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Category: nutrition

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This study was done on mice, but it would be great if it also holds true for human eyes. Another benefit from daily drinking of coffee! From Science Daily:

A cup of coffee a day may keep retinal damage away, study shows

Aside from java's energy jolt, food scientists say you may reap another health benefit from a daily cup of joe: prevention of deteriorating eyesight and possible blindness from retinal degeneration due to glaucoma, aging and diabetes.

Raw coffee is, on average, just 1 percent caffeine, but it contains 7 to 9 percent chlorogenic acid (CLA), a strong antioxidant that prevents retinal degeneration in mice, according to a Cornell study published in theJournal of Agricultural and Food Chemistry (December 2013).

The retina is a thin tissue layer on the inside, back wall of the eye with millions of light-sensitive cells and other nerve cells that receive and organize visual information. It is also one of the most metabolically active tissues, demanding high levels of oxygen and making it prone to oxidative stress. The lack of oxygen and production of free radicals leads to tissue damage and loss of sight.

In the study, mice eyes were treated with nitric oxide, which creates oxidative stress and free radicals, leading to retinal degeneration, but mice pretreated with CLA developed no retinal damage.

Previous studies have shown that coffee also cuts the risk of such chronic diseases as Parkinson's, prostate cancer, diabetes, Alzheimer's and age-related cognitive declines.

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Excellent reason to enjoy coffee every day. From Science Daily:

Increasing consumption of coffee associated with reduced risk of type 2 diabetes, study finds

New research published in Diabetologia (the journal of the European Association for the Study of Diabetes) shows that increasing coffee consumption by on average one and half cups per day (approx 360ml) over a four-year period reduces the risk of type 2 diabetes by 11%. 

The authors examined the associations between 4-year changes in coffee and tea consumption and risk of type 2 diabetes in the subsequent 4 years.

The authors used observational data from three large prospective, US-based studies in their analysis: the Nurses' Health Study (NHS) (female nurses aged 30-55 years, 1986-2006), the NHS II (younger female nurses aged 25-42 years 1991-2007), and the Health Professionals Follow-up Study (HPFS) (male professionals 40-75 years, 1986-2006). The final analysis included 48,464 women in NHS, 47,510 women in the NHS II, and 27,759 men in HPFS.

The authors documented 7,269 incident type 2 diabetes cases, and found that participants who increased their coffee consumption by more than 1 cup/day (median change=1.69 cups/day) over a 4-year period had a 11% lower risk of type 2 diabetes in the subsequent 4-years compared to those who made no changes in consumption. Participants who decreased their coffee intake by 1 cup a day or more (median change=-2 cups/day) had a 17% higher risk for type 2 diabetes. Changes in tea consumption were not associated with type 2 diabetes risk.

Those with highest coffee consumption and who maintained that consumption -- referred to as "high-stable consumers" since they consumed 3 cups or more per day -- had the lowest risk of type 2 diabetes, 37% lower than the "low-stable consumers" who consumed 1 cup or less per day.

While baseline decaffeinated coffee consumption was associated with a lower type 2 diabetes risk, the changes in decaffeinated coffee consumption did not change this risk. 

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More research on the benefits of exercise. From Science Daily:

Road to fountain of youth paved with fast food ... and sneakers? Exercise may prevent or delay fundamental process of aging

We all know that too much food combined with too little exercise can add up to poor health and disease. But overeating and inactivity also speed up the aging process, right down to our cells. At the end of a cell's lifespan, a process called senescence kicks in -- cells lose the ability to divide and begin to secrete substances that damage the surrounding cells. While unhealthy lifestyle habits can accelerate this process, researchers at the Mayo Clinic wanted to know if increased exercise could counteract it. 

The research team compared mice fed a fast food diet (FFD) for 5 months with those fed a standard chow diet (control). Unlike the controls, the FFD mice developed insulin sensitivity, impaired glucose tolerance, impaired exercise ability, and heart dysfunction. But when the FFD mice were given a running wheel, the exercise began to counteract the effects of a poor diet. White et al. observed a number of improvements including body weight, metabolism, and cardiac function. They also saw a significant decrease in signs of cell senescence and associated inflammation.

"Our data clearly show that poor nutritional choices dramatically accelerate the accumulation of senescent cells, and for the first time, that exercise can prevent or delay this fundamental process of aging. 

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Flatulence is good, and up to 18 a day is totally normal! From NPR:

Got Gas? It Could Mean You've Got Healthy Gut Microbes

We know that air often comes after eating nutrient-packed vegetables, such as cabbage, kale and broccoli. And researchers have found that fiber-rich foods, like beans and lentils, boost the levels of beneficial gut bacteria after only a few days, as we reported in December.

So all this got us wondering: Could passing gas, in some instances, be a sign that our gut microbes are busy keeping us healthy? Absolutely, says Purna Kashyap, a gastroenterologist at the Mayo Clinic in Rochester, Minn. "Eating foods that cause gas is the only way for the microbes in the gut to get nutrients," he says. "If we didn't feed them carbohydrates, it would be harder for them to live in our gut."

And we need to keep these colon-dwelling critters content, Kashyap says. When they gobble up food — and create gas — they also make molecules that boost the immune system, protect the lining of the intestine and prevent infections.

"A healthy individual can have up to 18 flatulences per day and be perfectly normal," he adds.

Gas gets into the digestive tract primarily through  two routes: Swallowing air (which we all do when we eat and chew gum) and your microbiome. That's the collection of organisms in the GI tract that scientists and doctors are currently all fired up about. (Check our colleague Rob Stein's recent series on it.) That microbiome includes hundreds of different bacteria. But there are also organisms from another kingdom shacking up with them: the archaea.

All these microbes are gas-making fools. They eat up unused food in your large intestine, like fiber and other carbohydrates we don't digest, and churn out a bunch of gases as waste. But that's not all they make. They also produce a slew of molecules (called short chain fatty acids) that may promote the growth of other beneficial bacteria and archaea.

And the more fiber you feed these friendly inhabitants, the more types of species appear, studies have found. "Undigested carbohydrates allow the whole ecosystem to thrive and flourish," Kashyap says. Most gas made by the microbiome is odorless. It's simply carbon dioxide, hydrogen or methane. But sometimes a little sulfur slips in there."That's when it gets smelly," Kashyap says.

But here's the hitch: Many of the smelly sulfur compounds in vegetables have healthful properties. Take for instance, the broccoli, mustard and cabbage family. These Brassica vegetables are packed with a sulfur compound, called sulforaphane, that is strongly associated with a reduced risk of cancer. Another possible benefit of a little smelly gas? It may reduce the total volume of air in the gut, Kashyap says. 

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Good news for those who enjoy drinking a little wine. From Medical Xpress:

A little wine might help kidneys stay healthy

An occasional glass of wine might help keep your kidneys healthy, new research suggests. And for those who already have kidney disease, which puts one at higher risk for cardiovascular problems, moderate wine drinking might help the heart. the researchers added.

"Those [with healthy kidneys] who drank less than one glass of wine a day had a 37 percent lower risk of having chronic kidney disease than those who drank no wine," said study author Dr. Tapan Mehta, a renal fellow at the University of Colorado Anschutz Medical Center, in Aurora.

"Those with chronic kidney disease who drank less than one glass a day had a 29 percent lower risk of cardiovascular events [than those who drank no wine]," he added.

Mehta and his colleagues looked at data from the 2003 to 2006 National Health and Nutrition Examination that included nearly 6,000 people. Of those, about 1,000 had chronic kidney disease.

Having chronic kidney disease increases the risk of cardiovascular disease. About 26 million Americans have chronic kidney disease, often caused by diabetes and high blood pressure, according to the National Kidney Foundation. Previous research has found that moderate drinking is linked to heart benefits.

Exactly why wine might do that is not known for sure, Mehta said. Drinking moderate amounts is linked with lower levels of protein in the urine. In those who have kidney disease, higher protein levels in the urine are linked with an increased risk of progression of kidney disease. The polyphenols found in wine have anti-inflammatory and antioxidant properties, which may help explain the protective heart effects, he said.

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It would be exciting if vitamin D supplementation improves cognitive function in the elderly. From Science Daily:

Vitamin D deficiency, cognition appear to be linked in older adults

Vitamin D deficiency and cognitive impairment are common in older adults, but there isn't a lot of conclusive research into whether there's a relationship between the two.

"This study provides increasing evidence that suggests there is an association between low vitamin D levels and cognitive decline over time," said lead author Valerie Wilson, M.D., assistant professor of geriatrics at Wake Forest Baptist. "Although this study cannot establish a direct cause and effect relationship, it would have a huge public health implication if vitamin D supplementation could be shown to improve cognitive performance over time because deficiency is so common in the population."

Wilson and colleagues were interested in the association between vitamin D levels and cognitive function over time in older adults. They used data from the Health, Aging and Body composition (Health ABC) study to look at the relationship. The researchers looked at 2,777 well-functioning adults aged 70 to 79 whose cognitive function was measured at the study's onset and again four years later. Vitamin D levels were measured at the 12-month follow-up visit.

The Health ABC study cohort consists of 3,075 Medicare-eligible, white and black, well-functioning, community-dwelling older adults who were recruited between April 1997 and June 1998 from Pittsburgh, Pa., and Memphis, Tenn.

"With just the baseline observational data, you can't conclude that low vitamin D causes cognitive decline. When we looked four years down the road, low vitamin D was associated with worse cognitive performance on one of the two cognitive tests used," Wilson said. "It is interesting that there is this association and ultimately the next question is whether or not supplementing vitamin D would improve cognitive function over time."

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An excellent reason to listen to your mother and eat your vegetables. From the U.S. Department of Health and Human Services site healthfinder.gov:

Vegetables in Childhood May Benefit Breast Health

Girls who ate the most fruits and vegetables rich in carotenoids were less likely to get benign breast disease, a new study suggests.

Carotenoids are a group of pigments that typically produce an orange, red or dark green color. They are believed to have antioxidant properties that may guard against disease. Benign breast disease describes a variety of noncancerous conditions of the breast; some forms raise the risk of breast cancer. 

For her study, Boeke and her colleagues looked at food reports from 1996 through 1998 and then evaluated reports in 2005, 2007 and 2010 from girls who got a diagnosis of benign breast disease from a doctor after having a biopsy. In all, Boeke studied nearly 6,600 girls, and 122 reported a diagnosis of benign breast disease.

When she looked at carotenoid intake, she found high intakes were protective. "The odds of benign breast disease in those who consumed the most beta carotene were about half that of those who consumed the least," she said. Girls in the highest intake group ate two to three servings of carotenoid-rich foods weekly, she said.

She did take into account other factors that might affect the risk of benign breast disease, such as alcohol intake, physical activity, family history and body mass index (a measure of body fat using height and weight).

Why might the fruits and vegetables help? It's not known for sure, but Boeke said it may be due partly to their antioxidant properties. Carotenoids absorb harmful substances known as free radicals which can harm cells.

The study looked only at food intake, not supplements, and Boeke said she would not recommend supplements since other research has found some harmful effects with supplement use. Other foods that are rich in carotenoids include yams, melons, spinach and kale.

The period of time between the start of a girl's period and the first birth is a sensitive one for the breasts, as they are very vulnerable to environmental exposures, according to background information in the study.

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Again, more support for eating a mainly plant based diet and lowering intake of saturated fat. From MedlinePlus:

High-Fat Diet May Boost Breast Cancer Risk

For more than three decades, experts have debated whether eating a high-fat diet increases breast cancer risk. Now, new research suggests it might boost the chances of three common types of breast cancer.

In a large European study evaluating more than 337,000 women in 10 countries over 11 years, researchers found that women who ate the most saturated fat were about 30 percent more likely to develop breast cancer than those who ate the least. The study is published April 9 in the Journal of the National Cancer Institute.

Sieri and her team found that a high intake of total fat and saturated fat was linked to an increased risk of breast cancer subtypes known as estrogen receptor-positive (ER-positive) and progesterone receptor-positive (PR-positive). High-fat diets also were tied to a raised risk of developing HER2-negative breast cancer, the investigators noted.

The breast cancer subtypes linked with fat intake are common, she said. "The majority of breast cancers in the U.S. and Europe are ER-positive, PR-positive, HER2-negative," she noted.

In the new study, women answered questions about their fat intake and other habits that could affect risk, including smoking, age at first period, pregnancy history, use of hormone therapy and their body mass index (a measurement of body fat based on height and weight). To correct for measurement errors in the diet questionnaire, the researchers interviewed a random sample of 8 percent of the women, asking for a 24-hour dietary recall.

After an average follow up of 11.5 years, just over 10,000 women were diagnosed with breast cancer.When the cases of cancer were compared with fat intake, "we found an association between exposure to saturated-fat intake and breast cancer," Sieri said.

Women in the group eating the most saturated fat averaged 48 grams a day, compared to 15 grams in the group eating the least. The link can't be explained with certainty, Sieri said, but it's possible that the high-fat intake raises the levels of the body's own estrogen, which can stimulate the growth of breast cancer cells.

Until more study is done, Sieri tells women: "In general, it is recommended that the percent of total calories from saturated fat should not exceed 10 percent for women." Gaudet agreed. "If you have a mainly plant-based diet, that is going to help you keep your fat intake low."

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Two studies published in the British Medical Journal (BMJ) looked at Vitamin D. From NY Times:

Low Vitamin D Levels Linked to Disease in Two Big Studies

People with low vitamin D levels are more likely to die from cancer and heart disease and to suffer from other illnesses, scientists reported in two large studies published on Tuesday.

The new research suggests strongly that blood levels of vitamin D are a good barometer of overall health. But it does not resolve the question of whether low levels are a cause of disease or simply an indicator of behaviors that contribute to poor health, like a sedentary lifestyle, smoking and a diet heavy in processed and unhealthful foods.

Nicknamed the sunshine nutrient, vitamin D is produced in the body when the skin is exposed to sunlight. It can be obtained from a small assortment of foods, including fish, eggs, fortified dairy products and organ meats, and vegetables like mushrooms and kale. And blood levels of it can be lowered by smoking, obesity, and inflammation.

Vitamin D helps the body absorb calcium and is an important part of the immune system. Receptors for the vitamin and related enzymes are found throughout cells and tissues of the body, suggesting it may be vital to many physiological functions, said Dr. Oscar H. Franco, a professor of preventive medicine at Erasmus Medical Center in the Netherlands and an author of one of the new studies, which appeared in the journal BMJ.

The two studies were meta-analyses that included data on more than a million people. They included observational findings on the relationship between disease and blood levels of vitamin D. The researchers also reviewed evidence from randomized controlled trials — the gold standard in scientific research — that assessed whether taking vitamin D daily was beneficial.

Dr. Franco and his co-authors — a team of scientists at Harvard, Oxford and other universities — found persuasive evidence that vitamin D protects against major diseases. Adults with lower levels of the vitamin in their systems had a 35 percent increased risk of death from heart disease, 14 percent greater likelihood of death from cancer, and a greater mortality risk overall.

When the researchers looked at supplement use, they found no benefit to taking vitamin D2. But middle-aged and older adults who took another form, vitamin D3 — which is the type found in fish and dairy products and produced in response to sunlight — had an 11 percent reduction in mortality from all causes, compared to adults who did not. In the United States and Europe, it is estimated that more than two-thirds of the population is deficient in vitamin D. In their paper, Dr. Franco and his colleagues calculated that roughly 13 percent of all deaths in the United States, and 9 percent in Europe, could be attributed to low vitamin D levels.

In the second study, also published in BMJ, a team of researchers at Stanford and several universities in Europe presented a more nuanced view of vitamin D.

They concluded there was “suggestive evidence” that high vitamin D levels protect against diabetes, stroke, hypertension and a host of other illnesses. But they also said there was no “highly convincing” evidence that vitamin D pills affected any of the outcomes they examined.

Dr. Theodoratou was not alone in suggesting people hold off on taking vitamin D supplements for now. Even though Dr. Franco found them to be beneficial, he said that more research was needed to show what levels are best. Instead of taking pills, people could improve their vitamin D levels with an adequate diet and 30 minutes of sunlight twice a week, he said.

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A small study, but interesting to see if it holds up. Note that watermelon extract is not actual watermelon. From Science Daily:

Chowing down on watermelon could lower blood pressure, study suggests

A new study by Florida State University Associate Professor Arturo Figueroa, published in the American Journal of Hypertension, found that watermelon could significantly reduce blood pressure in overweight individuals both at rest and while under stress.

The study started with a simple concept. More people die of heart attacks in cold weather because the stress of the cold temperatures causes blood pressure to increase and the heart has to work harder to pump blood into the aorta. That often leads to less blood flow to the heart.

Thus, people with obesity and high blood pressure face a higher risk for stroke or heart attack when exposed to the cold either during the winter or in rooms with low temperatures.

So, what might help their hearts? It turned out that watermelon may be part of the answer.

Figueroa's 12-week study focused on 13 middle-aged, obese men and women who also suffered from high blood pressure. To simulate cold weather conditions, one hand of the subject was dipped into 39 degree water (or 4 degrees Celsius) while Figueroa's team took their blood pressure and other vital measurements.

Meanwhile, the group was divided into two. For the first six weeks, one group was given four grams of the amino acid L-citrulline and two grams of L-arginine per day, both from watermelon extract. The other group was given a placebo for 6 weeks. Then, they switched for the second six weeks. Participants also had to refrain from taking any medication for blood pressure or making any significant changes in their lifestyle, particularly related to diet and exercise, during the study.

The results showed that consuming watermelon had a positive impact on aortic blood pressure and other vascular parameters. Notably, study participants showed improvements in blood pressure and cardiac stress while both at rest and while they were exposed to the cold water.