The ‘healthy’ foods that aren’t so good for you
Checking ingredients isn’t enough, Professor Robert Lustig argues in a new book. You need to know what has been done to food before you eat it.
Dr Robert Lustig does not intend to put you off shopping for food, but in reality there is a chance that he might. An endocrinologist and professor emeritus at the University of California, San Francisco (UCSF), Lustig is an established anti-sugar crusader whose 90-minute lecture on its health risks — Sugar: The Bitter Truth — has attracted more than 13 million views on YouTube, prompting a generation of consumers to be wary about the sweetness of their food.
In his latest book, Metabolical: The Truth about Processed Food and How it Poisons People and the Planet, a title that is unnerving in itself, he delves deeper into what he claims are the gross wrongdoings of the food industry, calling it to task for overengineering the food we eat to a point where it is damaging our health.
Lustig wants to wean us off food that is in any way different from its natural state — and don’t assume he just means bacon, burgers and ready meals. He also includes anything from ready-made hummus to green smoothies and salad pots to sushi.
“When you go shopping you don’t really know what is in your food, what has been added to it and what has been taken out,” Lustig says. “But we must assume that if a food has a label, then it is a warning label that something has been done to alter it.”
Food is inherently good for us, Lustig says — it is how it has been processed that is usually bad news. “A food label tells you what is in a food, but that is mostly irrelevant — what you really need to know is what’s been done to the food, and no label tells you that. If it’s processed it could have been stripped of its beneficial properties and sprinkled with toxins that stress the liver and gut, hastening our demise.”
Lustig became interested in food manufacturing and its effect on our health 15 years ago when lecturing at UCSF. “I was the master of a three-second lunch and I ate really badly,” he says. “I worked long hours, spent no time preparing food and used to eat out three times a week.” Now, he and his wife eat out “maybe once a month” when restaurants are open and he shops at selected independent purveyors of fresh produce — not expensive and fashionable organic supermarkets, he is keen to point out — and mostly cooks from scratch.
He insists he is not a healthy-eating zealot and simply advocates consuming more “real food”. “The bottom line is that I have discovered processed food diets can kill,” he says. “Normally they kill in the old-fashioned way, slowly by causing chronic disease, but they can also raise the risk of acute illnesses too.”
Making changes need not be expensive nor time consuming. “All you need in order to eat healthily are real foods that protect the liver and feed the gut,” he says. Here are his rules for real eating:
Shop around the edges of a supermarket
“If food is on a shelf in supermarket aisles, it generally means it has been processed. The only real food on the supermarket is fresh produce, meat and fish, and dairy in the refrigerated sections, all of which are always positioned around the edges of the store. That’s where you find the real food. There are nuances and different levels of real food — free-range or barn eggs are nutritionally better than those produced by hens in cages — but if you just stick to the edges of a supermarket you are at a good starting point, Once you start heading down the aisles, you are asking for trouble.”
Reduce all forms of added sweetness
“Don’t think that by choosing natural sugar alternatives such as agave, maple syrup or honey that you are necessarily making a huge step in a healthy direction. Like sucrose, or table sugar, they all contain some fructose and overconsuming it has major effects on the body.
“Firstly, fructose heads straight to the liver with any excess causing overloading in the organ, and the pancreas has to make more insulin, both of which will increase chronic disease and weight gain over time. It also drives up the ageing reaction of the body by producing damaging free radicals seven times faster than normal and it is extremely addictive, stimulating the reward centres of our brain in a way that pure glucose doesn’t.
“The more sugar we get in processed food, the more we want. The easiest way to reduce it is to assume that labelled food contains some fructose and to avoid it where you can. Artificial sweeteners are not a recommended alternative. Even though they contain no calories, the sweetness on the tongue tells the brain that sugar is coming so that insulin is still released, driving up the risk of weight gain and disease, albeit at a lower level. Artificial sweeteners have also been shown to alter our microbiome, causing gut inflammation. They are best avoided too.”
Cut down on added salt
“We all need to cut down on foods with salt added during the manufacturing process, although counterintuitively it is our sugar consumption that is responsible for our bodies’ salt intolerance. Our ancestors packed food in salt to preserve it and everyone who ate fish back then consumed an average 15g of salt a day, which is higher than the amount we eat today [British adults consume about 8.4g of salt a day] and much higher than the upper target set by the UK government of 6g a day.
“However, our ancestors didn’t get high blood pressure and strokes because their kidneys were very adept at getting rid of this extra salt in their diets, unlike our kidneys today. The reason? Our high-sugar diets have resulted in high insulin levels and, when that happens, our kidneys have difficulty excreting salt. It means that studies have shown even intakes of 2.3g of salt a day can be problematic and we all need to cut down.”
Probiotics usually don’t work . . .
“Everybody seems to think they need a probiotic food or supplement to enhance gut health. And while yoghurt and fermented foods like kombucha and kimchi are good for us and will help to maintain an already healthy gut, they are not an instant solution for fixing an unhealthy microbiome.
“In reality, none of them work. These products contain live bacteria and the idea is that, once you swallow them, the bacteria should take up residence in the gut, thrive and multiply. In theory, you should be able to repopulate your intestinal bacteria with a single dose of a probiotic, so why is it that we need to keep on consuming them? The answer is that the gut environment of most people is inhospitable for those bacteria and until they fix that environment by eating more real food, no amount of probiotic supplementation will do any good.”
. . . but prebiotic foods do
“Prebiotics are food for the beneficial microbes in your gut. Most are types of soluble dietary fibre, such as inulin and galacto-oligosaccharides — although not all forms of fibre are prebiotic — and they work by travelling to your lower digestive tract and feeding specific beneficial microbes. They have the capability of transforming your intestinal environment for the better in a short time, but we don’t need to consume them in supplement form. Real food is the best source and good prebiotics include bananas and dates, chicory root, garlic, Jerusalem artichokes and onions, barley, nuts and rye.”
Fibre will transform your gut health
“Most of us don’t get enough fibre. Our ancestors ate up to 100g a day of fibre, and while the recommended daily amount in the UK is only 30g, women consume a daily average of just 17.2g and men 20.1g. If you don’t eat enough fibre you are effectively allowing the bad bacteria in your gut to thrive, resulting in a rising risk of ill health.
“The 100 trillion bacteria in your gut need feeding and fibre fulfils that role, but without it the intestinal bacteria feed on you. They start to chew away at the mucin layer that protects the gut lining so that, eventually, there are holes in the intestinal barrier, causing leaky gut syndrome. If bacteria break through the barrier into the bloodstream, they are carried to the liver, causing inflammation and insulin resistance, both of which are damaging.
“Yet my colleagues at UCSF have shown in trials that you can take a crappy microbiome and turn it into a healthy one in two days by eating more fibre. We should eat more foods that contain it, including wholegrains, nuts and seeds, oats, barley and rye, berries, broccoli and leafy greens. Canned and frozen varieties of fruit and veg are what are termed minimally processed — just avoid any with added sugar.”
Have no more than one drink at a time
“A little alcohol is OK; a lot is not because of the sugar it contains. I enjoy an occasional drink myself, but try to make it as low a sugar choice as possible. Avoid sweet wines and sugary mixers or syrups for cocktails. Pre-packaged drinks such as canned gin and tonics are often the worst offenders in terms of sugar content so steer clear of those. Try to have just one drink or to limit your drinking days to one per week.”
Buy bread from a bakery (or make your own)
“Pre-sliced and supermarket made bread tends to be spiked with sugar, added because sugar is very useful at food engineering levels. Sugar is a browning agent, a preservative and a humectant, meaning it holds on to water molecules so that bread stays fluffier and fresh-looking for longer. Sugar is the reason it has a two-week sell-by date when real bread goes stale after a couple of days. Buy freshly made bread from a bakery or, if you have the time, bake your own.”
Eat more eggs, poultry and fish
“These three are all good to include in your diet. All are a source of tryptophan, the most important of the amino acids because it’s the hardest to come by — you can only get it from your diet. Tryptophan is converted by the brain into serotonin, the neurotransmitter that regulates happiness and sleep, but reduces anxiety and depression. Nuts also contain some, and spinach and soy have a little as well. A supplement will raise blood levels of tryptophan but can also come with side effects, so food is the best bet.
“Real food, in the form of wild fish and free-range eggs, is also the best way to ingest omega-3 fatty acids, which are probably among the healthiest things you can put in your mouth. The two kinds of omega-3 fatty acids — docosahexaenoic and eicosapentaenoic acids — both reduce the inflammatory response in the fat cell and prevent the release of damaging free fatty acids. They also protect the brain. Studies have shown that supplements can help to fix a deficiency, but fresh food is your best option long-term.”
Don’t avoid dairy
“Dairy is the single most misunderstood item in our entire food supply. It was demonised because of its saturated fat content, but that turned out to be utter trash of the highest level. The saturated fat in dairy is very different from the saturated fat in red meat — and even that is not as bad as was thought — and has a structure associated with protection against cardiovascular disease and type 2 diabetes as well as helping to prevent weight gain. Select unadulterated dairy such as plain, live yoghurt and milk. Again, any dairy with added ingredients is not a good choice.”
You can eat red meat occasionally
“In moderation, red meat can be a perfectly acceptable part of your diet as long as it isn’t consumed as something that is altered by manufacturers, processed or added to ready meals. It is now known that the saturated fat in red meat is not all good, but not that bad either.
“Red meat’s association with increased risk of cardiovascular disease is more likely down to its iron content, which possibly promotes oxidative stress and cell damage in the body, and because of the choline it contains. Choline is a neurotransmitter that we need in the diet and it comes from muscle. If you don’t eat red meat, you probably don’t get enough choline.
“Equally, too much choline from a high intake of red meat can be bad. An excess is feasted on by bacteria in the gut to produce trimethylamine [TMA]. Your liver then oxidises TMA to convert it into TMAO, which, as the stickiest substance made by our bodies, clogs the arteries. I eat red meat purchased from a very specific butcher with reliably sourced produce once a week and recommend other meat eaters to do the same.”
Whole fruit is fine (juices and smoothies are not)
“When you consume a piece of whole fresh fruit, you are feeding your gut bacteria and that’s a good thing. Yes, fruit contains exactly the same sugar as you find in Pop-Tarts and cookies, but the natural fibre in fruit acts as a protector.
“There are two types of fruit fibre. Insoluble fibres form a sort of fishnet inside the intestine and the soluble fibre forms little globules that plug the holes in the net and both work together to reduce the rate at which sugar is absorbed by the body. Because of the action of fibre, fruit both protects the liver and feeds the gut.
“It’s a different story with fruit juice. When you squeeze and juice any fruit, you obliterate the insoluble fibre it contains so that it is similar to any sugary drink. There is a sky-high spike in blood sugar, which drives up insulin and, over time, increases the risk of chronic disease. Smoothies that retain the pulp are slightly better than soda, but not by much.”
Metabolical: The Truth about Processed Food and How it Poisons People and the Planet by Dr Robert Lustig is out now
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