia (loss of muscle mass), poor muscle quality (low muscle radiodensity), and/or excess adiposity (obesity) and mortality rates in non-metastatic breast cancer. CT scans found 1,086 women (34%) had sarcopenia and 1,199 women (37%) had low muscle radiodensity.

Those women with sarcopenia had 41% higher all-cause mortality compared to the women with no sarcopenia.

Regarding adiposity, women in the highest tertile had a 35% increase in all-cause mortality compared to the women in the lowest tertile. When sarcopenia and adiposity rates were combined, it was associated with an 89% increase in all-cause mortality. Low muscle radiodensity was not associated with mortality rates.

The study suggests that sarcopenia might be present in as many as one-third of newly diagnosed women with non-metastatic breast cancer, although sarcopenia should be a significant concern even in cases of non-metastatic breast cancer. Occurrence of both sarcopenia and adiposity from CT scans in patients can provide valuable information to help identify high-risk groups and improve survival outcomes.


Diet can influence menopause onset

Contributed by Sheena Smith, MS (Biol)

Researchers in this study assessed data from 914 women participating in the UK Women’s Cohort Study who experienced menopause between baseline and the 4-year follow-up. Analyzing age at menopause in relation to food intake patterns assessed by a 217-item food frequency questionnaire, and adjusting for confounding factors such as physical activity and smoking status, showed that several food groups and nutrients had an association with earlier or later onset of natural menopause.

In the total cohort, in the non-vegetarian subset, and in the multiparous subset, higher intakes of oily fish, fresh legumes, vitamin B6, and zinc were each associated with older age at onset of menopause.

In these same three groups, a higher intake of refined pasta/rice was associated with younger age at menopause onset. Within the non-vegetarian subset, a higher consumption of savory snacks and soft drinks was associated with younger age at onset of menopause and, on average, non-vegetarians reached menopause later than vegetarians. An association was also found between higher consumptions of grapes and poultry and older age at menopause onset within the nulliparous subset.


EPA and DHA can benefit muscle function, muscle mass, and recovery from delayed-onset muscle soreness

Contributed by Jacqueline Jacques, ND

In this review from Japan, researchers reviewed existing data on supplemental fish oil and its relation to exercise – analyzing muscle strength, range of motion, muscle soreness/recovery, and muscle mass.

They found evidence that supplemental fish oil has a positive effect on muscle function, it supports the development of muscle mass (especially if there has been prior muscle loss), and it might support the recovery from delayed onset muscle soreness and swelling.

The authors noted that the benefits of fish oil supplementation in relation to exercise are typically most evident after 1-3 months at levels of 1-2 grams daily (not exceeding 3 grams).

  • Ochi E, Tsuchiya Y. Eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA) in muscle damage and function. Nutrients 2018 Apr 29;10(5). pii: E552. doi: 10.3390/nu10050552
  • http://www.mdpi.com/2072-6643/10/5/552

Regular saunas might reduce the risk of stroke

Contributed by Kathi Head, ND

In the Finnish Kuopio Ischemic Heart Disease Study, a prospective cohort study of 1,628 men and women, ages 53-74, were followed for an average of 15 years to determine the effect of regular sauna bathing on stroke risk. Subjects were divided into three groups based on the frequency of sauna bathing: once weekly, 2-3 times weekly, or 4-7 times weekly. During the 15-year median follow-up period there were 155 stroke incidents. Compared to the once-weekly sauna usage group, the group that engaged in 4-7 saunas weekly had a stroke hazard ratio of 0.39 – which was not modified by age or gender.

The authors conclude that frequent sauna bathing can significantly decrease the risk of stroke in the middle-aged or elderly population.