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 A large review of nut studies found that people eating a daily handful of nuts (about 20 g) have a lower risk of heart disease, cancer, stroke, premature death, and death from respiratory disease, type 2 diabetes, and infectious disease. Truly impressive. Benefits seem to be for all nuts, and also peanuts - which are called nuts, but are actually legumes (other posts about nut consumption benefits). An earlier post discussed how some of these effects could be to nuts lowering systemic inflammation throughout the body. Bottom line: try to eat a handful of nuts every day or most days a week for your health. And make it a variety of nuts - walnuts, almonds, hazelnuts, cashews, pistachios, pecans, Brazil nuts, and peanuts. From Science Daily:

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

A large analysis of current research shows that people who eat at least 20g of nuts a day have a lower risk of heart disease, cancer and other diseases. The analysis of all current studies on nut consumption and disease risk has revealed that 20g a day -- equivalent to a handful -- can cut people's risk of coronary heart disease by nearly 30 percent, their risk of cancer by 15 percent, and their risk of premature death by 22 percent. An average of at least 20g of nut consumption was also associated with a reduced risk of dying from respiratory disease by about a half, and diabetes by nearly 40 percent, although the researchers note that there is less data about these diseases in relation to nut consumption.

The study, led by researchers from Imperial College London and the Norwegian University of Science and Technology, is published in the journal BMC Medicine. The research team analysed 29 published studies from around the world that involved up to 819,000 participants, including more than 12,000 cases of coronary heart disease, 9,000 cases of stroke, 18,000 cases of cardiovascular disease and cancer, and more than 85,000 deaths. While there was some variation between the populations that were studied....the researchers found that nut consumption was associated with a reduction in disease risk across most of them.

The study included all kinds of tree nuts, such as hazel nuts and walnuts, and also peanuts -- which are actually legumes. The results were in general similar whether total nut intake, tree nuts or peanuts were analysed. What makes nuts so potentially beneficial, said Aune, is their nutritional value: "Nuts and peanuts are high in fibre, magnesium, and polyunsaturated fats -- nutrients that are beneficial for cutting cardiovascular disease risk and which can reduce cholesterol levels. "Some nuts, particularly walnuts and pecan nuts are also high in antioxidants, which can fight oxidative stress and possibly reduce cancer risk. Even though nuts are quite high in fat, they are also high in fibre and protein, and there is some evidence that suggests nuts might actually reduce your risk of obesity over time."

The study also found that if people consumed on average more than 20g of nuts per day, there was little evidence of further improvement in health outcomes. [ORIGINAL STUDY]

 Studies have found that increased nut consumption has been associated with reduced risk of cardiovascular disease and type 2 diabetes. A newly published study looked at large groups of people to see if this was due to nuts reducing systemic inflammation throughout the body - which can be measured by inflammatory biomarkers such as C-reactive protein (CRP) and  interleukin 6 (IL6).

The researchers found that nut consumption was inversely associated with concentrations of biomarkers CRP and IL-6 - that is, the more nuts eaten weekly, the lower the inflammatory biomarkers. They also found that substituting nuts for red meat, processed meat, eggs, refined grains, potatoes, or potato chips was associated with a healthier inflammatory biomarker profile. In the study, one serving of nuts was equivalent to 28 g (1 oz) of peanuts or other nuts. What's in nuts? Unsaturated fatty acids, high quality plant protein, fiber, minerals, vitamins, bioactive compounds such as phytosterols, antioxidants, magnesium, etc. Bottom line: eat a serving of nuts at least several times a week. From Science Daily:

Frequent nut consumption associated with less inflammation

In a study of more than 5,000 people, investigators from Brigham and Women's Hospital have found that greater intake of nuts was associated with lower levels of biomarkers of inflammation, a finding that may help explain the health benefits of nuts. The results of the study appear July 27 in the American Journal of Clinical Nutrition.

"Population studies have consistently supported a protective role of nuts against cardiometabolic disorders such as cardiovascular disease and type 2 diabetes, and we know that inflammation is a key process in the development of these diseases," said corresponding author Ying Bao, MD, ScD, an epidemiologist in BWH's Channing Division of Network Medicine. "Our new work suggests that nuts may exert their beneficial effects in part by reducing systemic inflammation."

Previously Bao and her colleagues observed an association between increased nut consumption and reduced risk of major chronic diseases and even death, but few prospective cohort studies had examined the link between nut intake and inflammation. In the current study, the research team performed a cross-sectional analysis of data from the Nurses' Health Study, which includes more than 120,000 female registered nurses, and from the Health Professionals Follow-Up Study, which includes more than 50,000 male health professionals.... looked at the levels of certain telltale proteins known as biomarkers in blood samples collected from the study participants. They measured three well-established biomarkers of inflammation: C-reactive protein (CRP), interleukin 6 (IL6) and tumor necrosis factor receptor 2 (TNFR2).

After adjusting for age, medical history, lifestyle and other variables, they found that participants who had consumed five or more servings of nuts per week had lower levels of CRP and IL6 than those who never or almost never ate nuts. In addition, people who substituted three servings per week of nuts in place of red meat, processed meat, eggs or refined grains had significantly lower levels of CRP and IL6.

Peanuts and tree nuts contain a number of healthful components including magnesium, fiber, L-arginine, antioxidants and unsaturated fatty acids such as α-linolenic acid. Researchers have not yet determined which of these components, or if the combination of all of them, may offer protection against inflammation, but Bao and her colleagues are interested in exploring this further through clinical trials that would regulate and monitor diet.

  More research support for extra virgin olive oil and Mediterranean diet associated with anti-cancer effects - here lower incidence of breast cancer. The Mediterranean diet stresses eating a lot of fruits, vegetables, seeds, nuts, legumes, whole grains, fish, and olive oil. From Science Daily:

Mediterranean diet plus olive oil associated with reduced breast cancer risk

Eating a Mediterranean diet supplemented with extra virgin olive oil was associated with a relatively lower risk of breast cancer in a study of women in Spain, according to an article published online by JAMA Internal Medicine.

The Mediterranean diet is known for its abundance of plant foods, fish and especially olive oil. Miguel A. Martínez-González, M.D., of the University of Navarra in Pamplona and CIBEROBN in Madrid, Spain, and coauthors analyzed the effects of two interventions with the Mediterranean diet (supplemented with extra virgin olive oil [EVOO] or nuts) compared with advice to women to follow a low-fat diet. Study participants in the two intervention groups were given EVOO (one liter per week for the participants and their families) or mixed nuts (30 grams per day: 15 grams of walnuts, 7.5 grams of hazelnuts and 7.5 grams of almonds).

From 2003 to 2009, 4,282 women (ages 60 to 80 and at high risk of cardiovascular disease) were recruited. Women were randomly assigned to the Mediterranean diet supplemented with EVOO (n=1,476), the Mediterranean diet supplemented with nuts (n=1,285) or the control diet with advice to reduce their dietary intake of fat (n=1,391). The women were an average age of 67.7 years old, had an average body mass index of 30.4, most of them had undergone menopause before the age of 55 and less than 3 percent used hormone therapy. During a median follow-up of nearly five years, the authors identified 35 confirmed incident (new) cases of malignant breast cancer.

The authors report that women eating a Mediterranean diet supplemented with EVOO showed a 68 percent (multivariable-adjusted hazard ratio of 0.32) relatively lower risk of malignant breast cancer than those allocated to the control diet. Women eating a Mediterranean diet supplemented with nuts showed a nonsignificant risk reduction compared with women in the control group.

The authors note a number of limitations in their study including that breast cancer was not the primary end point of the trial for which the women were recruited; the number of observed breast cancer cases was low; the authors do not have information on an individual basis on whether and when women in the trial underwent mammography; and the study cannot establish whether the observed beneficial effect was attributable mainly to the EVOO or to its consumption within the context of the Mediterranean diet. [The original study.]

This latest study finding health benefits of eating nuts was a review of 36 observational studies, involving a total of 30,000 people. Nut consumption was associated with a lower risk of cancer in general, and a decreased risk of some types of cancer (colorectal, endometrial, pancreatic), but not with type 2 diabetes. So go ahead - eat a small handful of nuts for your health at least several times a week.From Medpage Today:

A Nutty Way to Prevent Cancer?

Nut consumption was associated with a decreased risk of some types of cancer but not with type 2 diabetes in a large review.When patients eating the most nuts were compared with those eating the least, those in the first group had a lower risk of colorectal cancer in three studies (RR 0.76, 95% CI 0.61-0.96; I2=51.3%), of endometrial cancer in two studies (RR 0.58, 95% CI 0.43-0.79; I2=0%), and pancreatic cancer in one study (RR 0.68, 95% CI 0.48-0.96; I2 not available). Those results were reported in the meta-analysis of 36 observational studies, with a total population of more than 30,000 patients.

Nut consumption was also associated with a lower risk of cancer in general (RR 0.85, 95% CI 0.76-0.95;I2=66.5%), according to the authors. But it was not associated with other types of cancer or with type 2 diabetes (RR 0.98, 95% CI 0.84-1.14; I2=74.2%), found the researchers, who were led by Lang Wu, a PhD candidate at the Mayo Clinic. They published their results on June 16 in Nutrition Reviews.

"Overall, nut intake was associated with a decreased risk of cancer," wrote Wu and colleagues. "Given the scarcity of currently available data, however, evidence from additional studies is required to more precisely determine the relationship between nut consumption and risk of individual cancer types." Evidence for the association between nuts and cancer has been mixed, according to the authors. Follow-up time in the studies ranged from 4.6 years to 30 years, found the review.

The amount of nuts eaten ranged from none for some of the patients to eating nuts more than seven times a week....No associations were found between nut consumption and acute myeloid leukemia, breast cancer, gastric cancer, glioma, hepatocellular carcinoma, leukemia, lymphoma, ovarian cancer, prostate cancer, or stomach cancer.

Image result for Mediterranean dietMore support for health benefits of a Mediterranean diet. Results of a  study comparing brain health in groups of older people (in their 60s and 70s) suggest that a Mediterranean diet supplemented with olive oil or nuts may counter-act age-related cognitive decline (overall their cognitive test scores held steady). But the group assigned to the low-fat diet (the control group) worsened on cognitive tests. The Mediterranean diet emphasizes eating vegetables, fruits, legumes (beans), nuts, whole grains, seeds, olive oil, fish, moderate consumption of dairy products (mostly as cheese and yogurt), moderate wine consumption (optional), and low consumption of meat and meat products.From the Wall Street Journal:

Mediterranean Diet Boosts Brain Power, Clinical Study Finds

The Mediterranean diet, supplemented with a handful of nuts or a few tablespoons of olive oil a day, can counteract the effects of aging on the brain’s ability to function, a new clinical study suggests.

The study, published online Monday in JAMA Internal Medicine, was unusual in that it employed rigorous scientific practices to test the effect of the diet on health....Data gathered from previous observational studies suggested that adhering to a Mediterranean-type diet related to better cognitive function and a reduced risk of dementia, but observational studies have limitations, he said.

The Mediterranean diet, which has also shown benefits in cardiovascular health, emphasizes vegetables and fruits, unrefined grains and beans. It also includes fish and wine and minimal consumption of meat and full-fat dairy products.

The study involved 447 cognitively healthy participants, 55 to 80 years of age, who were divided into three groups. Two groups followed the Mediterranean diet and added either 30 grams of mixed nuts (walnuts, hazelnuts and almonds) a day, or five tablespoons of extra virgin olive oil a day. The third group, acting as a control, was advised to follow a low-fat diet. The subjects were followed for a median of just over four years.

The results showed that, compared with the control group, memory function remained stronger in the Mediterranean diet plus nuts group, while frontal (attention and executive function) and global cognition benefited in the Mediterranean diet plus olive oil group.

The diminished decline in cognitive function likely stems from the abundance of antioxidants and anti-inflammatory agents found in the supplemental foods, Dr. Ros said. Olive oil and nuts are rich in phenolic compounds that might counteract oxidative processes in the brain, leading to neurodegeneration, the study said. “If you can delay your age-related cognitive decline, you can process tasks with higher speed,” said Dr. Ros.

The research was a substudy of a larger investigation, designed by Dr. Ros, that found the Mediterranean diet, supplemented with additional olive oil or nuts, reduced the incidence of major cardiovascular events among people at high cardiovascular risk. That study, which involved nearly 7,500 participants and known by the acronym Predimed, was published in 2013.