In The News: May 2013

An article published in The Journal of Nutrition reports an association between high omega-3 levels and a reduced risk of age-related macular degeneration in older men and women.*

The investigation included 963 participants in The Antioxydants Lipides Essentiels Nutrition et Maladies Occulaires Study of residents of Bordeaux, France aged 73 and older.  Blood samples collected between 1999 and 2001 were analyzed for plasma alpha-linolenic acid and the long-chain omega-3 fatty acids eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA).  The subjects underwent eye examinations during 2006-2008 and were followed for an average of 31 months.

Having a higher level of total omega-3 fatty acids was associated with a decreased adjusted risk of macular degeneration in this age group in comparison with lower omega-3 levels. 

Editor’s Note:  When the effects of individual omega-3 fatty acids were separately analyzed, higher levels of alpha-linolenic acid and DHA were found to be significantly protective. 

In The Journal of Clinical Endocrinology & Metabolism, Welsh researchers report an increased risk of adverse effects, cancer, and death over a ten-year period among diabetics treated with insulin in comparison with other treatments.*

Craig J. Currie of Cardiff University and his associates evaluated data from the UK General Practice Research Database, 2000-2010 for 84,622 patients with type II diabetes who received glucose-lowering drugs.  Subjects were treated with metformin, sulfonylurea drugs, insulin, metformin plus sulfonylureas, or metformin and insulin for no less than 180 days. 

Compared with those who used metformin alone, treatment with insulin by itself was associated with an 80% greater risk of experiencing either an initial adverse cardiac event or cancer, or death from any cause during the decade examined, and for insulin combined with metformin, the risk was 31% higher. 

Editor’s Note:  Among those with no prior history of the events, insulin monotherapy was associated with nearly twice the risk of heart attack, a 73.6% higher risk of major adverse cardiac events, a 43.2% greater risk of stroke, a 43.7% greater risk of developing cancer, 3.5 times the risk of kidney complications, and more than twice the risk of neuropathy or dying from any cause in comparison with the risks experienced by those who used metformin. 

A group of scientists from the Department of Epidemiology and Health Statistics, Shandong University, People’s Republic of China, recently performed a meta-analysis to assess the effect of metformin intake on cancer incidence and mortality.*

MEDLINE, ISI Web of Science, and EMBASE databases were researched and relevant reviews were examined. Meta-analysis was applied to calculate the summary relative risk and their 95% confidence intervals. Sensitivity analysis was conducted to assess the robustness of the pooled estimator. According to the eligibility criteria, 37 studies comprising 1,535,636 participants were selected in terms of intervention and data of cancer incidence or mortality.

A recent study published in JAMA Ophthalmology adds to the evidence that elevated levels of high-sensitivity C-reactive protein (hsCRP) predict future risk of age-related macular degeneration (AMD).*

To investigate the relationship between hsCRP and future risk of AMD in US men and women, the scientists pooled analysis of prospective nested case-control data from the Women’s Health Study and 4 other cohorts, the Physicians’ Health Study, Women’s Antioxidant and Folic Acid Cardiovascular Study, Nurses’ Health Study, and Health Professionals Follow-up Study.

After identifying 647 cases with the proper matched controls, the scientists measured hsCRP in baseline blood samples. They used conditional logistic regression models to examine the relationship between hsCRP and AMD and pooled findings using meta-analytic techniques.

A group of German scientists recently examined the effect of tea flavonoids on stomach illnesses. Tea flavonoids belong to the large group of polyphenols and display antioxidative, anti-inflammatory, and anti-neoplastic activities. These phytochemicals are xenobiotics and are synthesized by tea plants such as Camellia sinensis and Camomilla recucita. These botanicals exhibit in vivo activities similar to that of biologicals which are widely used for chronic inflammatory diseases (rheumatoid arthritis, chronic inflammatory bowel disease).

Epigallocathechin gallate (EGCG) and apigenin from these plants inhibit cytokines, chemokines, and activated immune cells in vivo and in vitro.* Clinical disorders with induced inflammatory pathways could benefit from flavonoid treatment. Dietary supplementation with specific tea-flavonoids could be used for Crohn’s disease, ulcerative colitis, and irritable bowel syndrome. Suppression of cytokine production could ultimately lead to inhibition of carcinogenesis. This mechanism could explain why flavonoids are effective in the prevention of intestinal neoplasia. The scientists concluded that more studies using tea flavonoids should be conducted in controlled, randomized clinical studies.

A study published in PLOS Medicine revealed a greater risk of heart disease and death from any cause over a 2.8 year average follow-up period among men experiencing erectile dysfunction (ED).*

Australian researchers analyzed data from 95,038 men who participated in the 45 and Up Study.  Erectile dysfunction was graded as none, mild, moderate or severe based on questionnaire responses.  Hospital data reported 7,855 subsequent cardiovascular disease admissions among the current study’s subjects over a 2.2 year average period, and 2,304 deaths were documented over 2.8 years of follow-up. 

Among men who did not have previous cardiovascular disease diagnoses, those classified as having severe ED had a 60% greater risk of ischemic heart disease, an eight times greater risk of heart failure, a 92% higher risk of peripheral vascular disease and a 93% greater chance of dying over follow-up in comparison with men who did not report ED. 

Editor’s Note:  For those with previous cardiovascular disease diagnoses, the risk of ischemic heart disease was 70% higher, heart failure risk was 4.4 times greater, peripheral vascular disease risk was 2.46% higher and the risk of dying was more than twice as high over follow-up. 

People who consume vitamin and mineral supplements appear to be in a better mood than nonusers according to the results of a meta-analysis published in Psychosomatic Medicine:  Journal of Biobehavioral Medicine.*

Researchers at the University of Swansea analyzed eight placebo-controlled trials that evaluated the effects of multivitamin and mineral supplements on aspects of mood in a total of 1,292 healthy men and women. Stress, mild psychiatric symptoms, anxiety, depression, elation, perceived energy levels, confusion, and hostility were among the aspects of mood evaluated in the trials before and after treatment. 

Supplemented subjects had a 65% lower risk of perceived stress compared to those that received a placebo.  The analysis uncovered a 70% lower risk of mild psychiatric symptoms, a 68% lower risk of anxiety, a 73% reduction in experiencing fatigue and a 77.25% lower risk of confusion among supplemented participants. 

Editor’s Note:  Supplements that contained high doses of B vitamins tended to elicit greater benefits than those that had lower amounts. 

The Journal of the American Medical Association reports an association between decreased telomere length and greater susceptibility to the common cold.* Telomeres are DNA complexes at the end of the chromosomes which shorten with repeated cell division, leading to cell senescence and impaired function. 

The study included 152 men and women 18 to 55 years old. Blood samples were analyzed for telomere length of four types of leukocytes (white blood cells), and participants were quarantined for six days. Nasal drops containing a rhinovirus were administered after the first 24 hours of quarantine, and the subjects were monitored for the remaining period. 

Sixty-nine percent of the participants were determined to have been infected with the virus and clinical illness developed in 22%. Beginning at the age of 22, shorter telomere length of any of the white blood cell types examined was associated with a greater risk of infection, with the risk increasing with greater age.

Editor’s Note: A variety of white blood cell known as CD8CD28- was found to be the type of leukocyte in which decreased telomere length was associated with a significant increase in the risk of clinical illness. For those whose CD8CD28- cells had the shortest telomeres, the rate of clinical illness was twice that of subjects whose telomere length was longest. “These cells are important in eliminating infected cells and those with shorter telomeres in the CD8CD28- cell population may be at greater risk for infection because they have fewer functional cells available to respond to the virus,” Dr. Sheldon Cohen, a scientist with the study said.

In an article that appeared in Clinical Nutrition, London researchers report an association between reduced vitamin D levels and an increased risk of panic disorder and depression.*

The study included 5,966 men and women enrolled in the 1958 British birth cohort, which consisted of 18,558 individuals born in March 1958, who were followed to the age of 50 years.  Blood samples collected when the participants were 45 years of age were analyzed for 25-hydroxyvitamin D levels, and interviews ascertained the presence of common medical disorders including depression, anxiety, panic, and phobias. Additional questionnaires administered at 50 years of age identified and scored depressive symptoms.

Having a sufficient vitamin D level of at least 30 ng/mL at the age of 45 was associated with a 43% lower adjusted risk of depression and a 67% lower risk of having panic disorder in comparison with subjects whose levels were less than 10 ng/mL. 

Editor’s Note:  When depressive symptoms at age 50 were examined, 25-hydroxyvitamin D levels ranging from 20 to 34 ng/mL were associated with the lowest risk of depression after adjustment for several factors. 

The journal Cell Reports published the findings of Daren Knoell and colleagues at Ohio State University of an immune-regulating effect for the mineral zinc in sepsis, a systemic response to infection that frequently causes death in intensive care unit (ICU) patients.*  Zinc deficiency is estimated to occur in 40% of older individuals: a population that is also more likely to be admitted to the ICU.

The current research involved human immune cells known as monocytes.  In the immune response, a protein known as nuclear factor kappa-beta (NF-kB) is activated and enters the cell nucleus.  Dr. Knoell and colleagues report that this action triggers the expression of a gene that produces ZIP8, a zinc transporter, which locates to the cell wall where it facilities the entry of zinc from the blood.  Zinc then binds another protein in the NF-kB pathway known as IKKB, which halts further activity, thereby preventing excessive inflammation such as occurs during sepsis. 

Editor’s Note:  Dr. Knoell remarked that, “Without zinc on board to begin with, it could increase vulnerability to infection. But our work is focused on what happens once you get an infection – if you are deficient in zinc you are at a disadvantage because your defense system is amplified, and inappropriately so.”

Dr. Aubrey de Grey is a world-renowned biomedical expert on aging. He recently joined Dr. Mike on an episode of Healthy Talk radio to discuss his latest discoveries from the SENS Research Foundation, a non‑profit charity dedicated to combating the aging process.

His research interests encompass the characterization of all the accumulating pathogenic molecular and cellular side‑effects of metabolism that constitutes aging and the design of interventions to repair that damage. He discusses with Dr. Mike his comprehensive anti‑aging plan – Strategies for Engineered Negligible Senescence (SENS), which breaks aging into seven major classes of damage and identifies detailed approaches to addressing each one.