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

Nausea is something we don’t take as seriously as we should. Being persistently sick or ill can make everyday life incredibly challenging and make it difficult to get enough nutrition, impacting the rest of your health.

And both are incredibly common — half of all adults experience nausea at least once a year, and a third are actually sick.

It’s common because there are so many triggers, in addition to a stomach flu — including motion sickness, heart problems, and anxiety.

It is also simply a way for the body to get rid of things it considers harmful, such as too much alcohol or even certain medications.

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

I was reminded of this when a reader recently wrote that she was trying to manage her chemotherapy induced illness by sticking to a bland diet but understandably started eating this way ‘pall’ and she was confused about what is safe for to eat her.

She’s certainly not alone and I’ll get to her questions about what to eat later – first let me explain why this side effect occurs.

The body sees chemotherapy as a toxin – the nausea and nausea are its way of expelling it.

Once it identifies this potential threat, chemical messengers sound the alarm — 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 especially common. For example, the heart is also connected to the vagus nerve – so when the heart becomes stressed, such as when it is not receiving enough blood, messages hit the vagus nerve and can make them sick. Therefore, nausea can occur with heart disease or during a heart attack.

There are also other mechanisms that cause nausea.

Motion sickness, for example, is caused by an imbalance between what we see and the balance mechanism in the ear – the confused messages reaching the brain make it react as if it were being poisoned, thus causing nausea. (That’s why closing your eyes can help ease the sensation, as it stops the mixed messages.)

There’s also an emotional link to nausea – people with anxiety are prone to it – because there are so many nerves in the gut. So fear can literally give you an ‘upset’ feeling in your stomach.

So what can you do about it?

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

The logic behind this was that these foods are kind of bland and don’t have strong odors that might trigger the nausea reflex, but it’s fallen out of favor, not least because it doesn’t contain enough nutrients (there’s little muscle-building protein that you needs for example for the immune system or to repair cells).

The most effective way to eat for anyone experiencing nausea is to approach a little and often – eating a little bit of something every two hours.

The rationale behind this approach is twofold.

First, we know that having an empty stomach can make nausea worse because the hunger hormone ghrelin stimulates the production of stomach acid. If it doesn’t have food to mix it with, it irritates an already sensitive gut, making you feel nauseous.

Second, eating the standard three meals a day requires your stomach to stretch more, stimulating the already-triggered vagus nerve.

Eating small amounts on a regular basis will not stretch the stomach too much and activate this reflex.

And when you eat, it’s best to limit foods that are high in fat (since fat tends to hang in the stomach, putting more pressure on your stomach lining) or with a strong smell (cold foods without a strong smell are best ).

Stick to regular foods like dry crackers, and if you can handle something a little more hearty, a cold frittata (a dish made with fried eggs).

Especially during pregnancy (when hormonal changes trigger illness), studies have shown that protein-based foods fight nausea better than carbs alone — so eat eggs on toast or tuna on dry crackers, for example. Egg white is thought to calm stomach spasms that make nausea worse.

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

A review published in the Nutrition Journal in 2014, including 12 studies in 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 “trigger” the vagus nerve.

You can brew a tea with an inch of fresh ginger – but keep in mind that it can interact with blood-thinning drugs like warfarin, and if you have a high-risk pregnancy, don’t overdo it either.

The evidence for ginger in combating chemotherapy-related nausea is less convincing, but another strategy that works is breathing exercises. A trial in Turkey provided 60 breast cancer patients undergoing chemotherapy with either standard care or breathing exercises for six days — those who did breathing exercises notably had less nausea and vomiting, the journal Complementary Therapies and Clinical Practice reported in 2020.

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

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

The treatment can cause mild inflammation in the gut, making it more permeable and therefore easier for ‘bad’ bacteria and other infection-causing ‘bad guys’ to break through.

This is one of the reasons, in addition to treatment that reduces your 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 specifically say you’re craving beetroot and ham sandwiches. The good news is that vacuum-packed meats like ham should be safe to eat and the same goes for vacuum-packed or pickled beetroot.

So my advice is to get the sandwich and enjoy every crumb! For a more comprehensive resource on foods that are safe to eat, search: BDA neutropenic diets.