News Briefs – March 2016

A diet rich in green, leafy vegetables contains nitrates that reduce the risk of developing glaucoma.

Higher Intake of Leafy Greens Helps Prevent Glaucoma

Researchers have found that natural compounds in leafy green vegetables may lower the risk of getting glaucoma. (Glaucoma is a leading cause of blindness afflicting three million Americans. One in 10 people with this disease lose their eyesight despite treatment.)

Tracking of over 100,000 men and women showed that those who developed primary open-angle glaucoma (POAG) over the course of the study follow-up were far less likely to have included high levels of green leafy vegetables in their diet. Those who had consumed the highest amounts of greens demonstrated a corresponding 30% reduced risk of POAG (the most common form of glaucoma, characterized by increased eye pressure and a gradual loss of vision, which may be caused by restricted blood flow in the optic nerve.)

The highest greens-consumption group ate about 240 mg of nitrate per day, and the lowest consumed about 80 mg per day. A diet rich in green, leafy vegetables such as spinach and lettuce contains dietary nitrates that reduce the risk of developing the debilitating eye disease. Dietary nitrate is converted by the body into nitrous oxide, which has powerfully beneficial effects on blood circulation. This helps counter the reduced blood flow to the optic nerve, which is a critical factor in this disease. Nitrates are also present in supplements known as powdered greens.

This study was posted to the Online First section of the journal JAMA Ophthalmology on January 14, 2016. The full report can now be read at https://tinyurl.com/hlayrlk free of charge.

Zinc Supplements Increase Immune Function in Older Adults

A new study has demonstrated that zinc supplementation can enhance immunity among older adults and may reduce the incidence of, and risk of death from, infections such as pneumonia. (The immune system weakens as the body ages, making older adults more susceptible to infection. Low levels of zinc impair immunity, particularly in older adults.)

These researchers had previously found that 30% of nursing home residents have low serum zinc levels and that those with low serum zinc levels had a significantly higher incidence of pneumonia and morbidity from it. For this new double-blind, placebo-controlled trial, nursing home residents aged 65 and older were enrolled and found to have zinc levels that ranged from moderately deficient to very deficient. They were then given a multivitamin that contained either 5 mg or 30 mg of zinc. After three months, immune response was assessed by determining immune cell profile and function. Results showed that 30 mg of zinc reversed or substantially diminished deficiency and in turn boosted the number and effectiveness of infection-fighting immune cells known as T-cells.

The report strongly suggests that supplementation can help reverse zinc deficiency in older adults and can reduce the risk of infection and related mortality. In addition to older adults who may have trouble absorbing zinc, vegetarians and those with digestive disorders are at risk of zinc deficiency.

This study was released January 27, 2016 by the American Journal of Clinical Nutrition and will appear in a future issue in print. The full report can be read at https://tinyurl.com/zz3ssyl for a fee

Sugar Boosts Risk and Spread of Breast Cancer

A study has found that the high levels of sugar in the typical Western diet could increase the risk and spread of breast cancer. Researchers placed mice randomly into four different groups. Each group was fed a different diet with varying levels of sugar until the mice reached six months of age. A diet with a level of sugar similar to that in the typical Western diet led to an increase in the growth of tumours and the spread of cancer to the lungs when compared to a non-sugar starch diet, with 50 to 58% of mice that were fed a sucrose-enriched diet developing mammary tumuors. (The team believes that sugar increases the enzyme known as 12-LOX and the fatty acid known as 12-HETE in breast cancer cells, which could both be factors in the growth and spread of breast cancer.)

The results also found that fructose, found in table sugar and high-fructose corn syrup, was a particular risk factor contributing to the spread of breast cancer to the lungs.

The findings were published online in the journal Cancer Research. The full-text version of this study is available at https://tinyurl.com/z8yuw84 for a fee.

Diet of Father Before Conception Affects Health of Baby

Two new and independent studies have found evidence suggesting that what a father eats prior to conceiving can have a substantial impact on the baby. (For years, it has been assumed that the only impact male mammals can have on their offspring is from the DNA they carry in their sperm.)

These experiments suggest that what are known as transfer RNAs can carry information that adversely impacts offspring. The first study series tested the impact of male mice eating a high-fat, pre-mating diet on their offspring. The second experiment team tested the impact of a low-protein diet by male mice prior to siring offspring. Offspring had their weight monitored along with their level of glucose intolerance and insulin resistance.

In the first study, the offspring of males fed high-fat diets developed an impaired resistance to insulin and glucose intolerance, precursors to diabetes. In the second study, the researchers fed the males a low-protein diet and found negative changes to a group of genes responsible for the development of stem cells. Researchers suggested it is likely that the same results would occur with humans.

Both studies appeared in the journal Science. The abstract of the first study is at https://tinyurl.com/hkobnw6 without cost, while the full text is available at https://tinyurl.com/hs2kzxg for a fee. The abstract of the second study is at https://tinyurl.com/jfowne6 without cost, while the full text is at https://tinyurl.com/hvagqcl for a fee.

Daily Intake of Sugar-Sweetened Drinks Linked to Visceral Fat

Researchers have found that drinking sugar-sweetened beverages every day is associated with an increase in a particular type of body fat, called visceral fat, which has been linked to diabetes and heart disease risk. The study included data on middle-aged adults only. (Visceral fat or deep fat wraps around a number of important internal organs such as the liver, pancreas, and intestines. It affects how hormones function and might play a larger role in insulin resistance than other body fat. Insulin resistance could boost the risk of Type 2 diabetes and heart disease. Sugar-sweetened beverages are the largest contributor of added sugar intake in the U.S. Sucrose and high fructose corn syrup are two of the most common sugars found in these popular drinks.)

Researchers looked at consumption of both sugar-sweetened beverages and diet sodas. They did not find this connection with diet soda.

This study was released January 11, 2016 online before print, by the journal Circulation. It can be read in full at https://tinyurl.com/he6z5w9 free of charge.

Exercise May Slash Heart Disease in Depressed Individuals

Researchers have reported that exercise may reduce the risk of developing heart disease in people diagnosed with depression. Clinically depressed people who were not physically active were found to have stiffer and more inflamed aortas (the large artery carrying blood from the heart), each of which is a sign of potential heart disease. But in depressed people who exercised, aortic stiffening and inflammation were found to be significantly less common. (Depression has previously been linked to a higher risk of heart disease and other physical problems and to worse outcomes for people with heart disease. As many as 20% of people hospitalized with a heart attack are depressed. Patients with heart disease have three times the risk of developing depression.)

This study is not designed to prove a cause-and-effect relationship; about this association between depression and artery function, the team cautioned that further studies are needed before it can be concluded that exercise substantially reduces heart disease risk in depressed persons particularly. These systems are interrelated. Heart disease may be the result of lifestyle, environment, and genetics, and all of these can impact psychological well-being; increased inflammation and limited blood flow could have indirect or direct biochemical and mechanical effects on the brain; and exercise may boost compounds that improve mood.

This study was published in the January 16, 2016 edition of the Journal of the American College of Cardiology. The entire report can be read online at https://tinyurl.com/ztwdvgq for an access fee.

Did You Know…?

Scientists have found that a 325 mg daily supplement of phosphorus can reduce waistlines by an average of one inch within 12 weeks, as well as promote weight loss, according to a recent study in the journal Nutrition and Diabetes. The full report is free at https://tinyurl.com/jeqvwvc

Healthier Diet Promotes More Restorative Sleep

A study has found that a healthier diet results in greater sleep quality within one day. Human subjects given a diet high in fibre and low in sugar and fat subsequently fell asleep more quickly and slept more soundly than those persons allowed to eat freely. Also, another group provided with a diet that is low-fiber and contains high levels of saturated fat and sugar subsequently slept more lightly and experienced less restorative and more disrupted sleep. Researchers enlisted 26 volunteers of normal weight and an average age of 35 who spent five nights in a sleep lab. They were provided different controlled diets prepared by nutritionists or were allowed to eat freely. Sleep quality was objectively assessed using polysomnography. The participants slept the same duration no matter what diet they consumed, but the high-fibre, low-fat diet resulted in a deeper, less-interrupted sleep. This group also got to sleep earlier on average. Based on this research, the scientists suggested increasing intake of fruits, vegetables, and whole grains and reducing intake of processed foods in order to improve sleep quality. The team noted a vicious cycle with poor sleep quality triggering the later consumption of a higher-fat diet.

This study was published in the January 2016 issue of the Journal of Clinical Sleep Medicine. It can be read at https://tinyurl.com/hjztbnx for a subscription or access fee.

Prenatal Carnitine Supplements May Help Prevent Autism

Carnitine supplements taken prenatally may protect against a type of autism, scientists have found. They have suggested that carnitine deficiency may be associated with a higher risk of autism because it interferes with normal processes in which neural stem cells control fetal brain development. (Carnitine is a natural substance manufactured by the body or extracted from dietary sources and sold as a supplement. It is required for the transportation of fatty acids into mitochondria, the energy-generating compartments inside cells. Some women have inherited mutations in certain genes involved in producing carnitine, and these mutations have been previously linked to a higher risk of autism-spectrum disorders. One percent of Americans are afflicted with autism.) This research is the first-time use of cutting-edge technology that allows scientists to track individual neural stem cells in an actual developing brain. The end-result of the findings is that when at-risk neural stem cells are supplied with carnitine through supplements, they appear to avoid the problems that can cause autism. Carnitine supplements may be a sound precautionary measure for pregnant women, much as folic acid is now taken to prevent defects in the developing brain and spinal cord of developing fetuses.

This study will not be published until a future issue of the journal Cell Reports. However, it was released online on January 28, 2016 as a corrected proof. The full study can be read at https://tinyurl.com/gtypbpa free of charge.

Aged Garlic Supplement Reverses Arterial Plaque Buildup

Following a placebo-controlled clinical study, scientists have concluded that the supplement known as AGE, or aged garlic extract, has the potential to actually reverse the accumulation of arterial plaque in humans, which may in turn help roll back the risk and development of coronary artery and heart disease. The study was conducted only on individuals who have metabolic syndrome, a condition characterized by obesity, hypertension, and other factors known to boost the risk of heart disease. The specific type of plaque reduced in the arteries by the aged garlic extract was a soft plaque known as low-attenuation plaque. AGE also inhibited new plaque development, the researchers reported. The study involved 55 patients, aged 40 to 75 and diagnosed with metabolic syndrome. All were screened to measure the arterial buildup of different plaque types and then given 2.4 grams of AGE or placebo daily for a year. Followup assessments showed that AGE slowed total plaque accumulation by 80% and also lowered soft plaque.

This study was recently posted to the Articles in Press section of the website of the Journal of Nutrition. The report can now be accessed at https://tinyurl.com/zqjgrgr for a fee.