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High dietary niacin intake is associated with decreased chromosome translocation frequency in airline pilots
British Journal of Nutrition , 08 Oct 2010
Lee C. Yonga and Martin R. Petersen

Experimental studies suggest that B vitamins such as niacin, folate, riboflavin, vitamin B6 and vitamin B12 may protect against DNA damage induced by ionising radiation (IR). However, to date, data from IR-exposed human populations are not available. We examined the intakes of these B vitamins and their food sources in relation to the frequency of chromosome translocations as a biomarker of cumulative DNA damage, in eighty-two male airline pilots. Dietary intakes were estimated by using a self-administered semi-quantitative FFQ. Translocations in peripheral blood lymphocytes were scored by using fluorescence in situ hybridisation whole-chromosome painting. Negative binomial regression was used to estimate rate ratios and 95 % CI, adjusted for age and occupational and lifestyle factors. We observed a significant inverse association between translocation frequency and dietary intake of niacin (P = 0·02): adjusted rate ratio for subjects in the highest tertile compared with the lowest tertile was 0·58 (95 % CI 0·40, 0·83). Translocation frequency was not associated with total niacin intake from food and supplements as well as dietary or total intake of folate, riboflavin or vitamin B6 or B12. However, the adjusted rate ratios were significant for subjects with ≥ median compared with < median intake of whole grains (P = 0·03) and red and processed meat (P = 0·01): 0·69 (95 % CI 0·50, 0·96) and 1·56 (95 % CI 1·13, 2·16), respectively. Our data suggest that a high intake of niacin from food or a diet high in whole grains but low in red and processed meat may protect against cumulative DNA damage in IR-exposed persons.

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Association of facial skin aging and vitamin D levels in middle-aged white women,
Chang AL, Tang JY, et al, Cancer Causes Control, 2010 Sep 30; [Epub ahead of print].

Summary: In a cross-sectional study involving 45 women aged more than 40 years, results indicate an inverse association between skin aging and serum vitamin D levels. Standardized digital facial images of the women were examined and serum 25(OH)D concentrations were measured. After adjusting for potential confounders, women with greater photodamage were associated with more than a 5-fold increased odds of being vitamin D insufficient. Additionally, erythema/telangiectasias, hyperpigmentation, and wrinkling were significantly associated with vitamin D insufficiency. Thus, the authors of this study conclude, “Our results suggest an association between skin aging and 25(OH)D levels.”

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Effects of supplemental fish oil on resting metabolic rate, body composition, and salivary cortisol in healthy adults

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For the year 2005 (in the U.S.),

• Tobacco smoking accounted for 467,000 deaths,
• High Blood Pressure caused 395,000 deaths,
• Overweight/Obesity: 216,000 deaths,
• Physical Inactivity: 191,000 deaths,
• High Dietary Salt: 102,000 deaths,
• High Dietary Trans Fats: 82,000 deaths.

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Low-Carbohydrate Diets and All-Cause and Cause-Specific Mortality Two Cohort Studies
Teresa T. Fung, ScD; Rob M. van Dam, PhD; Susan E. Hankinson, ScD; Meir Stampfer, MD, DrPH; Walter C. Willett, MD, DrPH; and Frank B. Hu, MD, PhD

Background:

Data on the long-term association between low-carbohydrate diets and mortality are sparse.

Objective:

To examine the association of low-carbohydrate diets with mortality during 26 years of follow-up in women and 20 years in men.

Design:

Prospective cohort study of women and men who were followed from 1980 (women) or 1986 (men) until 2006. Low-carbohydrate diets, either animal-based (emphasizing animal sources of fat and protein) or vegetable-based (emphasizing vegetable sources of fat and protein), were computed from several validated food-frequency questionnaires assessed during follow-up.

Setting:

Nurses’ Health Study and Health Professionals’ Follow-up Study.
Participants: 85 168 women (aged 34 to 59 years at baseline) and 44 548 men (aged 40 to 75 years at baseline) without heart disease, cancer, or diabetes.

Measurements:

Investigators documented 12 555 deaths (2458 cardiovascular-related and 5780 cancer-related) in women and 8678 deaths (2746 cardiovascular-related and 2960 cancer-related) in men.

Results:

The overall low-carbohydrate score was associated with a modest increase in overall mortality in a pooled analysis (hazard ratio [HR] comparing extreme deciles, 1.12 [95% CI, 1.01 to 1.24]; P for trend = 0.136). The animal low-carbohydrate score was associated with higher all-cause mortality (pooled HR comparing extreme deciles, 1.23 [CI, 1.11 to 1.37]; P for trend = 0.051), cardiovascular mortality (corresponding HR, 1.14 [CI, 1.01 to 1.29]; P for trend = 0.029), and cancer mortality (corresponding HR, 1.28 [CI, 1.02 to 1.60]; P for trend = 0.089). In contrast, a higher vegetable low-carbohydrate score was associated with lower all-cause mortality (HR, 0.80 [CI, 0.75 to 0.85]; P for trend ≤ 0.001) and cardiovascular mortality (HR, 0.77 [CI, 0.68 to 0.87]; P for trend < 0.001).

Limitations:

Diet and lifestyle characteristics were assessed with some degree of error. Sensitivity analyses indicated that results were probably not substantively affected by residual confounding or an unmeasured confounder. Participants were not a representative sample of the U.S. population.

Conclusion:

A low-carbohydrate diet based on animal sources was associated with higher all-cause mortality in both men and women, whereas a vegetable-based low-carbohydrate diet was associated with lower all-cause and cardiovascular disease mortality rates.

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