inflammation

A review of 56 randomized clinical trials found that psychotherapy may be effective in reducing inflammation. The trials included several different types of interventions, including cognitive behavior therapy (CBT), CBT plus medication, grief and bereavement support, a combination of two or more psychotherapies, and psychoeducation, among others. CBT was the best at boosting the immune system, followed by multiple or combined interventions. The benefits of CBT on the immune system lasted for at least six months following treatment.

https://www.eurekalert.org/pub_releases/2020-06/uoc--cbt060220.php

Shields GS, Spahr CM, Slavich GM. Psychosocial Interventions and Immune System Function: A Systematic Review and Meta-analysis of Randomized Clinical Trials. JAMA Psychiatry. Published online June 03, 2020. doi:10.1001/jamapsychiatry.2020.0431 https://jamanetwork.com/journals/jamapsychiatry/article-abstract/2766707

A mouse study explains why excessive weight around our middle affects cognition. It seems that such fat, known as visceral adiposity, generates high, chronic levels of a signal that encourages the formation of inflammasome complexes that amplify the immune response and inflammation.

A protein called NLRP3 is a core component of the inflammasome complex in the fat, and it’s what promotes the production and release of interleukin-1 beta by fat cells. When NLRP3 was blocked in mice, they became protected against such inflammation and cognitive problems. When visceral adipose tissue from obese mice and obese mice missing NLRP3 was transplanted into lean mice, the tissue from those missing NLRP3 had no deleterious effect, but the tissue from the intact obese mice caused increased levels of interleukin-1 beta in the hippocampus, and impaired cognition.

Mice missing interleukin-1 beta’s receptor on the microglia were also protected.

There are indications that interleukin-1 beta also prompts microglia to wrap around synapses, potentially interfering with the communication between neurons.

https://www.eurekalert.org/pub_releases/2020-03/mcog-vfd030220.php

Guo, D.-H., Yamamoto, M., Hernandez, C. M., Khodadadi, H., Baban, B., & Stranahan, A. M. (2020). Visceral adipose NLRP3 impairs cognition in obesity via IL-1R1 on CX3CR1⁺ cells. The Journal of Clinical Investigation, 130(4), 1961–1976. https://doi.org/10.1172/JCI126078

A study measuring the levels of the six most common carotenoids in blood from 193 patients with coronary artery disease has found that lutein was the only carotenoid whose level was correlated with the inflammatory marker interleukin-6, IL-6. The higher the level of lutein in the blood, the lower the level of IL-6.

Cells taken from blood from patients with coronary artery disease confirmed that the inflammatory activity of the cells became significantly lower when they were treated with lutein.

Lutein is found in several highly coloured vegetables and fruits, and is particularly rich in vegetables with dark-green leaves, such as spinach.

https://www.eurekalert.org/pub_releases/2017-07/lu-vca070517.php

Chung, Rosanna W.S., Leanderson, Per, Lundberg, Anna K, Jonasson, Lena. 2017. Lutein exerts anti-inflammatory effects in patients with coronary artery disease. Atherosclerosis, 262, 87-93, published online 6 May 2017, doi: 10.1016/j.atherosclerosis.2017.05.008

Here are some nut studies that link to benefits in connection with diabetes, heart disease, and inflammation. However, it should be noted that they are often very small, and usually funded by nut organizations. I wouldn't put too much weight on such.

Nuts linked to improved type 2 diabetes health

A 3-month study involving 117 older adults (mean age 62) with diabetes found that 75g of nuts (½ a cup) a day, as a replacement for carbohydrate foods, can improve glycemic control and blood lipids in those with type 2 diabetes.

The nuts used were a mixed lot of tree nuts (almonds, Brazils, cashews, hazelnuts, pecans, pine nuts, pistachios, macadamias and walnuts) and peanuts. improved blood lipid levels and blood sugar levels in individuals with non-insulin dependent diabetes.

https://www.eurekalert.org/pub_releases/2018-05/mp-itn052218.php

Jenkins, D.J.A., C.W.C. Kendall, B. Lamarche, M.S. Banach, K. Srichaikul, E. Vidgen, S. Mitchell, T. Parker, S. Nishi, B. Bashyam, R. de Souza, C. Ireland, S.C. Pichika, J. Beyene, J.L. Sievenpiper, R.G. Josse, 2018. Nuts as a replacement for carbohydrates in the diabetic diet: a reanalysis of a randomised controlled trial. Diabetologia https://doi.org/10.1007/s00125-018-4628-9

Eating pecans had significant effect on biomarkers of heart disease and type 2 diabetes

A very small 4-week study involving 26 overweight and obese adults (average age 59) found that those given a diet with pecans substituted for 15% of the total calories significantly improved insulin sensitivity and had a significant effect on markers of cardiometabolic disease.

Both the control diet and the pecan-rich diet were low in fruits, vegetables and fiber.

https://www.eurekalert.org/pub_releases/2018-03/kc-n-eph032218.php

The study entitled "A Pecan-Rich Diet Improves Cardiometabolic Risk Factors in Overweight and Obese Adults: A Randomized Controlled Trial" is available online and was presented at the American Society for Nutrition Annual Conference, Nutrition 2018 held in Boston in June.

A handful of nuts a day cuts the risk of a wide range of diseases

A review of 29 studies involving some 819,000 participants has concluded that people who eat at least 20g of nuts (a handful) a day have a 30% lower risk of heart disease, as well as lower risks of cancer, respiratory disease, and diabetes.

The study included all kinds of tree nuts, and also peanuts. The results were in general similar. There was little evidence of further improvement in health outcomes as a result of eating more than 20g of nuts.

Nuts and peanuts are high in fibre, magnesium, and polyunsaturated fats. Some nuts, particularly walnuts and pecan nuts are also high in antioxidants.

https://www.eurekalert.org/pub_releases/2016-12/icl-aho120216.php

Link between nut intake and inflammatory biomarkers

Data from 5,013 men and women participating in the Nurses' Health Study and Health Professionals Follow-up Study has revealed that higher nut intake (5 or more times per week) was associated with lower levels of inflammatory biomarkers (C-reactive protein (CRP) and Interleukin 6 (IL6)).

Research has also shown that nut consumption may be inversely related to body mass index (BMI), which is a strong determinant of inflammatory biomarkers, so it may be that the associations between nut intake and inflammatory markers are mediated in part through BMI.

http://www.eurekalert.org/pub_releases/2016-07/mp-itn072716.php

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