Healthy aging benefits may be associated with walnut consumption

A new study published in the Journal of Nutrition suggests that consuming 1-2 servings of walnuts per week (1/4 cup per serving) was associated with reduced risk of developing impairments in physical function, which helps enable older women to maintain independence throughout the aging process. (1)

This paper emphasized that overall diet quality, rather than individual foods, may have a greater impact on reducing risk of physical function impairments. Specifically, diet quality traits most associated with reduced rates of incident physical impairment were higher intake of fruits and vegetables; lower intake of sugar-sweetened beverages, trans fat, and sodium; and moderate alcohol intake. Among food components, the strongest relations were found for increased intakes of oranges, orange juice, apples, pears, romaine or leaf lettuce, and walnuts.

"There's a lot of research that looks at specific health conditions in aging, such as diabetes and heart disease, but less attention to research on quality of life and ability to maintain independence with aging," said Dr. Francine Grodstein, ScD, professor of medicine at Brigham and Women's Hospital and Harvard Medical School. "The simple message from this study is that eating an overall healthy diet, including certain foods, such as walnuts and other whole foods, may help women with the ability to do key everyday tasks as they age, like carrying groceries or dressing themselves."

The researchers looked at data from 54,762 women in the Nurses' Health Study, which tracked women for over 30 years. Between 1992 and 2008, the women were asked questions about their physical function, including their ability to perform basic activities of daily living. This new paper prospectively examined the association between the dietary habits of the participants and subsequent impairment in physical function. Diet was assessed using the Alternative Healthy Eating Index (AHEI-2010), a measure of diet quality that incorporates foods and nutrients predictive of chronic disease risk based on scientific evidence.

"These results add to the large body of evidence that outline the many benefits of a healthy diet for women. Additional research is needed to better understand how diet and lifestyle choices can help maintain our health and well-being as we age," said Dr. Grodstein.

There are numerous possible active properties in walnuts that may be contributing factors in providing health benefits. Walnuts are unique among nuts in that they are primarily composed of polyunsaturated fat (13 grams per ounce), which includes alpha-linolenic acid (ALA), the plant-based omega-3 fatty acid. They are the only nut to contain a significant amount of ALA with 2.5 grams per one ounce serving.

Some study limitations should be considered. The sample only included women, so these results may not be generalizable to men. Additionally, participants were not assigned to eat walnuts or other foods, and were just asked about their dietary choices. It is also possible that subjects may have misreported their dietary intake since this information was collected by questionnaires. In addition, because this is an observational study, residual confounding cannot be ruled out (i.e. that other lifestyle habits which are more common in adults who eat walnuts could contribute to the study findings); and, thus, the results should be interpreted with caution.

Study links omega-3s to reduced mortality

A recent meta-analysis in Scientific Reports supports a link between EPA and DHA omega-3 intake and a reduced risk of death by any cause. The meta-analysis included 11 studies involving 371,965 participants and 31,185 death events, with a subset of the studies being used for different analyses.

In the analysis of n-3 LCPUFA intake, there was a 9% reduced risk of all-cause death associated with high versus low omega-3 intake. In the dose-response analysis, an increase in EPA/DHA intake of 300 mg/day was associated with a 6% lower risk of all-cause mortality. These findings suggest that both dietary and circulating n-3 LCPUFA are shown to be significantly associated with reduced risk of all-cause mortality.

According to study author Manfred Eggersdorfer, "The meta-analysis of 11 prospective observational studies demonstrates that each 1% increment of omega-3s in total fatty acids in blood may be associated with a 20% decrease in risk of all-cause mortality. This is an important finding for the potential contribution of adequate omega-3 intake to public health."

Some older adults live well, despite advancing years and the burdens of chronic diseases

You might believe that older adults who deal with extensive chronic illnesses or serious diseases would be more likely to be frail and to have a poorer quality of life than healthier older adults. That may be true for some elders--but not for all. Researchers writing in the Journal of the American Geriatrics Society suggest that an undefined coping mechanism of some sort may play a role in how well older adults are able to live despite having burdensome illnesses.

The researchers examined three groups of participants enrolled in the Cardiovascular Health Study, a large research project that examined adults 65-years-old and older from four cities around the country.

Researchers assigned people to one of three groups, based on the extent of their disease and their level of vigor or frailty:

1.    The expected agers (3,528 people) had higher disease but also higher frailty levels. They spent 47 percent of the remainder of their lives able and healthy.

2.    The adapters (882 people) had higher disease levels as well as relatively high vigor (being active and mobile) levels. They spent 55 percent of the reminder of their lives able and healthy.

3.    The prematurely frail (885 people) had lower disease levels but higher frailty levels. They spent 37 percent of their remaining lives able and healthy.

The researchers said "adapter" older adults who were more vigorous than expected, based on their disease burden, lived longer lives when compared to those who were more frail than expected based on their disease burden. These "adapters" could have unique characteristics, perhaps some undefined coping mechanism, that should be studied further, suggested the researchers.

More reasons to eat your broccoli

Love it or hate it, broccoli is touted as a superfood, offering an array of health benefits. And it's about to get even more super.

University of Illinois researchers have identified candidate genes controlling the accumulation of phenolic compounds in broccoli. Consumption of phenolic compounds, including certain flavonoids, is associated with a lower risk of coronary heart disease, type II diabetes, asthma, and several types of cancer.

"Phenolic compounds have good antioxidant activity, and there is increasing evidence that this antioxidant activity affects biochemical pathways affiliated with inflammation in mammals. We need inflammation because it's a response to disease or damage, but it's also associated with initiation of a number of degenerative diseases. People whose diets consist of a certain level of these compounds will have a lesser risk of contracting these diseases," explains U of I geneticist Jack Juvik.

The researchers crossed two broccoli lines and tested their progeny in terms of total phenolic content and their ability to neutralize oxygen radicals in cellular assays. They then used a genetic technique called quantitative trait locus analysis to search for the genes involved in generating phenolics in the most promising progeny.

By identifying the genes involved in accumulating these compounds, the researchers are one step closer to breeding broccoli and related Brassica vegetables like kale and cabbage with mega-doses of phenolic compounds.

"It's going to take awhile," Juvik notes. "This work is a step in that direction, but is not the final answer. We plan to take the candidate genes we identified here and use them in a breeding program to improve the health benefits of these vegetables. Meanwhile, we'll have to make sure yield, appearance, and taste are maintained as well."

The good news is that phenolic compounds are flavorless and stable, meaning the vegetables can be cooked without losing health-promoting qualities.

Once these vegetables are consumed, the phenolic compounds are absorbed and targeted to certain areas of the body or concentrated in the liver. Flavonoids spread through the bloodstream, reducing inflammation through their antioxidant activity.

"These are things we can't make ourselves, so we have to get them from our diets," Juvik says. "The compounds don't stick around forever, so we need to eat broccoli or some other Brassica vegetable every three or four days to lower the risk of cancers and other degenerative diseases."

Men with prostate cancer: nuts >4 times per week after diagnosis- 34% lower risk of overall mortality

In a large prospective study published online in the British Journal of Cancer*, researchers looked at the association between nut consumption and prostate cancer risk and mortality among 47,299 men in the Health Professionals Follow-up Study. While nut consumption was not associated with a reduced risk of prostate cancer, men who had prostate cancer and consumed tree nuts (almonds, Brazil nuts, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios and walnuts) five or more times per week after diagnosis, had a significant 34 percent lower risk of overall mortality than those who consumed nuts less than once per month (HR=0.66, 95% CI: 0.52-0.83, P for trend=0.0005).

"This is important," states lead researcher, Ying Bao, MD, ScD, from the Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, "since more men live with prostate cancer than die from it." Prostate cancer is the most commonly diagnosed and second most lethal cancer for men in the U.S.

According to Dr. Bao, of the 4,346 men diagnosed with non-metastatic (cancer that has not spread from the place where it started to other places in the body) prostate cancer during the 26 years of follow-up, only about 10 percent died from prostate cancer. Roughly one third of the cancer patients died from cardiovascular disease and the rest from other causes.

Increasing evidence suggests that insulin resistance, a condition in which the cells of the body become resistant to the hormone insulin, is involved in prostate cancer risk and progression. Tree nuts have been associated with improved insulin sensitivity and reduced risk of diabetes, cardiovascular disease and total mortality**. Nuts contain important nutrients such as unsaturated fats, high quality protein, vitamins (i.e., vitamin E, folate and niacin) minerals (i.e., magnesium, calcium and potassium) and phytochemicals--all of which may offer cardioprotective, anticarcinogenic, anti-inflammatory and antioxidant properties.

"These findings add to the growing body of evidence showing that nuts can and should be part of a healthy diet," states Maureen Ternus, M.S., R.D., Executive Director of the International Tree Nut Council Nutrition Research & Education Foundation (INC NREF). "During the summer months especially, tree nuts are a great, portable snack to take to the beach, on a hike, or camping," adds Ternus. "Just 1.5 ounces of nuts per day (about 1/3 cup) can have a positive impact on health."

Seven servings of whole grains a day keep the doctor away

Eating three more portions of dietary fiber a day--say, two pieces of whole grain bread and a bowl of whole grain breakfast cereal--is associated with a lower risk for all cardiovascular diseases and for dying of cancer, diabetes, and respiratory and infectious diseases, a study just published in the BMJ has shown. The study is strong proof that consuming lots of whole grains is good for our health, says first author Dagfinn Aune, a PhD candidate at the Norwegian University of Science and Technology who is currently working at Imperial College, London.

The meta-analysis isn't the first study that links whole grains to positive health effects, but it is the first one to look at how much whole grain one should eat to minimize health risks and that has examined the connection with various causes of death. In general, the study showed that the higher the consumption, the better protected you are.

"We saw the lowest risk among people who ate between seven and seven and a half servings of whole grain products a day, which was the highest intake across all the studies. This corresponds to 210-225 grams of whole grain products in fresh weight and about 70-75 grams of whole grains in dry weight, and is about the same as the health authorities in Norway and other Nordic countries recommend as the minimum daily allowance," says Aune.

Applies only to whole grain products

The researchers' analyses showed fewer risk factors for people who consumed more bread and cereal with whole grains, as well as foods with added bran. On the other hand, people who ate a lot of white bread, rice or cereals with refined grains did not show reduced risk.

"A lot of folks eat plenty of grains, but they choose refined breads instead of varieties with more dietary fiber. Our study suggests that you can reduce the risk of premature death by replacing a big part of the white flour in your diet with whole grain products," said Aune.

Some of the beneficial health effects of eating whole grains may lie in their high fiber content. A high intake of dietary fiber can stabilize blood sugar levels, lower blood pressure, cholesterol, and levels of inflammatory markers in the blood, and can positively affect the gut environment. All of this can contribute to a reduced risk of diabetes, cardiovascular disease and cancer.

Whole grain products also contain several other biologically active substances, such as antioxidants, B vitamins, iron, magnesium, and zinc. It is probably the whole package of favorable components that contribute to the positive effect on the risk of chronic disease and mortality.

Something is much better than nothing

Aune and an international group of researchers collected data from 45 different population studies that investigated whole grain intake in relation to risk of future illness or death due to specific causes.

To be included, the scientists required risk estimates in the studies to be adjusted for other factors that could affect the relationship between dietary fiber intake and health. The findings are now being published in The BMJ, one of the highest ranked medical journals, and reviewed in an editorial in the same issue.

In the editorial, Cecilie Kyrø and Anne Tjønneland from the research centre of the Danish Cancer Society, wrote, "Today, the Nordic countries have the most specific recommendations in the world for how much dietary fiber you should eat: 70-90 grams a day in dry weight, which corresponds to about 210-270 grams of product.

In Denmark, the intake of whole grains has doubled over the last ten years, thanks to the food and health authorities ensuring that food may not be labeled as whole grain if it does not meet strict content requirements. But even in Denmark, no more than 6% of the population follow the recommendations to eat seven or more servings of whole grains a day.

Nevertheless, the researchers believe it is possible to get more people to eat that much whole grain, both in Scandinavia and other countries.

"It may seem ambitious, but effective campaigns and product development can lead to much greater consumption of whole grains. When the health authorities implement measures to increase the population's dietary fibre intake, it is important not to promote whole grain products with a high sugar and salt content," write the Danish researchers, and they point out that greatest health impact at the population level can be achieved by getting more people to eat some whole grains instead of none.

This idea is also supported by the meta-analysis findings.

"We found the greatest risk reduction in people who consumed 0 grams up to those who ate 50 grams of whole grain products a day. The risk continued to decrease - but to a lesser extent - up to an intake of 225 grams a day," said Aune.

Reduced mortality risk for many diseases

Nine studies with a total of more than 700,000 participants examined the risk for all types of cardiovascular disease and correlated cardiovascular deaths. The half of the study subjects who ate the most whole grains had a 16% lower risk than those who consumed less, and every third portion more of whole grain a day reduced the risk by 22%.

The seven studies that looked at coronary heart disease (heart attack and angina) showed similar risk estimates, whereas the reduced risk of stroke was slightly lower in the combined analyses of the six studies that examined this. Analyses of whole grains and mortality from stroke showed a statistically significant 14% reduction in risk.

The risk of dying prematurely from all causes was 18% lower for individuals who consumed a lot of whole grains compared to those who consumed lesser amounts, while three additional servings each day were associated with a 17% reduction in mortality. The risk for deaths associated with cancer (15%), respiratory diseases (22%), diabetes (51%) and infectious diseases (26%) was also lower the more whole grains individuals consumed.

Still need more research

The researchers acknowledge the limitations in measuring how much grain was eaten via self-reported data and that the various studies may have had different definitions for what was regarded as whole grain products. The researchers also cannot rule out that the results may be influenced by people who eat lots of whole grains also living healthier in other ways, but point out that they got the same results when they only analysed studies that adjusted for smoking, alcohol consumption, BMI, physical activity and consumption of other foods such as red meat, sugary drinks and fruits and vegetables.

"Future studies need to improve the way grain intake is measured, and more research that looks at whether the different types of whole grains can have different effects on health is also needed. For example, some studies indicate that oats and rye are better whole grain sources than wheat in terms of reducing the risk of cardiovascular disease," the Danish researchers Kyrø and Tjønneland write.

And a lot of research is still missing on the relationship between dietary fibre intake and relatively rare causes of death.

Aune says that much of the research on whole grains so far has been focused on the most widespread illnesses such as cardiovascular diseases, cancers (mainly colorectal cancer) and type 2 diabetes. "However, our results suggest that consuming whole grain products may have beneficial effects on several other diseases, like mortality from respiratory diseases and infections, and the literature suggests that whole grains may even protect against rare cancers.

Now several very large population-based studies have been established, allowing us to examine less common diseases in more detail than previously. So we'll continue to examine the relationship between whole grains and diseases that have only been studied minimally or not at all," he says.

Piping hot drinks may lead to cancer of the esophagus

Drinking piping hot coffee, tea and the caffeine-infused beverage yerba mate probably causes cancer, the World Health Organization announced Wednesday.

Beverages surpassing 149 degrees Fahrenheit (65 degrees Celsius) may increase the risk of tumors in the esophagus, which resides in the chest area below the throat, according to USC's Mariana Stern and 22 other scientists from 10 countries. They met at the WHO's International Agency for Research on Cancer in Lyon, France, in May to determine if drinking coffee, mate or other very hot beverages causes cancer. Their results were published in the journal Lancet on June 15.

"Enjoy your coffee or mate, but make sure it's not very hot," said Stern, an associate professor of preventive medicine and urology at the Keck School of Medicine of USC. "There is physical evidence that very hot beverages can contribute to cell injury in the esophagus and thus contribute to cancer formation."

The group scoured more than 1,000 studies on over 20 different types of cancer. The scientists concluded drinking any beverage hotter than 149 degrees Fahrenheit is "probably carcinogenetic to humans," placing scalding hot drinks in the same category as DDT, frying food at high temperatures, consumption of red meat and the human papillomavirus.

According to the National Coffee Association, coffee waiting to be served should sit at 180-185 degrees Fahrenheit (82-85 degrees Celsius). That's around the temperature McDonald's restaurants served coffee before a well-known lawsuit prompted the fast food chain to sell coffee at a temperature of 10 degrees lower - still far above what the researchers consider safe.

In the United States, the average coffee drinking temperature is around 140 degrees Fahrenheit (60 degrees Celsius). The temperature varies between 99-190 degrees Fahrenheit (37-88 degrees Celsius), Stern said.

"We were now able to evaluate more carefully the effect of mate itself from the effect of temperature, and we concluded that the observed links between mate drinking and cancer of the esophagus seem to be largely driven by drinking mate very hot," Stern said. "Similar associations are seen for other very hot beverages, like tea or coffee."

Stern and her colleagues noted that drinking yerba mate at very high temperatures - between 150 and right below the boiling point of 212 degrees Fahrenheit (66-100 degrees Celsius) - is common practice in certain countries in South America, including Argentina, Uruguay and Paraguay.

A cup of coffee a day may keep liver cancer away

The scientists downgraded a cup of joe from "possibly carcinogenic" and hot mate from "probably carcinogenic" to safe for consumption as long as neither are scalding hot.

In 1991, the WHO gave coffee that classification based on a much smaller database of studies. Now, the scientists highlighted some studies that associated coffee with cancer when the real culprit was probably tobacco smoking, which is highly correlated with heavy coffee drinking, according to the report.

Late last year, Stern participated in a WHO group that concluded consuming processed meat - bacon, salami, sausages, hot dogs and deli meats - causes cancer.

However, the news about coffee was not grim. The researchers estimate that a cup of coffee a day decreases the risk of liver cancer by 15 percent. In other words, the scientists are giving coffee lovers a free pass to drink as much coffee as their bladders can handle.

"For many cancer types, we found clear evidence that coffee is not carcinogenic," Stern said. "In fact, we found that coffee protects against some cancers such as liver and uterine endometrium cancer."