Fueling the Alzheimer’s brain with fat

Implementing KDRAFT: Research team dishes the skinny on fats

The KDRAFT study diet is surprisingly flexible despite its strict ratio of fat to protein and carbohydrate, according to the University of Kansas research team that implemented it. It only took a few counseling sessions to get most study participants enthusiastically embracing the new eating plan, even one so radically different from the way they were accustomed to eating.

“We focused mainly on the macronutrient makeup,” said Matthew Taylor, PhD, who supervised the diet study on a day-to-day basis. Instead of distributing a rigid diet plan, with prespecified meals and snacks, “We talked more in general about foods they could have and foods they couldn’t have.”

“When people think ‘ketogenic,’ they think bacon, eggs, oil, butter and cream, and may have an automatic negative connotation that this is unhealthy eating,” Dr. Taylor said in an interview. “But yes, eggs were in there and, because a lot of people really like bacon, there was bacon, too!”

The educational sessions did include teaching about healthy and unhealthy fats, and Dr. Taylor “tried to steer people toward the healthier ones, like olive oil, avocados, and nuts. But I didn’t say, ‘Eat this one and not that one.’ If it took melting butter on vegetables to get to that fat ratio, I was not as concerned about where the fat came from as about getting there and maintaining ketosis.”

KDRAFT also had a twist that’s becoming more common among ketogenic eating plans: lots of vegetables. Dr. Taylor asked participants to concentrate on nonstarchy vegetables and forgo potatoes, corn, beans, and lima beans, although some people did enjoy peas occasionally.

“We used to be think we had to restrict vegetables or people would go out of ketosis more easily. But that doesn’t seem to be true. We focused a lot on eating vegetables, and everyone increased their vegetable intake dramatically. We actually tried to use vegetables as a vehicle for fat. For example, people would roast Brussels sprouts or broccoli in olive oil and then put melted butter on it. It was pretty much, ‘Eat all the vegetables you can and put fat on them.’”

Fruits are full of sugar, so they are not liberally used in most ketogenic diets, but KDRAFT did allow one type: berries, and blueberries in particular. “We had people eating a couple of small handfuls of berries throughout the day and still being able to maintain ketosis. We did severely cut back on the amount and type of fruit people could have, but berries seemed to work well.”

Whipping cream had a place, too. “It fit really well in the diet, because it’s basically all fat,” Dr. Taylor said. “It’s used more often in pediatric ketogenic diets as a milk substitute. One thing our subjects liked to do was use it to make a sweet snack. All it takes is a packet of [stevia] sweetener and some vanilla. Then you whip and freeze it and it’s like an ice cream dessert.”

After the initial drop-outs, the remaining study pairs embraced the intervention enthusiastically.

“When the study partner took the diet on too, we had our best success. One of our last pairs had an entire family join in – children, grandchildren, everyone decided to follow the diet. That is a very helpful piece to this. It’s difficult to always say, ‘Here’s our normal food and here’s the keto food over here.’”

The dropouts occurred very early. These study pairs, all of whom included patients with moderate Alzheimer’s, never embraced the plan at all, and this is a telling point, Dr. Taylor noted.

“When you get to a level of dementia there are so many other things in the caregiving process that taking on big behavioral changes is very difficult.”

Although the study showed that the diet wasn’t practical for sicker patients at home, it still might be beneficial in other settings, said Debra Sullivan, PhD, RD. Dr. Sullivan chairs the department of dietetics and nutrition at the University of Kansas Medical Center and holds the Midwest Dairy Council Endowed Professorship in Clinical Nutrition.

“I think that we might be able to create a version of the diet that could be used in an institutional setting for our more advanced patients,” she said. “But there’s no denying that this can be challenging. It’s a big change from the way the typical American eats.”

None of the KDRAFT participants experienced any lipid changes, for either better or worse. The 3-month intervention was long enough to have picked up such changes if they were in the offing, said principal investigator Russell Swerdlow, MD. While there are mixed data on ketogenic diets’ atherogenic effects, many people respond positively, with improved cholesterol.

“Much of what it comes down to is, are you in a catabolic or anabolic states? Are you building up or tearing down? Excessive cholesterol is a sign of being overfed and laying down energy supplies. You take in carbon and turn it into cholesterol. But if you can trick your body into a catabolic state – essentially make it think it’s starving, which a ketogenic diet does – then you have consistently low insulin levels, and you don’t turn on the cholesterol synthesis pathway. You may increase your cholesterol intake through diet, but you’re not synthesizing it in your body, and that synthesis is what really drives your cholesterol level. If you’re not overeating, your body’s production goes down.”