Table (1) recapitulates the COVID-19 symptoms that were investigated, namely fever, body pain, cough, nasal congestion, runny nose, sore throat, diarrhea, dyspnea, and loss of smell or taste. Most participants reported having had a moderate fever, cough, nasal congestion, runny nose, sore throat, diarrhea, and dyspnea (52%, 63.6%, 59%, 53.8%, 49.1%, and 53.2%, respectively). Then, the rest of participants had severe body pain and smell or taste loss (67.6% and 48.6%, respectively).
Thus, most participants had moderate symptoms, some had severe symptoms, and a minority was asymptomatic.
Table 1: COVID-19 symptoms investigated
Symptoms
|
Non
|
Moderate
|
Severe
|
Fever
|
N
|
48
|
180
|
118
|
%
|
13.9
|
52
|
34.1
|
Body pain
|
N
|
4
|
108
|
234
|
%
|
1.2
|
31.2
|
67.6
|
Cough
|
N
|
74
|
220
|
52
|
%
|
21.4
|
63.6
|
15
|
Nasal congestion and runny nose
|
N
|
80
|
204
|
62
|
%
|
23.1
|
59
|
17.9
|
Sore throat
|
N
|
62
|
186
|
98
|
%
|
17.9
|
53.8
|
28.3
|
Diarrhea
|
N
|
140
|
170
|
36
|
%
|
40.5
|
49.1
|
10.4
|
dyspnea
|
N
|
70
|
184
|
92
|
%
|
20.2
|
53.2
|
26.6
|
Loss of smell or taste
|
N
|
52
|
126
|
168
|
%
|
15
|
36.4
|
48.6
|
N: Number of participants |
Tables (2) to (6) present the relationship between COVID–19 symptoms (fever, body pain, cough, and dyspnea in tables (2), (3), (4), and (5), respectively) and intake of some foods (fruits or vegetables, yogurt, onions, and garlic). Each table was divided into three levels of food intake: 1) no intake, 2) little intake (weekly or monthly), and 3) intensive intake (more than once a week to daily).
Table (2) shows that participants experienced fever independently of their food intake. Data showed that among 166 recovered individuals who did not eat any of the investigated foods, 20 (12.5%) had been asymptomatic, whereas 146 (87.5%) had suffered from either moderate or severe fever. Among the 338 participants with little food intake (weekly or monthly), only 38 cases (11.24%) had no fever, whereas 300 (88.76%) had experienced moderate or severe fever. Finally, among the 877 subjects with intensive food intake (daily or more than once a week), 134 (15.26%) had had no fever, and 744 (84.74%) had suffered from moderate or severe fever.
These data indicate comparable fever occurrence rates (88% and 88.8%) in participants with no or little food uptake, whereas fever occurred less in subjects with intensive intake (84.7%). Additionally, the foods investigated here had different effects on the occurrence of fever. For example, fever was reported less (80%) by participants consuming no vegetables or fruits (no intake), whereas it occurred the most (92.9%) in subjects who did not eat yogurt. Participants with little intake (weekly or monthly) of yogurt, vegetables or fruits (87% and 87.5%, respectively) experienced fever less often. Fevers were more intense in subjects consuming only small amounts of onions and garlic (91.9% and 89.4%, respectively). Finally, 86.3%, 84.7%, 84.2%, and 83.3%) of participants with an intensive intake (daily or more than once a week) of fruits or vegetables, yogurt, garlic, and onion, respectively, had a fever.
There was a significant correlation between fever occurrence, onion, and total food consumption (Pearson’s correlation coefficient R = 0.141 and 0.135, respectively, p < 0.01).
Table (2): Relationship between the consumption of specific foods and the occurrence of fever
Level of intake
|
Foods
Symptom rate
|
Fruits or vegetables
|
Yogurt
|
Onions
|
Garlic
|
Total symptoms
|
N
|
%
|
N
|
%
|
N
|
%
|
N
|
%
|
N
|
%
|
No intake
|
Asymptomatic
|
4
|
20
|
2
|
7.1
|
6
|
10.7
|
8
|
12.9
|
20
|
12
|
Symptoms
|
Moderate
|
8
|
40
|
14
|
50
|
26
|
46.4
|
32
|
51.6
|
80
|
48.2
|
Severe
|
8
|
40
|
12
|
42.9
|
24
|
42.9
|
22
|
35.5
|
66
|
39.8
|
Total
|
16
|
80
|
26
|
92.9
|
50
|
89.3
|
54
|
87.1
|
146
|
88
|
Total
|
20
|
100
|
28
|
100
|
56
|
100
|
62
|
100
|
166
|
100
|
Little intake (monthly or weekly)
|
Asymptomatic
|
8
|
12.5
|
14
|
13
|
6
|
8.1
|
10
|
10.6
|
38
|
11.2
|
Symptoms
|
Moderate
|
34
|
53.1
|
58
|
53.7
|
38
|
51.4
|
48
|
51.1
|
178
|
52.3
|
Severe
|
22
|
34.4
|
36
|
33.3
|
30
|
40.5
|
36
|
38.3
|
124
|
36.5
|
Total
|
56
|
87.5
|
94
|
87
|
68
|
91.9
|
84
|
89.4
|
302
|
88.8
|
Total
|
64
|
100
|
108
|
100
|
74
|
100
|
94
|
100
|
340
|
100
|
Intensive intake (daily or more than once a week)
|
Asymptomatic
|
36
|
13.7
|
32
|
15.3
|
36
|
16.7
|
30
|
15.8
|
134
|
15.3
|
Symptoms
|
Moderate
|
138
|
52.7
|
108
|
51.4
|
116
|
53.7
|
100
|
52.6
|
462
|
52.6
|
Severe
|
88
|
33.6
|
70
|
33.3
|
64
|
29.6
|
60
|
31.6
|
282
|
32.1
|
Total
|
226
|
86.3
|
178
|
84.7
|
180
|
83.3
|
160
|
84.2
|
744
|
84.7
|
Total
|
262
|
100
|
210
|
100
|
216
|
100
|
190
|
100
|
878
|
100
|
Total
|
346
|
346
|
346
|
346
|
1384
|
R
|
0.063
|
0.075
|
0.141**
|
−0.068
|
0.135**
|
N: Number of participants |
R: Pearson’s correlation coefficient |
**: P-value of correlation was significant (p < 0.01), 2-tailed test. |
Data in Table (3) showed that 100% of participants not eating any of the investigated foods (no intake) had moderate or severe body pain symptoms. Moderate or severe body pain was experienced by 98.8% of the participants with little food intake (weekly or monthly) and 98.6% of those with an intensive intake (daily or more than once a week) of the foods. In view of the fact that the proportion of patients suffering from body pain decreased, these foods and their bioactive compounds may have affected the body’s resistance to pain.
Additionally, data in Table (3) revealed that 100% of participants who had experienced body pain were eating few fruits or vegetables and onions (weekly or monthly). In contrast, a slight decrease in the proportion of participants who had suffered from body pain occurred with the intensive consumption of yogurt, garlic, fruits or vegetables, and onions (99%, 98.9%, 98.5%, and 98.1%, respectively).
Table (3): Relationship between the consumption of specific foods and the occurrence of body pain
Level of intake
|
foods
Symptom rate
|
Fruits or vegetables
|
Yogurt
|
Onions
|
Garlic
|
Total symptoms
|
N
|
%
|
N
|
%
|
N
|
%
|
N
|
%
|
N
|
%
|
No intake
|
Asymptomatic
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
Symptoms
|
Moderate
|
8
|
40
|
8
|
28.6
|
14
|
25
|
18
|
29
|
48
|
28.9
|
Severe
|
12
|
60
|
20
|
71.4
|
42
|
75
|
44
|
71
|
118
|
71.1
|
Total
|
20
|
100
|
28
|
100
|
56
|
100
|
62
|
100
|
166
|
100
|
Total
|
20
|
100
|
28
|
100
|
56
|
100
|
62
|
100
|
166
|
100
|
Little intake (monthly or weekly)
|
Asymptomatic
|
0
|
0
|
2
|
1.9
|
0
|
0
|
2
|
2.1
|
4
|
1.2
|
Symptoms
|
Moderate
|
16
|
25
|
46
|
42.6
|
32
|
43.2
|
32
|
34.1
|
126
|
37
|
Severe
|
48
|
75
|
60
|
55.5
|
42
|
56.8
|
60
|
63.8
|
210
|
61.8
|
Total
|
64
|
100
|
106
|
98.1
|
74
|
100
|
92
|
97.9
|
336
|
98.8
|
Total
|
64
|
100
|
108
|
100
|
74
|
100
|
94
|
100
|
340
|
100
|
Intensive intake (daily or more than time weekly)
|
Asymptomatic
|
4
|
1.5
|
2
|
1
|
4
|
1.9
|
2
|
1.1
|
12
|
1.4
|
Symptoms
|
Moderate
|
84
|
32.1
|
54
|
25.7
|
62
|
28.7
|
58
|
30.5
|
258
|
29.4
|
Severe
|
174
|
66.4
|
154
|
73.3
|
150
|
69.4
|
130
|
68.4
|
608
|
69.2
|
Total
|
258
|
98.5
|
208
|
99
|
212
|
98.1
|
188
|
98.9
|
866
|
98.6
|
Total
|
262
|
100
|
210
|
100
|
216
|
100
|
190
|
100
|
878
|
100
|
Total
|
346
|
346
|
346
|
346
|
1384
|
R
|
−0.057
|
0.024
|
0.069
|
−0.018
|
0.037
|
N: Number of participants |
R: Pearson’s correlation coefficient |
Data in table (4) showed Cough symptoms occurred in participants who did or did not eat the investigated foods. According to the findings, 166 recovered individuals who did not consume any food had experienced either a moderate or severe cough. Among the 340 participants having little food intake (weekly or monthly), 258 (75.9%) had suffered from moderate or severe cough symptoms. Finally, among the 878 individuals with intensive food intake (daily or more than once a week), 684 (77.9%) had moderate or severe cough symptoms.
These data revealed a similar cough occurrence in individuals with little or intensive dietary intake (75.9% and 77.9%, respectively). This rate increased in participants eating none of the investigated foods (87.9%). Additionally, the foods tested in this study had different effects on cough occurrence. Participants eating no yogurt reported fewer cough symptoms (78.6%) than those who consumed no garlic, onions, or fruits or vegetables (90.3%, 90%, or 89.3%, respectively). Few individuals appeared to have cough symptoms (68.8%) with little intake (weekly or monthly) of fruits or vegetables, compared to those rarely eating yogurt or garlic (75.9% or 76.6%, respectively). Participants with little onion intake reported experiencing cough symptoms (81.1%). Finally, fewer subjects who often (daily or more than once a week) ate onions or garlic developed cough symptoms (75% and 75.8%, respectively). In contrast, the cough was most experienced by individuals who often had yogurt, fruits or vegetables (80% or 80.2%, respectively). There was a significant correlation between garlic consumption and cough severity (R = 0.116, p 0.05).
Table (4): Relationship between the consumption of specific foods and the occurrence of cough
Level of intake
|
Foods
Symptom rate
|
Fruits or vegetables
|
Yogurt
|
Onions
|
Garlic
|
Total symptoms
|
N
|
%
|
N
|
%
|
N
|
%
|
N
|
%
|
N
|
%
|
No intake
|
Asymptomatic
|
2
|
10
|
6
|
21.4
|
6
|
10.7
|
6
|
9.7
|
20
|
12.1
|
Symptoms
|
Moderate
|
15
|
75
|
18
|
64.3
|
34
|
60.7
|
34
|
54.8
|
101
|
60.8
|
Severe
|
3
|
15
|
4
|
14.3
|
16
|
28.6
|
22
|
35.5
|
45
|
27.1
|
Total
|
18
|
90
|
22
|
78.6
|
50
|
89.3
|
56
|
90.3
|
146
|
87.9
|
Total
|
20
|
100
|
28
|
100
|
56
|
100
|
62
|
100
|
166
|
100
|
Little intake (monthly or weekly)
|
Asymptomatic
|
20
|
31.2
|
26
|
24.1
|
14
|
18.9
|
22
|
23.4
|
82
|
24.1
|
Symptoms
|
Moderate
|
38
|
59.4
|
62
|
57.4
|
34
|
45.9
|
52
|
55.3
|
186
|
54.7
|
Severe
|
6
|
9.4
|
20
|
18.5
|
26
|
35.2
|
20
|
21.3
|
72
|
21.2
|
Total
|
44
|
68.8
|
82
|
75.9
|
60
|
81.1
|
72
|
76.6
|
258
|
75.9
|
Total
|
64
|
100
|
108
|
100
|
74
|
100
|
94
|
100
|
340
|
100
|
Intensive intake (daily or more than time weekly)
|
Asymptomatic
|
52
|
19.8
|
42
|
20
|
54
|
25
|
46
|
24.2
|
194
|
22.1
|
Symptoms
|
Moderate
|
167
|
63.7
|
98
|
46.7
|
110
|
50.9
|
92
|
48.4
|
467
|
53.2
|
Severe
|
43
|
16.4
|
70
|
33.3
|
52
|
24.1
|
52
|
27.4
|
217
|
24.7
|
Total
|
210
|
80.2
|
168
|
80
|
162
|
75
|
144
|
75.8
|
684
|
77.9
|
Total
|
262
|
100
|
210
|
100
|
216
|
100
|
190
|
100
|
878
|
100
|
Total
|
346
|
346
|
346
|
346
|
1384
|
R
|
0.022
|
−0.086
|
0.014
|
−0.116*
|
−0.002
|
N: Number of participants |
R: Pearson’s correlation coefficient |
*: P-value of correlation was significant (p < 0.05), 2-tailed test. |
Data in Table (5) presented the link between the consumption of some foods and the development of dyspnea. Data revealed that 36 out of 166 recovering participants who did not eat the foods did not develop symptoms (21.7%), whereas 130 (78.3%) had suffered from either moderate or severe dyspnea. Among the 340 who had a small intake (weekly or monthly) of foods, only 74 (21.8%) had not had dyspnea, whereas 266 (78.2%) had suffered from either moderate or severe dyspnea. Finally, among the 878 individuals consuming the foods regularly (daily or more than once a week), 170 (19.4%) had not experienced dyspnea, whereas 708 cases (80.6%) developed moderate or severe dyspnea. The data also showed that many individuals had developed dyspnea regardless of their general food consumption (78.3%, 78.2%, and 80.6%, for no, little, and intensive uptake, respectively). Among the participants having no intake of the foods, dyspnea symptoms were less observed in those who did not eat fruits or vegetables (70%), followed by those who did not eat garlic (77.4%), yogurt (78.6%), or onions (82.2%).
Additionally, fewer individuals with a low intake (weekly or monthly) of yogurt reported dyspnea symptoms (74.1%) than those eating little fruit or vegetables, garlic, or onions (78.1%, 80.9%, or 81.1%, respectively). Finally, participants eating regularly (daily or more than once a week) yogurt experienced dyspnea symptoms more often (82.9%) than those eating high levels of onions, garlic, or fruits or vegetables (78.7%, 80.9%, or 80.9%, respectively).
There was a significant correlation between total food consumption and the development of dyspnea (R = 0.062, p < 0.05).
Table (5): Relationship between the consumption of specific foods and the occurrence of dyspnea
Level of intake
|
Foods
Symptom rate
Symptoms rate
|
Fruits or vegetables
|
Yogurt
|
Onions
|
Garlic
|
Total symptoms
|
N
|
%
|
N
|
%
|
N
|
%
|
N
|
%
|
N
|
%
|
No intake
|
Asymptomatic
|
6
|
30
|
6
|
21.4
|
10
|
17.8
|
14
|
22.6
|
36
|
21.7
|
Symptoms
|
Moderate
|
8
|
40
|
18
|
64.3
|
26
|
46.5
|
34
|
54.8
|
86
|
51.8
|
Severe
|
6
|
30
|
4
|
14.3
|
20
|
35.7
|
14
|
22.6
|
44
|
26.5
|
Total
|
14
|
70
|
22
|
78.6
|
46
|
82.2
|
48
|
77.4
|
130
|
78.3
|
Total
|
20
|
100
|
28
|
100
|
56
|
100
|
62
|
100
|
166
|
100
|
Little intake (monthly or weekly)
|
Asymptomatic
|
14
|
21.9
|
28
|
25.9
|
14
|
18.9
|
18
|
19.1
|
74
|
21.8
|
Symptoms
|
Moderate
|
28
|
43.8
|
52
|
48.2
|
36
|
48.6
|
48
|
51.1
|
164
|
48.2
|
Severe
|
22
|
34.3
|
28
|
25.9
|
24
|
32.5
|
28
|
29.8
|
102
|
30
|
Total
|
50
|
78.1
|
80
|
74.1
|
60
|
81.1
|
76
|
80.9
|
266
|
78.2
|
Total
|
64
|
100
|
108
|
100
|
74
|
100
|
94
|
100
|
340
|
100
|
Intensive intake (daily or more than time weekly)
|
Asymptomatic
|
50
|
19.1
|
36
|
17.1
|
46
|
21.3
|
38
|
20
|
170
|
19.4
|
Symptoms
|
Moderate
|
148
|
56.5
|
114
|
54.3
|
122
|
56.5
|
102
|
53.7
|
486
|
55.4
|
Severe
|
64
|
24.4
|
60
|
28.6
|
48
|
22.2
|
50
|
26.3
|
222
|
25.2
|
Total
|
212
|
80.9
|
174
|
82.9
|
170
|
78.7
|
152
|
80
|
708
|
80.6
|
Total
|
262
|
100
|
210
|
100
|
216
|
100
|
190
|
100
|
878
|
100
|
Total
|
346
|
346
|
346
|
346
|
1384
|
R
|
0.063
|
−0.083
|
0.091
|
0.018
|
0.062*
|
N: Number of participants |
R: Pearson’s correlation coefficient |
*: P-value of correlation was significant (p < 0.05), 2-tailed test. |
Table (6) summarizes the data from Tables (2), (3), (4), and (5) regarding the link between the food consumption history of individuals having recovered from COVID-19 and the rate of specific symptoms. The proportions of individuals who consumed a specific food, never (no intake), sometimes (little intake), or regularly (intensive intake) and developed a specific symptom were calculated. Moreover, the average proportion of participants developing symptoms according to their average intake of specific foods and the average proportion of individuals developing a specific symptom according to their global food consumption level were calculated. The data showed that symptoms were present in 88.1% of participants consuming none of the listed foods, 85.54% of those consuming these foods sometimes, and 85.55% of those eating these foods regularly.
This data draws attention to the fact that the food consumption history of recovered people might have increased their resistance to some symptoms, as fewer participants with little or intensive food intake presented symptoms than those who did not consume any of the foods.
Table (6): Relationship between the consumption of all investigated foods and the proportion of participants having symptoms.
level of intake
|
Foods
Kind of symptoms
|
Fruits or vegetables
|
Yogurt
|
Onions
|
Garlic
|
Average
|
%
|
%
|
%
|
%
|
%
|
No intake
|
fever
|
80
|
92.9
|
89.3
|
87.1
|
87.3
|
Body pain
|
100
|
100
|
100
|
100
|
100
|
Cough
|
90
|
78.6
|
89.3
|
90.3
|
87.1
|
Dyspnea
|
70
|
78.6
|
82.2
|
77.4
|
77.1
|
Average
|
85
|
87.5
|
90.2
|
88.7
|
87.9
|
Little intake (monthly or weekly)
|
fever
|
87.5
|
87
|
91.9
|
89.4
|
89
|
Body pain
|
100
|
98.1
|
100
|
97.9
|
99
|
Cough
|
68.8
|
75.9
|
81.1
|
76.6
|
75.6
|
Dyspnea
|
78.1
|
74.1
|
81.1
|
80.9
|
78.6
|
Average
|
83.6
|
83.8
|
88.5
|
86.2
|
85.6
|
Intensive intake (daily or more than time weekly)
|
fever
|
86.3
|
84.7
|
83.3
|
84.2
|
84.6
|
Body pain
|
98.5
|
99
|
98.1
|
98.9
|
98.6
|
Cough
|
80.2
|
80
|
75
|
75.8
|
77.8
|
Dyspnea
|
80.9
|
82.9
|
78.7
|
80
|
80.6
|
Average
|
86.3
|
86.7
|
83.8
|
84.7
|
85.4
|