Gut Health Guru Dr Meghan Rossi on how eating little and often can help fight nausea

Nausea is something we don’t take as seriously as we should. Constantly feeling or being ill can make everyday life incredibly demanding and make it difficult to get adequate nutrition, affecting the rest of your health.

And both are incredibly common: Half of all adults feel nauseous at least once a year, and a third are actually sick.

It’s common because there are so many triggers, other than having an upset stomach including motion sickness, heart problems, and anxiety.

It’s also simply a way for the body to rid itself of things it perceives as harmful, such as too much alcohol or even some medications.

Earlier in my career, I worked in a cancer ward supporting patients undergoing chemotherapy, for whom nausea and vomiting can be one of the more difficult side effects of their treatment.

This occurred to me when a female reader wrote to me recently to say that she was trying to manage her chemo induced disease by sticking to a bland diet but, understandably, eating this way was starting to “juggle” and she was confused about what is safe for her to eat.

She is certainly not alone and before I answer her questions about what to eat, let me explain why this side effect occurs.

The body perceives chemotherapy as a toxin, nausea and malaise are its way of trying to expel it.

Once this potential threat is spotted, chemical messengers sound the alarm by activating the vagus nerve (which connects the abdomen to the brain), where an area called the dorsal vagal complex triggers the gag or gag reflex. (Nausea is also part of the body’s way of keeping us from ingesting a potential danger in the first place.)

But many different organs and systems fuel this response, which is why nausea is particularly common. The heart, for example, is also connected to the vagus nerve, so if the heart is stressed, as it does when it doesn’t get enough blood, then the messages hit the vagus nerve and can trigger disease. That is why nausea can occur with heart disease or during a heart attack.

Earlier in my career, I worked in a cancer ward supporting patients undergoing chemotherapy, for whom nausea and vomiting can be one of the more difficult side effects of their treatment, writes Dr. Megan Rossi (pictured)

There are also other mechanisms that trigger nausea.

Motion sickness, for example, is caused by an imbalance between what we see and the balance mechanism in the ear. The confused messages that reach the brain make it react as if it were poisoned and therefore trigger nausea. (That’s why closing your eyes can help ease the sensation, as this interrupts the mixed messages.)

There is also an emotional link to the nausea people with anxiety are prone to because there are so many nerves in the gut. So anxiety can literally give you an “upset” feeling in your stomach.

So what can you do about it?

Did you know?

Potatoes can count for your daily fiber intake. In addition to eating the fiber-rich skin, letting a cooked potato cool changes the structure of the starch in the flesh, turning it from digestible starch to resistant starch, a type of fiber that feeds the friendly bacteria in your gut.

For a long time, people thought the BRAT diet (consisting of bananas, rice, applesauce, and toast) would help.

The rationale behind this was that these foods are rather bland and do not have strong odors that could trigger the gag reflex, but it has fallen out of favor, partly because it does not provide enough nutrients (there is little protein for building muscle which is needed for the immune system or to repair cells, for example).

The most effective way of eating for anyone suffering from nausea is to take a little and approach often to eat a little something every two hours.

The rationale behind this approach is twofold.

First, we know that having an empty stomach can make nausea worse since the hunger hormone ghrelin stimulates the production of stomach acid, which, if it has no food to mix with, irritates an already sensitive gut, making you feel sick.

Secondly, if you eat the standard three meals a day, this prompts your stomach to stretch more, stimulating the already activated vagus nerve.

Regularly eating small amounts won’t stretch your stomach too much or trigger this reflex.

And when you eat, it’s best to limit foods that are high in fat (since fat stays in the stomach, putting more pressure on the stomach walls) or with a strong smell (cold food without a strong scent is best).

Stick to simple foods like dry crackers and, if you can handle something heartier, a cold omelet (a baked egg dish).

Especially during pregnancy (when hormonal changes trigger illness) studies have found that protein foods fight nausea better than carbohydrates alone, so, for example, eat eggs on toast or tuna on dry crackers. Protein is thought to calm stomach spasms that exacerbate nausea.

Stick to simple foods like dry crackers and, if you can handle something heartier, a cold omelet (a baked egg dish). [File image]

If you suffer from severe morning sickness (e.g. hyperemesis gravidarum), according to a study published in the journal Scientific Reports in 2020, crunchy and sweet raw foods are best such as apple or watermelon. Ginger has traditionally been used to combat nausea in pregnancy and there is scientific evidence to support this.

A review, published in the Nutrition Journal in 2014, which included 12 studies of pregnant women, concluded that ginger significantly improved nausea symptoms compared to a placebo.

Ginger uniquely contains compounds called gingerols, which are thought to speed up intestinal emptying so food doesn’t sit there too long and “prime” the vagus nerve.

You can make tea with an inch of fresh ginger, but keep in mind that it can interact with blood-thinning medications like warfarin, and if you’re having a high-risk pregnancy, make sure you don’t overdo it.

The evidence for ginger’s use in fighting chemotherapy-related nausea is less compelling, but another strategy that works is breathing exercises. A study in Turkey offered 60 breast cancer patients receiving chemotherapy standard care or breathing exercises for six days, those who performed breathing exercises had significantly less nausea and vomiting, the journal Complementary Therapies and Clinical Practice reported in 2020.

This was a small study, but diaphragmatic belly breathing has been shown over and over again to calm the vagus nerve, which explains the findings of this study.

And now a word to my reader who asked me what to eat during chemotherapy.

Treatment can cause low-grade inflammation in the intestines making it more permeable and therefore easier for “bad” and other “bad” bacteria to cause infection.

This is one reason, along with treatment that reduces infection-fighting white blood cells, why you need to be a little more careful about what you eat. Now is not the time for unpasteurized dairy products or fermented foods like kimchi.

You expressly say you’re craving beet and ham sandwiches. The good news is that vacuum-packed meat like ham should be safe to eat and the same goes for vacuum-packed or pickled beets.

So my advice is to get the sandwich and savor every crumb! For a more comprehensive resource on foods that are safe to eat, search for: BDA Guide to Neutropenic Diets.