Health

Initial findings from the Walnuts and Healthy Aging (WAHA) study indicate that daily walnut consumption positively impacts blood cholesterol levels without adverse effects on body weight among older adults.

The study involved 707 healthy older adults of whom some were told to add significant daily amounts of walnuts (~15% of caloric intake) to their usual diet. They were not given any advice on what they should be eating, apart from that.

After a year, a comparison of the two groups found that those eating the walnuts were not any heavier than those who hadn't included walnuts in their diet, but the walnut-diet resulted in significant reductions in LDL cholesterol. There was minimal effect on triglycerides and HDL cholesterol.

Another study reported at the conference found that daily consumption of 1.5 ounces of walnuts significantly affected the bacteria in the human gut in a way that was favorable to decreasing inflammation and cholesterol. This was a small study involving only 18 healthy adults. However, a 2015 study with rats similarly found that a diet with walnuts had a significant effect on gut bacteria communities.

Walnuts are unique among nuts in being primarily composed of polyunsaturated fat. This includes alpha-linolenic acid (ALA), the plant-based omega-3 fatty acid, which is known to reduce inflammation. Walnuts are the only nut that contain a significant amount of alpha-linolenic acid.

Walnuts are also said to be an excellent source of antioxidants — indeed, second only to blackberries.

http://www.eurekalert.org/pub_releases/2016-04/es-nri040116.php

Ros E, Rajaram S, Sala-Vila A, et al. Effect of a 1-Year Walnut Supplementation on Blood Lipids among Older Individuals: Findings from the Walnuts and Healthy Aging (WAHA) study [abstract]. FASEB J. 2016;30(Supp 1)293.4. Available at: http://www.fasebj.org/content/30/1_Supplement/293.4.abstract

Guetterman HM, Swanson KS, Novotny JA, et al. Walnut Consumption Influences the Human Gut Microbiome [abstract]. FASEB J. 2016;30(Supp 1)406.2. Available at: http://www.fasebj.org/content/30/1_Supplement/406.2.abstract

Vinson, JA & Cai, Y. (2012) Nuts, especially walnuts, have both antioxidant quantity and efficacy and exhibit significant potential health benefits. Food & Function, 3(2), 134-140 . http://pubs.rsc.org/en/Content/ArticleLanding/2012/FO/C2FO10152A#!divAbstract

A new review of 87 studies linking moderate drinking to health benefits has concluded that many were flawed, with designs suggesting benefits where there were likely none.

A key problem was how "abstainers", the typical control group, were defined. As “current abstainers”, they can include people in poor health who've cut out alcohol. Unfortunately, only 13 of the 87 studies avoided biasing the abstainer comparison group (65 studies included former drinkers in the abstainer group, while 50 studies included occasional drinkers). Those 13 showed no health benefits for moderate drinkers.

Even without correcting for this, it was actually "occasional" drinkers — people who had less than one drink per week; a biologically insignificant amount of alcohol — who lived the longest.

http://www.eurekalert.org/pub_releases/2016-03/joso-imd031616.php

Stockwell, T., Zhao, J., Panwar, S., Roemer, A., Naimi, T., & Chikritzhs, T. (March 2016). Do "moderate" drinkers have reduced mortality risk? A systematic review and meta-analysis of alcohol consumption and all-cause mortality. Journal of Studies on Alcohol and Drugs, 77(2), 185-198. http://dx.doi.org/10.15288/jsad.2016.77.185

A new meta-analysis supports the link between intake of EPA and DHA omega-3 fatty acids, and reduction in major depressive disorder (MDD).

The meta-analysis only included studies in adult patients with MDD assessed using standardized clinical interviews, and excluded studies that specifically studied perinatal/perimenopausal or comorbid MDD, in order to get a more homogenous population. Studies not applying a randomized placebo-controlled trial design were also excluded. This criteria resulted in 13 studies with a total of 1233 participants (out of an original pool of 1955 studies).

The analysis of these studies showed a benefit for these omega-3 acids that was comparable to effects reported in meta-analyses of antidepressants. The effect was greater in studies supplementing higher doses of EPA and performed in patients already on antidepressants.

http://www.eurekalert.org/pub_releases/2016-03/g-nss031716.php

Mocking, R. J. T., Harmsen, I., Assies, J., Koeter, M. W. J., Ruhe, H. G., & Schene, A. H. (2016). Meta-analysis and meta-regression of omega-3 polyunsaturated fatty acid supplementation for major depressive disorder. Transl Psychiatry, 6, e756. Retrieved from http://dx.doi.org/10.1038/tp.2016.29

A small study involving 22 students with depression and 30 mentally healthy students had positive results from a program that combines mental training through meditation and physical training through aerobic exercise. After eight weeks, those with depression showed a nearly 40% reduction in depressive symptoms, and said they did not spend as much time worrying about negative situations taking place in their lives as they did before the study began. There were also changes in brain activity that may reflect better cognitive control.

Interestingly, those in the control group also reported fewer depressive symptoms.

The program involved two sessions a week, with each one having 30 minutes of focused attention meditation followed by 30 minutes of aerobic exercise. They were told that if their thoughts drifted to the past or the future they should refocus on their breathing - enabling those with depression to accept moment-to-moment changes in attention.

http://www.eurekalert.org/pub_releases/2016-02/ru-eam021016.php

Alderman, B. L., Olson, R. L., Brush, C. J., & Shors, T. J. (2016). MAP training: combining meditation and aerobic exercise reduces depression and rumination while enhancing synchronized brain activity. Transl Psychiatry, 6, e726. Retrieved from http://dx.doi.org/10.1038/tp.2015.225

Research using data from 2131 participants in the 2008 U.K. Health Survey suggests that regular exercise can partly counteract the negative health effects of being sedentary. The analysis grouped people into the following categories:

• physically active and low sedentary 'busy bees' (18.6% of the sample)
• physically active and high sedentary 'sedentary exercisers' (36.7%)
• physically inactive and low sedentary 'light movers' (6.8%)
• physically inactive and high sedentary 'couch potatoes' (37.9%).

Overall, physical activity was significantly associated with lower BMI, lower waist circumference, lower HbA1c levels (HbA1c is a modified form of haemoglobin, commonly used to measure glucose concentration; higher levels indicate poorer control of blood glucose levels), and higher HDL-cholesterol (the 'good' cholesterol). Sedentary time was associated with lower HDL-cholesterol levels.

None of that is a surprise, of course. The interesting aspect of this study is its attempt to disentangle physical activity and sedentary time.

In comparison to the couch potatoes, both busy bees and sedentary exercisers had significantly lower BMI and HbA1c levels, and higher HDL-cholesterol levels.

Busy bees (but not sedentary exercisers) also had lower waist circumferences. Compared to couch potatoes, light movers had only one improvement: higher HDL-cholesterol levels.

What all this shows is not simply the importance of physical activity for health, but that physical activity offsets some of the evils of a high sedentary time. It also suggests that not being sedentary doesn't take you all that far — you still need to exercise.

http://www.eurekalert.org/pub_releases/2016-04/uol-ecs040516.php

Bakrania, K., Edwardson, C. L., Bodicoat, D. H., Esliger, D. W., Gill, J. M. R., Kazi, A., … Yates, T. (2016). Associations of mutually exclusive categories of physical activity and sedentary time with markers of cardiometabolic health in English adults: a cross-sectional analysis of the Health Survey for England. BMC Public Health, 16, 25. http://doi.org/10.1186/s12889-016-2694-9

A pilot study involving 14 overweight or obese adults (average age 56) on a calorie-restricted diet, found that those whose diet had higher levels of protein showed greater improvements in their sleep score, regardless of the source of the protein.

In a follow-up study, 44 overweight or obese participants followed a normal-protein or a higher-protein weight loss diet (either 0.8 or 1.5 kg of protein for each kg of body weight) for 16 weeks. Sleep quality improved for those on the high-protein diet, but not for those on the normal-protein diet.

Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) questionnaire.

The sources of protein were beef and pork, or soy and legume.

Higher protein intake has also been linked to promoting body fat loss, retention of lean body mass and improvements in blood pressure.

http://www.eurekalert.org/pub_releases/2016-03/pu-lww032416.php

Zhou, J., Kim, J. E., Armstrong, C. L., Chen, N., & Campbell, W. W. (2016). Higher-protein diets improve indexes of sleep in energy-restricted overweight and obese adults: results from 2 randomized controlled trials. The American Journal of Clinical Nutrition, 103(3), 766–774. http://doi.org/10.3945/ajcn.115.124669

A number of studies have pointed to a link between depression and type 2 diabetes, but a new study indicates that this is not as straightforward as it seemed. The large Canadian study involving 2,525 adults aged 40-69 has found that it is not depression alone that increases the risk of developing diabetes, but depression in conjunction with metabolic risk factors such as obesity, high blood pressure and unhealthy cholesterol levels,.

The study found that those with metabolic symptoms but not depression were around four times more likely to develop diabetes than normally healthy people, while those with both depression and metabolic risk factors were more than six times more likely to develop diabetes. The combined effect of depression and metabolic symptoms was greater than the sum of the individual effects. But those with depression alone had no more risk than normally healthy people.

There are probably two main causes for this effect. One is that, as evidence shows, people suffering from depression are less likely to adhere to medical advice aimed at tackling metabolic symptoms. This makes the metabolic symptoms worse, which can exacerbate the symptoms of depression, and so it goes, in a horrible negative cycle.

The second reason is that some forms of depression are associated with changes in the body's metabolic systems which can lead to weight gain, high blood pressure and problems with glucose metabolism. Some antidepressant medications can also cause weight gain.

http://www.eurekalert.org/pub_releases/2016-04/mu-hdm041216.php

Schmitz, N., Deschenes, S. S., Burns, R. J., Smith, K. J., Lesage, A., Strychar, I., … Wang, J. L. (2016). Depression and risk of type 2 diabetes: the potential role of metabolic factors. Mol Psychiatry. Retrieved from http://dx.doi.org/10.1038/mp.2016.7

A small, Israeli study involving 48 overweight and obese older adults with Type 2 diabetes (average age 59) has found that those who ate a large breakfast containing whey protein managed their diabetes better.

Participants in the study were randomly alloted to one of three diets that contained the same number of calories, and followed the pattern: large breakfast, medium-sized lunch and small dinner. They followed this diet for 23 months. The groups varied in the type of breakfast: primarily whey protein; other proteins such as eggs, soy and tuna; a meal high in carbohydrates or starch.

After 12 weeks, the group on whey protein lost the most weight: 7.6 kg (16.7 pounds), compared to 6.1 kg (13.4 pounds) for those on the other proteins, and 3.1 kg (6.8 pounds) for those in the carbohydrate group. Those on whey protein were also more satiated and less hungry throughout the day, with lower glucose spikes after meals compared to the other two diets, and their HbA1C also decreased more than with the other two diets.

http://www.eurekalert.org/pub_releases/2016-04/tes-lwp040116.php