Can Saturated Fats Be Healthy?

For nutrition, it is best to avoid rote assumptions and stereotypes. Science teaches us new things every day, and some older knowledge changes.

Fat is a macronutrient playing a key role in food enjoyment. Because many natural flavors are fat-soluble, flavor and fat are linked. Fat also gives food a pleasant texture.

There are 3 main types of fat:

• saturated
• unsaturated
• trans fats

What Is Saturated Fat?

Saturated fat is solid at room temperature. Biochemically, it contains no double bonds: between two carbon molecules there is a single bond , leaving no room for new atoms, hence the name saturated fat.

Depending on the number of carbon atoms, saturated fats are subclassified as long, medium or short-chain fatty acids. Short-chain fatty acids have 6 or fewer carbon atoms, medium-chain fatty acids have 8-10, and long-chain fatty acids have 12 or more.

What Is Unsaturated Fat?

Unsaturated fatty acids contain one or more double bonds. The double bond between two carbon atoms can break and new atoms can be added, hence “unsaturated.” They are less stable than saturated fatty acids. Some fragments created through oxidation give food distinctive volatile properties. Think of crushed greens, cucumbers, and deep-fried food aromas. Antioxidants such as beta-carotene and vitamins C and E can prevent oxidative damage in fats and oils.

Unsaturated fatty acids form part of cell-membrane phospholipids and help maintain membrane fluidity.

They occur particularly in plants and animals living in cold environments. Oleic acid (omega [ω]-9), linoleic (ω -6), and α-linolenic (ω-3) are among those we consume most.

- Detailed information: What Are Omega 3, 6, and 9 Fatty Acids? Benefits, Differences, and Risks

Unsaturated fats are divided into monounsaturated and polyunsaturated fatty acids.

Foods rich in monounsaturated fats (omega-9) include:

• olive oil
• peanut oil
• canola oil
• avocado
• most nuts
• most seeds

Polyunsaturated fats have two types: omega-3 and omega-6 fatty acids

Foods rich in omega-3 fatty acids include:

• oily fish such as sardines, tuna, salmon, trout, mackerel, and herring
• ground flax and flaxseed oil
• non-hydrogenated soybean oil
• safflower oil
• sunflower oil
• canola oil
• walnuts
• sunflower seeds
• chia seeds
• hemp seeds

Omega-6 fatty acids can be found in:

• safflower oil
• soybean oil
• sunflower oil
• walnut oil
• corn oil

Trans Fatty Acids

Trans-fatty acid metabolism resembles that of saturated fatty acids. During partial dehydrogenation of vegetable oils (for example, margarine manufacture), cis- fatty acids are converted into trans-fatty acids. “Hydrogenated” margarines contain %15-40 trans- fatty acids. Consuming them raises coronary heart disease risk by increasing artery-clogging low-density lipoprotein (bad cholesterol, LDL). It also reduces anti-atherogenic or cardioprotective (cardiovascular-protective) high-density lipoprotein (good cholesterol, HDL).

Hydrogenated vegetable oils were developed as alternatives to animal and tropical fats mainly used for frying, baking, and spreading. Evidence links trans-fatty acid intake to increased cardiovascular disease risk. There is no benefit to consuming trans fats , and limiting them as much as possible seems wise. These concerns have led to indicating the percentage of energy from trans fats, producing foods with lower trans-fat levels, and requiring nutrition labels..

What Are the Sources of Saturated Fat?

Butter, goose fat, cheese, dairy, red meat, and animal foods. Plant-based oils such as date oil, date-kernel oil, coconut oil, and palm oil mainly contain saturated fat but no cholesterol.

A Special Form of Saturated Fat: Medium-Chain Triglycerides (MCTs)

Medium-chain triglycerides (MCTs) are currently popular plant-derived saturated fats. More specifically, they are processed saturated fats from a mixture of coconut and date-kernel oil. Many wellness advocates and dietitians recommend them for weight loss, exercise performance, and brain health.

Can Saturated Fat Improve Brain Health?

Researchers at George Washington University School of Medicine reviewed evidence and conducted studies on saturated fat and brain health, with widely varying results. Saturated fat intake was, among 4 studies, positively associated with Alzheimer’s risk in 3. A positive association means those consuming saturated fat were more likely to have Alzheimer’s. The fourth study found an inverse association. Another review found saturated fat positively associated with dementia among 2 studies, in only 1.

- Dementia Is Not the Same as Aging! What Can We Do Without Losing Mental Health?

Medium-chain triglycerides (MCTs) deserve special mention. They are metabolized into ketone bodies, considered brain-health-promoting agents. A recent study examined an MCT-based ketogenic formula in 20 Japanese patients with mild-to-moderate Alzheimer’s. It compared a single dose with 12 weeks of use. A single dose provided no cognitive benefit. After 8 weeks, immediate and delayed logical memory tests improved significantly from baseline. After 12 weeks, digit-symbol coding and logical memory improved significantly. The authors concluded that MCTs may help verbal abilities and rapid processing.

Some new, interesting data on MCT saturated fats exist, but these remain preliminary, and more studies are needed.

Does Saturated Fat Cause Cancer?

This is highly controversial. Saturated fat was previously thought to cause cancer. Let us examine two important cancer types.

Colorectal (Large Bowel) Cancer

In 2018, a comprehensive Korean review examined dietary fat and colorectal cancer. Data from 18 studies showed no association between dietary fat intake and colorectal cancer risk. However, processed meats significantly increase colon and rectal cancer risk.

- You may be interested in: What You Need to Know About Colon and Rectal Cancer

Breast Cancer

An analysis in 2001 examined dietary fat and breast cancer by replacing % 5 of daily carbohydrates with saturated fat, finding only a very weak positive association. In 2014, Iranian researchers re-examined the subject using data from 68 studies:

They noted that meat cooked at high heat or barbecued may contain carcinogens , so saturated fat from meat sources cannot be directly compared with fat from other sources.

Reducing total dietary fat alongside saturated fatty acids may help women reduce breast cancer risk. A meta-analysis on breast cancer mortality in 2017 showed saturated fat intake adversely affected breast cancer survival. However, evidence on saturated fat and cancer remains far from definitive.

Do Saturated Fats Contribute to Cell Membranes?

Cell membranes consist of a lipid bilayer. These lipids come from fats, including saturated fats. No specific study has examined what this may mean clinically.

Our Food Choices Affect Health, for Better or Worse

In 2014, a systematic review and 12 meta-analyses examined over 7000 participants and found replacing saturated fatty acids with polyunsaturated fatty acids was not associated with heart disease risk.

In 2016, an important study titled “Re-evaluating the Traditional Diet-Heart Hypothesis” was published. Replacing dietary saturated fat with linoleic acid (omega-6) lowered serum cholesterol but did not reduce coronary heart disease risk.

The Prospective Urban Rural Epidemiology (PURE) study produced interesting results from 18 countries and 125 287 participants across North America, South America, Europe, Africa, and Asia. Data suggest that reducing saturated fatty acids or replacing them with carbohydrates adversely affects blood lipids. Those eating more fat (averaging 35.3 percent of calories) were less likely to die than those with low fat intake (averaging 10.6 percent of calories), by % 23.

The authors concluded that “focusing on a single lipid, such as LDL cholesterol alone, does not capture nutrients’ net clinical effects on cardiovascular risk.”

Another review assessed 12 619 vegans and 179 630 omnivores across 40 studies. Food questionnaires showed lower energy and saturated fat intake among vegans. In most countries (except Taiwan, for some reason), a vegan lifestyle showed a more favorable cardiometabolic profile than a regular diet.

Important Information

A low-saturated-fat diet may lower bad cholesterol, but it is difficult to say this improves health. Our focus should be, as part of a balanced diet , which saturated fats to consume.

Does Saturated Fat Reduce Stroke Risk?

Siri-Tarino and colleagues’ 2010 meta-analysis found no convincing evidence that saturated fat increased stroke risk. Newer data take the relationship to a new level. The 2017 Mente study found higher-fat diets associated with lower stroke risk.

Finally, a study published in late 2018 investigated saturated fats and stroke. A high-saturated-fat diet was associated with lower risk of different stroke types, but only in people of Japanese ancestry.

Conclusion: Are Saturated Fats Safe for Health?

This is a multibillion-dollar question. Previously, the answer would have been a misleading “NO.” Now it is less certain. It may be safe to say we should be less dogmatic about dietary fat. Saturated fats are no longer public enemy number one. We probably have more questions than answers at this stage.

Enjoying a small amount of saturated fat rather than a fat-free diet may be pleasurable. Nevertheless, maintaining limits is useful.