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What is the Best Diet for Preventing Alzheimer’s Disease?

nutrition alzheimer's disease

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If you’re looking for the best diet to prevent Alzheimer’s, you should be aware that a variant in the ApoE gene, called ApoE ε4, increases the risk for developing Alzheimer’s Disease considerably.

As such, and because they will likely have different dietary needs, the best diet for preventing Alzheimer’s won’t be the same for all people. In most cases, those carrying one or two copies of ApoE ε4 will have to be more careful about dietary fat intake, emphasizing bursts of good quality omega-3 fats and excluding high saturated fat foods altogether.

By contrast, someone with better heart health genes may get away with a diet that is higher in fats and lower glycemic (lower sugar).

The message of this post is – test, don’t guess. Know your numbers. If you’re on a low fat, high carb diet to “protect your brain,” but you’re walking around with elevated LDL-P and high blood pressure, you’re likely doing it wrong.

Conversely, if you’re a heavy bread and refined carbohydrate plant based eater and have a boat load of triglyceride rich LDL-P and insulin resistance to show for it, you’re not winning either.

In some cases (not all) people tend to get out of balance towards one of two general sides: either the sugar side or the fat side. Sometimes it’s both, but the Tim Russert example (sugar imbalance) is a good one. The famous newsman had a heart attack despite the fact that his LDL-C was low. He had sky high LDL-P, but the particles were triglyceride rich, meaning he was insulin resistant. 1 His body couldn’t efficiently use the carbohydrates he was eating as fuel, so it turned them into fat.

By contrast, someone else might have low, or moderate triglycerides, but sky high LDL-C and LDL-P. These are the people who are often classified as hyper responders. In response to a high fat diet, they make a ton more cholesterol and high LDL-C has been linked to early onset Alzheimer’s, which is the scariest kind.

What dietary changes move the needle?

You pull on the sugar “lever” by cutting out the breads, cereals, pizzas and desserts.

You pull on the fat lever by cutting back on the eggs, vegetable oils, meat, butter, MCT oil, and even avocados in extreme cases.

The best diet for Alzheimer’s takes into account the metabolic predispositions of each individual and crafts a diet aimed at keeping both blood sugar and cholesterol in the sweet spot.

Plant based diets, Alzheimer’s and ApoE ε4

Several strategies have been proposed to help prevent or slow the onset or progression of Alzheimer’s disease. Nutrition is among these widely investigated approaches, with two basic strategies emerging – those that explore the best macronutrient balance (i.e. fats vs. carbs vs. protein) and those that identify micronutrients (supplements) that could be particularly helpful.2 We highlight a few of the supplements with the best data below, but the consensus seems to be that attacking diet over a period of years is probably the best way to leverage nutrition in the fight against Alzheimer’s.

Put another way, there isn’t yet a pill or supplement that we can take to protect the brain from dementia.

Know your cholesterol levels

Usually, those with the ApoE ε4 genotype have hypercholesterolemia (high cholesterol), which in turn can boost the production and accumulation of the toxic amyloid plaques that lead to dementia.3 4 5 6

You may have heard about the “new thinking” on saturated fat – namely that fat in the diet doesn’t cause heart disease and that sugar is the root of all evil. Well, there is some truth to that line of thinking – sugar, and the high triglycerides that come with sweets, are deadly to the health of your brain. 7 However, and especially for those of you with ApoE ε4 variants, a high saturated fat diet can be just as problematic. This is the case because ApoE ε4 carriers are more likely to have an inflammatory reaction to high fat diets. When ApoE ε4 carriers eat foods like fatty beef, eggs and cheese, their bodies make more cholesterol and their LDL-P count tends to rise. These changes in blood lipids contribute to poor cardiovascular health that over time can contribute to dementia.

Note: not everyone has this response, but if you are someone who sees elevated lipids when you eat a high fat diet, a whole foods plant based diet is probably the right path for you.

If you inherited the ApoE ε4 genotype, you should take special care to follow a heart healthy diet avoiding saturated fats and other foods that promote major upticks in LDL-C, as changes in the LDL:HDL ratio are associated with increased ApoE expression in the brain.8

In fact, many of the plant based diets in our nutrition plan scoring system, such as Villager, Okinawan, Wayoan, and Vegetarian are often scored that way, in part, because of an ApoE ε4 marker.

In practical terms, this means eating Vegan at least 3-4 days a week and completely avoiding butter, ice cream, fatty meats and supplements like MCT oil.

Note, that MCT oil has actually shown promise in some studies for treating dementia (once it has already set in), but like fish oil, doesn’t appear to help ApoE ε4 carriers. Again, the plant based diet for staving off Alzheimer’s is predicated on status as someone who sees a major uptick in lipid markers when eating a high fat diet. If you can take MCT oil and maintain an LDL-P count of around 1,000 or below, you may be better suited to a diet higher in some healthy fats.

Researchers suggest that avoiding excess saturated fat and taking in enough Omega 3 PUFAS may decrease the risk or postpone the onset of dementia for this group.9 10

So, the lesson here is if you have high LDL and cholesterol, a diet that emphasizes whole plant based foods with the addition of some wild salmon or good quality cod liver oil is the best diet for Alzheimer’s prevention, especially if you have ApoE ε4. Please do note that a plant based diet does not mean eating refined grains! Flour based foods that spike blood sugar are just as deadly to brain health as are cheese and red meat for the ApoE ε4 group.

Insulin resistance and dementia

There is evidence that insulin resistance, characterized by an inability to use blood sugar effectively, leaving large amounts of glucose circulating in the blood, contributes to dementia. 11

Plant based doctors say eating meat and fat causes insulin resistance, and in some cases, it might. But we also have vegetarian populations that develop dementia. 12 Note: this is not to say that a perfectly constructed whole foods plant based diet is going to result in type 2 diabetes, or insulin resistance. However, I bring it up because sugar and low quality carbs can cause things to go downhill just as fast as eating fats your body doesn’t deal well with.

But let’s ask this question: is Alzheimer’s disease one disease? Likely, no, which means it also doesn’t have one dietary cause. It’s probably very bad advice for those with a family history of high cholesterol and elevated lipids to charge ahead on a high fat diet because a blog said it was the best course (as many low carb blogs do). Our view is that you most certainly should NOT ignore elevated lipids or be casual with the idea that there is a vascular component to dementia.

Having said that, most of us do not have ApoE4. Some skew towards elevated triglycerides and blood sugar more so than elevated cholesterol. In our diet matrix, the Forager or Paleo Plus diet types may be more in this range. In these folks, a diet that is lower in carbohydrate, as suggested by books like Dr. Perlmutter’s Grain Brain could be the best diet, however, this is only the case if you can eat this way and keep lipids and blood pressure in range. It’s hard not to acknowledge the fact that different people respond differently to different diets, but attacking the value of established biomarkers, such as LDL-P, is not where we would put our money in the fight against Alzheimer’s. Put simply, some trend towards elevated insulin and triglycerides. These people are said to be insulin resistant and may do better with a lower carbohydrate approach. Others trend towards high cholesterol and elevated LDL-C. These are the groups who often do better being very strict with dietary fats.

Mediterranean diet and Alzheimer’s prevention

And while ApoE ε4 carriers should avoid the Bulletproof diet, and other diets high in saturated fat, it is important to keep in mind that avoiding saturated fat does not necessarily mean cutting out all fat.

Publicly funded research by the NIH has shown that a group following a Mediterranean diet had a slower build up of the amyloid plaques that cause Alzheimer’s than did a group eating a standard Western diet high in refined sugar, red meat, and saturated fat.13

The Mediterranean diet is essentially a plant based diet plus a few servings a week of fish, and occasional goat or sheep cheese and small servings of high quality lean poultry.

We have a library of Mediterranean recipes for our readers to peruse.

However, not everyone agrees that ApoE ε4 carriers should eat poultry. Dr. David Gundry, author of The Plant Paradox, recommends that ApoE ε4 carriers remove poultry entirely from their diets.14

This balanced approach to regulating cholesterol levels may explain why the traditional Mediterranean diet is associated with a reduced incidence of Alzheimer’s disease (as well as several other disorders).15 16 For example, in another small study, patients with Alzheimer’s following a Mediterranean diet improved survival almost 5 times compared to those on a normal Western diet. 17

But once again, due to a lack of understanding about the exact causes of Alzheimer’s we can’t home in on exactly why this diet is beneficial.

Foods rich in flavonoids and polyphenolic compounds — like fruits, vegetables, red wine, and tea — are also thought to have a protective role due to their antioxidant and anti-inflammatory activity. Vitamins from the B family and vitamin D will exert a benefit, too. 18

However, it is important to note that these recommendations seem to address Alzheimer’s prevention broadly. Dietary interventions can be more difficult for ApoE ε4 carriers. 19

What about ketogenic diets?

We’ve established that high saturated fat diets are not a great idea for those with ApoE ε4. But for a more detailed break down, take a look at Aaron’s post specifically on the topic of whether ketogenic diets can prevent Alzheimer’s.

Does Vitamin E slow Alzheimer’s progression?

Increased oxidative stress is said to be a risk factor for Alzheimer’s disease, which has led researchers to look at antioxidants, like Vitamin E in the treatment of Alzheimer’s, but not necessarily prevention. After promise in mouse models, some trials have looked at high dose Vitamin E for Alzheimer’s patients, however, the results have been mixed.  Having said that, it appears the pro Vitamin E camp may be winning out. The Alzheimer’s Disease Cooperative Study Group (ADCS) supports the use of high dose Vitamin E with Vitamin C for the treatment of the disease. This recommendation is based on this large clinical trial. To quote the study:

Over the mean (SD) follow-up of 2.27 (1.22) years, participants receiving alpha tocopherol had slower decline than those receiving placebo as measured by the ADCS-ADL. The change translates into a delay in clinical progression of 19% per year compared with placebo (approximately 6.2 months over the follow-up period). Caregiver time increased least in the alpha tocopherol group.

Can fish oil help with ApoE ε4?

You may have read about some clinical trials that show the omega 3 fatty acids found in fish oil demonstrate promise for easing dementia symptoms. This is true.

Interestingly, there is some speculation in the literature that the rise of Alzheimer’s has mirrored the corresponding increase in omega 6 ratios to omega 3 ratios. However, no benefit was found in ApoE ε4 carriers who took fish oil supplements. 20 ApoE4 carriers seemed to do best with eating wild fish, but Dr. Rhonda Patrick’s recent paper sheds some light on the best omega-3 strategy for ApoE4 carriers. Her position is that getting fish oil in phospholipid form, which means krill oil, is the key for ApoE4 carriers. 20

Nutrients to support APOE4

NutrientMechanismStudy
NADImproves DNA repair in the brain(R)
CurcuminReduces beta amyloid plaques(R)
Grape seed extractIncreases NAD production(R)
NiacinNiacin deficiency linked to dementia, supports LDL:HDL ratio(R)

Final thoughts

Early onset Alzheimer’s has a strong genetic risk element, with many individuals already aware of the elevated risk.

Although it is just that, an elevated risk, not a diagnosis, it is understandable that those with ApoE4 especially will want to make lifestyle changes to protect against disease development, or severity.

Unfortunately given our relatively poor understanding of what triggers Alzheimer’s disease onset, none of us can say for sure what the best Alzheimer’s disease prevention regimen is for any one individual.

Be very wary of any healthy guru, MD or otherwise, selling a one size fits all diet for brain health. If there is one thing the science in this field has taught us, it’s that there is no one size fits all for Alzheimer’s prevention.

If it was my family or a friend asking my advice, I would suggest working with a doctor that administers Boston Heart Diagnostics panels and tailoring diet to get, and to keep, as many markers as possible in the green on those tests. Especially, homocysteine, LDL-P, cRP, and insulin.

Good luck!

John O'Connor

John O'Connor is the founder of Gene Food. Read his full bio here.

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