Diet

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

An animal study comparing five diets shows that one diet really doesn't fit everyone, and what works for some may not be best for others.

There were four groups of genetically (almost-)identical animals, with genetic differences between any two of the groups translating to roughly the same as those of two unrelated people. The test diets included: an American-style diet (higher in fat and refined carbs, especially corn); Mediterranean (with wheat and red wine extract); Japanese (with rice and green tea extract); and ketogenic, or Atkins-like (high in fat and protein with very few carbs). The fifth diet was the control group.

One of the four genetic types did very poorly when eating the Japanese-like diet, developing signs of liver damage. Two types did well on the Atkins-like diet, but two did very badly (one became very obese, while the other became 'skinny-fat' — apparently a healthy weight but with a high percentage of body fat.

Two types became very obese, with signs of metabolic syndrome, on the American-style diet, while the other two were less negatively affected. With the Mediterranean diet, some groups were healthy, while others experienced some weight gain.

https://www.eurekalert.org/pub_releases/2017-11/tau-dsm113017.php