Evan Watson, NatureCity author & contributor

Two carotenoids, lutein and zeathanthin, may benefit eye health, especially among the mature population according to a recent study.

The study was published in the December 2009 issue of the Journal of Food Science.

Carotenoids are organic pigments found mainly in green leafy vegetables or in supplement form. Their main function is the absorption of light for photosynthesis.

This recent study builds on a body of science that links dietary carotenoids to eye health that goes back to 1782.

In 1782, a scientist found that the yellow pigments in the macula of the eye are related to improvements in vision. In 1866, a different scientist discovered that these pigments are obtained from the lutein and zeathanthin in our diet.

Additional studies have shown that carotenoids improve glare performance of our eyes by absorbing short wave (blue) light and improve our ability to see colored edges.

Research has also shown that lutein and zeaxanhin protect the lens and retina of our eyes and prevent age related eye diseases such as macular degeneration.

With the aging population, eye diseases are beginning to increase but eating more foods that promote eye health may help you avoid these problems.

Beyond carotenoids, there are also several foods sources that have been shown to promote good eye health including citrus fruits, vegetable oils, nuts, whole grains, dark leafy vegetables and cold water fish.

Sarah McGowan-Freije, NatureCity author & contributor

The findings of a new study published in the December 2009 issue of the journal Cell may help researchers create better preventions and vaccines for the flu.

The researchers from Harvard Medical School, discovered a new family of natural anti-viral proteins in the human cell. These proteins are called interferon-indicible transmembrane proteins.

They discovered these proteins by using a new cutting edge technique called RNA interference. This technique allows the researchers to turn off specific genes in a cell then expose that cell to different strains of viruses.

When the researchers blocked the interferon protein, they found that viruses replicated 5-10 times faster. This demonstrated that the protein works as a guard to the cell that literally will not let viruses gain entry and cause harm.

These proteins protect us every day and appear to fight the H1N1 virus, the West Nile virus and dengue virus, and even showed potential for fighting yellow fever.

The researchers also found that if they make the cell produce more of the protein, they become more resistant to the flu.

Although the research is still ongoing, the researchers are confident that these findings will soon lead to better vaccines and more effective ways to protect people from the flu.

Scott Greenberg, NatureCity author & contributor

A study published in the December 2009 issue of the American Journal of Clinical Nutrition found that mature men and women that drink green tea are regularly in a better mood and have a much lower risk of depression.

Japanese researchers from Tohoku University Graduate School of Biomedical Engineering in Sendai, recruited 1,058 healthy individuals over 70 for the study.

The researchers found that participants who drank 4 or more cups of green tea daily had a 44% reduced risk of depression compared to those who drank 1 cup or less.

The link remained even after researchers accounted for social and economic status, gender, diet, history of medical problems, use of antidepressant medications, smoking, and physical activity.

The researchers are confident that the results are not simply due to caffeine because no link was found between depressive symptoms and consumption of oolong tea or coffee, both of which contain caffeine.

Further studies will help to target the mechanism behind these findings. However, the researchers noted that an amino acid called theanine, which has been shown to have a tranquilizing effect on the brain in previous studies, may play a prominent role.

This study builds on the findings of a similar study published in the September 2009 issue of The American Journal of Clinical Nutrition.

The study, which included over 40,000 Japanese men and women, found that 20% of people who drink 5 or more cups of green tea daily have a 20% reduction in psychological stress compared to those who drink 1 cup or less.

The science behind the cognitive benefits of green tea is still growing. However, green tea has already been linked to a number of other health benefits ranging from digestion to protection against some cancers.

These benefits are often attributed to the high amount of naturally occurring antioxidants in green tea called polyphenols. These antioxidants protect our cells from dangerous free radicals. A recent study even found that the cells of regular tea drinkers actually have a younger biological age than non-tea drinkers.

Evan Watson, NatureCity author & contributor

A shea tree extract called Vitellaria Paradoxa may reduce inflammation and boost joint health according to a recent study by Australian researchers.

The results of the study were published in the December 2009 issue of the journal Phytotherapy Research.

The researchers conducted the study because extracts from the seed of the tree Vitellaria Paradoxa have been used for many years as a treatment for arthritis yet little is known about the specific mechanisms behind its benefits.

To fill this gap in research, 89 participants with osteoarthritis of the knee or hip were recruited for the study.

The participants were randomly assigned to receive the shea extract or a placebo for 15 weeks.

Urine samples and blood samples were taken to measure biomarkers of inflammation and arthritis at baseline and 1, 10, and 15 weeks into the study.

The researchers found a 23% decrease in the inflammation biomarker TNF-alpha among the shea extract group after 15 weeks compared to only 6% in the placebo group.

They also observed a 28% decrease in cartilage degradation compared to placebo.

The researchers found that participants with the highest levels of osteoarthritis biomarkers saw the most positive results.

Osteoarthritis costs the US over $60 billion a year and is the second highest cause of work disability among men over 50. Although more research needs to be done, shea tree extract may prove to be an exciting addition to the joint health market.

Evan Watson, NatureCity author & contributor

A diet high in methionine, an amino acid found in many foods including red meats, fish, beans, eggs, garlic, lentils and onions, may increase the risk of Alzheimer’s disease. This is the finding of a study published in the December 2009 issue of the journal Current Alzheimer’s Research.

For the study, Temple University researchers split mice into two groups. The mice, which were the equivalent age of a 70 year old human, were fed either a regular diet for eight months or a diet high in the amino acid methionine.

At the conclusion of the 8 month period, the methionine group had much higher levels of an amino acid called homocysteine which has been shown to significantly increase the risk of Alzheimer’s in previous studies.

As methionine levels increase, the body, the body tries to protect itself by transforming it into homocysteine.

The methionine group also had 40% more amyloid plaque, which is used to measure the extent to which Alzheimer’s has affected the brain.

In addition, the researchers tested the mice for their ability to learn new tasks. The mice fed methionine performed much more poorly than the other group.

Methionine is an essential amino acid in the body so completely eliminating consumption would be unwise. Instead, people who who consume too much of the amino acid, such as people with diets high in red meat, should consider changing their eating habits.

The findings of this study build on previous research showing that dietary habits do in fact affect your risk of developing Alzheimer’s.

The good news is that some foods have actually been shown to potentially decrease rather than increase your risk of Alzheimer’s such as grapes, wine, legumes and foods high in antioxidants and essential vitamins.

Scott Greenberg, NatureCity author & contributor

Following a low-fat diet may do little for your waistline according to a study published in the December 2009 issue of the American Journal of Clinical Nutrition.

For the study, researchers from the Institute of Metabolic Science in Cambridge, England analyzed data on nearly 90,000 men and women from the European Prospective Investigation into Cancer and Nutrition Study. The participants were followed for up to 10 years and their dietary habits were recorded.

The average fat intake among the participants ranged from 31% to 37% of total calories. US dietary recommendations state that people should maintain a daily fat intake of 20%-35% of total calories.

The participants gained an average of about a quarter of a pound every year but the researchers found no association between weight gain and fat intake.

The researchers also saw no difference in weight gain based on the specific kind of fat the participants consumed.

These findings seem to indicate that focusing on fat intake may not the best way to maintain a healthy weight.

The researchers warn that this should in no way encourage people to eat as much fat as they want because diets high in fat have been shown to cause numerous health issues such as heart disease.

When trying to lose weight it is much more important to keep an eye on total calorie intake and reduce the amount of sugar, alcohol and junk food you eat. Exercising and eating a healthy diet are obviously essential as well.

To best maintain your health, try eating more healthy fats like nuts, fish and vegetable oils and less unhealthy fats like saturated and trans fats.

Sarah McGowan-Freije, NatureCity author & contributor

A recent study has found that an appetite hormone called leptin may reduce the risk of Alzheimer’s and boost brain volume.

Leptin is a hormone that is released by your fat cells. The hormone was discovered in 1995 and was tested as a weight loss tonic. When the hormone was injected in mice, they lost weight. Among humans, however, leptin only temporarily helps you lose weight and injections are costly and tedious.

However, researchers from Boston University found that leptin may provide cognitive benefits that were initially overlooked. The study was published in the December 2009 issue of the Journal of the American Medical Association.

For the study, the researchers analyzed data from a huge study called the Framingham Heart Study which began back in 1948.

The researchers took a representative pool of 785 individuals from the Framingham Study who displayed no signs of dementia in the years 1990 to 1994.

After an average of 8 years of follow-up, 111 of the participants developed dementia and 89 were diagnosed with Alzheimer’s.

The researchers found that participants with the lowest leptin levels at the beginning of the study had a 25% risk of developing Alzheimer’s whereas people with the highest levels had only a 6% risk.

The researchers also conducted brain scans on 200 of the participants and found that higher leptin levels were associated with more brain volume in the hippocampus. The hippocampus is the main memory center of the brain and decreases in volume are closely linked to Alzheimer’s and dementia.

While leptin appears to have promise as an aid in the prevention of Alzheimer’s, research is still in its early stages.

Alzheimer’s is becoming an epidemic as the world population continues to age. The mind robbing disease already affects over 26 million people worldwide and is estimated to cost the US alone over 100 billion dollars annually.

Further research will help determine if leptin is a safe and effective way to help prevent Alzheimer’s, but in the meantime there are a number of things that can be done to significantly lower your risk.

Here are some good ways to avoid cognitive decline, dementia and Alzheimer’s:

Eat a brain-healthy diet such as foods high in omega-3 fatty acids.

Keep your mind active by attending social events or solving puzzles.

Do moderate intensity exercises like walking, biking or yoga 3 times a week

Sleep regularly and restfully

Learn to relax

Evan Watson, NatureCity author & contributor

Estimates show that by the year 2025, approximately 380 million people worldwide will be affected by type 2 diabetes.

Researchers have been actively searching for ways to quell this epidemic. The most recent findings of a study conducted by researchers from the University of Sydney, Australia show that drinking more tea or coffee may actually help reduce the risk of diabetes.

The findings of this study were published in the December 2009 issue of Archives of Internal Medicine.

The researchers analyzed eighteen studies involving coffee consumption and seven studies on tea consumption. Combined the studies included over 500,000 participants with over 21,000 individual cases of type-2 diabetes.

The researchers found that each additional cup of regular coffee consumed daily resulted in a 7% reduction in diabetes risk. They also found that people who drank 3-4 cups of decaffeinated coffee a day had a 33% reduced risk of diabetes compared to people who drank no coffee.

The results for tea drinkers were almost as good. Those who drank 3-4 cups daily saw a 20% reduction in diabetes risk compared to non-decaf drinkers.

The researchers did not look into the mechanisms behind their results but said it was unlikely that caffeine was responsible for the positive results. Instead, the high amount of antioxidants and magnesium in tea and coffee may play a large role.

Beyond diabetes prevention, coffee has been shown to reduce the risk of cirrhosis and oral cavities. At least six different studies have also shown that people who drink coffee regularly are up to 80% less likely to develop Parkinson’s.

Tea has also been associated with a number of other health benefits including heart health and reduction in Alzheimer’s risk due to high levels of a powerful antioxidants called polyphenols.

Evan Watson, NatureCity author & contributor

A study published in the December 2009 issue of the Journal of Food Science shows yet another heart benefit of oily fish.

The study included 934 people with acute coronary syndrome (ACS). ACS is an umbrella term that covers a number of symptoms, including angina and heart attack, that are related to the heart not receiving enough blood.

The participants were followed for 3 years and over that time period 437 of them developed a dangerous heart condition called left ventricular systolic dysfunction (LVSD). LVSD is the condition where the left ventricle can only manage to eject approximately 40% of the blood in it with each contraction. Left untreated, LVSD will ultimately lead to heart failure.

Using food frequency questionnaires, the researchers found that moderate fish consumption (1-2 times per week) was associated with a 53% reduction in LVSD risk.

The researchers also found that consumption of oily fish helps relax blood vessels and improve blood flow.

This was not the first study to link oily fish withheart health. In fact, the science goes all the way back to the 1970s.

To date these studies have shown that oily fish is linked to improvements in blood lipid levels, a reduced tendency of thrombosis, blood pressure and heart rate improvements and improved vascular function.

The omega-3 essential fatty acids in oily fish have also been shown to provide numerous health benefits beyond the heart including improved cognitive function and aiding in weight loss.

With the body of evidence backing the health benefits of omega-3s growing daily, it makes sense to try incorporating more of these essential fatty acids in your everyday diet.

Salmon, mackerel, lake trout and albacore tuna all have very high omega-3 levels. If you opt for a supplement, be sure that it is a quality supplement high in DHA and EPA and certified for purity.

Evan Watson, NatureCity author & contributor

A group of scientists at Brigham Young University recently conducted an analysis of 6 separate studies and found that magnesium may reduce the risk of heart disease among men. They did not find any evidence that the same holds true for women.

Their findings were published in the December 2009 issue of the Journal of the American Academy of Nurse Practitioners.

The six studies included supplementation of magnesium ranging from 130 to 800 milligrams per day.

The researchers found that maintaining a high level of magnesium in the body helps prevent further complications of heart disease following a diagnosis of coronary heart disease. At the moment, however, there is insufficient research to show that magnesium can help reduce the future risk of coronary heart disease.

The studies showed that magnesium plays a role in over 300 biochemical reactions in the body. Additionally, supplementation was rarely associated with any negative effects.

The researchers noted that magnesium may also reduce the risk of stroke, improve skeletal growth and development and lower blood pressure.

Based on these findings, the researchers recommend magnesium supplementation for the general population and especially for people already diagnosed with coronary heart disease.

Currently most American adults do not get the recommended daily value for magnesium, which is 320 mg for women and 420 mg for men.

A supplement is a great way to get your daily magnesium but there are also a good amount of dietary sources of magnesium such as green leafy vegetables, meats, starches, grains and nuts and milk.