Nice story, but false. Marco Polo’s journeys to the far east occurred in the late 13th century, while the the earliest known written reference to pasta in Italy – Sicily specifically – dates from the year 1154, over 100 years earlier. There’s no reason to doubt that the Chinese had their own noodles, but the folks in Italy were making and eating noodles long before Marco Polo.

Among some folks, it is an article of faith that one should avoid cholesterol in the diet to lessen the risk of heart disease. So, foods such as eggs, liver, shellfish, butter, and cheese were on many people’s restricted or avoid list. That’s too bad, because research over the past decade or so has shown pretty conclusively that there’s no association between dietary cholesterol and heart disease. It is true that the amount and types of cholesterol in your bloodstream are connected with heart disease, but cholesterol metabolism is a very complex matter and blood levels are affected by many factors, but not by dietary cholesterol (except in so-called hyperresponders, a very small percentage of the population). So, you still may want to limit cholesterol-containing foods if only because they tend to be high-calorie, but there’s no reason to shun them over concern with your cholesterol levels.

The paleo diet is one of the latest fads to hit the world of dieting. It is supposedly based on eating only foods that our ancestors in Paleolithic times, some 12,000 years ago, supposedly would have eaten. Thus, the diet permits meat, fish, fruit, most vegetables, nuts, and plant-based oils (such as olive and avocado) while excluding dairy, grains, cereals, legumes (beans, peanuts), processed oils, processed sugar, alcohol, and coffee. The idea behind the diet is the claim that our bodies had, by the end of the Paleolithic, evolved to survive on the foods available at the time and are not designed to process foods that were introduced since then. There are many fatal flaws in this whole idea.

The most serious flaw is the assumption that evolution “designed” us to be an ideal match for our environment and diet 12,000 years ago. This is completely wrong, as any high school biology student should be able to tell you. Evolution doesn’t “design” anything, all it does is favor the continuation of genes that are associated with leaving more offspring. Thus, a caveman who was sickly and died at 25, but left 12 children, was an evolutionary success and his genes would continue in the population. In contrast, another caveman who lived a healthy life to the age of 60, but left only 1 or 2 children, was not a success in evolutionary terms. In other words, the notion that Paleolithic folks were ideally adapted to their diet is pure nonsense. As long as their diet allowed them to leave children, that was enough.

A second serious flaw is the diet’s assumptions about what foods people did and did not eat back then. There is, for example, quite a bit of evidence that Paleolithic humans ate grains and legumes, but these foods are forbidden by the diet. In fact, there is evidence that humans were cooking and eating tubers and other starchy vegetables as much as 300,000 years ago. Paleo humans did not eat peppers, tomatoes, avocados, potatoes, pineapple, or blueberries (among others) because these are new world plants that were not available during Paleolithic evolution. Yet the diet allows them all. Dietary flexibility was a hallmark of humans and one reason for our evolutionary success—we did not evolve to eat certain specific foods, we evolved to eat pretty much anything. Would anyone care to argue that Paleolithic humans in the sub-arctic zones, the rain forest, the plains, and the tropical coastal regions ate the same or even similar diets? I don’t think so.

A third flaw is the claim by diet proponents that human genetics have not changed in any meaningful way since Paleolithic times and therefore the human digestive and metabolic systems cannot have adapted to deal with “new” foods. This is flat-out false. It is well documented that human genes have changed in response to the introduction of dairy into the diet and to the development of agriculture, with the greater availability of wheat and other grains. While on the subject of genetics, it’s impossible to understand why humans have multiple copies of the gene for amylase, an enzyme whose sole purpose is digesting starches, if starchy foods had not been an important part of the human diet for a long time.

That’s strike three, I believe!

As if we needed a strike four, the life expectancy of humans in Paleolithic times was somewhere in the mid-30s. Is theirs the diet you want to eat? Of course, many other factors have contributed to the increase in life expectancy, including improvements in medicine, public health, and nutrition. Oh wait, did I say nutrition? You know, like eating grains, legumes, and dairy?

There are good aspects to the paleo diet, namely the avoidance of overly processed foods and of excess carbs and sugar (emphasis on excess). But, there’s nothing “paleo” about these ideas, they are part of many dietary regimes. So if you want yet another trendy fad diet to waste your time and money on, be my guest and go paleo.

Gluten is a protein found in wheat and some other grains (barley, rye, bulgur, farro, kamut, spelt, triticale, and according to some people, oats). Gluten gives bread dough its elasticity and helps it to rise. Gluten has been getting a bad rap lately, a rap that is undeserved. Unfortunately, it has become trendy to avoid gluten, and all too many people leave their brains in neutral and buy into all the scare-mongering that has grown up around gluten (much of which, needless to say, comes from people trying to sell you gluten-free products).

It’s true that about 1% of people have a true gluten allergy (celiac disease), and consuming even small amounts of gluten can cause these people great distress and serious medical problems. For the rest of us, however, there is nothing to worry about. After all, gluten has been part of the human diet for some 10,000 years, and there is not a single shred of legitimate medical evidence linking gluten to autism, Alzheimer’s, or any other health issues. Really, not a shred! Some folks claim to have lost weight with a gluten-free diet. Well duh, if you don’t eat any bread, bagels, cake, or pasta, that will happen! Some folks claim to simply “feel better” without gluten, but that’s a subjective response that may be more the result of eating a lot fewer carbs without being directly related to gluten at all. It’s also the case that when eating gluten-free, it’s very easy to short yourself on the fiber, vitamins, and minerals that are found in gluten-containing grains.

So, if you want to be trendy by avoiding gluten, go right ahead, but don’t fool yourself into thinking you are getting any health benefits.

GMO (genetically modified organisms) refers to crops, such as soybeans, corn, and cotton, whose genome has been modified in the lab to provide some advantage, such as herbicide resistance, improved nutrition, resistance to insect pests, improved yield, or reduced water needs. When GMO food crops were first introduced in 1996, there was perfectly understandable concern that there might be some health consequences from eating foods made with GMO ingredients. However, since then many studies and a lot of real-world experience has shown these worries to be unfounded. Hundreds of millions of people have eaten an untold number of meals containing GMO ingredients, and there has not been a single documented case of anyone’s health suffering as a result – NOT A SINGLE CASE! As a result of this and other evidence, dozens of scientific organizations have declared GMO food to be as safe as any other food – these organizations include the French Academy of Sciences, the World Health Organization, the European Commission, the Royal Society, and the U.S. National Academy of Sciences.

Yet, opposition to GMO foods on health grounds remains widespread. It’s hard to figure out why, other than the all-too-common human propensity to ignore facts and believe what feels good (or what fits in with their conspiracy theories, such as the hare-brained idea that the above-listed scientific societies are in the pay of Monsanto). The opposition is also fueled by charismatic hucksters such as Vandana Shiva who travel around spreading lies and distortions about GMO food and making up “facts” as it suits them. Unfortunately there seems no end of gullible people ready to swallow this nonsense (for example, GMO foods cause autism, Alzheimer’s, suicide of farmers, cancer, allergies, and so on.). There is no evidence for any of these claims.

This is not to say that there are no legitimate concerns related to GMO crops, such as industrial farming, monoculture, corporate ownership of seeds, and loss of genetic diversity. There is also growing concern over the heavy use of the herbicide Roundup (a GMO crop that is Roundup-resistant allows the herbicide to be sprayed freely to kill weeds). The ingredients in Roundup have been linked to cancer in a recent World Health Organization report, and the product has been banned in many countries, but not the U.S. These are separate issues, however, unrelated to the (nonexistent) health risks of eating GMO food.

Update: While GMO foods seem to present no health dangers, a new report (October 2016) indicates that they are not bringing about the predicted benefits of higher yields and lowered pesticide use. Comparing the US and Canada, where GMO crops are widely used, with western Europe, where they are banned, no yield benefits from GMO crops were seen. Insecticide use in the US/Canada has decreased, but it has decreased even faster in France. And while herbicide use in the US/Canada has shot up, it has decreased in Europe. So, the “great promises” of the GMO revolution have yet to be realized, except perhaps for seed and herbicide manufacturers’ bottom lines.

Many folks have paid for a pressure gauge on their propane tanks in the mistaken belief that it tells you how much propane is left. Me too, I got one before I figured out that it is useless. How come? High school physics class to the rescue!

In the tank, the propane is mostly liquid. At the top of the tank, above the liquid propane, is gaseous propane. When you open the valve, some of the propane gas is released, and some of the liquid vaporizes to maintain what physicists call the vapor pressure – the pressure at which liquid and gaseous propane are in equilibrium. As long as there is some liquid propane in the tank, this pressure remains the same (although it does vary with temperature, being higher when the temperature is warmer). Whether 95% full or 5% full, the pressure is the same. Only when there is no more liquid propane in the tank will the pressure shown on your gauge drop. You can tell how much propane is left by weighing the tank, but that’s a bother. You can also tell by feeling the side of the tank when it is in use (when your grill is on). At some place the tank will be colder below, warmer above. That’s the level of the liquid propane. Bottom line? Keep an extra tank on hand.

Both the terms “stock” and “broth” refer to a flavorful, savory liquid made by simmering ingredients in water for a long time until all of the flavor is extracted, then straining and discarding the solids. Meat is usually part of the recipe, but not always. Some people will insist that the two are different. Stock is made with bones, they say, and broth is not. Broth is for drinking, they claim, and stock is for cooking. It’s true that some cookbook authors make these claims, but they are not consistent–what one famous chef says is stock is another chef’s broth. Let’s face it–who cares? Good stock/broth is essential to many kinds of cooking. Bad stock/broth should be fed to the pigs.

I have met more than one person who claims to be a vegetarian, but happily chows down on fish, scallops, and other seafood. Sorry, this just won’t wash. Fish are animals, and by definition a vegetarian does not eat animals. No, Virginia, a clam is not a vegetable!

Of course there is nothing wrong with eating seafood, it is tasty and healthy. But, it is not vegetarian. If you eat seafood but no other animals, then you are a piscaterian.

Well, it sure looks like a grain and is usually used like a grain, so what’s up? Fact is, quinoa is the seed of a plant in the goosefoot family, which is not a grass—and grains like wheat, rye, and corn are the seeds of grasses. Of course this technicality does not change the fact that it is tasty and nutritious, but it might be useful in a game of trivia!

This seems to make sense, right – I mean, fresh is always better than canned. Or is it? It turns out that canned tomatoes often beat out fresh for making sauce. There are several reasons for this:

• The makers of canned tomatoes can grow multiple varieties with different taste characteristics and blend them for an ideal taste profile in their product.
• The tomatoes are grown for canning near the processing plant, so they can be left on the vine until ideally ripe and at the peak of flavor – no need to account for transport time.
• The tomatoes do not have to be bred to transport well or to look pretty on the shelf in the market. As long as they taste good, they can be delicate and ugly.

This is not to say you can’t make great sauce from fresh tomatoes–of course you can, but only if you have the ideal locally grown and perfectly ripe tomatoes. My point is that you should not dismissed canned tomato products just because they are processed. And, you do not have to buy the super-expensive imported and/or organic varieties. In fact, one of the US’s major brands beat all of those out in a taste test held by a notoriously fussy cooking magazine.

Here’s an interesting Mark Bittman article on this topic:

http://opinionator.blogs.nytimes.com/2013/08/17/not-all-industrial-food-is-evil