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Are Grain Free Diets Healthy? Why I am 75% but not 100% Grain Free

Bowl of oatmeal with blueberries in it

Are grain free diets “healthy,” or do they increase the risk for heart disease?

As we will learn in this post, the answer depends on a number of different factors and is likely to vary greatly from individual to individual.

With that said, let’s announce a principle that will provide a “strategic guidepost” for many of us as we decide whether we want to eat grains.

Insulin sensitivity is often greatest in the morning. 1

Put simply, we do the best job of using the “carb fuel” from foods like oats and sweet potatoes (even toast) in the morning. As the day wears on, the carbs we eat aren’t as rapidly burned for energy and the body tends to store what it can’t use, first as glycogen and then as triglycerides. Elevated serum levels of triglyceride, both immediately after a meal in the “post prandial” period, and over the long haul, increase the risk for heart disease. 2

If blood sugar is the reason you are shying away from grain, the timing of when you eat grain heavy meals could make a difference to your overall state of health.

Common reasons people go grain free

Theories in timing of insulin sensitivity notwithstanding, grain free diets are growing in popularity for both humans and even for dogs.


  1. Weight loss – low carb diets help some people lose weight;
  2. Insulin resistance and type 2 diabetes – some find blood sugar is easier to control when they remove grain, especially processed grains 3 ;
  3. Lectin and autoimmunity – celiac is the big one here, but consistent with Dr. Gundry style protocols, some people find they are sensitive to the proteins in grains, especially wheat and the cereal grains 4 ;
  4. Pesticides – sadly, many popular grain products contain growing levels of toxins such as glyphosate;
  5. Heart health – grain heavy diets can spike triglyceride levels in some people with genetic predispositions. 5

So, the million dollar question – should you go grain free?

Let’s briefly summarize the major positions for and against.

The anti-grain camp

On one side of the aisle you have the Mark Sisson / Dr. Gundry / Dr. Hyman / Dr. Perlmutter camp – for the most part, their position is no grains ever.

To quote Dr. Hyman, head of functional medicine at the Cleveland Clinic:

You don’t have to eat grains to be healthy. In fact, you might be healthier if you didn’t.

Why does Dr, Hyman take this position?

For some people, the proteins in grain can trigger chronic illness, and or raise blood sugar to unhealthy levels triggering insulin resistance, a “metabolic gateway” to type 2 diabetes. 6

The argument here is that it’s not the burger, it’s the bun that is causing Americans to be ill.

It’s true that some of us see our health decline when we eat a high carb diet, especially when lots of processed wheat is on the menu. Celiac and gluten sensitivity are real problems plaguing millions of Americans, some of whom have no idea grains are the culprit behind their nagging health issues.

And despite what more balkanized plant based nutrition camps lead you to believe, some of us see health decline when we eat grains at all. Lectins tend to get all the attention, but sadly, many grain products in America contain nontrivial levels of a carcinogenic pesticide called glyphosate.

But here’s the rub – taking grains entirely out of the diet can be an issue for some of us because of the foods that inevitably replace grains, not necessarily because grains are so healthy in and of themselves.

Just as not all of us can thrive eating grain, not everyone does well on the high fat diets many who eschew grains tend to turn to.

In the Gene Food scoring matrix, the following diets are often implemented grain free or close to grain free:

However, these diets are not all high in saturated fat either.

Those with ApoE4, those who tend to hyper absorb cholesterol, or those who have a genetic predisposition to some degree of familial hypercholesterolemia, may not be able to follow the full monty low carb orthodoxy and maintain optimal health. In other words, to you the reader at home – yes, there is a new paradigm when it comes to dietary cholesterol, and also yes, bacon and eggs every morning might shorten your life.

The pro-grain camp

On the other side of the grain debate sits the Ornish / Gregor / Esselstyn / Kahn camp – whole grains at every meal. Their pro-grain position is tied to large scale epidemiology indicating diets higher in whole grains confer modest reduction in risk for chronic illness when compared to the standard American diet. 7

Eating oats has been shown to lower levels of LDL-C, an important biomarker for cardiovascular risk. 8

Dr. Esselstyn, also of the Cleveland Clinic, takes the exact opposite position on grain from his colleague Dr. Hyman.

For those with robust ability to deal well with dietary carbohydrate (and who actually stick with a diet that is entirely whole grain as opposed to refined grain / flour based), and who are not sensitive to the proteins in cereal grains, this style of eating could and does work.

In the Gene Food scoring matrix, the following diets are often very high in whole grains:

In our case, we slot people into diets that incorporate lots of whole grains when genetics indicate they do a better job with blood sugar clearance. The theory here is that there are people who are genetically predisposed to greater insulin sensitivity throughout the day.

But the grain heavy camp has some challenges.

Dr. Ornish and Esselstyn effectively recommend Vegan diets across the board. But, how many people can stay 100% Vegan (as these doctors suggest) and get adequate calories? A theme seems to be emerging – when you eliminate huge categories of foods from your diet getting adequate calories and nutrients becomes more difficult. It also becomes more likely you will have to overeat other types of foods.

If you’re trying to lose weight, that’s one thing, but if you have are predisposed to being thin, and skew plant based to optimize lipids, you will rapidly shrink to a skeleton (Vegan bodybuilding propaganda notwithstanding) eating nothing but whole food plant based.

In other words, on the insanely strict Esselstyn style diets you will likely be forced to add in some processed carbs to maintain body weight.

In turn, eating processed carbs can increase heart disease risk in some people (usually to the triglyceride side of the lipid fence) just the same as an excess of saturated fat can bump up cholesterol (in those with a genetic predisposition).

The grain middle ground

So what are we to do?

Grain free and high fat is not a long term solution for people who trend towards higher blood pressure and poor lipids on Paleo and Keto style diets.

On the flip side, many people have autoimmune like reactions to cereal grains. 4 Even when they are able to eat grain, a strict Vegan diet ultimately puts them in a state of caloric and nutrient deficiency.

Sounds like quite the nutritional quagmire.

Welcome to the grain middle ground, friends! The place where you avoid grains you’re sensitive to, but eat the ones your body tolerates at the times when it tolerates them best.

Questions to ask about your body and grains

The first question to ask yourself is this: are you one of the people who is sensitive to grains themselves or are you someone who is experiencing blood sugar problems when eating a grain heavy diet? Keep in mind you could have both issues. Also keep in mind that you may have a grain sensitivity now, after say a course of antibiotics, but that sensitivity could lessen as your microbiome repopulates.

When searching for a “hard grain sensitivity,” Celiac or documented gluten sensitivity is an obvious first place to look.

Although it’s far from a proven method, accurate food sensitivity screening is possibly another avenue to explore.

Next, the blood sugar angle. Look at your lab tests. What does fasting insulin, fasting glucose and HbA1c look like?

Important note: Don’t ignore what happens to your blood sugar immediately after eating grain. This “post prandial” period can be more dangerous for inflammatory signaling than longer term metrics like HbA1c. 9 Unfortunately, the only way to truly know what your blood sugar is doing after a grain heavy meal (or after any meal) is to measure blood sugar in real time using a continuous blood glucose monitor.

Next, to the fat side of the coin, when you eat a high fat diet, do you see big upticks in cholesterol markers like LDL-C?

If your blood sugar numbers are out of range (but cholesterol is normal) and you are inflamed, you may be looking at a situation where you can achieve a better state of health by limiting consumption of grain, or exclusively eating grain in morning when you are most insulin sensitive.

It’s fundamentally important to identify as best as possible whether the grain problem is a blood sugar problem (which is an immune system problem by itself) or a more insidious fundamental grain sensitivity. If it is a grain sensitivity, don’t throw the baby out with the bath water. Just because you are sensitive to oats it does not follow that you can’t eat buckwheat or rice.

If you skew towards high cholesterol when you go high fat and low carb, it’s likely you want to hold on to grains as a source of nutrition that won’t threaten lipids from the fat side of the aisle. Especially if there is no autoimmune issue and blood sugar is the challenge, try heating grains, letting them cool overnight and then re-heating in the morning. This will cause the foods to form resistant starch and lower the glycemic response when you eat them the next morning.

Keeping a grain meal in your diet, for example morning oats, can be a nice step towards managing LDL-C even if you plan to eat a lower carb diet the rest of the day.

Why I eat grains in moderation

Maybe you’re like me and have gone grain free in the past only to add back the rice, oats and buckwheat into your diet after finding strict carbohydrate restriction unsustainable.

In my case, I avoid wheat, farro, and other glutenous grains unless I’m offered a piece of birthday cake or want homemade bread at an amazing Italian restaurant.

I have noticed a diet of whole grains all day increases inflammation in my body and causes the emergence of nagging sports injuries.

However, I eat oats or buckwheat almost every morning for breakfast.

Why do I do this?

Because I have learned that the timing of when I eat grains makes a big difference in how I feel. If I eat eggs and avocado every morning, then follow up with two more meaty meals, my blood pressure seems to creep up and when I get my blood drawn cholesterol markers don’t look great (LDL-C around 115 mg/dl). I am extra vigilant with LDL-C as I have a tendency towards slightly elevated Lp(a) and since Lp(a) is cholesterol rich, I try not to go all in on keto type foods.

I am a hyper absorber of sterol at a minimum and likely of cholesterol as well, so a mega-dose of cholesterol won’t play well for me every morning.

However, I have isolated the inflammation caused by eating grain as more of a blood sugar issue than one of an inability to deal with lectin, and I am most insulin sensitive in the morning, so that is when I get a burst of starchy calories. I eat this way more as a replacement for foods I don’t want as a staple, more so than as an endorsement of a grain heavy diet.

Then, with the carbohydrate base in place, I largely avoid portions of grain throughout the rest of the day that will cause spikes in my blood sugar.

When my lipids are at their worst, I actually believe they are more triglyceride rich than they are cholesterol rich, so keeping lower carb for the bulk of my day is the best strategy I have to keep my LDL-P in range.

When I go full on Vegan, I see discordance between my  LDL-C, Triglycerides and my LDL-P.

What I am outlining here is a dietary strategy where I do my best to attack LDL-P from two fronts – I limit pulling on the saturated fat lever to avoid LDL-C over 100 mg / dl AND I also watch the blood sugar level to keep triglycerides on the lower side.

As a California Coastal genotype, a 75% grain free diet where I limit most grain consumption to the mornings seems like the best overall strategy for me.

John O'Connor

John O'Connor is the founder of Gene Food, host of the Gene Food Podcast and a health coach trained at Duke's Integrative Medicine Program. Read his full bio here.

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