CRP and cancer
Running lowers macular degeneration
Reducing sugar drinks helps weight
Veggie diets healthier than headlines
Red meat increases mortality
C-reactive protein (CRP) is a serum marker of inflammation that has been shown to be directly associated with an increased risk of cardiovascular disease. Recent information shows that high levels of CRP in the blood are also correlated with a higher risk of cancer. (Allin KH, et al., Baseline C-Reactive Protein Is Associated With Incident Cancer and Survival in Patients With Cancer. J Clin Oncol. 2009 Mar 16 [Epub ahead of print])
Danish researchers measured CRP in 10,408 subjects and followed them for 16 years. By that time, 1624 of the patients had developed cancer, and 998 had died. Those with the highest CRP levels had a 30 percent increase in the incidence of cancer, more than twice the risk of death from lung cancer, and a higher overall mortality from cancer.
This does not mean that CRP is a cause of cancer. It is more likely that the underlying chronic inflammation increases the cancer risk as well as the risk of heart disease. Chronic inflammation may be the result of gingivitis, arthritis, respiratory ailments, immune system disorders, and other conditions. It is likely that the process of inflammation leads to biochemical changes that lead to the development of both cancer and heart disease (and possibly other degenerative diseases).
Long distance running appears to help reduce the risk of developing age-related macular degeneration (ARMD). Researchers evaluated 29,532 male and 12,176 female runners and followed them for 7.7 years. They then correlated the incidence of ARMD with average running distance. Those subjects who ran 17 percent longer distance had a significantly lower incidence of ARMD.
After all the statistical adjustments for age, smoking, diet, and other variables, they found that the risk of ARMD decreased by 10 percent for every extra kilometer per day in running distance. (Williams PT, Prospective study of incident age-related macular degeneration in relation to vigorous physical activity during a 7-year follow-up. Invest Ophthalmol Vis Sci. 2009 Jan;50(1):101-6.)
Compared to runners averaging less than 2km/d, those who ran 2 to 4 km/d had a 19 percent lower risk of ARMD, and those who averaged more than 4 km/d had a 42 to 54 percent lower risk. The male longer-distance runners also had a significantly lower risk of developing cataracts (while not enough women developed cataracts to make a statistically meaningful analysis).
Diet was one of the variables for which they had to adjust their data. In the diet analysis, they found that those participants who ate more meat had a higher incidence of ARMD. This was true for both men and women. Other studies have also shown a correlation of meat intake with ARMD. Macular degeneration is the leading cause of blindness among older people.
Childhood obesity is an increasing health problem for individuals and a societal problem. A simple change in health habits can have a significant effect on weight among children and adolescents. One of the most significant contributors to the problem (in addition to the location of fast food outlets near schools) is the high consumption of soft drinks. These are high-sugar, high-calorie liquids that offer no nutritional value (commonly referred to as “empty calories”).
Two studies show that elimination or reduction of soft drink consumption is possible and effective to help weight loss and improve other obesity parameters, such as the amount of fat that surrounds internal organs.
In one observational study, researchers evaluated 3098 children and adolescents for sugar-sweetened beverage consumption and total caloric intake. Substituting water for sugar beverages reduced caloric consumption by 106 calories for each 8 ounces, and the subjects did not compensate by increasing their consumption of other calorie sources. (Wang YC, et al., Impact of change in sweetened caloric beverage consumption on energy intake among children and adolescents. Arch Pediatr Adolesc Med. 2009 Apr;163(4):336-43.)
The authors estimated that replacing all of the sugar beverages with water would lead to reduction of 235 calories per day. This would lead to a reduction of about a pound of body weight every 15 days (of course, when normal body weight was reached, calorie consumption would likely increase to maintain it).
In a related interventional study, 54 overweight Latino adolescents were divided in to three groups, a control group, a nutrition group that reduced sugar intake by eliminating one soda per day (47 grams less sugar per day), and a nutrition group that also added strength-training exercise to their program. The two nutrition groups increased fiber intake by 5 grams per day, a 59 percent increase (equal to about one cup of beans per day). They were then followed for 16 weeks.
The nutrition intervention led to improvements in blood sugar and insulin levels. These groups also had a two percent reduction in body mass index, compared to a two percent gain in the control groups. They lost fat that surrounds the internal organs (visceral fat). (Ventura E, et al., Reduction in risk factors for type 2 diabetes mellitus in response to a low-sugar, high-fiber dietary intervention in overweight Latino adolescents. Arch Pediatr Adolesc Med. 2009 Apr;163(4):320-327.) All of these improvements indicate significant reductions in the risk of developing type 2 diabetes.
Finally, in a Dutch study of 1108 adolescents at 18 schools, those at the test schools reduced soft drink consumption by about 10 ounces per day compared to the control schools. They were reviewed at 12 months and again at 20 months after the study started. (Singh AS, et al., Dutch obesity intervention in teenagers: effectiveness of a school-based program on body composition and behavior. Arch Pediatr Adolesc Med. 2009 Apr;163(4):309-17.)
In both boys and girls, measures of body composition were significantly improved in the intervention group compared to the controls. These results were achieved without increases in exercise or changes in other snacking habits. I have often heard that it is difficult for adolescents to change these habits, but with the right education, encouragement, and support it can be done.
A recent article in the Journal of the American Dietetic Association showed a very positive improvement in dietary intake and weight in adolescents and young adults on a vegetarian diet. The authors noted, however that some of the youngsters chose to be vegetarian because they had eating disorders and tried what they considered to be unusual eating habits.
The news report of the study carried the headline: “The Dark Side of Vegetarianism” (HealthDay News, April 1, 2009). This is a totally misleading headline! The article starts with the sentence “Despite its proven health benefits, a vegetarian diet…”
Well, it turns out that the vegetarian diet was healthier in many ways. The vegetarian students ate more fruits and vegetables, had less fat intake, and were less likely to be either overweight or obese. (Robinson-O'Brien R, et al., Adolescent and young adult vegetarianism: better dietary intake and weight outcomes but increased risk of disordered eating behaviors. J Am Diet Assoc. 2009 Apr;109(4):648-55.)
The teens with eating disorders were mostly those who were experimenting with vegetarian diets temporarily, among their many other efforts to deal with their problem. This has nothing to do with any negative effect of the vegetarian diet, and even the authors of the study (and eventually the news article author) reported this. The lead researcher was quoted in the news article: “Eating mostly plants -- and even only plants -- is good for us, and certainly far better for health than the typical American diet.” It is too bad that the news headline might put people off from making this healthful change in their dietary habits.
Yet another article reports the health problems associated with eating red meat. In the latest study, increasing consumption of either red meat or processed meat increases the risk of mortality from all causes, not just heart disease and cancer. In the NIH-AARP Diet and Health Study of a half million people from 50 to 71 years old, during 10 years of follow-up there were 47,976 male deaths and 23,276 female deaths. Those with the highest red meat intake had a 31 to 36 percent higher overall mortality compared to those with the lowest intake. ) Sinha R, et al., Meat intake and mortality: a prospective study of over half a million people. Arch Intern Med. 2009 Mar 23;169(6):562-71.)
In addition to cancer and heart disease, there was an increased risk of Alzheimer’s disease and stomach ulcers, among other conditions. In this study, chicken did not have such an effect, and in fact appeared to be associated with reduced mortality. The problem with drawing this conclusion is that they included fish among the white meats, and fish is known to lower some disease-related mortality. In addition, numerous other articles show that a mostly plant-based diet is still the healthiest choice.
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