The problem is that these are two separate issues: health claims for probiotics in general, and health claims for yogurt. The yogurt claims are dubious, yes, since (1) companies sometimes generalize their claims, assuming that a certain strain of bacteria will have the same benefit for middle-aged men as for children, which isn’t always borne out by the studies, and (2) there’s no guarantee that the beneficial bacteria will survive the transportation process and be alive by the time they are consumed: the guarantees on the packages say “X amount of bacteria were present at the time of manufacture.”

Bottom line: if you DO want the health benefits of probiotics, don’t rely on yogurt. There are other really great ways to get them. See intestinalgardener.blogspot.com

As with many nutrition studies, it’s important to note the great difficulty (near impossibility?) of drawing correlations between the consumption of a specific food item and a particular health outcome. ”

Excellent point. Experts and studies have to be viewed collectively, or as a whole, and society should not follow just one or two studies because our understanding of causation/correlation are terrible. 

“Most people can count calories. Many have a clue about where fat lurks in their diets. However, fewer give carbohydrates much thought, or know why they should.

But a growing number of top nutritional scientists blame excessive carbohydrates — not fat — for America’s ills. They say cutting carbohydrates is the key to reversing obesity, heart disease, Type 2 diabetes and hypertension.”

http://articles.latimes.com/2010/dec/20/health/la-he-carbs-20101220

Other than avoiding obesity – which is nonsense on stilts – lifestyle described above would benefit average person of moderate health. Common sense – no cigs and everything else in moderation is best way to live if you want maximum best health. 

However, avoiding obesity is much easier said than done because there is plenty of evidence that appetite is controlled by genes. 

“Height, weight, and body mass index (BMI) were assessed in a sample of 1974 monozygotic and 2097 dizygotic male twin pairs. Concordance rates for different degrees of overweight were twice as high for monozygotic twins as for dizygotic twins. Classic twin methods estimated a high heritability for height, weight, and BMI, both at age 20 years (.80,.78, and.77, respectively) and at a 25-year follow-up (.80,.81, and.84, respectively). 

Height, weight, and BMI were highly correlated across time, and a path analysis suggested that the major part of that covariation was genetic. These results are similar to those of other twin studies of these measures and suggest that human fatness is under substantial genetic control.”

http://jama.ama-assn.org/content/256/1/51.abstract

McArdle: Over the last five years or so, I’ve noticed that public health efforts about obesity are not just amping up the volume, but exploring increasingly coercive methods to induce weight loss: taxes on junk food, lawsuits against fast food companies (which are basically a tax on junk food), and so forth. Does that match your analysis?

Campos: It’s the classic pattern of moral panics. As public concern about the damage being done to the fabric of society by the folk devils increases, increasingly intense demands are made on public officials to “do something” about the crisis, usually by eliminating the folk devils. 

That of course is the strategy for this crisis. If fat people are the problem, then the solution is to get rid of them, by making them thin people. The most amazing aspect of this whole thing, for me, has always been the imperviousness of policy makers, and even more so people who consider themselves serious academics and scientists, to the overwhelming evidence that there’s no way to do this. 

I mean, there’s no better established empirical proposition in medical science that we don’t know how to make people thinner. But apparently this proposition is too disturbing to consider, even though it’s about as well established as that cigarettes cause lung cancer. So all these proposals about improving public health by making people thinner are completely crazy. They are as non-sensical as anything being proposed by public officials in our culture right now, which is saying something. 

http://www.theatlantic.com/business/archive/2009/07/americas-moral-panic-over-obesity/22397/

The podcast can be found here: http://www.podbean.com/podcast-detail?pid=18177 It’s one of the “Foods that make Billions” series at the top.