Episode 29

Are Vegetables just BS?

Published on: 11th January, 2023

Are Vegetables BS?

If you have ever seen Paul Saldino, his famous line is that Kale is BS. He even sells the shirt. But are they? Saldino isn't the only one who proposes this.

Dr. Gundry, a former heart surgeon, has his own take. Gundry claims modern health problems come from eating lectins. Lectins are compounds found in beans that are natural pesticides.  Thus, Gundry claims lectins harm people. Copying destroys lectins.

Toxins in Vegetables

Plants make compounds to protect them against predators - other plants, pests, and the like. But do they harm humans?

It turns out that some plant defense compounds are beneficial to humans. Take coffee. Yes, coffee - the caffeine is a defense mechanism. Some people will tell you that coffee is bad for you - but they don't get up in the early morning or have kids.

List of the "Toxins"

  • Gluten
  • People who don't have celiac disease or gluten sensitivity do not need gluten-free diets (ref).
  • Oxalates
  • Potassium-rich vegetables such as Brussels sprouts, broccoli, and kale reduce calcium loss and prevent kidney stones from forming. These vegetables are rich in antioxidants that decrease the risk of bladder, prostate, and kidney cancer. Check with your local dietician for a diet based on the type of kidney stone you have. (ref)
  • Caffeine
  • If you don't drink coffee, you will lose all joy in life. (reference is me)
  • Polyphenols
  •  Plant polyphenols have antioxidant, anti-inflammatory, anti-allergic, anti-atherogenic, anti-thrombotic, and anti-mutagenic effects - they are healthy for you (ref)
  • Phytates
  • Consuming a phytate-rich diet, such as a colorful, plant-based diet, the benefits exceed the impacts on mineral absorption. In addition, phytates are anti-oxidants. (ref)
  • Saponins
  • These compounds are among the most well-studied compounds to decrease risk and help treat cardiovascular diseases. (ref)
  • Isothiocyanates
  • Brassica vegetables contain many valuable metabolites that are effective in chemoprevention of cancer (ref)
  • salicylates
  • These anti-inflammatory compounds are the basis of aspirin
  • Phytosterols
  • phytoestrogen-containing foods, such as legumes, grains, seeds, nuts, fruits, and vegetables, are rich sources of vitamins, minerals, fiber, and other health-promoting phytochemicals.
  • Lectins
  • Cooking destroys lectins. Lectin-rich foods, legumes, and whole grains show reduced inflammatory biomarkers in both animals and humans (ref).

What the literature says

What do human trials say about vegetables? They improve health, reduce the risk of heart disease, and reduce the risk of cancer.

Do some of them contain anti-nutrients? Well, some do bind them, but health benefits outweigh any potential harm.

Who to believe?

You can believe a shirtless salesman of supplements and scams. Someone who was trained as a psychiatrist, who goes into a grocery store shirtless and yells at kale - or you can believe science.

Fiber as an essential nutrient


The most abundant solid ingredient in breast milk is a fiber. That fiber is human milk oligosaccharides. These oligosaccharides are a prebiotic that is carbohydrate based. They meet the definition of fiber. This fiber is important to infants, especially neonates.

When people say fiber is non-essential, they are incorrect. Why? Because the definition of an essential nutrient is:

“A nutrient required for normal body function that either cannot be made by the body or cannot be made in amounts adequate for good health and therefore must be provided by the diet”

Fiber is also important in adults.

Every study looking at increasing fiber has shown an improvement in human health. But what does fiber help with?

It's more than a good poo

Fiber will bulk up your stool and make it easier to have bowel movements. This gives you less constipation, fewer hemorrhoids, and less risk of colon diverticular disease.

If your stool is too loose, you need more fiber. If your stool is too hard, you need more fiber and water.

But fiber has other important roles

It Binds Cholesterol

Your body makes cholesterol, and that cholesterol goes through your gut. When you have increased fiber in your gut, some cholesterol gets bound to it. Thus, increasing fiber means less blood cholesterol.

It stabilizes blood sugar

Fiber decreases spikes in blood sugar. Want an example? Take an apple and a doughnut. A doughnut has less sugar than an apple, but a doughnut will spike your blood sugar more than an apple. Why? Part of the reason is the increased fiber in the apple (and fat, a doughnut has 15 grams of fat) – an apple has 3 grams of fiber, a doughnut has 0.9 grams.

It decreases inflammation

Fiber binds to bile acids (ref). When you eat meat and increase meat in your diet, you increase fat. To digest fat, your body increases the production of bile acids, which are released into the gut. Your gut reabsorbs 95%, but about 5% makes it to the colon, where other bacteria encounter them, and then bad things happen.

Bacteria break down these bile acids into pro-inflammatory and pro-carcinogenic compounds. This is in contrast to a plant-based diet with high fiber. Fiber binds to the bile acids allowing them to pass without causing harm to the colon.

When a person consumes fiber, the fiber is used as food by some bacteria. These bacteria metabolize the fiber and excrete short-chain fatty acids.

The Gut Microbiome

Inside your bowels, there are many microorganisms, from bacteria to yeast. What determines which bacteria thrive? There are bad bacteria and bad yeast, and to encourage the growth of the good bacteria, you have to feed them. How do you feed them?

The favorite food of the good bacteria? Fiber.

Bacteria "eat" fiber and produce short-chain fatty acids, which are great because:

They decrease inflammation, improve blood sugar control, and blood lipids.

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About the Podcast

Fork U with Dr. Terry Simpson
Learn more about what you put in your mouth.
Fork U(niversity)
Not everything you put in your mouth is good for you.

There’s a lot of medical information thrown around out there. How are you to know what information you can trust, and what’s just plain old quackery? You can’t rely on your own “google fu”. You can’t count on quality medical advice from Facebook. You need a doctor in your corner.

On each episode of Your Doctor’s Orders, Dr. Terry Simpson will cut through the clutter and noise that always seems to follow the latest medical news. He has the unique perspective of a surgeon who has spent years doing molecular virology research and as a skeptic with academic credentials. He’ll help you develop the critical thinking skills so you can recognize evidence-based medicine, busting myths along the way.

The most common medical myths are often disguised as seemingly harmless “food as medicine”. By offering their own brand of medicine via foods, These hucksters are trying to practice medicine without a license. And though they’ll claim “nutrition is not taught in medical schools”, it turns out that’s a myth too. In fact, there’s an entire medical subspecialty called Culinary Medicine, and Dr. Simpson is certified as a Culinary Medicine Specialist.

Where today's nutritional advice is the realm of hucksters, Dr. Simpson is taking it back to the realm of science.

About your host

Profile picture for Terry Simpson

Terry Simpson

Dr. Terry Simpson received his undergraduate, graduate, and medical degrees from the University of Chicago where he spent several years in the Kovler Viral Oncology laboratories doing genetic engineering. Until he found he liked people more than petri dishes. Dr. Simpson, a weight loss surgeon is an advocate of culinary medicine, he believes teaching people to improve their health through their food and in their kitchen. On the other side of the world, he has been a leading advocate of changing health care to make it more "relationship based," and his efforts awarded his team the Malcolm Baldrige award for healthcare in 2018 and 2011 for the NUKA system of care in Alaska and in 2013 Dr Simpson won the National Indian Health Board Area Impact Award. A frequent contributor to media outlets discussing health related topics and advances in medicine, he is also a proud dad, husband, author, cook, and surgeon “in that order.”