Does a Healthy Lifestyle Result in Better Outcomes?

It’s easy to become discouraged that sensible actions may not be effective due to general pessimism and sometimes conflicting medical reports.  On the positive side of the ledger, a recent study (AV Khera et al. NEJM 2016; 375: 2349-58) provides compelling data that a combination of healthy lifestyle changes make a BIG difference.

The study focused on 4 healthy lifestyle factors: no smoking, no obesity, regular physical activity, and a healthy diet.  The study examined three large prospective cohorts with a total of more than 55,000 patients.

Key finding:

  • Among participants with high genetic risk, a favorable lifestyle was associated with a 46% lower relative risk of coronary events compared to those with an unfavorable lifestyle over the 10-year study period.

In the same issue, a review of the human intestinal microbiome (pages 2369-79) notes that “dietary intake appears to be a major short-term and long-term regulator of the structure and function of gut microbiota.  Still, only a relatively small number of randomized, clinically controlled dietary interventions targeting the gut microbiota have been reported in humans and these show that energy restriction and diets rich in fiber and vegetables are associated with gut microbial changes that, in turn, are associated with a health benefit.”

My take: To enhance your odds of good health, avoid smoking, stay fit, and eat your fruits/veggies.

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For Increased Longevity: More Greens are Good

From NPR, link:http://t.co/07NyZaXqzE

 Excerpt:

A new study linking animal protein-rich diets to increased mortality in middle age adds fuel to the controversy over how much protein — and from what sources — is ideal for health. One thing that seems pretty clear: It doesn’t hurt to go heavy on the greens.

Americans who ate a diet rich in animal protein during middle age were significantly more likely to die from cancer and other causes, compared with people who reported going easy on foods such as red meat and cheese, fresh research suggests.

The study, published Tuesday in the journal Cell Metabolism, was based on an analysis of data from NHANES, an ongoing federally funded study that surveys Americans about their eating habits and behaviors.

In this particular study, researchers tracked about 6,000 older adults included in the survey to find connections between dietary patterns, death and disease.

“The research shows that a low-protein diet in middle age is useful for preventing cancer and overall mortality,” wrote co-author Eileen Crimmins, the AARP Chair in Gerontology at the University of Southern California, in a release about the paper.

But here’s the catch: The researchers also found that for older people, ages 65 and up, there may be a benefit to eating more protein. In this age group, higher levels of protein seemed to be protective against cancer and premature death…

When we’re young, IGF-1 help promotes growth, which is good. But as we age, too much protein in our diets may lead to overly high levels of IGF-1, which may contribute to aging and DNA damage, Longo explains.

Then, after 65, when IGF-I levels trail off, our bodies may benefit from more protein in the diet to help fend of frailty and decline…

In the new study, Longo and his colleagues found that high-protein foods derived from plants, such as beans and nuts, did not have the same effect on mortality as did high-protein foods from animals.

Singling out the effects of protein in the diet is hard to do. For starters, our diets are complex, and sussing out the independent effect of any one component is tough. What’s more, surveying people on what they have eaten, as NHANES does, and then trying to figure out how that influences their health years later is a tricky business. So there are still lots of questions about how to interpret these findings.

In an age when advocates of the Paleo Diet and other low-carb eating plans such as Atkins talk up the virtues of protein because of its satiating effects, expect plenty of people to be skeptical of the new findings.

That said, as we’ve previously reported, several other studies have found a link between a high intake of red meat — especially processed meats like bacon and salami — and other animal proteins and an increased risk of mortality…

according to Dr. Frank Hu, a researcher at the Harvard School of Public Health who studies the links between health, diet and lifestyle.

“The harmful effects of smoking on cancer and mortality are well-established to be substantial, while the harmful effects of red meat consumption are modest in comparison,” Hu wrote to us in an email.

For instance, in a study Hu authored, people who ate a serving of red meat every day had a 13 percent increased risk of mortality, compared with those who ate little meat… Choosing chicken and other poultry decreased the risk by 14 percent, fish decreased the risk by 7 percent and legumes decreased the risk by 10 percent….In the meantime, if you’re feeling confused, consider the one strategy that almost all experts agree on: moderation.

The simplest way to maintain a healthy body weight and cut the risk of so many weight-related diseases is to limit calories.

So eat what you enjoy. Upsize servings of greens and other vegetables. And downsize servings of meat, cheese and other high-calorie foods.

Eat your veggies…if you don’t want to get sick

Maybe your mother was right –you should eat your vegetables!   For a long time, it has been known that dietary changes can be used to treat Crohn’s disease.  The specifics about what type of diet and the reasons for how diet promotes a healthy gastrointestinal tract are being unraveled.  A person’s diet affects their microbiome; and, a number of recent articles have highlighted the microbiome in both functional and nonfunctional disorders (see below).

An even more fascinating article is in last week’s New England Journal of Medicine (NEJM 2012; 366: 181).  This article discusses two publications which show how certain dietary components interact with intestinal immune receptors.

  • Kiss EA et al. Science 2011 October 27 (Epub ahead of print).
  • Li Y et al. Cell 2011; 147: 629-40.

This NEJM article implicates a typical ‘Western’ diet as a contributor to inflammatory bowel disease (IBD).  However, a diet high in vegetables may prevent or reduce inflammation.  One mechanism whereby vegetables affect the GI tract is through the AhR (aryl hydrocarbon) receptor.  Some vegetables, like broccoli, cabbage, and brussel sprouts, are natural ligands for this receptor.  A mouse model has shown that AhR deficiency “results in increased epithelial vulnerability, immune activation, and altered composition of the microbiota.”  In addition, AhR is down-regulated in the intestinal tissue of persons with IBD.  AhR ligands are associated with increased interleukin-22 which promotes intestinal integrity.

Additional work regarding the optimal diet are ongoing.  There has been an interest in a ‘carbohydrate specific diet.’  This year’s NASPGHAN meeting (abstract #48)  presented data on this diet from a retrospective study.  This poster described five patients on monotherapy (diet alone) and at 6 months –good results in four patients (80%).  A few prospective studies are underway; in fact, a prospective study with patients from our office will be presented at this year’s DDW.  Initial results look promising (personal communication from lead investigator, Stan Cohen).

Additional references:

  • -Gastroenterology 2010; 139: 1816, 1844.  Microbiome & affect on IBD vs mucosal homeostasis.
  • -J Pediatr 2010; 157: 240.  Microbiota in pediatric IBD -increased E coli and decreased F praunsitzil in IBD pts.
  • -Gastro 2011; 141: 28, 208.  GM-CSF receptor (CD116) defective expression & function in 85% of IBD pts. n=52.
  • -Scand J Gastro 2001; 36: 383-8.  Elemental & polymeric diets successful in maintaining remission in ~43% of adults with complete steroid withdrawal.
  • -Clin Gastro & Hepatology 2006; 4: 744.  10 weeks of exclusive modulen (along with clears) had 79% response rate (n=37).  Better histologic response than steroids.
  • -J Pediatr 2000; 136: 285. Nutritional treatment w polymeric diet is effective w/in 8 weeks in 32/37.
  • -JPGN 2000; 31: 3 & 8.  EN about as effective as steroids for primary Rx.
  • -Can J Gastroenterol 1998; 12(8):544-49. Patients, diets and preferences in
    a pediatric population with Crohn’s disease.
  • -Gastroenterology 1988; 94:603-610. Chronic intermittent elemental diet improves growth failure in  children with Crohn’s disease.
  • -JPGN 1989; 8:8-12. Nutritional support for pediatric patients with inflammatory bowel disease.
  • -J Pediatr 2000; 136: 285-91. The role of nutrition in treating pediatric Crohn’s disease in the new millennium.