A Winning Combination
At first, eating seems simple, why think about it? If it tastes good and has nutrients in it then why not shovel it down? Well for the lucky few with iron guts and an indomitable digestion it’s not a problem but for the majority if us this just simply isn’t the case. Fortunately, there’s a science to digestion – food combining! By applying this science of food combining conscientiously we can immediately see vast improvements in digestion, with regards to both symptom improvement and nutrient absorption.
An enzyme is a protein that functions as a catalyst; speeding up a reaction without being consumed in the process. Different enzymes have different purposes, and function optimally in different environments. The premise behind food combining is to enable these optimal environments for our enzymes to make it easier for them to do their jobs – breaking down and digesting your food. “Several factors affect the rate at which enzymatic reactions proceed – temperature, pH, enzyme concentration, substrate concentration, and the presence of any inhibitors or activators”. With all of these factors in mind we can work on optimising our enzyme function, and ultimately optimise the function of our digestion.
Whilst at first you might think “Well, there’s not much I can do about temperature because my body does that for me without me thinking?’” but there’s another angle we can take on it – cooking. Cooking will denature and destroy enzymes, and this is something we should bear in mind. Cooking certainly has its place, we can consume a lot more food once cooked, and it improves bioavailability of certain nutrients – particularly protein. I think this shows us how balance is important in the diet. All ancestral aboriginal cultures consume some food cooked and some food raw. Without a doubt the best way to get an abundance of enzymes is through vegetable juicing. Consuming a kilo of vegetables in a small glass of liquid, with fibre removed to improve absorption is unbeatable. We can also obtain a lot of enzymes from fermented foods, including fermented animal foods, like kefir, sauerkraut, kimchi and fermented spicy salsa.
Substrate and Enzyme Concentrations
This is a very short segment as it’s fairly simple to explain. Put simply, the more reactions you have that need to take place, and the more enzymes available to catalyse these reactions the higher the rate of enzymatic processes. The best takeaway here is to chew your food – increasing the amount of reactions that can occur due to increased surface area. You can also increase enzyme quantities by consuming high enzyme foods and exogenous enzyme supplements
Inhibitors and Activators
Also another short section as I have a whole other article exploring this topic in depth. Explained briefly certain foods contain compounds that inhibit, slow or prevent certain enzymes from functioning. to save me rewriting the whole topic go and check it out here!
pH stands for potential hydrogen. For a simple and easy to comprehend understanding read here. “The PH scale is logarithmic, meaning that an increase or decrease of an integer value changes the concentration by a 10 fold value. For example, a ph3 solution is 10x more acidic than a ph4 solution.” why do we need to know this? Well put simply, it’s the variable that we have the most control over when we’re eating, and our digestive enzymes have WILDLY different optimal ph ranges depending on what foods we are eating. For simplicity’s sake we will look at foods divided into their macro groups: protein, fat, and carbs.
Starting with protein, we have the enzyme pepsin. Pepsin breaks proteins down into amino acids so we can assimilate them through our intestines. Pepsin has an optimal pH of around 1.5 which is an incredibly acidic environment! For this reason it’s very important to keep your stomach acidic. The most important thing you can do to keep your stomach acid strong is to avoid drinking around meals. The more you dilute your stomach acid the harder your stomach has to work to reach the optimal pH. You can also consume acidic foods such as lemon or vinegar with higher protein meals to increase acidity; tastes great too!
Fats and oils
Moving on we have fats and oils, both of which require lipase to be digested. There’s an important distinction that we have to make though! Fats and oils, also known as lipids, require emulsification for digestion. Lipids are hydrophobic, and because of this, it’s difficult for lipase (a water soluble enzyme) to work on the fat. This is where bile comes into play; bile is like washing up liquid, emulsifying the lipids into water soluble droplets to allow lipase to work. Lipase has an optimal pH of around 4.5. Our liver, gallbladder and pancreas release bile, lipase and a bicarbonate solution into our chyme (half digested food) after it exits the stomach, we can see how this delicate orchestration of pH shift enables the extremely acidic chyme from the stomach to be neutralised by the highly alkaline bicarbonate of soda and bile solution, to emulsify and alkalise the Chyme to optimise the function of lipase and other enzymes produced by our pancreas.
Finally we have carbohydrates. Starches are long chains of sugar and the enzyme that breaks them down for us is called amylase. Amylase has an optimal pH of 7. We secrete amylase at two separate times during digestion: firstly in our mouths, and then from our pancreas after our stomach. Once starch has been broken down into maltose, a disaccharide (two sugars bound together) it is, along with our other dietary disaccharides like lactose and sucrose, broken down into monosaccharides by enzymes present on the exterior of our small intestines (called brush border enzymes) and is finally ready to be absorbed.
As we can see the pH of our digestive system fluctuates constantly, but with these fluctuations in mind we can provide our digestion as much support as possible. To begin, chewing. Not only does chewing break food into smaller pieces, to allow our enzymes more surface area to work, it also stimulates our mouth to secrete amylase, so chewing is particularly important for proteins and starches. The pH at this point is around 6. Moving down to the stomach we have some real heavy machinery. Your stomach and its Parietal cells works hard to create an extremely acid environment. The pH is as low as 1 here, and this is CRUCIAL for many reasons. Firstly, almost no microbes can survive at a pH this low, and this is your first level of protection against acute infections like food poisoning, and more chronic infections like SIBO and candidiasis. Secondly we have our pepsin enzyme that wants to get to work on the protein we have eaten. It’s hard to overstate the importance of essential amino acids in the diet – essential meaning we quite literally can’t live without them. Thirdly, this potent stomach acid is a signal to the next part of our digestion. Our stomach needs to reach this very low ph (Below 3 at a minimum) to trigger your stomach to empty its contents into the small intestine. If this pH isn’t reached then gastroparesis can occur, and when food is eventually passed into the small intestine it is poorly digested and in no state to be absorbed. This is why it’s Imperative to avoid diluting your stomach acid! Your pancreas and liver then produce their bicarbonate, bile, and other pancreatic enzymes including lipase and amylase.
Now everything has been mixed together, digestion reaches its final stages and absorption can occur. Straight off most protein has already been digested and in now absorbing into the small intestine. Minerals that have been liberated from the food from the strength of our stomach acid also begin to absorb through the small intestinal wall. Fats begin to become emulsified as they’re churned together with the bile. The Bicarbonate has neutralised the pH some and so lipase is in its optimal pH range and the fats continue to be catalysed by lipase doing its job. Simultaneously starches are being broken down to Maltose by amylase, and from there down to glucose molecules by maltase (a brush border enzyme on the wall of the small intestine) to finally be absorbed. It’s worth noting that through all of this process, fibre remains largely unchanged and further and further down the intestine there are larger quantities of bacteria that will begin fermenting the fibres (and improperly digested carbohydrates (starches and disaccharides) to produce gas and short chain fatty acids like butyrate). In the case of those with small intestinal dysbiosis these bacteria that would traditionally produce beneficial butyrate and other important chemicals like neurotransmitters and B vitamins for us are replaced with pathogenic microbes that produce endotoxins that damage the intestinal lining and contribute to all types of diseases, along with uncomfortable symptoms like bloating and indigestion.
Appliance of Science!
Diets like the SCD and GAPS diet are founded around avoiding foods that can’t be properly digested when the brush border enzymes are deficient or damaged (starch and disaccharide avoidance) and following a diet like this can promote GI healing and in the long run allow the gut to heal and restore its ability to digest these carbohydrates properly. put simply, in an easy to remember format I made an infographic for you all. Happy food combining!
- Consume fruit on an empty stomach, preferably as a mono meal.
- Always consume carbohydrates with some fat to slow digestion and increase absorption
- Always consume fat with protein, just like you find it in nature
- Don’t drink water with food, particularly high protein meals
- Don’t consume starches with proteins as their optimal enzyme pHs conflict
- Don’t consume starches or disaccharides if you have a damaged gut lining