Cognitive functions and vasomotor symptoms were assessed in this randomised control prospective two-arm interventional study on 108 perimenopansal women (age 40-55 years). Mann—Whitney test to compare the two groups showed that there was significantly better improvement in the yoga group compared with the control group in hot flushes and attention task in SLCT. In PGIMS, there was significant improvement within both groups with significant difference between groups, the effect sizes being better in the yoga group than in the control group in PGIMS-I (remote memory), III (mental balance), IV i and ii]) (attention and concentration [i and ii]), VI (immediate recall) and X tests (recognition test). There was significant improvement only in yoga group and not in control group with significant dif­ference between groups in PGIMS-V (delayed recall) and PGIMS-IX (visual retention). In PGIMS-VIII (verbal retention-ii), both groups improved with higher effect size in control group and significant difference between groups. The PGIMS-II (recent memory) and PGIMS-VII (verbal retention-i) tests showed no change in both the groups.

The preferred option for complementary and alternative medicine (CAM) by women43 has triggered interest into research on these therapies. Of the four studies (two on cognitive behavioural therapy (CBT) and two on relaxation response), only one was a well-designed RCT on 33 women taking relaxation response training compared with a reading group, demonstrated a significant reduction in hot flush intensity, tension-anxiety and depression in perimenopausal women after 10 weeks of intervention.44 Our recent rando­mised control study in the Indian population has shown the reduction in vasomotor and other menopausal symptoms 8 weeks after the supervised practice of the integrated approach of yoga therapy as measured by Greene climacteric scale (GCS) with a significant difference between groups with higher effect sizes in the yoga group than the control group in all factors of GCS.45
There are no studies on changes in cognitive functions with nonpharmacological therapies. In comparison, the present study on IAYT that combined both body and mind level practices of self-management (lifestyle change) has shown significant improvement in both frontal lobe and memory functions for the first time through a nonpharmacological intervention. A study on the interaction of HRT and physical activity (PA) showed a beneficial relationship between PA and cognitive performance in postmenopausal women irrespective of HRT use.46 These studies tend to point out that the self-corrective techniques that the person puts in by applying her mind, be it a PA or IAYT, influences the cognitive functions.

SLCT measures the attention capacity, a frontal lobe function. A self-control study on the effect of CM (that has been incor­porated in the IAYT for the experimental group in the present study) has shown significant increase in SLCT scores imme­diately after CM, suggesting enhanced efficiency and shorter time in cortical neural processing.47
Etectrophysiological studies during cognitive functions of the brain have reported that P300 (a specific positive wave that occurs at the 300th millisecond in the tracing of evoked potential) is generated from hippocampus and other associ­ated areas.48 Estrogen receptors have been detected in the pyramidal cells nuclei of the ventral hippocampus and other specific brain areas that are involved in learning, memory and cognition. Cyclic changes in synaptic genesis and spine den­sity of the hippocampus have been shown to be induced by estrogen,'8 which gets depleted in this age; hence, memory functions may undergo a declining change. However, con­trary to our expectation, estrogen replacement therapy (ERT) per se may not improve the cognitive functions,46 A study on the effect of CM observed that there was reduction in the peak latencies of P300 after CM compared with the prevalues that suggest enhanced efficiency and shorter time in processing. Also, the P300 peak amplitudes after CM were higher compared with the prevalues, suggesting an increased in attentional resources.49 Thus, it may be hypothesised that the improvement in the cognitive functions observed in this study is due to the effect of yoga in bringing about better information processing in the subtle layers of the frontal lobe. This in turn could be due to the alertful rest that CM may offer and may not be related to estrogen-mediated response. CM developed on a subtle principle suggested by a rarely used authentic scripture (Memdukya karika) that includes stimula­tion—relaxation combination for achieving deeper degree of rest. This principle is made practical by knitting yoga postures interspersed with periods of supine relaxation and has been shown to provide deeper degree of rest than simple supine rest or the commonly used meditative techniques.50

This is the first RCT that has looked at cognitive functions after yoga practice in climacteric. An objective measure, serum FSH level, was used as the inclusion criterion rather than only the subjective symptoms of menopausal rating scale. Control group also had the supervised practices for the same duration as the experimental group.
One limitation of the study with regard to external validity was that because the tests were in English, the sample was restricted to women with knowledge of the English language. Thus, our sample should be taken to be fairly representative of women in urban India.
Other limitations were that the estradiol levels were not measured. Although we have used FSH levels as the only objec­tive inclusion criterion,51 it will be interesting to see the effect of long-term practice of IAYT on FSH and estradiol levels.

Functional studies to look at the changes in neurohormonal changes in the brain during IAYT in climacteric would throw light on the mechanism.

Thus, the present study has shown that the practice of IAYT for 8 weeks improves the cognitive functions like attention, concentration, mental balance, verbal retention and recogni­tion abilities in menopausal women compared with physical exercises.
The control group practices that comprised of physical exercises also showed improvement in many of the memory functions similar to earlier studies on the efficacy of PA in perimenopausal women.46 Thus, the present study shows the superiority of yoga over PA in improving the cognitive func­tions that could be attributed to emphasis on correctness in breathing, synchronising breathing with body movements, relaxation and mindful rest.

This study was funded by the parent institution: Swami Vivekananda Yoga Research Foundation, Bangalore, India.

R.C.: Involved in designing, conducting and writing the man­uscript R.N.: Regular supervision of the study in all phases including the manuscript writing. V.P.: Gynaecologist who assessed the clients for recruitment, contributed in all phases of the study by regular supervision and guidance. Inputs for the manuscript writing. H.R.N.: Guidance and advice on the yoga component of the design, training the therapists and writing the manuscript