Healthy Food & Healthy Living by Dr. Ayala

Can healthy food improve your mental health?

Depression is a common and serious disorder, and while its causes are multiple and complex, diet may also play a role.

Inflammation has been implicated in many diseases, depression among them. Inflammation is the body’s beneficial defense from injury and infection by invaders such as bacteria and viruses. On the other hand, chronic low-grade inflammation in the absence of attack or threat is harmful and can lead to serious trouble – it has been linked with heart disease, cancer, Alzheimer’s, arthritis, premature aging and also depression.

The inflammation-depression connection is a fascinating discovery that is gaining ground. Previous research has shown that inflammatory cytokines – substances such as interferon and interleukin that are secreted from immune system cells when those are activated or when they are used as drugs – can trigger major depression. There have been several studies that show improvement of depression symptoms when inflammation is controlled, either with drugs or with and an anti-inflammatory diet. A recent large prospective study published in the Journal of Nutrition found that an anti-inflammatory diet lowered the risk of depression, especially in men.

Can you modify the risk of depression by changing your diet?

A new meta-analysis in Public Health Nutrition gathered the findings of four studies, including about 50,000 people, to see if the inflammatory potential of their diet is linked with developing depression.

The tool used in this and in most research of pro- and anti-inflammatory foods is the Dietary Inflammatory Index. The index is based on thousands of scientific articles, which enabled scoring of every food and nutrient.

The researchers found that a pro-inflammatory diet was associated with a higher incidence of depression, and that people eating diets with the highest inflammatory score had a 23 percent higher risk of developing depression.

Foods that protect mood

The anti-inflammatory diet shows promise. So should we get a copy of the Dietary Inflammatory Index and post it on the fridge? Here’s what the index tells us:

Foods and nutrients that have strong anti-inflammatory activity include certain spices and seasonings: turmeric, fiber, tea, wine, ginger; phytochemichals in plant-foods – flavones, flavonols, flavonones, anthocyanidins, isoflavones. They also include vitamins such A, E, D, C, and many from the B family, magnesium, mono and poly unsaturated fats, and omega-3 fats.

Foods and nutrients with pro-inflammatory activity include total fat, saturated fat, trans-fat, protein, refined carbs and iron.

This list, you’ll agree, is not particularly practical and doesn’t sound like a fun way to eat. Luckily, the index is pretty easy to internalize since it pretty much follows a pattern that you may find familiar.

The personification of a pro-inflammatory diet is a stereotypical American diet – low on fruits and veggies, high on highly processed food, meat, refined grain, desserts and sugary drinks.

The epitome of an anti-inflammatory diet would be a classic Mediterranean diet – a diet that highlights vegetables, fruit, spices and herbs, whole grains, garlic, onion, olive oil, fish and wine.

Another way to look at it: A healthy diet – which happens to also score as a low inflammatory diet – might protect from depression and ease its symptoms.

Again, depression is a complex and a very serious disease, its treatment usually requires many modalities, concurrently, and these studies are quite preliminary.

But since we already know that a healthy diet mitigates the risk of so many diseases, a low-inflammatory diet is already worth trying even without conclusive proof. It may also help fight depression. To do so, crowd your plate with foods that fight inflammation: veggies, fruits, whole grains, spices, herbs, nuts. Enjoy these, and there’ll be less room for pro-inflammatory foods such as soda, refined carbs, fried foods, red and processed meat.

Dr. Ayala

So, is coffee really good for you?

How do we know if a food is healthy? Some of it is plain common sense, so steeped in tradition that it hardly needs proof, but for less obvious food items it usually starts with an observation.

We noticed, for instance, that people who drink lots of soda tend to gain weight and have a higher incidence of several chronic diseases, or that people who take multi-vitamins tend to be healthier.

An observation is followed by careful study to verify that there is indeed an association between the observed exposure and an outcome. If the association actually exists, we try to find out what explains the connection, and to see if the association is a result of a cause and effect connection. In the case of soda and obesity link, it has been established that drinking soda actually drives obesity; with vitamins it turns out that taking vitamins is what healthy people that engage in various other beneficial habits – they also exercise, wear seatbelts and bike helmets – tend to do. The extra vitamins are just an association and not the cause of their superior health.

Most Americans drink coffee, and it was good news to hear that drinking coffee regularly is associated with lower risk of several chronic diseases, such as type 2 diabetes, heart disease, Parkinson’s and several types of cancer. This association has been seen in many studies, and a recent review of many meta-analysis concluded that (with the exception of certain conditions such as pregnancy and women with risk of fractures) coffee is “more likely to benefit health than harm.”

The ideal next step would have been to test coffee as an intervention in a double blind, long-term study, a study in which environmental, nutrition and lifestyle parameters would be controlled. This is, of course, very difficult and expensive to do.

Coffee and health,  just an association?

When it comes to studying nutrition such studies are rarely feasible.

But there are other ways to move forward. Another method to examine a connection between two correlated findings is to see whether there’s a plausible mechanism that would make the exposure cause the outcome.

This is precisely what a new study, just published in the American Journal of Clinical Nutrition set out to do.

Chronic inflammation, insulin resistance and hormonal dysregulation are thought to be behind the development of many chronic diseases. The new study looks at biomarkers – measurable biological markers that are characteristic of biological processes and indicate particular diseases or physiological states. The researchers looked at 14 biomarkers found in blood, including some from the insulin family (C-peptide, insulin-like growth factor 1), at several sex hormones (testosterone, estradiol,) and at inflammation markers such as C-reactive protein and interleukin 6. These were studied in two very large cohorts of about 15,500 women and more than 7000 men whose coffee habits were known.

And the results: Coffee consumption was associated with favorable shifts in the levels of the biomarkers tested. There were lower levels of insulin markers – high insulin secretion markers are linked with several cancers. There were lower concentrations of inflammatory biomarkers. Estrogen levels were lower – high estrogen is associated with higher risk of breast, ovarian as well as prostate cancer – and higher levels of testosterone (testosterone can act against breast cancer cells).

This was true for the participants who drank caffeinated as well as decaf drinks.

Because besides caffeine, coffee contains very many substances, such as polyphenols, trace minerals and diterpenoids that are thought to affect health conditions.

Time for a coffee break?

If you love coffee the latest research about coffee and health is encouraging.

Drinking coffee used to come with a dose of worry. The reason for that is that older coffee studies did not account for confounding unhealthy behaviors such as smoking and inactivity, which used to be more common among heavy coffee drinkers. Newer, better studies are finding that coffee is actually associated with good health, and the mechanism of benefit is plausible. This study adds another layer of credibility and evidence.

That being said, coffee may not benefit all people: People who metabolize caffeine slowly may not find coffee helpful in the same way that people who metabolize it normally do. The reason the studies of coffee show conflicting results may be due to a genetic variability in the way people react to caffeine.

Coffee also isn’t for kids. Major health organizations, including the American Academy of Pediatrics, recommend that kids avoid caffeine in coffee and energy drinks altogether, at least until age 12. Pregnant women are advised to limit coffee to about 2 cups a day.

And when you think of coffee and health, a reminder: Coffee is in essence a calorie free, unsweetened drink. Coffee drinks with sugar, syrups and cream can become calorie bombs ­– these aren’t a healthy habit.

Dr. Ayala