Whole milk is better for you than skim milk. It is a great example of how efforts by food companies to make food better for you often can result in food that is worse for you.

I read “In Defense of Food” by best-selling food journalist Michael Pollan, the author of “The Omnivore’s Dilemma.” “In Defense of Food” is his latest book, and in it he says:

“Very often food science’s effort to make traditional foods more nutritious make them much more complicated, but not necessarily any better for you. To make dairy products low fat, it’s not enough to remove the fat. You then have to go to great lengths to preserve the body or creamy texture by working in all kinds of food additives. In the case of low-fat or skim milk, that usually means adding powdered milk. But powdered milk contains oxidized cholesterol, which scientists believe is much worse for your arteries than ordinary cholesterol, so food makers sometimes compensate by adding antioxidants, further complicating what had been a simple one-ingredient whole food. Also, removing the fat makes it that much harder for your body to absorb the fat-soluble vitamins that are one of the reasons to drink milk in the first place.”

In the book, Pollan describes how nutrition science’s reductionist approach to food has given people some insight into food but the field only touches the tip of an iceberg of knowledge. Nutrition scientists, with the help of journalists, announce discoveries about aspects of food but fail to grasp just how complex food really is in the also complex human body.

What this does is leave a public that is wildly confused about what food is good for you and what food is bad for you.

But, Pollan says, this is good for business. After all, most of the research into food is funded by food companies, and he points out how food scientists tend to find what the sponsors are looking for when they pay for studies.

You can tell just how young of a science nutrition is by looking at how back and forth the field was over butter and margarine. The field shifts its likings every few years. This also produces food fads, which is also good for business. Low-carb this. Low-fat that. Atkins. South Beach. Shifting food pyramids. Food with unpronounceable lists of ingredients.

This connects to the real problem that nutritionists make: They look at food as nutrients, rather than as food. They tell us to eat food with beta-carotene, rather than tell us to eat carrots. It boomed in the 1980s, when terms in the grocery stores about fiber, cholesterol, saturated fat and such increased in prominence. Eat what’s high in this, low in that.

Pollan calls this nutritionism. Actually, he borrows the term from Gyorgy Scrinis, who first used the term in 2002 in an Austrialian quarterly called Meanjin. In a piece called “Sorry Marge,” Scrinis said how margarine shifts its identity based on the prevailing winds of nutrition science. Scrinis asked readers to step back and take a greater view of the butter-margarine debate: “namely, that we should understand and engage with food and our bodies in terms of their nutritional and chemical constituents and requirements — the assumption being that this is all we need to understand.”

Pollan adds: “In the case of nutritionism, the widely shared but unexamined assumption is that the key to understanding food is indeed the nutrient. … Since nutrients, as compared with foods, are invisible and therefore slightly mysterious, it falls to the scientists (and to the journalists through whom the scientists reach the public) to explain the hidden reality of foods to us. In form this is a quasireligious idea, suggesting the visible world is not the one that really matters, which implies the need for a priesthood. For to enter the world where your dietary salvation depends on unseen nutrients, you need plenty of expert help.”

It’s a powerful book. He goes on to describe how the lipid hypothesis — you know, that fat is bad for you — began in the 1950s but grew in the 1970s, and finally became big in the 1980s, when food companies jumped on the fad and gave consumers all this low-fat food. Yet America remains obese partly because many foods that make health claims are actually worse for you. Furthermore, the lipid hypothesis was only a hypothesis, and it was wrong. Yes, wrong. You didn’t hear much fanfare about that, did you?

Pollan writes: “At this point, you’re probably saying to yourself, ‘Hold on just a minute. Are you really saying the whole low-fat deal was bogus? But my supermarket is still packed with low-fat this and no-cholesterol that! My doctor is still on me about my cholesterol and telling me to switch to low-fat everything.’ I was flabbergasted at the news, too, because no one in charge — not in the government, not in the public health community — has dared to come out and announce: ‘Um, you know everything we’ve been telling you for the last 30 years about the links between dietary fat and heart disease? And fat and cancer? And fat and fat? Well, this just in: It now appears that none of it was true. We sincerely regret the error.’

“No the admissions of error have been muffled, and the mea culpas are impossible to find. But read around in the recent scientific literature and you will find a great many scientists beating a quiet retreat from the main tenets of the lipid hypothesis. Let me offer just one example at the Harvard School of Public Health. In a recent review of the relevant research called ‘Types of Dietary Fat and Risk of Coronary Heart Disease: A Critical Review,’ the authors proceed to calmly remove, one by one, just about every strut supporting the theory that dietary fat causes heart disease.”

Pollan quotes portions of the review — such as how people switched from butter to margarine in the hopes of heart health or stayed away from eggs — but this quote from the study is the bombshell: “It is now increasingly recognized that the low-fat campaign has been based on little scientific evidence and may have caused unintended health consequences.”

For instance, many people ended up taking on food with trans fats to avoid dietary fat and the one part of the lipid hypothesis that was correct was that trans fats do lead to heart disease. Oops. And the research says because the low-fat diet purported weight loss many people took on more carbohydrates — as dietary advice suggested for 30 years — which leads to weight gain. Oops.

I know, I know, Pollan challenges nutrition science with more nutrition science. But it does shed light on the greater issue of how we shouldn’t place so much trust in nutrition science.

OK, that’s all for this week. Next week, I’ll share with you what Pollan suggests we eat. Here’s a clue: real food.

Tribune Managing Editor Tim Engstrom’s column appears every Tuesday.