The Best Nutrition for Cognitive Function

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Takeaways

• Prevalence of Chronic Diseases: A significant majority of Americans are either suffering from chronic diseases or are at risk of developing them. Poor diet is a major contributor to chronic conditions, including Alzheimer’s disease and dementia.

• Healthcare Costs: The healthcare costs associated with treating chronic diseases affect the entire population. Chronic diseases are a leading cause of death and disability in the U.S., and they contribute significantly to healthcare expenses.

• Holistic Approach: Dr. Hyman recognizes that addressing chronic diseases requires a holistic approach beyond medical treatment, involving changes in diet, lifestyle, and food policies.

America and Chronic Diseases

The majority of Americans today suffer from chronic diseases or are at risk for getting one. Poor diet is a significant risk factor in chronic diseases, including Alzheimer’s disease and dementia.

The cost of healthcare for Americans with chronic diseases affects everyone. Consider the following staggering statistics:

• Six out of 10 Americans live with at least one chronic disease, such as heart disease and stroke, cancer, or diabetes.
• Chronic diseases are the leading causes of death and disability in the U.S.
• Chronic diseases are a leading driver of healthcare costs.
• 88 million Americans are at risk for Type 2 diabetes.
• Only 12% of Americans are metabolically healthy, which is defined as having optimal levels of blood glucose, triglycerides, high-density lipoprotein cholesterol, blood pressure, and waist circumference, without the need for medications.
• By 2024, $1 out of every $5 in the U.S. is expected to be spent on healthcare.

The more Dr. Hyman saw anecdotal evidence of poor health related to patients’ unhealthy habits, the more committed he became to helping patients make meaningful changes. “I realized I couldn’t cure diabetes in the office,” he says.

Instead, Dr. Hyman thought chronic disease would be cured on the farm, in the grocery, in restaurants, in the kitchen, and in the workplace.

“I could not fix my patients if I didn’t deal with the upstream causes,” says Dr. Hyman.

It didn’t take long for Dr. Hyman to realize that food policies and the food industry directly affect what Americans eat.

He started a nonprofit, [The Food Fix Campaign](https://www.foodfix.org/), for grassroots change and an advocacy group to advance policy changes.

One example of Dr. Hyman’s recent lobbying activities includes pushing for medical schools to build nutrition education and chronic disease into the curriculum. “It’s the single biggest cause of chronic disease and the single biggest cure. Yet doctors know nothing about it,” he says.

Dr. Hyman adds that the food system is among the biggest causes of climate change. “All these are interconnected problems, and we have to think of them as one whole problem.”

Diet can improve overall health, including brain health

Dr. Hyman is making strides with his approach to diet in the medical exam room as well.

Since starting to consider nutrition as a key way to support patient health, Dr. Hyman has seen hundreds of patients improve and heal after making dietary changes, including in brain health.

One patient who comes to mind for Dr. Hyman is a woman in her early 80s, who had been a successful business-woman and on the board of major companies. She was diagnosed with mild cognitive impairment (MCI) and told to get her affairs in order.

Instead, she found Dr. Hyman who says he “looked what’s under the hood.” She had severe vitamin B12 deficiency, which is not uncommon in seniors because of low stomach acid and diet. She also had problems with methylation and other B vitamins, which affect cognitive function. Dr. Hyman prescribed B12 shots and B vitamins that help with methylation, such as folate and B6.

In spite of her previous diagnosis of mild cognitive impairment, Dr. Hyman says, “She was back to normal.”

He heard from her five years later when she called to see what she should bring with her trekking in Bhutan.

Other patients’ cases aren’t as simple, says Dr. Hyman, but this is why he finds functional medicine so helpful in addressing a collection of issues. “If you have 36 holes in your roof and you plug up five of them, it’s still going to rain in your house. You have to find all the holes and plug them all,” says Dr. Hyman.

For everyone, though, Dr. Hyman has one effective antidote: improving diet.

“If there was a single thing I would recommend, it would be to really dramatically reduce or even eliminate refined sugar and refined carbohydrates,” says Dr. Hyman. “Those are the things that are driving so much of the problem.”

How diet affects brain health and the body

Americans consume about 152 pounds of sugar and about 133 pounds of flour per person per year. Dr. Hyman says just as we think of the overuse of alcohol as a health risk, similarly, the biggest cause of liver damage in America is sugar and starch. Fatty liver affects 90-100 million Americans, making it the nation’s most common chronic liver condition.

Chronic disease, like diabetes, is a risk factor for Alzheimer’s disease and dementia. The variant of the “Alzheimer’s gene,” APOE4, seems to interfere with brain cells’ ability to use insulin. This may eventually cause the cells to starve and die. Alzheimer’s disease is unofficially considered Type 3 diabetes because of its insulin resistance in the brain.

After reading this research along with anecdotal evidence in his office, Dr. Hyman considers overconsumption of sugar and flour as “dangerous” in the same way alcohol can be dangerous. “I think of them as recreational drugs,” he says.

The idea that refined sugar and flour are culpable for so many Americans’ ailments is contrary to the past when nutrition recommendations were based on thinking that high cholesterol was caused by eating too much fat. Instead, Dr. Hyman states that what causes the liver to manufacture cholesterol is starch and sugar. This causes high triglycerides, low HDL, small LDL particles, and mini LDL particles. Those are what we call atherogenic dyslipidemia. “The kind of cholesterol that causes heart disease and hardening of the arteries in your heart, can also affect your brain.”

A lot of dementia cases can be caused by the [hardening of the arteries in the brain](https://www.hopkinsmedicine.org/health/conditions-and-diseases/dementia/vascular-dementia), which occur through similar mechanisms as the hardening of arteries in the heart.

Healthy fats are good for brain health

Fats, which were thought to be all bad in the 1980s, can actually be good for the heart and brain when it comes to certain healthy fats. The brain is predominantly made of fat, which makes the right fats fundamental to brain health.

However, most processed foods lack healthy fats and protein. This keeps people eating addictive sugar and starch without ever feeling full. This is great for processed food companies but detrimental to health.

Dr. David Ludwig, a professor of pediatrics at Harvard Medical School and of nutrition at the School of Public Health, specializes in endocrinology and obesity, and he [studied](https://www.harvardmagazine.com/2016/05/are-all-calories-equal) how two diets with identical calorie intake can have different outcomes by swapping out the fat and carbohydrates. Those who ate high-fat, low-carbohydrate diets, had a higher metabolism and burnt 325 more calories per day when compared to low-fat, high-carbohydrate diets.

Healthy fats that support brain health include the following:

– Avocados
– Whole eggs
– Fatty fish like salmon, trout, mackerel, sardines, and herring
– Nuts
– Chia seeds
– Olive oil

The foundation of functional medicine is understanding that food is information, not just calories. Food intake is like a code that can affect every system of the body, says Dr. Hyman, including:

– Immune system
– Microbiome
– Hormones
– Detoxification system
– Mitochondrial function
– Structural system
– Blood-brain barrier
– And more

The diet that Dr. Hyman promotes for optimal health is the “pegan diet,” which he created. The goal, he says, is to lower blood sugar and inflammation in the body to reduce the risk of certain chronic conditions like [Type 2 diabetes](https://my.clevelandclinic.org/health/diseases/21501-type-2-diabetes), heart disease, and cognitive decline.

Unlike the paleo diet, which includes many animal products, the pegan diet offers the following benefits:

– It’s environmentally friendly because it focuses on plant-based and sustainable foods.
– It focuses on nutrient-rich foods and minimizes or avoids unhealthy choices.

A person who eats pegan would eat a diet that looks like the following

– 75% plants, including fruits, vegetables, nuts and seeds.
– 25% meat, poultry, eggs, and fish (preferably grass-fed, organic or sustainably raised options).

Dr. Hyman says the pegan diet emphasizes three principles that support overall health and healthy brain function:

1. Quality of foods: “Most of the stuff we eat is not food. It’s highly processed ingredients that are pretty far from what they looked like when they came off a farm.”
2. Food as medicine: “It is literally, coded instructions that are programming your biology with every bite.”
3. Personalization to each person’s needs and taste

Improving the health of patients and all Americans doesn’t have to be so hard, says Dr. Hyman. It’s about understanding the imbalances in the body, and correcting those imbalances by taking out the bad stuff and putting in the good stuff. “The body can recover. It’s really remarkable.”

Dr. Mark Hyman is a practicing family physician and an internationally recognized leader, speaker, educator, and advocate in the field of functional medicine. He’s the founder and director of the UltraWellness Center, the head of strategy and innovation of the Cleveland Clinic Center for Functional Medicine, and a 14-time New York Times bestselling author and board president for clinical affairs for the Institute for Functional Medicine. He’s also the host of one of the leading health podcasts, “The Doctor’s Pharmacy.“