Health News Briefs – October 2012
CHOLINE IN PREGNANCY MAY REDUCE STRESS DISEASES IN CHILD
New research suggests that mothers-to-be taking the B vitamin – choline – in amounts that are almost twice the recommended level, may give birth to infants with lower cortisol levels. This may improve the infants’ response to stress and reduce the risk of some stress-related diseases during the lifetime of the child. Choline at higher levels appears to trigger epigenetic changes that ultimately lead to lower cortisol levels. (Epigenetic changes affect how a gene functions, even if the gene itself is not changed. High levels of cortisol are linked to problems ranging from mental health to metabolic and cardiovascular disorders.)
Choline is available in some foods and in supplements. Top food sources include beef liver, wheat germ, cod, cauliflower, and milk. Current dietary (food) recommendations are 480 mg of choline daily; some women in the study were given 930 mg daily. Maternal blood, cord blood, and placenta tissue were collected to measure the blood levels of cortisol and the expression levels of genes that regulate cortisol; those from mothers who consumed the higher levels of choline showed reduced cortisol. This study was released earlier and then print-published in the August 2012 issue of the FASEB Journal. It is now available online.
DID YOU KNOW…?
Diacetyl, a compound found in margarine, microwave popcorn, and to some extent in fermented beverages such as beer and wine, intensifies the plaque-forming effects of Alzheimer’s disease, reports the journal Chemical Research in Toxicology.
CHOCOLATE MAY HELP PREVENT STROKE IN MEN
Scientists have found that men who fall into the highest 25 percent of weekly chocolate consumption have a 17 percent lower risk of stroke than those who fall into the lowest 25 percent of weekly chocolate consumption. On average this group consumed 63 grams per week, equal to a third of a cup of chocolate chips. This study is the first to find stroke protection tied to weekly consumption rather than overall longer-term intake. (A previous review of five studies found that men who overall consumed the highest levels of chocolate were 19 percent less likely to suffer a stroke relative to men with the lowest consumption levels.) The study author suggested the beneficial effect of chocolate consumption on stroke may be related to the flavonoids in the cocoa. (Cocoa is the main component of chocolate.) Flavonoids appear to protect against cardiovascular disease through antioxidant, anti-clotting, and anti-inflammatory properties, and they may protect against stroke by decreasing blood concentrations of bad cholesterol and reducing blood pressure. This research was released August 29, 2012 ahead of later publication in the journal Neurology.
WEIGHT TRAINING CAN REDUCE THE RISK OF TYPE 2 DIABETES
Researchers have identified a link between a 34% reduced risk of Type 2 diabetes and weight training.
Researchers have identified a link between a 34 percent reduced risk of developing Type 2 diabetes and participating in weight training exercise for an average of 30 minutes a day, five days a week. The study team also found that combining daily weight training with aerobic exercise such as running or brisk walking reduces the risk of diabetes by a total of 59 percent. (Previous studies have reported a substantially lower risk of Type 2 diabetes among those who participate in aerobic exercise; but this is the first study to examine the role of non-aerobic weight training in diabetes risk reduction.)
The results suggest that weight training can be a valuable alternative for cutting the risk of Type 2 diabetes among people who, due to other health issues, are unable to take part in aerobic exercise. It also suggests that people who combine the two can cut their diabetes risk by more than half. This study was first released online August 6, 2012, in advance of print publishing in the journal Archives of Internal Medicine. The full study can now be read online at https://tinyurl.com/8apnbfl with access fee or journal subscription.
EVEN MILD DEPRESSION, ANXIETY, HURTS THE HEART
A study has found that even mild depression or anxiety can raise the risk of dying from cardiovascular disease and other causes; and the greater the level of psychological distress, the higher the odds of death from heart disease. (Antidepressants, which may improve depression, are themselves linked to a greater risk of heart disease.) The lead researcher suggested that, possibly, treatment of common, minor symptoms can reduce this increased risk of death.
The team analyzed 10 studies of men and women, which included data on more than 68,000 adults aged 35 and older. Each study looked for connections between chronic psychological distress and the risk of dying from heart disease and other causes, including cancer. Even very mild, or subclinical, depression or anxiety appears to raise the risk of all-cause death, including cardiovascular disease, by 20 percent; and even mild psychological distress raises the risk of death from heart disease alone by 29 percent. For high levels of depression or anxiety, the risk of all-cause death rises by 94 percent. The link may arise from increased cortisol, chronic inflammation, and un-healthy lifestyle factors.
This study was released July 31, 2012 by the British Medical Journal; it is available at https://tinyurl.com/ceob7uf without cost.
INADEQUATE SLEEP – NEW RISK FACTOR FOR AGGRESSIVE BREAST CANCERS
Scientists have found a link between more biologically aggressive breast cancers and women who get six or fewer hours of nightly sleep. (Short sleep duration has been linked to greater risk of obesity, diabetes, and heart disease. This is the first study to suggest a link between cancer, the level of aggressiveness of breast cancer, and the number of routine sleep hours.) Aggressiveness of cancer was measured using a score known as the Oncotype DX tumour recurrence score, which assigns a tumour recurrence number based on the expression level of 21 genes. More aggressive and recurring breast cancer tumours were observed in women getting the least sleep. All women showing greater cancer aggressiveness with reduced sleep were post-menopausal; there was no correlation in pre-menopausal women. It is well known that different mechanisms underly pre-menopausal and post-menopausal breast cancers. The data suggest that sleep may affect the carcinogenic pathway specifically involved in development of post-menopausal breast cancer, but not pre-menopausal cancer. This study was published in the August 2012 issue of the journal Breast Cancer Research and Treatment, and it is available online at https://tinyurl.com/8ad4jkv for a fee or subscription.
DIETARY ANTIOXIDANTS MAY CUT PANCREATIC CANCER RISK
Researchers have found that higher intake of foods containing antioxidant vitamins C, E, and selenium may help lower the risk of pancreatic cancer by two thirds. If the link turns out to be causal, then one in 12 pancreatic cancers might be prevented by increased dietary intake. (Pancreatic cancer kills over 250,000 people annually and has the worst prognosis of any cancer, with a mortality rate of 95 percent. Risk factors include genes, smoking, and Type 2 diabetes.) Dietary selenium intake in the top 25 percent was linked to a 50 percent drop in risk; combined dietary intake of vitamins C and E and selenium in the top 25 percent was linked to a 67 percent drop in risk. The scientists warned that this link stemmed from an increased intake of these antioxidants from food, and supplements did not produce the same effect. They also warned this is not necessarily a cause-and-effect relationship; higher dietary intake of these antioxidants and the lower pancreatic cancer risk could both result from a third cofactor. This study, released online July 23, 2012 by the journal Gut, will be published in a future issue. It is accessible now at https://tinyurl.com/cgr52hz with journal subscription or fee.
THOSE WITH TYPE O BLOOD AT LOWEST RISK OF HEART DISEASE
Scientists have found that, compared with those who have type O blood, people with type A, B, or AB have a higher risk of developing coronary heart disease (CHD). The study included over 27,000 men and 62,000 women, who were studied for 24 and 26 years, respectively. (Previous data on this subject was conflicting and this very large study is considered scientifically reliable.) People with type AB blood are at greatest risk of coronary heart disease, with a 23 higher risk than those with type O. People with type B blood have an 11 percent greater risk of CHD than those with type O; and those with type A blood have a 5 percent greater heart disease risk than those with type O. All of the findings were found to be significant associations, meaning they were too substantial to be due to chance variations.
The team advised that it is best to know your heart disease risk numbers, because you can then reduce that risk by adopting a healthier lifestyle, such as eating right, exercising, and not smoking. This study was released online ahead of print in a future issue of Arteriosclerosis, Thrombosis, and Vascular Biology.
SMOKING INCREASES RISK OF BLOOD AND BONE MARROW CANCERS
Scientists have shown that women who smoke dramatically increase their risk of developing certain cancers of the blood, immune system, and bone marrow; and their risks of Hodgkin’s lymphoma and some bone marrow cancers were doubled by smoking about 20 cigarettes a day. Blood cancer risks were also increased among smokers, but to a lesser extent. (The results confirm existing evidence of the impact of smoking on Hodgkin’s lymphoma, and on the link with other types of lymphoma, leukemia, and cancers of the bone marrow.
Few people realize that smoking raises the risk of many types of cancer, not just lung cancer, and also the risk of heart attack and stroke. Smoking causes a fifth of all new cancer cases. Half of all long-term smokers die from their habit.)
The results are considered especially sound due to the very large number of subjects studied: 1.3 million middle-aged women. The study followed these women for a 10-year period. This study was announced August 9, 2012 and will be published in an upcoming issue of the British Journal of Cancer. It is accessible online at https://tinyurl.com/8q9kpwh with access fee or subscription.
YO-YO DIETING DOES NOT AFFECT METABOLISM OR FUTURE WEIGHT LOSS
Researchers have found that the prevalent habit of repetitive gain and loss of weight, called weight cycling or yo-yo dieting, does not affect future ability to lose weight; and does not affect body metabolism or body composition. (Two thirds of the population is overweight, and half of all women are now trying to lose weight. Obesity increases risk for heart disease, diabetes, and many cancers. The relationship between body fat and production of certain hormones and inflammatory markers is believed to increase cancer risk.)
This is the first such study, and the study author suggested a history of weight cycling should not deter weight loss efforts. Scientists measured weight loss and physiological outcomes of overweight, inactive women, some with a lifetime history of yo-yo dieting. All subjects followed a 12-month diet and exercise regimen. The program effect was the same for weight cyclers as the controls, in terms of weight loss and body composition. This study was released August 14, 2012 by the journal Metabolism.
GRAPEFRUIT JUICE CUTS NEED FOR CANCER DRUG
Scientists have found that a glass of grapefruit juice a day lets patients derive the same benefits from an anti-cancer drug as they would get from more than three times as much of the drug by itself. The combination could help patients avoid side effects associated with high doses of the drug and reduce the cost of the medication. Researchers studied the effects that foods have on the uptake and elimination of drugs used for cancer treatment, and found that eight ounces a day of grapefruit juice slows the body metabolism of a drug called Sirolimus, which is sometimes taken by people with cancer.
Without taking more drug quantity, patients taking grapefruit juice increased their blood levels of the drug by 350 percent. Grapefruit juice appears to work by inhibiting enzymes in the intestine that break down the drug, and works within a few hours. Drugs are sometimes prescribed to work with cancer drugs so lower doses can be used, which reduces side effects; but grapefruit juice has an advantage in that it is non-toxic, with no risk of overdose.
This study was published in the August 2012 issue of the journal Clinical Cancer Research. The full-text study is now available online at https://tinyurl.com/brdo83r with access fee or subscription.
TAI CHI SHOWN TO IMPROVE COPD EXERCISE CAPACITY
A study has found that a form of tai chi known as Sun-style can be used effectively for people with chronic obstructive pulmonary disease (COPD) to improve exercise capacity and quality of life in people and may be beneficial as a form of pulmonary rehabilitation. (It is well known that moderate forms of exercise can help COPD patients to improve their exercise tolerance, symptoms of breathlessness and their overall quality of life. This form of tai chi has been shown to help people with chronic conditions such as arthritis and involves less difficult movements enabling people of all ages to perform this martial art.) Compared to those completing the standard medical management program for COPD, those completing the tai chi exercise training were found to be able to walk significantly longer in a walking test, and had improved scores on a standard quality of life test. The research also found the intensity of the tai chi program was moderate, meeting recommendations for COPD patients. This study was released August 9, 2012 ahead of print in the European Respiratory Journal. It has now been made available online at https://tinyurl.com/9n46umb with access fee or subscription.
WOMEN WITH ALZHEIMER’S DETERIORATE FASTER THAN MALE PATIENTS
Scientists have discovered that women with Alzheimer’s disease show greater mental deterioration than men with the disease, even when at the same stage of the condition. (Alzheimer’s disease is the most common progressive condition affecting memory, thinking, behaviour, and emotion. There are 30 million people in the world with dementia, with 4.6 million new cases every year. Incidence is greater among women than men, with the difference increasing with age.)
Surprisingly, female patients also scored lower in verbal skills, which is the opposite of the situation among the general population where women show higher verbal ability than men on average. The reason for the more rapid deterioration of women patients may be due to estrogen loss, or it may stem from men having a greater unused cognitive reserve. Further study is needed to explain this difference. This research was a meta-analysis, which combined the observations of 15 different studies. This study was released August 23, 2012, but will not appear in print until an upcoming issue of Journal of Clinical and Experimental Neuropsychology. It is available online now at https://tinyurl.com/blh69ds without cost.
COCOA IMPROVES MILD COGNITIVE IMPAIRMENT IN ELDERLY
The beneficial effect of chocolate – lowering the risk of stroke – may be related to flavonoids.
Scientists have found convincing new evidence confirming previous research which showed that regular consumption of cocoa flavanols improves cognitive function in elderly subjects with mild cognitive impairment (MCI) or memory decline. (Flavanols are natural compounds that are particularly abundant in cocoa; substantial evidence has shown that consuming cocoa flavanols provides potent antioxidants and helps support healthy circulation and cardiovascular health. Previous studies finding a cognitive benefit were either short-term or failed to show a consistent cognitive improvement.) In this study, test subjects showed significant improvement in scores of cognitive ability and verbal fluency after 8 weeks of consuming a daily drink of cocoa. Cocoa was also shown in the study to beneficially modulate insulin sensitivity, blood pressure, and lipid peroxidation. This study was released August 14, 2012 and will be published in a future issue of Hypertension. It can now be accessed online at https://tinyurl.com/8mq75ar with access fee or journal subscription.
CALORIE RESTRICTION SHOCKER: CR FAILS TO EXTEND HUMAN LIFESPAN
A 25-year study on rhesus monkeys has found that a calorie restriction (CR) diet, in which 30 percent fewer calories than normal are consumed, does not extend lifespan or reduce age-related deaths in primates, nullifying the promising 2009 results of a 20-year study on the same species. (CR involves substantially reducing daily calorie intake without reducing nutrition. In the 2009 study, investigators found that 13 percent of the dieting group died from age-related causes, compared with 37 percent of the control group. In studies on other species, animals fed 10 percent to 40 percent fewer calories lived 30 percent longer, and in some studies, twice as long. If valid, this longevity effect would’ve translated to a maximum human lifespan of roughly 130 to 150 years.)
CR did extend some health aspects in both studies. The 2009 study found that age-related disease, including diabetes, arthritis, diverticulosis, and cardiovascular problems, occurred at an earlier age among the control group; the new study found healthier hearts and immune systems and lower rates of diabetes, cancer, or other ills.
Since the 1930s, studies on different species have shown that CR extends maximum lifespan, rather than simply increasing lifespan within the normal maximal range; in other words, CR was shown to raise the absolute ceiling to which a healthy member of any species could possibly live. In prior research, conducted on mice, rats, worms, flies, and yeast, CR was also shown to produce greater youthfulness, and reduce disease and disability, during the senior years. Yet the longevity effects were not found with certain species of mice, suggesting before now that genetics may play a role in CR. Limited human studies have been underway.
The newest rhesus study found no longevity effect while the earlier rhesus study found a significantly longer lifespan and a lower risk of many age-related diseases among CR monkeys; however, the newest study found a lower cancer risk if CR was begun during adolescence. Scientists speculate the different results may reflect different nutrition and genetics; the primates in the latest study had more diverse genetic origins, and their diet was slightly better, and also included vitamin and mineral supplements. The diet used in the study that showed a CR-longevity benefit was less healthy; so eating less of that diet would produce longevity effects unrelated to calorie restriction itself.
The news is a huge blow to many who believed CR would expand the maximum human life span among practitioners, and those who hoped a single genetic protein or switch might turn on longevity. Scientists will now start looking at CR effects on cell metabolism, gene expression, insulin signaling pathways, and other basic biological processes to pinpoint how reducing calorie intake may attenuate the negative consequences of aging. The researchers suggested it is time to realize that better health does not correspond well with longer life, despite entrenched belief. This study was reported August 29, 2012 in the online issue of Nature.
LOW VITAMIN D LEVELS LINKED TO HIGHER MORTALITY AMONG OLDER ADULTS
A new study concludes that among older adults, low levels of vitamin D can mean a 30 percent greater risk of death. Also, frail older adults with low levels of vitamin D tripled their risk of death over people who were not frail and who had higher levels of vitamin D. (About 70 percent of North Americans, and up to a billion people worldwide, have insufficient levels of vitamin D. Past studies have separately associated frailty and low vitamin D levels with a greater mortality risk, but this is the first study to look at the combined effect.) The scientists defined frailty as when a person experiences a decrease in physical functioning characterized by at least three of the following five criteria: muscle weakness, slow walking, exhaustion, low physical activity, and unintentional weight loss; people are considered pre-frail when they have one or two of the five criteria. The team suggested that older adults should try to get more exercise outdoors in the sun; and that there is an opportunity for intervention with those who are in the pre-frail group, but who could live longer, more independent lives if they get proper nutrition and exercise. It is important to note that a causal effect could not be ascertained; that is, it is not clear whether frailty resulted from low vitamin D, or whether people became vitamin D deficient due to health problems that made them frail. This study was released July 26, 2012 by the European Journal of Clinical Nutrition.
DID YOU KNOW…?
People exposed to second-hand smoke show a higher rate of insulin resistance, indicating incipient or existing Type 2 diabetes, and a higher body mass index (BMI) than those not exposed, according to a study released in June 2012.
BINGE DRINKING INCREASES COGNITIVE DECLINE RISK IN SENIORS
Researchers have found that those aged 65 or older who binge drink alcohol twice a month or more are two-and-a-half times more likely to fall into the group experiencing the greatest 10 percent of decline in cognitive function and two-and-a-half times more likely to be in the group experiencing the greatest 10 percent of decline in memory. (Binge drinking is defined as consuming four or more alcoholic drinks on a single occasion. The risk of dementia, including Alzheimer’s disease, is greater among those who experience cognitive decline. Binge drinking was previously shown to increase the risk of damaging the cardiovascular system, and of developing heart disease.) The research also found that those seniors who binge drink just once a month are 62 percent more likely to be in the group experiencing the greatest 10 percent of decline in cognitive function, and 27 percent more likely to be in the group experiencing the greatest 10 percent of memory decline. Adjustments were made to allow for other known risks for cognitive decline, such as age. (The team also found that the percentage of seniors in the study who participated in binge drinking once a month or more to be 8.3 percent of men and 1.5 percent of women, placing more men at risk; binge drinking twice a month or more was reported to apply to 4.3 percent of men and 0.5 percent of women.) Presented July 18, 2012 at the Alzheimer’s Association International Conference 2012 in Vancouver, this study has not yet been published or posted.
