A study in which 157 healthy adult volunteers were asked to regulate their emotional reactions to unpleasant pictures, has found that those who showed greater brain activation when regulating their negative emotions also had higher blood levels of interleukin-6 (a marker for inflammation) and increased thickness of the carotid artery wall (a marker of atherosclerosis).
The finding helps explain why stress increases the risk for stroke and heart attack.
Data from a survey of 20,000 people across the UK has found that people who cycle, walk, or take public transport to work had a lower risk of being overweight than those who drove or took a taxi. People who walked to work were 40% less likely to have diabetes than those who drove and 17% less likely to have high blood pressure. Cyclists were around half as likely to have diabetes as drivers.
http://www.eurekalert.org/pub_releases/2013-08/icl-wtw080513.php
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.
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
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 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
McKay, D. L., Eliasziw, M., Chen, C. Y. O., & Blumberg, J. B. (2018). A Pecan-Rich Diet Improves Cardiometabolic Risk Factors in Overweight and Obese Adults: A Randomized Controlled Trial. Nutrients, 10(3), 339. Retrieved from https://www.mdpi.com/2072-6643/10/3/339
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
Yu, Z., Malik, V. S., Keum, N., Hu, F. B., Giovannucci, E. L., Stampfer, M. J., … Bao, Y. (2016). Associations between nut consumption and inflammatory biomarkers. The American Journal of Clinical Nutrition, 104(3), 722-728. Retrieved from https://academic.oup.com/ajcn/article/104/3/722/4564733
Data from AREDS2, involving 4,203 older adults with age-related macular degeneration, has found that daily dietary supplements of either omega-3 polyunsaturated fatty acids (also found in fish) or lutein and zeaxanthin (nutrients found in green leafy vegetables) were not associated with reduced risk for cardiovascular disease (CVD).
http://www.eurekalert.org/pub_releases/2014-03/tjnj-sna031414.php
A review of research from 1957 to the present has concluded that a whole diet approach, and specifically Mediterranean-style diets, has more evidence for reducing cardiovascular risk than strategies that focus exclusively on reduced dietary fat.
http://www.eurekalert.org/pub_releases/2014-02/ehs-ssw020514.php
A six-month study involving 138 overweight and obese older adults (50-75) with Metabolic Syndrome found that eating one cup of blueberries per day resulted in sustained improvements in vascular function and arterial stiffness, reducing the risk of cardiovascular disease by 12-15%. There was no benefit of a smaller 75 gram (half cup) daily intake of blueberries.
https://www.eurekalert.org/pub_releases/2019-05/uoea-ebe053019.php
Curtis, P. J., van der Velpen, V., Berends, L., Jennings, A., Feelisch, M., Umpleby, M., … Cassidy, A. (2019). Blueberries improve biomarkers of cardiometabolic function in participants with metabolic syndrome—results from a 6-month, double-blind, randomized controlled trial. The American Journal of Clinical Nutrition, 109(6), 1535-1545. Retrieved from https://academic.oup.com/ajcn/article/109/6/1535/5499342
Two studies help explain why kidney disease increases the risk of cardiovascular diseases such as high blood pressure and vascular calcification. The mediator seems to be a hormone called FGF23, which is sensitive to the level of phosphates in the body.
Phosphate rich foods include processed cheese, Parmesan, cola, baking powder and most processed foods.
http://www.eurekalert.org/pub_releases/2014-05/uovm-nco050514.php
A meta-analysis of 72 studies with over 600,000 participants from 18 nations has concluded that total saturated fatty acid, whether measured in the diet or in the bloodstream as a biomarker, was not associated with coronary disease risk. Nor was there any significant association between consumption of total monounsaturated fatty acids, long-chain omega-3 and omega-6 polyunsaturated fatty acids, and cardiovascular risk.
Data from the very large U.S. National Health and Nutrition Examination Survey (NHANES), involving 23,168 people, has found a significant association between low dietary fiber intake and risk of metabolic syndrome, cardiovascular inflammation, and obesity.
Dietary fiber intake was also consistently below recommended intake levels: 38g per day for men aged 19-50 years, 30g per day for men 50 and over, 25g for women aged 19-50 years, and 21g per day for women over 50. Mean dietary fiber intake was only 16.2g per day across all groups.
An updated systematic review of 25 years of research on the effect of walnut consumption on cardiovascular risk factors suggest that walnut-enriched diets may lead to significantly greater reductions in total cholesterol, LDL cholesterol, triglycerides, and apolipoprotein B, compared to control diets.
Walnut consumption had no adverse effects on body weight or blood pressure.
Most of the trials in this review had relatively small sample sizes, which could limit the ability to determine significant effects, and in some cases, the amount of walnuts consumed was relatively large and might be difficult to maintain in a real-world setting. However, researchers still saw significant benefits when lower amounts of walnuts were consumed (less than 28 grams per day), particularly with total and LDL cholesterol.
https://www.eurekalert.org/pub_releases/2018-07/es-sre071218.php
Guasch-Ferré M, Li J, Hu FB, et al. Effects of walnut consumption on blood lipids and other cardiovascular risk factors: an updated meta-analysis and systematic review of controlled trials [published online ahead of print June 21, 2018]. Am J Clin Nutr. doi: 10.1093/ajcn/nqy091
Banel HK, Hu FB. Effects of walnut consumption on blood lipids and other cardiovascular risk factors: a meta-analysis and systematic review. Am J Clin Nutr. 2009;90(1):56-63.