We all know that what we eat affects how we feel. Who hasn’t enjoyed the uplifting effect of a chocolate bar, the feeling of contentment after eating Thanksgiving dinner, or the quick (but short-lived) pick-up of a cup of coffee?
And scientific research has proven that we are right: what, when and how – and how much – we eat and drink affects not only our weight, gut microbiome, hormones, blood sugar levels, blood fat distribution, and energy levels, but also our brain neurotransmitters, emotions, blood flow, and even our thinking processes and our mood.
Sugar works Like an antidepressant drug
For example, eating a high-carb breakfast, like your typical breakfast cereal, makes you feel happier and more alert right away. This is the effect of sugar. Simple carbs increase sugar and also serotonin levels in the brain, making you feel good. It’s like popping an antidepressant pill.
The downside of this is that high-sugar foods like this typical breakfast cereal lead to only a short-lived sugar (and serotonin) peak in the body, followed by a strong insulin response. (Insulin brings the sugar into the cells so they can use it for immediate energy needs; or for storage, meaning fat.)
The strong insulin response then leads to a crash – the blood sugar levels go below normal, which in turn makes you feel a craving for sweets.
At the same time your serotonin “high” wears off and you may feel moody, weak, irritable, and even sad and tired. This hormone roller-coaster can lead to an addictive and increasing cycle of cravings for sweets that in the long run leads to insulin resistance (also known as metabolic syndrome). This Type 2 diabetes damages blood vessels in the eyes, kidneys and – yes – the brain. (Some researchers call Alzheimer’s dementia Type 3 diabetes.)
You may also suffer from inflammation and brain fog and have trouble focusing or paying attention for long anymore.
Other factors like stress, thought patterns and environmental toxins, dehydration, food additives, and many others also influence your brain and how you feel.
What does brain health have to do with food?
Overall, the brain, which weighs about 3lbs (1,250g) in an adult and about 2% of our body weight, needs as much as 25% of our total oxygen, nutrients, and energy to function well. It is one of the most energy-and nutrient-hungry organs in our body, with thousands of mitochondria (energy generators) in each cell that use the oxygen and nutrients to produce the energy our brain needs to think, feel, and act.
Our brain needs these three things to work well:
- Blood flow: to get the oxygen and nutrient to the cells
- Oxygen: to fuel energy consumption
- Nutrients: the right foods and drinks in the right balance
Everything that negatively affects any of these 3 points will affect brain function: our thoughts, emotions, feelings, mood, concentration, focus, attention, and ability to plan, judge, and take purposeful action. This will hurt our ability to be successful in life.
Malnutrition results in the brain redirecting all its energy sources towards the basic life-supporting systems like fight or flight, heartbeat, and breathing.
This results in reduced activities, changes in hormone levels, decreased immune system efficiency, and reduced transport of nutrients and oxygen to the brain. All these factors influence mental health, either directly or indirectly.
Could overweight people be malnourished?
Even people who are overweight or even obese can be malnourished, as many popular foods like candy, cakes, and chips contain mostly “empty” calories. They even “steal” basic nutrients, vitamins, and minerals that the body pulls from other areas to help break them down.
People with this kind of “empty” nutrition are more likely to become sad, depressed, and anxious. It works the other way too: when you don’t feel well, you are more likely to crave junk foods.
On a more positive note, studies have shown that eating more vegetables and fruit (up to 8 servings per day) has a linear correlation with your mood. You just feel better.
That means, if you eat 2 servings of vegetables and fruit a day, you feel twice as happy as if you only have one or no servings, and if you eat 4 servings you feel 4 times as happy as if you eat 2 servings, and so on. And this effect can be felt within 24 hours! Try it!
The nutrient content of food influences brain health. Let’s look at another example: protein. Neurotransmitters are made of amino acids, the building blocks of all proteins. We often lack amino acids because of bad protein digestion and absorption in the gut, or insufficient intake of protein.
If you don’t eat enough protein or you can’t break it down properly, your gut and brain can’t make enough neurotransmitters like serotonin, and you may experience low mood, anxiety, and even aggression.
A third example: fat. Our mood and brain health are also associated with eating enough of the right fats. The dry mass of our brain consists of 60% fat, and the right balance of saturated, unsaturated, and polyunsaturated fats (like omega 3 and omega 6-fatty acids) is crucial for mitochondrial and general brain function.
Studies have shown that lack of omega-3 fatty acids, a certain type of fat found mostly in certain fish and krill (and to a lesser extent in marine algae), can lead to decreased stress resistance and symptoms of many mental illnesses like depression, anxiety, or even bipolar disorder.
Directly or indirectly, nutrition – and the physical functioning of your brain – has a major effect on mental health. What you eat and drink impacts directly how you feel, think, and act.
About the Author
Dr. Christine Sauer is a retired physician and naturopath as well as a Certified Brain and Mental Health Professional on the Teaching Team of Dr. Daniel Amen,MD, as well as a Licensed Neuroencoding Specialist (Dr. Joseph McClendon III) and a “Mental Health Survivor.” As a mental health coach and educator, she helps people to live better and longer and to overcome depression and anxiety by using cutting-edge neuroscience and the Brain Power System.