Diets vs longevity

[Guest guest]

The below paper is pdf-availed.

http://voices.washingtonpost.com/checkup/2010/12/this_healthful-eating_thing_mi.html?wpisrc=nl_health

Posted at 7:00 AM ET, 12/28/2010 Study links diet to longevity, but with confusing findingsBy LaRue Huget

What you eat might well determine how long you live.

But it's not exactly clear what the optimal diet should be.

In a study published in the January 2011 edition of the Journal of the American Dietetic Association, researchers found that among 2,500 adults ages 70 to 79, those who maintained a diet consisting largely of foods deemed "healthy" were less likely to die and more likely to remain healthy than those whose diets included more of less-healthful foods during the 10-year period examined.

Researchers divvied the study subjects into six groups according to their predominant food choices among 108 food items tallied. Here's how the clusters fell out:

"Healthy foods" (374 participants)

"High-fat dairy products" (332)

"Meat, fried foods, and alcohol" (693)

"Breakfast cereal" (386)

"Refined grains" (458)

"Sweets and desserts" (339)

That "healthy foods" category was defined by relatively higher consumption of low-fat dairy, fruit, whole grains, poultry, fish and vegetables and lower intake of meat, fried foods, sweets, high-calorie beverages and added fat.

After all kinds of controls were applied to rule out the effects of gender, age, physical activity, smoking, race, total calorie intake and other variables, the numbers showed that the "high-fat dairy products" group had a 40 percent higher risk of mortality than the "health foods" group and that the "sweets and desserts" group had a 37 percent higher risk than the "healthy foods" group.

The study concludes:

A dietary pattern consistent with current guidelines to consume relatively high amounts of vegetables, fruit, whole grains, poultry, ï¬sh and low-fat dairy products may be associated with superior nutritional status, quality of life and survival in older adults.

But what to make of that "meat, fried foods and alcohol" group -- the one that you might notice is nearly twice the size of the "healthy foods" group? That group's not even mentioned in the news release (the study is not yet posted online) -- despite the fact that, when the numbers were crunched, that group's mortality risk was about the same as that of the healthy-eating group.

The study notes:

Unexpectedly, in this and several other studies, a pattern higher in red meat was not signiï¬cantly associated with increased risk of mortality when controlled for relevant confounding factors. One suggested explanation is that plant-based diets may lower health risk because plant foods are protective, whereas diets high in animal foods may be more likely to increase risk only if the animal foods displace protective plant foods in the diet.

The study's lead author, Amy of the University of land department of nutrition and food science, was good enough to make herself available to talk on the phone over the holiday weekend and tried to help me sort things out. I couldn't understand why the meat/fried food/alcohol group's relative good health wasn't singled out as helping keep folks alive longer, leaving all the credit to the "healthy foods" group.

followed up with an e-mail reviewing what she'd told me on the phone:

As mentioned on the phone, while we can't give definite reasons for our results, Table 1 in the paper [which shows percentage of total energy intake from selected food groups each cluster's diet] may provide some ideas for why the "meat, fried foods and alcohol" group didn't have a statistically significantly higher risk of mortality than the "healthy foods" group after controlling for many variables including education, physical activity, and smoking -- in other words, these other variables being equal. As Table 1 shows, the name of the "meat, fried foods and alcohol" group may be a bit misleading, because this group had a more similar diet to the "healthy foods" group than some of the others. We named the groups according to foods that people ate relatively more of in comparison to the other groups. The "meat, fried foods and alcohol" group ate on average about 4 percent of calories from meat, while the "healthy foods" group ate on average about

2.8 percent of calories from meat. The differences in fried food and alcohol intake between the "meat, fried foods and alcohol" group and the "healthy foods" group were also about 1 to 3 percent. In contrast, the "sweets and desserts" group ate on average about 25.8 percent of calories from sweets, while the "healthy foods" group ate on average about 6 percent of calories from sweets -- a difference of almost 20 percent in this food group. The "high-fat dairy products" group ate about 17.1 percent of calories from high fat dairy products, while the "healthy foods" group ate about 3.4 percent of calories from high fat dairy products -- a difference of almost 14 percent in this food group. In other words, it is not as though the "meat, fried foods and alcohol" group within this study population of 70-79 year-olds ate enormous quantities of these foods, just slightly more on average than the other groups. The "sweets and desserts" and "high-fat dairy

products" groups, on the other hand, showed some more stark differences from the "healthy foods" group in their diets.

I appreciate 's taking pains to help me with this. But the cynic in me has to wonder whether the finding that people who eat a bit more meat, fried food and alcohol manage to do all right, mortality-wise, may have been too out of whack with current dietary recommendations for comfort. Especially as the new Dietary Guidelines for Americans 2010, which are likely to promote consumption of whole grains and other plant-based foods, are about to be issued, I hope researchers will keep at it and tease this confusing situation out further.

Because if it really is okay to eat meat and fried food and enjoy alcohol after all, people should know about it.

Dietary patterns and survival of older adults. AL, TB, Tylavsky FA, SE, Houston DK, Hue TF, Strotmeyer ES, Sahyoun NR; Health ABC Study.J Am Diet Assoc. 2011 Jan;111(1):84-91.PMID: 21185969

Abstract

Background

Recent research has linked overall dietary patterns to survival in older adults.

Objectives

The objective of this study was to determine the dietary patterns of a cohort of older adults, and to explore associations of these dietary patterns with survival over a 10-year period. A secondary goal was to evaluate participants' quality of life and nutritional status according to their dietary patterns.

Design

The Health, Aging, and Body Composition Study is a prospective cohort study of 3,075 older adults. In this study, all-cause mortality was assessed from baseline through Year 10. Food intake was estimated with a modified Block food frequency questionnaire, and dietary patterns of 2,582 participants with complete data were derived by cluster analysis.

Results

Six dietary pattern clusters were identified, including a Healthy Foods cluster, characterized by higher intake of low-fat dairy products, fruit, whole grains, poultry, fish, and vegetables. Both the High-Fat Dairy Products and Sweets and Desserts clusters had a 1.4-fold higher risk of mortality than the Healthy Foods cluster after adjusting for potential confounders. The Healthy Foods cluster also had significantly more years of healthy life and more favorable levels of selected nutritional biomarkers than the other clusters.

Conclusions

A dietary pattern consistent with current guidelines to consume relatively high amounts of vegetables, fruit, whole grains, poultry, fish, and low-fat dairy products may be associated with superior nutritional status, quality of life and survival in older adults.

Table 4. Relative risk (95% confidence interval) of all-cause mortality of Health, Aging, and Body Composition Study participants by dietary pattern cluster-------------------------------------------------------------------------- Healthy foods (n=374) High-fat dairy products (n=332) Meat, fried foods, and alcohol (n=693) Breakfast cereal (n=386) Refined grains (n=458) Sweets and desserts (n=339) --------------------------------------------------------------------------Number of deaths 77 109 209 105 135 104% 21.0 34.0 30.9 28.2 30.2 32.0-------------------------------------------------------------------------- Relative risk (95% confidence interval)--------------------------------------------------------------------------Model 1a 1.00 1.59 (1.19, 2.14)* 1.39 (1.06, 1.82)* 1.25 (0.93, 1.69)

1.32 (0.99, 1.76) 1.52 (1.13, 2.04)*Model 2b 1.00 1.40 (1.04, 1.88)* 1.21 (0.92, 1.60) 1.16 (0.86, 1.56) 1.08 (0.80, 1.45) 1.37 (1.02, 1.86)*-------------------------------------------------------------------------- a Adjusted for sex, age, and race. b Adjusted for sex, age, race, clinical site, education, physical activity, smoking status, and total energy intake. * Significantly different from the Healthy Foods cluster at P<0.05, based on proportional hazards regression.

-- Al Pater, alpater@...-- Aalt Pater