Tag Archives: healthy diet

Dear Dr. Gottlieb, Full Fat Dairy is “Healthy”. Why Are You Pushing Low-Fat Dairy?

By all accounts, Scott Gottlieb, the Trump appointed director of the FDA is doing a good job.

Vox points out, he has announced substantial FDA moves to reduce cigarette consumption and is committed to improving competition in generic drugs.

However, he gave a recent speech at the National Food Policy Conference  on “Reducing the Burden of Chronic Disease” which indicates he is misinformed on crucial aspects of nutritional science.

Gottlieb indicated he wanted the FDA to play a bigger role in guiding Americans to eat a healthier diet to reduce the burden of chronic disease.

To facilitate this he is looking to define what foods are “healthy”:

We’re keeping all these considerations in mind as we pursue rulemaking to update the definition of “healthy” so it’s based on nutrition criteria and food considerations that are more up-to-date than those being used for the current definition….

Once updating the definition, Gottlieb wants to label food as “healthy” In a way that makes it easier for consumers to understand:

To address this, we’ve had discussions about whether there should be a standard icon or symbol for the word “healthy” that everyone could use on food packages.

Gottlieb goes on to bemoan a focus on nutrients rather than foods but in the very  next sentence recommends a food, dairy, in a form that has one important nutrient stripped from it-fat.

Traditionally, we’ve focused primarily on the nutrients contained in food in considering what is healthy. But people eat foods, not nutrients.

This is why we’re asking the important question of whether a modernized definition of “healthy” should go beyond nutrients to better reflect dietary patterns and food groups, like whole grains, low fat dairy, fruits and vegetables and healthy oils?

Obviously, the first step in getting Americans to eat healthier is to make sure you are doling out the correct advise and in his speech Dr. Gottlieb indicates he has bought into  long-standing fundamental errors. I wrote him the following letter hoping to correct these errors.


Dear Dr. Gottlieb,

Congratulations on your recent appointment as FDA director and kudos for your fine work to date. I read your recent comments on developing an updated definition of “healthy” and the importance of  conveying that information to American consumers  I applaud your efforts in this area as well as your ongoing efforts to limit cigarette smoking and improve generic competition.

I am fine with guiding consumers to healthy foods but I beg of you, let this determination of what is healthy be guided by the actual science, not prior dogma.

In your recent speech you indicate that Americans are not consuming enough dairy and you recommend low-fat dairy which implies that you and the FDA believe that scientific studies have demonstrated that dairy fat is unhealthy.

Five years ago I, too , thought dairy fat was unhealthy and recommended my patients avoid butter, full-fat yogurt and cheese. However, when challenged on this belief, I reviewed the scientific literature on dairy fat and cardiovascular disease.

It turns out when objectively analyzed (as I have written about here and here ) there is no scientific evidence that supports the concept that dairy processed to remove dairy fat is healthier than the original unadulterated product.

In fact, evidence suggests full fat dairy reduces central obesity, diabetes, cardiovascular disease and atherosclerosis in general.

As a result of misguided recommendations to avoid dairy fat, it is virtually impossible in most grocery stores to find full fat yogurt or milk. The vast majority of the dairy aisle is devoted to various low or non fat concoctions which have had loads of sugar and chemicals added and are arguably worse than a Snickers bar.

Dr. Gottlieb ,I am not cherry-picking the data here or relying on out of date studies. I’ve reviewed everything I can find on this issue and reviewed it without bias. Evidence continues to accumulate supporting the healthiness of full fat dairy.

For example, here’s a 2018 review from researchers totally unaffiliated with the dairy industry which asks the question “Dairy Fats and Cardiovascular Disease: Do We Really Need to Be Concerned?”

After a exhaustive review they conclude the answer is no.

recent research and meta-analyses have demonstrated the benefits of full-fat dairy consumption, based on higher bioavailability of high-value nutrients and anti-inflammatory properties. … In general, evidence suggests that milk has a neutral effect on cardiovascular outcomes but fermented dairy products, such as yoghurt, kefir and cheese may have a positive or neutral effect.

Flawed Reasons for Low Fat Dairy Recommendations

As I have written previously, I believe there are three reasons for the failure of major nutritional recommendations such as the 2015  Dietary Guidelines For Americans  to correct previously  flawed advice to choose  non or low-fat dairy over full fat:

1. In  few randomized dietary studies showing benefits of a particular diet over another, non fat or low fat dairy was recommended along with a portfolio of other healthy dietary changes.

The overall benefit of the superior diet had nothing to do with lowering the dairy fat but was due to multiple other changes.

2. The dairy industry has no motivation to promote full fat dairy. In fact, they do better financially when they can take the fat out of milk and sell it for other purposes such as butter, cheese, and cream. (Please read my interview with a plastic surgeon dairy farmer on the skim milk scam here.)

3. Saturated fat is still mistakenly being treated as a monolithic nutritional element.  Although dairy fat is mostly saturated, the individual saturated fats vary widely in their effects on atherogenic lipids and atherosclerosis. In addition, the nature of the saturated fat changes depending on the diet of the cow.

4. Since authorities have been making this low fat dairy recommendation for so long they are extremely reluctant to reverse their advice. It lowers their credibility.

There Is No Scientific Consensus On What Constitutes A Healthy Oil

Finallly, Dr. Gottlieb, I would like to briefly point out that there is considerable ongoing scientific debate about what constitutes a “healthy oil.”

I summarized this last year on a post on coconut oil (which I fear you will also pronounce “unhealthy”).

In many respects, the vilification of coconut oil by federal dietary guidelines and the AHA resembles the inappropriate attack on dairy fat and is emblematic of the whole misguided war on dietary fat. In fact, the new AHA advisory  after singling out coconut oil goes on to cherry-pick the data on dairy fat and cardiovascular disease in order to  support their faulty recommendations for choosing low or nonfat dairy.

Canola and corn oil, the products of extensive factory processing techniques, contain mostly mono or polyunsaturated fats which have been deemed “heart-healthy” on the flimsiest of evidence.

The most recent data we have on replacing saturated fat in the diet with polyunsaturated fat comes from the Minnesota Coronary Experiment performed from 1968 to 1973, but published in 2016 in the BMJ.

Data from this study, which substituted liquid corn oil in place of the usual hospital cooking fats, replaced corn oil margarine for butter and added corn oil to numerous food items, showed no overall benefit in reducing mortality. In fact, individuals over age 65 were more likely to die from cardiovascular disease if they got the corn oil diet.

So, Dr. Gottlieb, please continue your efforts to make Americans healthier but make sure the current scientific evidence actually supports your recommendations. Keep in mind, the disastrous public health experiments of previous decades.


Skeptically Yours,

-ACP

N.B. Some of my posts on dairy fat are below.

Dairy Fat Makes You Thinner

The Skim Milk Scam

More Evidence That Diary Fat is associated with a lower risk of heart disease

What happens to cholesterol levels when you switch to low or non fat dairy?

Dietary Guidelines 2015: Why Lift Fat and cholesterol limits but still promote low fat dairy?

In defense of real cheese.


h/t to the always excellent Conscien Health for bringing Gottlieb’s speech to my attention.


Credit for the featured image of dairy cows from the wonderful Trader’s Point Creamery

Low-Fat Versus Low-Carb Diet: DIETFITS Show Both Can Work If They Are “Healthy”

In the ongoing nutritional war between adherents of low-fat and low-carb diets, the skeptical cardiologist has generally weighed in on the side of lower carbs for weight loss and cardiovascular health.

I’ve questioned the vilification of saturated fat and emphasized the dangers of added sugar. I’ve even dabbled in nutritional ketosis.

The science in  nutrition is gradually advancing and the DIETFITS study recently published in JAMA is a welcome addition.

DIETFITS is a  really well done study which provides important insights into three huge questions about optimal diet:

  1. Should we choose a low-fat or a  low-carb diet for  weight loss and cardiovascular health?
  2. Do baseline insulin dynamics predict who will respond to low-fat versus low-carb diet?
  3. Can we predict who will respond to low-fat versus low-carb by genetic testing?

The Details Of DIETFITS

Stanford investigators recruited 609 San Francisco area individuals between the ages of 18 to 50 years with BMI of 28 to 40  and randomized them to a “healthy” low-fat diet or a “healthy” low-carb diet.

During the first 8 weeks of the study, low-fat participants were instructed to reduce fat consumption to <20 gm/ day while the low carb participants were instructed to reduce digestible carbohydrate to <20 gms/day.

Then individuals were allowed to add back fats or carbs back to their diets in increments of 5 to 15 g/d per week until “they reached the lowest level of intake they believed could be maintained indefinitely.”  Importantly no explicit instructions for energy restriction were given.

The “healthy” instructions for both groups were as follows

  1. maximize vegetable intake
  2. minimize intake of added sugar, refined flours and trans-fats
  3. focus on whole foods that are minimally processed, nutrient dense and prepared at home whenever possible

Dietfits Outcomes-Diet And Weight

Major findings

  1. Total energy intake was reduced by 500-600 kcal/d for both groups
  2. The low-fat vs the low-carb intake at 12 months was 48% versus 30% for carbs, 29 vs 43% for fat and 21 vs 23% for protein.
  3. Mean 12 months weight change was -5.3 kg for low-fat vs 6-6.0 kg for low-carb which was not significantly different
  4. There was no difference between groups in body fat percentage or waist circumference
  5. Both diets improved lipid profiles and lowered blood pressure, insulin and glucose levels
  6. LDL (bad cholesterol) declined more in the low-fat group whereas HDL (good cholesterol) increased more and triglycerides declined more in the low-carb group.

Thus both diets were successful for weight loss and both improved risk markers for cardiovascular disease after a year.

DIETFITS- Can Genes and Insulin resistance Predict Best Diet?

Surprisingly, the study found no significant diet-genotype interaction and no diet-insulin secretion interaction with weight loss.

This means that they could not predict (as many believed based on earlier studies) who will benefit from a low carb diet based on either currently available genetic testing or a generally accepted measure of insulin resistance.

As the authors point out, these findings “highlight the importance of conducting large, appropriately powered trials such as DIETFITS for validating early exploratory analyses.”

DIETFITS-Perspectives

As you can imagine this study has led to quite an uproar and backlash from dedicated combatants in the macronutrient wars.

A reasoned summary and response from Andreas Eenfeldt, a low carb proponent can be found on his excellent low carb/keto Diet Doctor site here.

Eenfeldt concludes

If I’m allowed to speculate, the reason that we did not see any major additional benefit from low carb in this study is that the groups ended up so similar when it came to bad carbs. The low-fat group ended up eating fewer carbs too (!) and significantly less sugar, while the low-carb group ended with a somewhat weak low-carb diet, reporting 130 grams of carbs per day.

Eenfeldt emphasizes that low-fat diets never “win” these macronutrient dietary skirmishes:

On the whole, this study adds to the 57 earlier studies (RCTs) comparing low carb and low fat for weight loss.

From a standing of 29 wins for low carb, zero for low fat and 28 draws, we now have 29 wins for low carb and 29 draws. The wins for low fat stay at zero.

Larry Husten at Cardiobrief.org in his analysis of the study quotes a number of experts including Gary Taubes, the low carb pioneering journalist

Taubes speculates “that the weight loss may have been similar not because any diet works if you stick with it and cut calories (one possible interpretation) but because of what these diets had in common — avoid sugar, refined grains, processed foods. Whether the low-carb arm would have done even better had Gardner kept their carbohydrates low is something this study can’t say. (And Ornish [low-fat diet proponent] would probably say the same thing about fat consumption.)”

The low-fat or vegan disciples seem to have had a muted response to this study. I can’t find anything from John McDougal , Dean Ornish, Caldwell Esselstyn or Joel Fuhrman.

Readers feel free to leave comments which  link to relevant analysis from the low-fat proponents.

Dietfits-Perspective Of The Participants

Julia Volluz at Vox wrote a fascinating piece recently which involved interviewing some of the participants in this study.

She points out that although the average DIETFITS participant lost over 10 pounds, “Some people lost more than 60 pounds, and others gained more than 20 during the year.”

LOW_FAT_LOW_CARBS_DIETS1__1_

She obtained permission from the lead author, Christopher Gardner  and interviewed  “Dawn, Denis, Elizabeth*, and Todd — two low-fat dieters and two low-carb dieters — about their experiences of succeeding or faltering in trying to slim down”

LOW_FAT_LOW_CARBS_DIETS1

I highly recommend reading the entire article for details but Volluz concludes

And that leads us to one of the burning mysteries of diets: how to explain why some people fail where others succeed — or the extreme variation in responses. Right now, science doesn’t have compelling answers, but the unifying theme from the four study participants should be instructive: The particulars of their diets — how many carbs or how much fat they were eating — were almost afterthoughts. Instead, it was their jobs, life circumstances, and where they lived that nudged them toward better health or crashing.

DIETFITS-Importance of “Healthy” Diet

Most likely the success of both of these diets is due to the instruction that both groups received on following a “healthy” diet. This guidance is remarkably similar to what I advocate and is something that combatants in the diet wars ranging from paleo to vegan can agree on.

The JAMA paper only provides the description I listed above but Volluz adds that participants were instructed to:

… focus on whole, real foods that were mostly prepared at home when possible, and specifically included as many vegetables as possible, every day … choose lean grass-fed and pasture-raised animal foods as well as sustainable fish ... eliminate, as much as possible, processed food products, including those with added sugars, refined white flour products, or trans-fats … prepare as much of their own food as possible. …

Indeed, if you want to see a very detailed description of the instructional process for participants check out the very detailed description of the methods here.

Yours in Health,

-ACP

N.B. I was searching for a reasoned response to this study from the low fat camp and to my surprise came across this fascinating video featuring the lead author of the study, Christopher Gardner, on (no fat/vegan) John McDougal’s YouTube site. Gardner is clearly on the side of sustainable, local , ethical food consumption but to his credit, his research , publications and comments on DIETFITS don’t reveal this.