If you’ve embarked on the Paleo journey, then chances are, you’ve come across the term ‘nightshades’ before – and you might be asking yourself what all the fuss is about.
To help you understand what nightshades really are – and why they’re such a hot topic when it comes to Paleo lifestyles, read on, as we unravel their mysteries.
What are nightshades?
Nightshades are plants that are part of the Solanaceae family. They include both a variety of edible and non-edible plants – one of the nastiest nightshades you’ve probably already heard of is ‘deadly nightshade’ – aka Belladonna, a highly poisonous plant.
Not all nightshades are deadly poisons though, and a lot of them form a major part of our daily diet – while we don’t usually eat the leaves themselves, we do eat their fruits. The most common edible nightshades you’re likely to come across are tomatoes, aubergines, potatoes (excluding sweet potato) and peppers.
What’s so different about nightshades?
You might be wondering what the big deal is about this group of veggies, especially considering they form the staple part of so many diets around the world! For starters, nightshades can be spotted by that little green lampshade-like top that all fruits of this family of plants sport – from tomatoes to chilli peppers, they all have this characteristic little topper.
More importantly, nightshades produce a unique compound called glycoalkaloids, that is the source of all their controversy. It’s a compound found all through the plant – from its flowers, leaves and fruits. And it can have a big impact on the human body.
What are glycoalkaloids?
Glycoalkaloids are chemicals produced naturally by all nightshade plants. They act as a kind of natural pesticide, defending the plant against bacteria, viruses and pests. They do this is a couple of ways – by binding to the cholesterol in the cell membranes of a predator – causing the cells to burst, or by acting as neurotoxins, which work in a similar way to nerve gases – albeit, on a much smaller scale. Ideal for ensuring nasty insects don’t destroy a plant – but potentially not so ideal for humans!
But before you panic about tucking into your favourite nightshades, let’s take a closer look at how they can actually affect the human body.
Potential issues with nightshades
The alkaloids in nightshades are great at keeping away pests. But one of the ways they can sometimes affect the human body is by increasing inflammation. This is because they contain one particular type of alkaloid called Solanine, which blocks an important enzyme found in nerve cells. This can sometimes lead to joint stiffness and pain.
Another harmful chemical found in nightshades is called calcitrol. This is a hormone that encourages the body to take in more calcium. While calcium is definitely good for you, excessive calcium can result in calcium deposits, which can cause painful tendons and ligaments.
Lastly, another common issue with nightshades is their high lectin content. Lectins cannot be digested by humans and can potentially damage the intestinal lining as they pass through. While all food causes minor damage to the GI tract as it makes its way through, lectins impair the natural regeneration of cells, causing the gut to become ‘leaky’ and stopping important molecules from being absorbed, while allowing things that should be kept out of the blood stream to pass through.
The presence of lectins can result in a variety of effects, but the more there are, the worse the results. You could experience anything from flatulence, to nausea, diarrhea and vomiting.
Should you avoid nightshades?
Because nightshades have such a wide variety of risk factors, they’ve become a hotly contested issue in Paleo and other dietary circles, and super traditional Paleo diets will often exclude them completely.
But they’re also some of the most popular foods on the planet – from salsa sauces to tomato ketchup, French fries and a host of other classic dishes! Do you really need to cut them out of your diet altogether?
The answer to that is: it depends. One of the most important issues to consider is if you are susceptible to any of the issues that could be exaggerated or worsened by nightshades. Health issues such as arthritis, osteoporosis, inflammatory disorders and autoimmune diseases, could all potentially be worsened by including nightshades in your diet.
If you’re not sure whether or not to keep them, try the 30-day test. This simply means eliminating all nightshades from your diet, for 30 days. Keep a diary of how you feel and if there are any changes. Some people find removing nightshades from their diet can eradicate recurring migraines and joint pain, while others find that persistent digestive issues clear up.
Not everyone is sensitive to nightshades though – if you’re in this group, feel free to continue enjoying them, alongside other Paleo foods. It’s best to consume them in moderation – and opt for ripe, fully cooked nightshades whenever you eat them – choose ripe red tomatoes over green tomatoes, and red peppers over green ones, and remove peels wherever possible.