Oats, Eggs, and Dairy:
Key Health Implications
of Breakfast Foods

Oats

Oats are generally regarded as a satisfying staple breakfast. However, depending on preparation and processing, they carry both advantages and potential drawbacks.

Purported Health Benefits of Oats

The benefits of oats are often linked to their rich content of soluble fibers, especially a type called beta glucan.

• Cardiovascular and Cholesterol Health: Oats may improve cholesterol levels. A meta-analysis of 74 randomized controlled trials found that daily servings of oats (as oat bran meal or porridge) lowered total and low-density lipoprotein (LDL) cholesterol. They contain beta glucan, which helps lower cholesterol levels by binding bile acids and increasing their excretion. High intake (3 to 5 servings) of whole grains per day was shown to have a 21% reduced risk of heart disease. They also contain phytosterols that have a lowering effect on lipoproteins.
• Blood Sugar and Satiety: Beta glucan can slow down the absorption of glucose sugar into the bloodstream. Oats can keep you feeling fuller for longer. Their structure allows them to form viscous gels in the intestine, slowing sugar absorption, which theoretically prevents blood sugar spikes. They delay gastric emptying, which further prevents sharp rises in blood sugar and insulin levels after a meal. Minimally processed, thick oat flakes can improve blood glucose and insulin responses compared to refined grains.
• Nutritional and Other Benefits: Oats are packed full of nutrients, including B vitamins, magnesium, and phosphorus. They contain phytochemicals and antioxidants that have anti-inflammatory effects and flavonoids. Oat intake has been shown to improve the gut microbiota by increasing beneficial bacteria (such as lactobacilli and bifidobacteria) and increasing concentrations of short-chain fatty acids.

Potential Disadvantages and Concerns Regarding Oats

• Blood Sugar Spikes: Oats are known to cause blood sugar spikes as they are still considered a high-carb food.
• Processing Differences: Not all oats are created equal. Highly processed oats are less effective at reducing serum cholesterol. Instant quick oats have been steamed and rolled flatter for a shorter cooking time and softer texture. Thin, quick instant oat flakes cannot improve blood glucose and insulin responses compared to refined grains, unlike minimally processed thick flakes. Processing disrupts the food matrix, leading to a quicker absorption of the starches found in oats.

Eggs

Eggs are a highly debated food in nutritional science, once regarded as the "original superfood".

Purported Health Benefits of Eggs

Eggs are considered healthy primarily because they are valuable sources of nutrition and amino acids.

• Protein and Amino Acids: A large egg provides six grams of protein and contains all nine essential amino acids.
• Fats and Nutrients: The egg yolk fat is primarily oleic acid (a monounsaturated fatty acid), but also contains some saturated fats and polyunsaturated fatty acids (PUFAs). Eggs are an important source of choline. They contain high levels of carotenoids, particularly lutein and zeaxanthin, which may offer benefits against inflammation and oxidation. They also contain vitamins such as A, D, thiamine, and riboflavin.
• Cardiovascular Risk (General Population): Overall observational studies generally do not show an increased risk of cardiovascular disease from egg consumption. A recent meta-analysis of observational studies found no conclusive evidence on the role of eggs in the risk of cardiovascular disease.

Potential Disadvantages and Concerns Regarding Eggs

• Cholesterol Content: Eggs contain a notable amount of cholesterol (about 180mg per large egg), which has been the primary source of concern regarding heart health.
• Increased Risk Markers: Evidence suggests that eating more than 1 to 1.5 eggs per day may be associated with a higher risk of death from all-cause mortality, cardiovascular disease, and cancer (based on a Nutrition Review in 2022).
• Recommendations for High-Risk Individuals: Individuals who already have high cholesterol may want to limit their egg intake. Reducing egg intake to zero may be required for those who have experienced a cardiovascular event and have elevated cholesterol if the goal is to lower these levels.
• Dietary Context: The impact is highly dependent on what they are consumed with. Eggs eaten alongside high-saturated fat foods (like bacon) can contribute to a high burden of cholesterol, as saturated fat in the diet causes the liver to make more cholesterol.

Dairy

Overall, the effects of dairy foods are not entirely understood, making it a complex area of study.

Purported Health Benefits of Dairy

• Overall Health and Disease Risk: A recent umbrella review linked total dairy consumption with a decreased risk of colorectal cancer, high blood pressure, cardiovascular disease, and fatal stroke. There is a possible decreased risk of breast cancer, metabolic syndrome, stroke, and type two diabetes. The general conclusion is that dairy may be part of a healthy diet.
• Nutritional Content: Dairy provides protein, probiotics, minerals, and vitamins, especially calcium, phosphorus, and B vitamins.
• Benefits of Fermented Dairy (Yogurt and Kefir): Fermented dairy is suggested as the preferred type of dairy. It supports gut health and is renowned for its probiotic status, improving the composition of the gut microbiota. Fermentation improves the digestibility of proteins and sugars and can improve lactose tolerance. Human trials demonstrated that yogurt or kefir with live active cultures significantly enhanced lactose digestion and reduced symptoms of intolerance.

Potential Disadvantages and Concerns Regarding Dairy

• Disease Risk: There is some evidence for an increased risk of prostate cancer and Parkinson's disease linked to dairy consumption, though more studies are needed.
• Processing Concerns: If lower-fat dairy products are chosen, the sugar content tends to increase.