Can Food Affect Your Mood?

Written by Dr. Steve Chaney on . Posted in current health articles, Food and Health, Healthy Lifestyle, Healthy Living

An Apple A Day Keeps The Blues Away

Author: Dr. Stephen Chaney

 

Can food affect your mood? In rural North Carolina you still occasionally see bumper stickers that say “Life Happens”. Of course, the word they use isn’t exactly “Life”, but you get the point.

can food affect your moodWe can’t always control what happens to us. What is important is how we react when bad things happen to us. Do we brush them off and move on, or do we let them get us down? There is no shortage of experts telling us how we can keep the blues away. We are told to count our blessings, meditate, think happy thoughts, develop support groups – the list goes on and on.

But is there perhaps one important parameter that most of these experts are missing? Could the foods we eat make us blue?

The standard American diet (S.A.D.) is high in processed foods, fat (especially saturated and trans fats), refined grains, simple sugars, salt and calories. As I’ve said before, almost anything would be better.

You probably already know that the S.A.D. leads to obesity and a whole host of diseases – including heart disease, cancer and diabetes – just to name a few. But did you know that the S.A.D. could make you sad? That’s what two recent studies suggest.

Can Foods Affect Your Mood? Does Junk Food Make You Sad?

The first study by Akbaralay et al (British Journal of Psychiatry, 195: 408-413, 2009) looked at the dietary patterns and mental health outcomes of 3486 participants in the Whitehall II Prospective Study.

In case you didn’t know it, Whitehall is the central district in London where most of the British government offices are located. So the 3486 participants in this study were bureaucrats. They were middle aged (average age 55.6 years old) office staff (74% men, 26% women) who spent most of their day sitting and really didn’t like their jobs very much. (I made up the part about not liking their jobs. It is hard to imagine that kind of job would be deeply fulfilling, but I’m sure that some of the bureaucrats liked their jobs better than others – which is the whole point of this study.)

At the beginning of the study the participants were given a 127 item food frequency quiz to fill out. Interestingly enough, the food preferences of the participants in this study clustered neatly into two groups.

The diets of the processed foods groups predominantly consisted of sweetened desserts, chocolates, fried foods, processed meats, refined grains and high fat dairy products. In short the diet of this group was pretty similar to what we think of as the Standard American Diet (S.A.D.). In contrast, the diets of the whole foods group consisted mostly of vegetables, fruits, fish and whole grains.

Five years later the study participants were analyzed for depression using a 20 item standardized depression scale.

The results were pretty eye-catching. The processed food group was 58% more likely to suffer from depression than the whole food group! And this was after correction for age, gender, weight, marital status, education, employment grade, physical activity, smoking and diseases (high blood pressure, heart disease, diabetes, and stroke).

The reasons for this astounding correlation between diet and depression are not clear. Can food affect your mood? Does this give us more insight?

The authors speculated that the diets of the whole food group were likely higher in antioxidants, folic acid and omega-3 fatty acids than the diets of the processed food group – and studies have suggested that each of these nutrients may protect against depression.

The authors also suggested that it might be an indirect effect. Diets that are high in saturated fats and refined grains and low in omega-3 fatty acids increase inflammation, and studies have suggested that inflammation can lead to depression.

Can Food Affect Your Mood? Does Healthy Food Make You Glad?

an apple for healthy fruitThe previous study suggested that junk food may make you sad. So you might be asking: “Does that mean that healthy foods can make you glad?” According to one recent study (Br J Health Psychol, Jan 24, 2013, doi: 10.1111/bjhp.12021) the answer may be yes.

A team from the University of Otago in New Zealand enrolled 281 young adults (average age = 20) in a study that looked at the effect of diet on their mood. Each day for 21 consecutive days they recorded their mood and what foods they ate using an online questionnaire. In particular, they reported the number of servings of fresh fruit and vegetables and of several unhealthy foods such as biscuits or cookies, potato chips or French fries and cakes or muffins.

The investigators correlated the foods eaten with the moods reported by the participants on the same day, and again on the day after those foods were eaten. Once again, the results were pretty impressive.

On the days when people ate more fruits and vegetables they reported feeling calmer, happier and more energetic than they did on other days (p = .002 – anything less than .05 is considered a statistically significant difference). And the good effects of fruit and vegetable consumption carried over to the next day as well (p < .001).

Can food affect your mood? While I paraphrased the “apple a day” quote to introduce this study, one apple won’t quite do it. According to this study it takes about 7-8 servings of fruits and vegetables to positively affect mood. In addition, it probably wasn’t just the fruits and vegetables that made the difference. Based on the previous study I would guess that the participants in the study may have eaten other healthy foods such as whole grains and fish on their good days.

Can Food Affect Your Mood?

Taken together these two studies suggest that the next time you feel a little blue you may want to look at your diet. You may want to include a healthier diet along with the meditation and positive thinking.

Of course, these studies both measured correlations between diet and mood, and any good scientist will tell you that correlations do not prove cause and effect. It could be that when people are “down in the dumps” they just naturally reach for junk foods rather than fruits and vegetables.

However, since there is no downside to consuming fruits and vegetables, I feel fully comfortable recommending more fruits and vegetables in our diets. If their health benefits aren’t enough to motivate you, maybe the possibility of improving your mood will!

There are some things you just can’t control. To paraphrase those country songs, you can’t keep your girl and dog from running off. Life happens to all of us. Can food affect your mood? If you want to keep your mood where it should be, you can always reach for those fresh fruits and vegetables, whole grains and sources of omega-3 fatty acids.

 

The Bottom Line

  • Two recent studies have suggested what we eat can affect our mood.
  • The first study showed that people who habitually consumed a diet consisting of sweetened desserts, chocolates, fried foods, processed meats, refined grains and high fat dairy products were 58% more likely to suffer from depression than people who habitually consumed a diet consisting mostly of vegetables, fruits, fish and whole grains.
  • The second study showed that the subjects in their study reported feeling calmer, happier and more energetic on the days when they ate more fruits and vegetables than they did on the days they ate junk foods.
  • Of course, these studies both measured correlations between diet and mood, and any good scientist will tell you that correlations do not prove cause and effect. It could be that when people are “down in the dumps” they just naturally reach for junk foods rather than fruits and vegetables.
  • However, since there is no downside to consuming a healthier diet, I feel fully comfortable recommending more fruits and vegetables, whole grains and omega-3s in our diets. If their health benefits aren’t enough to motivate you, maybe the possibility of their improving your mood will!

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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Latest Article

Can Plant-based Diets Be Unhealthy?

Posted September 10, 2019 by Dr. Steve Chaney

Do Plant-Based Diets Reduce Heart Disease Deaths?

Author: Dr. Stephen Chaney

 

plant-based diets vegetablesPlant-based diets have become the “Golden Boys” of the diet world. They are the diets most often recommended by knowledgeable health and nutrition professionals. I’m not talking about all the “Dr. Strangeloves” who pitch weird diets in books and the internet. I am talking legitimate experts who have spent their life studying the impact of nutrition on our health.

Certainly, there is an overwhelming body of evidence supporting the claim that plant-based diets are healthy. Going on a plant-based diet can help you lower blood pressure, inflammation, cholesterol and triglycerides. People who consume a plant-based diet for a lifetime weigh less and have decreased risk of heart disease, diabetes, and cancer.

But, can a plant-based diet be unhealthy? Some people consider a plant-based diet to simply be the absence of meat and other animal foods. Is just replacing animal foods with plant-based foods enough to make a diet healthy?

Maybe not. After all, sugar and white flour are plant-based food ingredients. Fake meats of all kinds abound in our grocery stores. Some are very wholesome, but others are little more than vegetarian junk food. If you replace animal foods with plant-based sweets, desserts, and junk food, is your diet really healthier?

While the answer to that question seems obvious, very few studies have asked that question. Most studies on the benefits of plant-based diets have compared population groups that eat a strictly plant-based diet (Seventh-Day Adventists, vegans, or vegetarians) with the general public. They have not looked at variations in plant food consumption within the general public. Nor have they compared people who consume healthy and unhealthy plant foods.

This study (H Kim et al, Journal of the American Heart Association, 8:e012865, 2019) was designed to fill that void.

 

How Was The Study Done?

plant-based diets studyThis study used data collected from 12,168 middle aged adults in the ARIC (Atherosclerosis Risk in Communities) study between 1987 and 2016.

The participant’s usual intake of foods and beverages was assessed by trained interviewers using a food frequency questionnaire at the time of entry into the study and again 6 years later.

Participants were asked to indicate the frequency with which they consumed 66 foods and beverages of a defined serving size in the previous year. Visual guides were provided to help participants estimate portion sizes.

The participant’s adherence to a plant-based diet was assessed using four different well-established plant-based diet scores. For the sake of simplicity, I will include 3 of them in this review.

  • The PDI (Plant-Based Diet Index) categorizes foods as either plant foods or animal foods. A high PDI score means that the participant’s diet contains more plant foods than animal foods. A low PDI score means the participant’s diet contains more animal foods than plant foods.
  • The hPDI (healthy plant-based diet index) is based on the PDI but emphasizes “healthy” plant foods. A high hPDI score means that the participant’s diet is high in healthy plant foods (whole grains, fruits, vegetables, nuts, legumes, coffee and tea) and low in animal foods.
  • The uPDI (unhealthy plant-based diet index) is based on the PDI but emphasizes “unhealthy” plant foods. A high uPDI score means that the participant’s diet is high in unhealthy plant foods (refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts) and low in animal foods.

For statistical analysis the scores from the various plant-based diet indices were divided into 5 equal groups. In each case, the group with the highest score consumed the most plant foods and least animal foods. The group with the lowest score consumed the least plant foods and the most animal foods.

The health outcomes measured in this study were heart disease events, heart disease deaths, and all-cause deaths. Again, for the sake of simplicity, I will only include 2 of these outcomes (heart disease deaths and all-cause deaths) in this review. The data on deaths were obtained from state death records and the National Death Index. (Yes, your personal information is available on the web even after you die.)

 

Do Plant-Based Diets Reduce Heart Disease Deaths?

plant-based diets reduce heart deathsThe participants in this study were followed for an average of 25 years.

The investigators looked at heart disease deaths over the 25 years and compared people with the highest intake of plant foods to people with the highest intake of red meat and other animal foods. The results were:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods (whole grains, fruits, vegetables, nuts, legumes, coffee and tea) had a 19-32% lower risk of dying from heart disease than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods (refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts) had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

When the investigators looked at all-cause deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had an 11-25% lower risk of dying from any cause than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

What Else Did The Study Show?

The investigators made a couple of other interesting observations:

  • The association of the overall diet with heart disease and all-cause deaths was stronger than the association of individual food components. This underscores the importance of looking at the effect of the whole diet on health outcomes rather than the “magic” foods you hear about on Dr. Strangelove’s Health Blog.
  • Diets with the highest amount of healthy plant foods were associated with higher intake of carbohydrates, plant protein, fiber, and micronutrients, including potassium, magnesium, iron, vitamin A, vitamin C, folate, and lower intake of saturated fat and cholesterol.
  • Diets with the highest amount of unhealthy plant foods were associated with higher intake of calories and carbohydrates and lower intake of fiber and micronutrients.

The last two observations may help explain some of the health benefits of plant-based diets.

 

Can Plant-Based Diets Be Unhealthy?

plant-based diets unhealthy cookiesNow, let’s return to the question I asked at the beginning of this article: “Can plant-based diets be unhealthy?” Although some previous studies have suggested that unhealthy plant-based diets might increase the risk of heart disease, this study did not show that.

What this study did show was that an unhealthy plant-based diet was no better for you than a diet containing lots of red meat and other animal foods.

If this were the only conclusion from this study, it might be considered a neutral result. However, this result clearly contrasts with the data from this study and many others showing that both plant-based diets in general and healthy plant-based diets reduce the risk of heart disease deaths and all-cause deaths compared to animal-based diets.

The main message from this study is clear.

  • Replacing red meat and other animal foods with plant foods can be a healthier choice, but only if they are whole, minimally processed plant foods like whole grains, fruits, vegetables, nuts, legumes, coffee and tea.
  • If the plant foods are refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts, all bets are off. You may be just as unhealthy as if you kept eating a diet high in red meat and other animal foods.

There is one other subtle message from this study. This study did not compare vegans with the general public. Everyone in the study was the general public. Nobody in the study was consuming a 100% plant-based diet.

For example:

  • The group with the highest intake of plant foods consumed 9 servings per day of plant foods and 3.6 servings per day of animal foods.
  • The group with the lowest intake of plant foods consumed 5.4 servings per day of plant foods and 5.6 servings per day of animal foods.

In other words, you don’t need to be a vegan purist to experience health benefits from adding more whole, minimally processed plant foods to your diet.

 

The Bottom Line

A recent study analyzed the effect of consuming plant foods on heart disease deaths and all-cause deaths over a 25-year period.

When the investigators looked at heart disease deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had a 19-32% lower risk of dying from heart disease than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

When the investigators looked at all-cause deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had an 11-25% lower risk of dying from any cause than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

The main message from this study is clear.

  • Replacing red meat and other animal foods with plant foods can be a healthier choice, but only if they are whole, minimally processed plant foods like whole grains, fruits, vegetables, nuts, legumes, coffee and tea.
  • If the plant foods are refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts, all bets are off. You may be just as unhealthy as if you kept eating a diet high in red meat and other animal foods.

A more subtle message from the study is that you don’t need to be a vegan purist to experience health benefits from adding more whole, minimally processed plant foods to your diet. The people in this study were not following some special diet. The only difference was that some of the people in this study ate more plant foods and others more animal foods.

For more details on the study, read the article above.

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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